Classic Rotary Phones Forum

Telephone Talk => Pay Station Telephones => All Other Pay Telephones => Topic started by: Spanish_phones on December 03, 2013, 08:14:12 PM

Title: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 03, 2013, 08:14:12 PM
Hi everyone!

I have a Spanish payphone, I bought a few months ago, and I have restored it to look good and work. The problem that I have is I would like to make it work as it used to back in the sixties, and I'll need help to develop a controller (as the ones you have for USA payphones).

They used to work like this:

· You hung up, and have dial tone but yo cannot dial (it works like this right now)
· You put at least one token, you still have dial tone, then you can dial (so far, so good)
· When the phone you're calling to answers, the payphone collects the first token (this doesn't happen)
· Then, while you're talking on the phone, each 1 minute more or less ( I really don't now the time period), one token was collected by the payphone (this neither happen)
· Then you have to possibilities:

1: You hung up and still have tokens in the visor: the unused tokens don't collect and exit from the front door (this works)
2: if the last token is collected while talking, a beeeep is heard on the transmitter and the call is down. (this doesn't happen)

Every single part on the payphone is in perfect condition, so the only thing that I need is a payphone controller to make the coil collect the tokens: the first when the phone call is answered and the rest ones while talking by a certain period of time, and the beeep with the last one. I hope somebody can help me with this.

Here are photos of it, the wiring diagrams and the link of the post I made of it. In the last photo you can see a big cylinder: that's the "coil" that collects the tokens.

http://www.classicrotaryphones.com/forum/index.php?topic=10569.0

Thank you very much to every of you

Iñaki
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 04, 2013, 01:39:17 AM
The method of supervision of coins/tokens for this type of payphone is entirely different than that used for American coin-telephones.

It most likely uses the Karlsen system which was widely used in Asia and Europe while U.S. payphones used either +/-110 Vdc (in some cases, polarity reversals as well) for refund/collect functions while it appears that yours relied on separate timing pulses from the central office.

A description of this method is the TCI Library.

I believe another member of this forum, located in one of the Nordic countries was successful in replicating this function for his payphones, so perhaps he will provide further input.
Thanks
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 04, 2013, 03:47:13 PM
The easiest thing to try, are polarity reversal, commonly used in many European countries.
I use an old Lego switch for testing.

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 04, 2013, 05:57:23 PM
I already did that! With the polarity reversed, the collect mechanism acts, and if I disconnect the current, it stops acting. But with the polarity reversed, the other electrical components doesn't work, In other words, you cannot dial for example.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: poplar1 on December 04, 2013, 09:06:58 PM
Quote from: Spanish_phones on December 04, 2013, 05:57:23 PM
I already did that! With the polarity reversed, the collect mechanism acts, and if I disconnect the current, it stops acting. But with the polarity reversed, the other electrical components doesn't work, In other words, you cannot dial for example.

Then would the controller need to *momentarily* reverse the polarity at certain intervals, so that one token would be collected each time this happens?
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 04, 2013, 09:43:26 PM
I'll reiterate:

It most likely uses the Karlsen system which was widely used in Asia and Europe while U.S. payphones used either +/-110 Vdc (in some cases, polarity reversals as well) for refund/collect functions while it appears that yours relied on separate timing pulses from the central office.

A description of this method is the TCI Library.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 04, 2013, 10:11:13 PM
Quote from: G-Man on December 04, 2013, 09:43:26 PM
A description of this [Karlsen] method is the TCI Library.[/i]

For the search engine challenged, can you supply a link?

Thanks
Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: poplar1 on December 04, 2013, 10:41:35 PM
Quote from: G-Man on December 04, 2013, 09:43:26 PM
I'll reiterate:

It most likely uses the Karlsen system which was widely used in Asia and Europe while U.S. payphones used either +/-110 Vdc (in some cases, polarity reversals as well) for refund/collect functions while it appears that yours relied on separate timing pulses from the central office.

A description of this method is the TCI Library.


Sorry, but I didn't understand whether "timing pulses" meant reversals or just interruptions of battery.
Since he indicated that reversing battery caused the phone to collect a token, I was merely wondering whether momentary *pole reversing* function could be incorporated into the controller.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 04, 2013, 11:40:11 PM
There were several pulse schemes employed including the use of different frequencies and polarities, but the general description provided below gives an overview.

Since there is a rectifier is one of the components it likely uses polarity to determine when the tokens should be collected, but first the model number should be supplied so that the precise method used for this payphone can be determined.

Otherwise it would be the same as attempting to guess what type of coin-control supervision that an unidentified American payphone used.

The second of the aforementioned categories is one that has hitherto not seen significant usage in the United States. It employs a special type of coin station set which allows the calling customer to deposit coins throughout the call conversation.

In prior art versions of this "escrow" type of coin station the rates for calls are calculated at the central office by translating the call signalling dial pulses sent by the calling customer. Rate analysis is conducted at the central office in accordance with various factors such as distance, time of day, etc.

With the rate thus determined, the central office returns metering impulses, preferably uniformly spaced in time, to the station set to operate a coin collecting relay therein.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 05, 2013, 05:55:35 AM
Thank to all of you!

I think I understood almost everything you said. The controller should have a pole reversing automatic switch or something similar. But It has to be really fast, if not, the call will end up. The switch should do: on-off just the time to collect the token and not end up the phonecall.

G-man, you said you need the model number, the only things that I know are the codes inside of the payphone, the ones you can see in the photos I posted at the beginning. Here you are:

                                         5580-A                                   5543-A

APARATO DE ABONADO 5536-A                           PS-8222 (3ª)  

The first ones are in the plastic cover of the wiring. I think are related to the electric components is has. The other ones, are printed in the black wiring diagram. I think the bold one refers to the payphone model, here is the link of the Spanish historic telephones, and it says the model is the one I wrote in bold letters:

http://www.fundacion.telefonica.com/es/arte_cultura/patrimonio_ht/detalle/14
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 06, 2013, 02:49:10 PM
Hi
I'm trying to understand the diagram.
As far as I understand:
You connect positive wire to L1. current travels trough hook-switch, induction coil 1-2, transmitter, dial, diode, to L2 (neg line).  You may not dial until the token opens the contacts marked L. (shorts dial until token entered the switch mechanism)

When the current are reversed the token is collected, but the diode blocks current, and all current has to go trough the relay windings. Since one winding are 5000 ohms, its to high resistance to keep the line engaged.  (This was probably prevented by the original equipment at the exchange.)

The 5000 ohms winding are shortened by contact C so it would be interesting to know in what state this contact set opens and closes.

All this makes me sure that the only way to operate this one is by a short reverse pulse.
I see no way it could send a signal causing the beep at last token used.

dsk

Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 06, 2013, 05:29:15 PM
I tried to simplify the diagram, so I removed the dial shunting circuits.
Then we ends up with a quite ordinary voice circuit, quite similar to W.E. 302.
The dial are a typical European version, probably equal to most Antwerp dials.

The last parts are: (whats making a payphone)
- the relay (token collecting unit) with 2 windings and the diode.
- the contact un-shortening the dial pulse contact when at least one token has entered the system.
- and the mystery contact marked C

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 06, 2013, 10:23:22 PM
dsk, you're right!

The token relay has points 1, 2, 3 and 4, and I think is commanded by L and C contacts and the polarity reversal

The L contact opens when the first token is placed
When the phone starts collecting,  the token relay acts, its passes the token a little bit further, so contact C is closed with the token is being collected
Then, the relay should act on the other way, or just return to it's repose position, to finally collect the token and retain the next token in L place, and wait until the time passes to collect the next one.

So, I think C acts in collecting tokens, returning the relay to it's repose position.
But, there is one thing I still don't understand. How does the payphone end the phone call when the last token is collected, if you have dial tone when no tokens are inserted?

Thank you so far, each post I know more about how it works ;)
Title: Re: Spanish Payphone, I need help to make a controller
Post by: xhausted110 on December 07, 2013, 12:40:33 AM
Quote from: Spanish_phones on December 06, 2013, 10:23:22 PM
dsk, you're right!

The token relay has points 1, 2, 3 and 4, and I think is commanded by L and C contacts and the polarity reversal

The L contact opens when the first token is placed
When the phone starts collecting,  the token relay acts, its passes the token a little bit further, so contact C is closed with the token is being collected
Then, the relay should act on the other way, or just return to it's repose position, to finally collect the token and retain the next token in L place, and wait until the time passes to collect the next one.

So, I think C acts in collecting tokens, returning the relay to it's repose position.
But, there is one thing I still don't understand. How does the payphone end the phone call when the last token is collected, if you have dial tone when no tokens are inserted?

Thank you so far, each post I know more about how it works ;)

I would think that the central office would disconnect the call, requiring you to hang up, and thus reset the phone.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 07, 2013, 03:41:44 AM
This is an exiting learning process.   :)

It may be like this.
Normal polarity...token inserted, and L opens. You may dial.
When party answers, polarity reverses. Relay acts, and C closes when token is passed on mechanical step. 100 ohms winding keeps the relay in this position, and lets the signal pass. (This should happens fast enough to not break the connection, but a modern line may sense it as a short flash. (100 millisecond are one std. EU value)
Conversation keeps on until a new signal (not sure how) comes from the exchange, or you hang up.

The hook-switch is mechanically connected to the token mechanism, and lets the rest of the coins return to tray.
The lost current or normal polarity current resets the relay and collect the coin resting on C contacts.

(A short of the line, or drop of voltage for a few millisecond (50-100???), may let the phone collect a new token. Still reversed voltage all the time)

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 07, 2013, 05:39:45 AM
Dsk,

The low coin indication is probably the coin window; I can't see how the exchange would know that there in no coin available for the next coin collection.

My thoughts on the C contact:

When there are no more coins, contact C is closed shorting the 5k section of the coin relay. When the next reversal happens, there is a much larger current drain telling the exchange that there is no coin and the connection is ended.

Regards
Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 07, 2013, 08:27:11 PM
This phone show one more secret each time I open it! I have discover the two coils that where on the diagram and I didn't know where they were (pictures below)

Also I have made a polarity switch, and it works! The relay collects the tokens one by one! And I think I guessed how the call is ended when there are no tokens left. If you continue with the polarity reversed, then you don't have dial tone, that means the call is ended.

I think the most difficult feature would be the first token collected, when the party answers, I have no clue to make it. The other things should be easy: a circuit with two relays, for changing the polarity, and the electronic circuit for timing and operate the relays. I think the controller should work with the 6V DC of the telephone line.

I think I could do the relay circuit myself, but I don't know anything about electronics, so I need help in that part of the circuit, the timer.

;)

Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 08, 2013, 04:20:07 AM
I have been looking at some different systems, and you do not get a signal indicating answer in the other end, except for lines with polarity reversal. The only way to get this is by using an ATA and voip. The timer circuit will be an additional thing. The polarity reversal are at least mentioned in this thread:   http://tinyurl.com/nw293d2 (http://tinyurl.com/nw293d2)

The controller circuit might be a complex thing, and the only way I could solve it will be with a PLC and that's unreasonable expensive. 

Some other people at the forum has mad other controllers, and might help.

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 08, 2013, 04:24:18 AM
Quote from: Jack Ryan on December 07, 2013, 05:39:45 AM
My thoughts on the C contact:

When there are no more coins, contact C is closed shorting the 5k section of the coin relay. When the next reversal happens, there is a much larger current drain telling the exchange that there is no coin and the connection is ended.

I didn't say so explicitly but I believe that the reversals are fleeting. Each fleeting reversal collects a token and when no tokens remain, the last fleeting reversal terminates the call.

Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 08, 2013, 04:46:30 AM
I have just been looking for timers, and this one: http://tinyurl.com/q3fdfjp (http://tinyurl.com/q3fdfjp) may be good enough.
My idea are: If a polarity sensor (diode and relay, or indicator contact C ) tells when the ATA reverses the line, (first token are collected) the timer starts, and after some time it gives another relay signal to reverse polarity. (2 contact sets) and breaks the timer current.  The relay will loose its current, normalize polarity, and start the counter again.
This will keep on until hanging up.

This is just an idea, and I do not know if it will work for real.

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 08, 2013, 05:07:21 AM
It most likely would be an extremely simple task to inexpensively emulate the original metering pulses with a timing circuit derived from a 555 or similar i.c. driving an equally inexpensive polarity reversing relay at regular intervals. 

I suspect the circuit could be constructed for under $20.00.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 08, 2013, 08:40:32 AM
Very creative switch:(http://www.classicrotaryphones.com/forum/index.php?action=dlattach;topic=10658.0;attach=62270;image)

If you add a function able to short the line (doorbell-switch)

I would like to ask you to make a test.

1- With normal polarity (able to dial) listen for dial tone, put inn some tokens, and dial ( at least 1 digit)
2- Reverse polarity (and leave it reversed)    Do it collect 1 token? Are you still holding the line, able to hear yourself (transmitter working)?
3- press and release the doorbell switch.  Does it collect one more token? Whats happening?
4- Hang up. Does it return the unused tokens?
5- Switch back to normal polarity. Nothing should happend, or???

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 08, 2013, 06:02:49 PM
Dsk,

Do you disagree with my suggestion or have you not noticed it?

Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 08, 2013, 10:56:37 PM
Dsk, I'm afraid I cannot make the test you asked me until I make a two relay switch circuit, because the manual switch that I made doesn't work properly and it's really slow. With a fast relay reversal should work just has you said.

Just for clearing doubts:

For collect a token: only changes the polarity less than a second, then it must return to normal polarity yo hear the conversation

I don't know the function of contact C jet, but I think call must end at the las polarity reversal, NOT returning to normal polarity, so you cannot hear dial tone neither the conversation.

;)
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 09, 2013, 02:25:39 AM
Quote from: Jack Ryan on December 08, 2013, 06:02:49 PM
Dsk,

Do you disagree with my suggestion or have you not noticed it?

Jack


No, I'm pretty sure you are right, but it might be a minor possibility of just a short, or power loss will do the job, but that's depending on a working state with reverser polarity during conversation. (current goes trough the 100 ohms coil.) 

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 09, 2013, 05:14:06 AM
Dsk,

I don't claim to be right, I just wanted to bounce some ideas.

The circuit is hard to read because all the contacts look like hook switch contacts. I am just assuming that L and C are token contacts and that with a token present, L opens and C closes. Can this be checked by observation?

If that is the case, I had it the wrong way around:

- Each fleeting reversal collects a token unless there is no token
- If there is no token, the exchange sees a high impedance (5k1) loop on the fleeting reversal and terminates the call.

I don't think the high impedance for the duration of a fleeting reversal is sufficient to terminate the call in itself; the exchange would have to look for it.

Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 09, 2013, 08:07:23 PM
Well, here you are a few answers to your posts.

First, a photo of the contacts L and C. L permits to dial, I think C should end the call when the last token is collected. They work separately, but together, in other words, the position of L doesn't affect on C and viceversa, the work independently.

I've also made a video of how the system should work:

http://youtu.be/bSDMtUCeMBs

As you can see, collecting one token requires two movements, only one pulse/reversal, which make the first movement, then when the current returns to normal polarity, a spring pulls the big coil back. In the video, the last token collected gets stuck, leaving C contact closed and L contact open, so this combination should end the call ( when there are more token left, L contact is open by the next token)

I'm afraid reversing the polarity is going to affect on the quality of the call, or even end it. Maybe I have to develop a device that sends negative pulses to the telephone, in order to control the collect system without ending the call meanwhile? Anyway, I think I'll make a test with the two relays reversing polarity and see if it works or not. Does anybody know were can I buy relays?

Thank you so much ;)
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 09, 2013, 09:08:00 PM
Thanks for the additional picture.

I don't want to labour the point but I'd like to ask some more questions.

The L and C contacts are physically separated and so won't work in unison (at the same time). With no tokens inserted, L is closed and C is open.

1. What is the state of L and C with one token inserted.
2. What is the state of L and C with two tokens inserted.

In the two step collection process (reversal and then return to normal), does the token move with the reversal, pause and then fall into the collection box when the voltage returns to normal?

There must be a reason that the L and C contacts are physically separated and that reason will be part of the explanation for call completion.

Thanks for that.

I am surprised that I can't find any information from Standard Electric or the Spanish telephone operating company regarding the operation of their payphones. Has anyone else had any success?

Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 10, 2013, 12:03:34 AM
Iñaki,
I think your video has answered some of my questions.

1.   With no tokens inserted, L is closed and C is open.
2.   When a token is inserted, L opens and C remains open
3.   When the reversal happens, the token moves forward and C closes shorting the 5k section of the coin relay so the exchange sees a low impedance when a token is collected.
4.   When the voltage returns to normal, the token is collected and C opens.
5.   On the next reversal there is no token to move forward so C remains open. The exchange sees a high impedance telling it there is no token so the call in terminated.
6.   The line voltage returns to normal

So my guess as to how the phone works is as follows:

1.   Lift handset & get dial tone but the dial is disabled (Contact L is closed, shorting the dial pulse contacts)
2.   Insert token(s) to enable dialling (Contact L opens)
3.   Dial the required number
4.   A fleeting reversal on answer takes the first token
5.   Subsequent fleeting reversals timed at the current charge rate collect additional tokens
6.   When there are no more tokens, a fleeting reversal is presented with a high impedance causing the exchange to end the call.

A fleeting reversal in this case is:
1.   A reversal
2.   A delay of 500 to 1000 ms (maybe even more) – enough for the token to move forward to close contact C and for the exchange to measure the loop impedance.
3.   A reversal to return the line polarity to normal.

If this is correct, a controller would not be too complicated. For example a Grandstream Networks, Inc. HT502 would give you pulse dialling and a line reversal on answer. The line reversal could be used to enable a timer to give fleeting reversals to collect coins.
The hardest part would be detecting the loop impedance when the token is collected and disconnecting the call when there is no token (a high impedance).

Is (was) this type of payphone common in Europe?

Thanks
Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 10, 2013, 02:28:49 AM
"I'm afraid reversing the polarity is going to affect on the quality of the call, or even end it."

Audible clicks were inherent with the Karlsson System Message Register Impulses, which is what your payphone relied on.

Here is an excerpt detailing this manifestation:

QuoteWhile the escrow coin station system allows for time
independent coin deposits, it has the disadvantage that
the metering pulses appearing on the loop during con
versation manifest themselves to the conversing parties
as annoying and disruptive audible clicks. To resolve
this problem the prior art has resorted to transmission
improvement techniques that serve to attenuate this
effect.

Note that it states that it can be attenuated; not completely eliminated.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 10, 2013, 03:23:30 AM
The Karlsson System for subscriber billing is still in use around the world, albeit the payphones and other equipment are now microprocessor controlled instead of relay based technology.

Searches for newly manufactured payphones reveal that they are commonly available with Karlsson Systems relying on 50KHz, Polarity reversal, 12kHz, and 16kHz pulses.

One such product is the T597 Outdoor Coin Payphone:

•   http://www.weiku.com/products/3546964/T597_Outdoor_Coin_Payphone_Powder_coated_zinc_plated_steel_.html

Note that in the listing for "Supported Charging Signal" it list Polarity Reversal, 12kHz, 16kHz pulses for coin/token collection.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 10, 2013, 04:01:21 AM
Great, this makes me even more sure that the normal state of conversation are reversed polarity, with the relay engaged, and 5000 ohms winding shorted. When the last token are ejected, the resistance of the 5000 ohms coil will prohibit any conversation.

A short of the line will let the springloaded relay return to rest position, this will collect the coin. When line short are removed. the 5000 ohms coil engaged the relay, next token falls down, and shorts the 5000 ohms coil, while the 100 ohms coil holds it engaged.

dsk

PS if this was a normal operation in Europe???  Not sure. but it would fit right in here in Oslo. As far as I recall local calls were only one coin, no time limit. Did not call  long distance before the 16kHz system was introduced.  DS
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 10, 2013, 05:05:27 AM
Quote from: G-Man on December 10, 2013, 03:23:30 AM
The Karlsson System for subscriber billing is still in use around the world, albeit the payphones and other equipment are now microprocessor controlled instead of relay based technology.

I still haven't found any documentation for a Karlsson System.

Quote
Searches for newly manufactured payphones reveal that they are commonly available with Karlsson Systems relying on 50KHz, Polarity reversal, 12kHz, and 16kHz pulses.

It must be a broad specification because of the wide variations between each of these.

Any pointers to documentation?

Thanks

Jack
(Only recently interested in payphones)
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 10, 2013, 05:09:11 AM
Quote from: dsk on December 10, 2013, 04:01:21 AM
PS if this was a normal operation in Europe???  Not sure. but it would fit right in here in Oslo. As far as I recall local calls were only one coin, no time limit. Did not call  long distance before the 16kHz system was introduced.  DS

It's interesting that STC had much to do with payphones in Australia but none of ours work like this one.

Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 10, 2013, 07:04:09 AM
Wow!!! How many answers!!!!! I think we almost guessed how it works!!

Unfortunately, I have no clue if this system was usual in Europe, but I'm completely sure it was the system used in Spain since payphones appeared in the 50's until the 80's, when touch tone payphones arrived (I don't know if touch tone also continued with this system or not)

Well, so the only thing that I don't know how to make is collect the first token when party answers. I'm afraid is going to work like USA controllers, collecting the first token when a certain period of time is passed.

I know the collecting system works with reversals, so I made a reversal circuit with a double relay (8 contacts). Anyway, I would like to test if the payphone also works with pulses as some of you have said. Any ideas of what circuit it would be? I measured with the multimeter and the payphone works with 6V DC and 21,5mA

Last, but not least, yesterday at the university, the professor taught us electronic components, and one of those was the timer (NE555), maybe one of those could control the time between pulses/reversals.

One more time, thank you so much!!!!

Iñaki ;)
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 10, 2013, 09:36:16 AM
Quote"Last, but not least, yesterday at the university, the professor taught us electronic components, and one of those was the timer (NE555), maybe one of those could control the time between pulses/reversals."

Yes, to repeat myself, I already suggested using a 555 timer along to generate the pulses. Coupled with a relay it would comprise a simple and inexpensive circuit to emulate the original polarity reversal pulses. The initial collection could be initiated by polarity of the first reversal of polarity of answer-supervision from the VoIP modem.

It would be a very, very elemental circuit so it should be extremely easy and inexpensive to construct.

Karlsson Message Rate Pulses generated message unit pulses for message rate billing which included answer pulse recognition signals and answer supervision from a central office for providing a variable number of pulses based on call duration, time of day and distance of call.

These pulses were optionally extended to payphones for coin collection as well as to subscribers for call-accounting purposes.

It did not matter whether the pulses were delivered by d.c. or high-frequency pulses, it was the same system that also drove the messages registers located in the central offices.

If I recall correctly, Karlsson developed the system in Norway for WECo International/ITT-Standard Electric but I would have to research it once more to refresh my memory to be certain.

This system was widely used throughout Europe and Asia and apparently in Australia as well, allowing what you folks call STD toll calling. This system was not used in the U.S. because it did not provide enough billing detail required by American subscribers and their regulatory agencies.

It is a very robust system since various incarnations of it appears to still be in use as evidenced by a reference to it in a 2003, CISCO publication:

Quote"The associated meter pulses are transmitted at the end of each timing interval. The asychronous method (also referred to as Karlsson) starts at the first timing interval at a random value..."
Cisco MGC Software Release 9.5(2)
Meter Pulse Messages Support
Document Release History
Feature History
The Metering Pulse Messages (MPM) Support Feature is described in the following sections:
• Feature Overview, page 1
• Supported Platforms, page 4
• Prerequisites, page 4
• Configuration Tasks, page 4
• Charging Data Structures, page 4
• Provisioning Examples, page 12
• Command Reference, page 13
• Reference Information, page 15
• Glossary, page 17
Feature Overview
The Metering Pulse Feature enables the handling of meter pulse message pass through, modification,
and generation. Billing information is derived from and provided to the billing mediator using Call
Detail Records (CDRs)).
Publication Date Comments
06/02/03 Initial version of the document.
Release Modification
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 10, 2013, 09:53:49 AM
Though there are various incarnations of how they are generated, Karlsson Message Register pulses were delivered by means of D.C. polarity reversals, and High Frequency formats including 50 KHz, 12 KHz and 16 KHz.

Certainly not any different than voice transmissions being delivered via d.c. over copper wires or superimposed upon those same wires by using carrier frequencies; still the same voice-information, merely delivered by different formats.


Quote from: Jack Ryan on December 10, 2013, 05:05:27 AM
Quote from: G-Man on December 10, 2013, 03:23:30 AM
The Karlsson System for subscriber billing is still in use around the world, albeit the payphones and other equipment are now microprocessor controlled instead of relay based technology.

I still haven't found any documentation for a Karlsson System.

Quote
Searches for newly manufactured payphones reveal that they are commonly available with Karlsson Systems relying on 50KHz, Polarity reversal, 12kHz, and 16kHz pulses.

It must be a broad specification because of the wide variations between each of these.

Any pointers to documentation?

Thanks

Jack
(Only recently interested in payphones)

Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 10, 2013, 10:19:42 AM
Further research shows that this system was used throughout the world and "was developed by S.A. Karlsson, technical director of the Helsinki Telephone Company, who championed the technically simplest solution of keeping the metering pulse sequence out of phase with the theoretical beginning of the call (sending of the called subscriber's answer signal).

The first pulse in the series was transmitted within a certain margin of exact time determined in respect of the answer criterion.

After much initial hesitation, the Karlsson method swiftly became a great success."


Some of the countries adopting this system included:
Argentina, Australia, Austria, China, Denmark, Ethiopia, Germany, France, Ireland, Italy, Japan, The Netherlands, Norway, Poland, Portugal, Spain, Sweden, Switzerland, United Kingdom, Yugoslavia.

Countries that DID NOT adopt it include:
The United States, Canada, USSR, Belgium who favored detailed billing information.


Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 10, 2013, 10:55:40 AM
Quote from: Spanish_phones on December 09, 2013, 08:07:23 PM
Well, here you are a few answers to your posts.

First, a photo of the contacts L and C. L permits to dial, I think C should end the call when the last token is collected. They work separately, but together, in other words, the position of L doesn't affect on C and viceversa, the work independently.

I've also made a video of how the system should work:

http://youtu.be/bSDMtUCeMBs

As you can see, collecting one token requires two movements, only one pulse/reversal, which make the first movement, then when the current returns to normal polarity, a spring pulls the big coil back. In the video, the last token collected gets stuck, leaving C contact closed and L contact open, so this combination should end the call ( when there are more token left, L contact is open by the next token)

I'm afraid reversing the polarity is going to affect on the quality of the call, or even end it. Maybe I have to develop a device that sends negative pulses to the telephone, in order to control the collect system without ending the call meanwhile? Anyway, I think I'll make a test with the two relays reversing polarity and see if it works or not. Does anybody know were can I buy relays?

Thank you so much ;)

Great film. and it is fantastic to be able to do this in the forum, not that many years ago it would have been just fantasy.

I  would like to ask you to do one more test, and film the relay as you did.

1) Connect the phone with reversed polarity from the start, and leave it that way. (no dial tone when you go off hook)
2) Have 2 tokens ready, go off hook and insert 2 tokens (within 15 seconds)
3) Hang up.

4) Do 1 and 2 again, and Dial a number, your own number = OK

What I expect to happen:
1) You connect the phone, and the relay moves when going off hook, and releases when you hang up.
2)The relay operates immediately when going off hook, first token passes directly to contact C and relay stays but you get dial tone. The next token stops at contact L.
3) One coin is collected, and one coin is returned.

4) 2 possibilities: A it just works and it rings, or you get a busy signal, or the pulses forces the relay to act, and the tokens are collected. (the last at hangup).

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 10, 2013, 04:11:13 PM
Hi dsk!

First of all, I assumed that "off hook" means lift the handset and go for listen to the dial tone.

The first step works as you said, I lift the handset and you don't have dial tone
The rest of them don't work, because when the phone is connected always on reversed polarity, the tokens are stopped BEFORE contact L, so you don't have never dial tone. Then both of the tokens are returned, because when you hung up, the mechanism open the "door/lever" and it collects both.

With the polarity reversed:

-When you lift the handset, have no dial tone, main coil acts
-When you hung up, the coil returns to rest position
-If you open the phone and close contact C, yo have dial tone but you cannot dial
-if you open the phone, close C and open L, you have dial tone and are able to dial, but this never happens inserting tokens with polarity reversed
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 10, 2013, 06:28:15 PM
Karlsson Message Register pulses
Quote from: G-Man on December 10, 2013, 09:53:49 AM
Though there are various incarnations of how they are generated, Karlsson Message Register pulses were delivered by means of D.C. polarity reversals, and High Frequency formats including 50 KHz, 12 KHz and 16 KHz.

Certainly not any different than voice transmissions being delivered via d.c. over copper wires or superimposed upon those same wires by using carrier frequencies; still the same voice-information, merely delivered by different formats.

Still without a reference, I searched for "Karlsson Message Register pulses" and found a Cisco document. The subject of this document is meter pulse pass-through for CDR generation. Payphones are not mentioned.

In addition, the reference to Karlsson applies to a subtle difference in the way the pass-through meter pulses start (synchronously or asynchronously), not to the general method.

With respect, without a reference to a clear definition, I can't see how using a reference to Karlsson helps.

Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 10, 2013, 06:44:32 PM
Iñaki,

Quote from: Spanish_phones on December 10, 2013, 07:04:09 AM
Well, so the only thing that I don't know how to make is collect the first token when party answers. I'm afraid is going to work like USA controllers, collecting the first token when a certain period of time is passed.

I'd like to know what the problem is with the first collection (on answer).

Originally, you said:
· You [pick] up, and have dial tone but yo cannot dial (it works like this right now)
· You put at least one token, you still have dial tone, then you can dial (so far, so good)
· When the phone you're calling to answers, the payphone collects the first token (this doesn't happen)

On answer, instead of applying a reversal for answer supervision, apply a fleeting reversal to collect the first token. In other words, apply a reversal, pause and then apply another reversal so that the line voltage is back to normal.

Does this collect the first token?

In Australia, at about this time or perhaps a bit later, payphones no longer required a reversal on answer; they required a charge pulse (of whatever type).

If there are too many cooks (too many people asking questions) let me know.

Thanks
Jack

Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 10, 2013, 07:31:37 PM
Jack, the problem here in Spain is that when party answers, nothing happens on the line voltage, there is no reversal for answer supervision, line voltage doesn't change unless for the dial pulses. Do you see now the difficulty of collecting the first token just when party answers?  That's why I thought of collecting the first token with the timer also, giving you enough time to dial and the party to answer, but then it wouldn't work exactly as it used to do :(
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 10, 2013, 08:07:33 PM
Iñaki,

I understand that on the PSTN, there is no longer a line reversal for answer supervision. I am suggesting that one was never needed for your payphone to operate.

To collect a token, your payphone requires a "fleeting" reversal; that is, a reversal, a pause and than another reversal to return the line voltage to normal. I am suggesting that on answer, your payphone requires a fleeting reversal to collect the first token.

If the call is timed (is charged per unit time), additional fleeting reversals would be generated by the exchange to collect additional tokens.

If you supply a fleeting reversal on answer, the first token will be collected on answer.

If this is, indeed, how the phone works, a simple reversal on answer from an ATA won't help. You will need to use the reversal from the ATA to:
- generate the first (on answer) fleeting reversal to collect the first token
- enable a timer to generate additional fleeting reversals to collect additional tokens.

Your controller will need to perform those tasks and, in addition, detect the no token situation and disconnect the call.

I am talking ATA here because it will give you an indication that the call was answered. This no longer happens on most PSTN lines and that makes the controller more complicated.

Jack

Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 11, 2013, 02:20:56 AM
Quote from: Spanish_phones on December 10, 2013, 04:11:13 PM
Hi dsk!

First of all, I assumed that "off hook" means lift the handset and go for listen to the dial tone.

The first step works as you said, I lift the handset and you don't have dial tone
The rest of them don't work, because when the phone is connected always on reversed polarity, the tokens are stopped BEFORE contact L, so you don't have never dial tone. Then both of the tokens are returned, because when you hung up, the mechanism open the "door/lever" and it collects both.

With the polarity reversed:

-When you lift the handset, have no dial tone, main coil acts
-When you hung up, the coil returns to rest position
-If you open the phone and close contact C, yo have dial tone but you cannot dial
-if you open the phone, close C and open L, you have dial tone and are able to dial, but this never happens inserting tokens with polarity reversed

Thank you.
I have modified your drawing, slightly,
The circuit are just for testing, and will be slightly different when you have put in timers.
For testing, the relay circuit could even be your polarity changing switch.

What I expect to happen are:
-Lifting handset (= going off-hook), and getting dial tone,
-inserting a token (ore more). (Contact L open dial short )
-Dialing and getting an answer.
-Polarity reverses (manually/by timer/by  ATA)
-(token falls one step) and you may talk to the other party.
-I the call lasts you may get a signal to collect one more token. (pressing button for 1/2 a second, or activited by timer)
- The relay collects one token, and when short are removed the relay acts, next token are closing the contact C and you may speak for one more timer interval.

If you run out of tokens, the line will hold for a short time, and you might be lucky to put in a new token and keep on (not for sure).

When you hang up, the line returns to normal, (by manually or automatically change polarity to normal) You may not place call again before the polarity has returned to normal.

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 11, 2013, 03:39:27 AM
So far I have provided direct quotes from a well respected engineering journal regarding its adaptation in a large number of countries around the world.

I am surprised that you are not familiar with it since Australia implemented it as well. It was used to generate a pulse to indicate when the payphone was to collect the coins.

Aside from regular subscriber message-rate recording functions, pulses generated by this system were used to instruct the payphone as to when to collect the coins/tokens. The message register pulses are delivered via d.c. interruptions, polarity reversals or high-frequency pulses.

Without the pulses delivered from the Karlsson (or any other call accounting) system the payphone would not know when to collect the coins or tokens so yes, it is very relevant to the operation of this payphone. If these pulses were not received by the payphone, it would not be able to collect tokens or coins.

The upshot is that these pulses are very easy to emulate so it will be easy to construct a timing circuit that will collect the tokens, allowing the payphone to be demonstrated to visitors.

*In a recent discussion regarding the use of this system regarding payphones, Steph Kerman incorrectly referred to it as the Karlsen System. Others frequently misspell his name as well.


Quote from: Jack Ryan on December 10, 2013, 05:05:27 AM
Quote from: G-Man on December 10, 2013, 03:23:30 AM
The Karlsson System for subscriber billing is still in use around the world, albeit the payphones and other equipment are now microprocessor controlled instead of relay based technology.

I still haven't found any documentation for a Karlsson System.

Quote
Searches for newly manufactured payphones reveal that they are commonly available with Karlsson Systems relying on 50KHz, Polarity reversal, 12kHz, and 16kHz pulses.

It must be a broad specification because of the wide variations between each of these.

Any pointers to documentation?

Thanks

Jack
(Only recently interested in payphones)

Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 11, 2013, 04:14:11 AM
Quote from: G-Man on December 11, 2013, 03:39:27 AM
So far I have provided direct quotes from a well respected engineering journal regarding its adaptation in a large number of countries around the world.
Well respected but secret – still no reference.

Quote
I am surprised that you are not familiar with it since Australia implemented it as well. It was used to generate a pulse to indicate when the payphone was to collect the coins.
I know what was implemented in Australia but nowhere is it referred to as a Karlsson System.

Quote
Without the pulses delivered from the Karlsson (or any other call accounting) system the payphone would not know when to collect the coins or tokens so yes, it is very relevant to the operation of this payphone. If these pulses were not received by the payphone, it would not be able to collect tokens or coins.
I am well aware of the requirements with respect to tariff and coin/token collection. That is not the issue.

For my education, supply a reference that defines and describes the Karlsson System. Otherwise let's just drop all reference to a Karlsson System.

Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 11, 2013, 05:17:04 AM
Quote from: Jack Ryan on December 11, 2013, 04:14:11 AM
Quote from: G-Man on December 11, 2013, 03:39:27 AM
So far I have provided direct quotes from a well respected engineering journal regarding its adaptation in a large number of countries around the world.
Well respected but secret – still no reference.

Quote
I am surprised that you are not familiar with it since Australia implemented it as well. It was used to generate a pulse to indicate when the payphone was to collect the coins.
I know what was implemented in Australia but nowhere is it referred to as a Karlsson System.

Quote
Without the pulses delivered from the Karlsson (or any other call accounting) system the payphone would not know when to collect the coins or tokens so yes, it is very relevant to the operation of this payphone. If these pulses were not received by the payphone, it would not be able to collect tokens or coins.
I am well aware of the requirements with respect to tariff and coin/token collection. That is not the issue.

For my education, supply a reference that defines and describes the Karlsson System. Otherwise let's just drop all reference to a Karlsson System.

Jack


You were already given a reference. Contact Steph Kerman or other TCI members if you wish further information regarding it, though there are thousands(?) of hits regarding it on the established search engines.

I am not fixated on the developer's name and it was given only as an historical context and anyone that is knowledgeable of message-rate billing systems is familiar with it so I thought it would be easier to refer to it as such than to give an overly technical description for it.

Aside from technical details, it is also important to also provide an educational perspective for a full overview. Since I am not aware that you are one of the moderators for this forum, I will not concern myself with your snide remarks. It may suit you better to confine them to your post on the other (3-letter) listseve. I would also suggest that if you feel to post further venomous comments please spare the other members and contact me off-list.

Also, coin/token collection ARE the issue at hand.

Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 11, 2013, 05:21:13 AM
Well, well...

Dsk, I see your point, because I said with polarity reversed, and contact C open, you have dial tone, which means you can talk in the phone. But when I was reading your post, I remembered what happened to me last weekend. I connected the payphone in normal polarity to my Ericsson SIM adapter, to talk on the mobile phone on the payphone. My father called me, and when I answered the phone on the payphone, the polarity changed (because I heard the relay activation inside), and call was ended, and immediately have dial tone but cannot dial neither. When I hung up, polarity reversed to normal. That's why I think the payphone cannot work as you said. These used to receive calls, and you were able to answer without inserting tokens, and that's another problem. How could I make a controller that only works with outgoing calls and not with the incoming ones?

Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 11, 2013, 06:36:26 AM
Re: Karlsson

I suspect that the Karlsson System describes the payphone method in question but outside the USA the method is ubiquitous and has no name. Searches from here receive no hits except the cisco document I mentioned earlier.

The name Karlsson System only exists where it is not used.

Enough said.

Thanks
Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 11, 2013, 07:04:03 AM
Quote from: Jack Ryan on December 11, 2013, 06:36:26 AM
Re: Karlsson

I suspect that the Karlsson System describes the payphone method in question but outside the USA the method is ubiquitous and has no name. Searches from here receive no hits except the cisco document I mentioned earlier.

The name Karlsson System only exists where it is not used.

Enough said.

Thanks
Jack


Actually I have not been able to find technical papers by North American authors, only those by Chapuis, Norwegian and U.K. sources from which I previously quoted from.

So yes, Europe and other countries listed in the quotes by noted International Telecommunications Union Engineer (mentioned above) recognized it specifically as the Karlsson* system.

Since it is a specialized area dealing with message-register toll accounting, I am not surprised that you and others are unfamiliar with it. I am only slightly familiar with it because of my previously research into how other suspension escrow payphones functioned.

But hey, this is what these forums are about, educating ourselves and others about all aspects of telephony.

Thanks.

*As I previously noted Karlsson's name is often misspelled.





Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 11, 2013, 07:25:47 AM
Quote from: G-Man on December 11, 2013, 07:04:03 AM
Actually I have not been able to find technical papers by North American authors, only those by Chapuis, Norwegian and U.K. sources from which I previously quoted from.
That's really all I was after; the references.

Quote
Since it is a specialized area dealing with message-register toll accounting, I am not surprised that you and others are unfamiliar with it.
I am quite familiar with the method - just not the name

Quote
But hey, this is what these forums are about, educating ourselves and others about all aspects of telephony.
Indeed

Anyway, enough of this - it's getting in the way of the payphone analysis. Sorry guys.

Thanks
Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 11, 2013, 07:43:54 AM
I had not heard the name Carlson system on this, but it is commonly used her for payphones. 16 kHz when party answers, and with intervals depending on call rates. 

On the other hand the Spanish payphone here are depending on an abandoned polarity reverse system. This has to be emulated some way.
The line used here are far to sensitive to whats happening, and causes trouble.

The controller has to solve some problems, it must detect incoming calls, and let this signal tell the unit to do nothing. When calling out, it should hold the line while relay changes (a delay) it should detect party answers (ore a suitable timer, and it should collect tokens controlled by another timer.   It may be the the delay could be solved by putting a capacitor of e.g. 5 microfarad across the 100 ohms relay winding, on the other hand this capacitor may cause problems collecting tokens....

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: G-Man on December 11, 2013, 08:08:25 AM
Quote from: dsk on December 11, 2013, 07:43:54 AM
I had not heard the name Carlson system on this, but it is commonly used her for payphones. 16 kHz when party answers, and with intervals depending on call rates. 

On the other hand the Spanish payphone here are depending on an abandoned polarity reverse system. This has to be emulated some way.
The line used here are far to sensitive to whats happening, and causes trouble.

The controller has to solve some problems, it must detect incoming calls, and let this signal tell the unit to do nothing. When calling out, it should hold the line while relay changes (a delay) it should detect party answers (ore a suitable timer, and it should collect tokens controlled by another timer.   It may be the the delay could be solved by putting a capacitor of e.g. 5 microfarad across the 100 ohms relay winding, on the other hand this capacitor may cause problems collecting tokens....

dsk


Interesting that you previously haven't heard of your fellow countryman. As I have previously quoted, S.A. Karlsson was the technical director of the Helsinki Telephone Company. I will once more repeat that the pulses were delivered in various formats including d.c. interruptions or reversals, 50 KHz, 12 KHz, and 16 KHz signals.


Further research shows that this system was used throughout the world and "was developed by S.A. Karlsson, technical director of the Helsinki Telephone Company, who championed the technically simplest solution of keeping the metering pulse sequence out of phase with the theoretical beginning of the call (sending of the called subscriber's answer signal).

The first pulse in the series was transmitted within a certain margin of exact time determined in respect of the answer criterion.

After much initial hesitation, the Karlsson method swiftly became a great success."

Some of the countries adopting this system included:
Argentina, Australia, Austria, China, Denmark, Ethiopia, Germany, France, Ireland, Italy, Japan, The Netherlands, Norway, Poland, Portugal, Spain, Sweden, Switzerland, United Kingdom, Yugoslavia.

Countries that DID NOT adopt it include:
The United States, Canada, USSR, Belgium who favored detailed billing information.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 12, 2013, 07:43:23 PM
Hi there! I'm afraid I bring you bad news...

I made the simple circuit I showed you and it collects tokens correctly, but affects the call ending it (as I supposed earlier) 

So, I think we have now 2 options:

Try to control the collect coil with "negative pulses/signals", with an extra current and don't reversing the line current.

Try to control the coil shorting the contacts with another current (I don't like this idea very much)

So, now I need how to produce negative pulses and I have no clue of how to make them. :(

Iñaki
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 13, 2013, 12:35:55 AM
Iñaki,
I am getting a bit lost. The circuit you are using is quite simple but there are many combinations of starting conditions and many possible timing variations that can be applied.

We saw the phone collecting tokens in the video; we know it works. Let's just take stock of where we are:
1.   At the start of this thread, you explained how the phone worked but that tokens were not collected and were returned when the handset was returned to the hook. You were able to make and receive calls.
2.   You made a video that demonstrated the collection of tokens (even though the last token got stuck – that, I think, is a different issue).

To make the phone collect tokens in the video, I believe you reversed the line polarity and then returned it to normal. That is, the sequence "reversal --> pause --> reversal" caused a token to be collected.

If this is not correct, stop here and report back to the list.

The sequence "reversal --> pause --> reversal" is what I have been calling a "fleeting reversal". Below, where I say apply a complete fleeting reversal, I mean the complete three step sequence; don't apply a single reversal or the phone will stop working.

So, to make your phone work:
1.   Lift handset & Insert at least three tokens
2.   Dial the required number.
3.   When the called party answers, apply a complete fleeting reversal to collect the first token.
4.   Continue the call
5.   Apply another complete fleeting reversal to collect the second token
6.   Continue the call
7.   Replace the handset to end the call.
8.   The remaining tokens will be returned.

Did this work as described? If YES, go to Success, otherwise go to Failure.

Failure:
If this sequence does not work, record exactly where it goes wrong and exactly what happened. Report this to the list.

Success:
If this worked then we know (mostly) how the phone works and there are two remaining issues:
1.   How to detect if there is no token when we try to collect one and end the call.
2.   How to create the fleeting reversals automatically.

We'll worry about that next.

Take your time, good luck.
Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 13, 2013, 02:27:37 AM
I guess I have to focus a little on the line intended to use for this.

Could you please describe the line:

Volts?
max current?
Does it accept rotary?
Do it deliver reverse polarity, and if yes, when?
Does it accept flash or recall pulse? If yes what kind?

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 13, 2013, 06:50:41 AM
I'm sorry for not expressing myself correctly.

Jack Ryan, the fleeting reversal is not the one you described. The polarity stays in normal polarity. To collect a token, you have to reverse polarity only milliseconds, and return it to normal. So the sequence would be:

Normal-->reverse-->normal

Another point is the video that I make. When I showed you how collecting works, a couldn't make a call, dial or anything, because the phone was connected with polarity reversed, and for each token I connected and disconnected the phone from the current, so the coil could do the movements it should do while collecting. But as I explained before, if you have connected the phone with reversed current, you neither have dial tone nor able to dial.

The, in the steps you described, apart from the kind of fleeting it does, it goes wrong in step 4: 3 goes perfectly, collects the first token, but after is collected, I have a busy signal or kind of, maybe is a waiting call signal, because beeping is faster, then if I collect another token, call is reestablished. Really strange. That happens if you reverse polarity just the time to permit the coil to collect the token, if you reverse less time, nothing happens, phone does not collect the token and call continuous.

DSK, here hare the data you required (I measured them with the payphone)

6/6.4 volts (DC obviously)
21.5 mA
Yes, it accepts rotary dialing
No, it doesn't delivers any reversal of polarity
I don't know what flash pulse means. And redial works, but only with the ones they have redial button, and I think redial have nothing to do with the characteristics of the line, only with the phone.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 13, 2013, 09:27:25 AM
Iñaki,
OK, there is a minor language problem.

Quote
Jack Ryan, the fleeting reversal is not the one you described. The polarity stays in normal polarity. To collect a token, you have to reverse polarity only milliseconds, and return it to normal. So the sequence would be:
Normal-->reverse-->normal

What you describe as "Normal-->reverse-->normal" is what I mean by a "fleeting reversal".
The term "reversal" means to reverse the line voltage so "reversal -->pause-->reversal" means:
1.   Change the line voltage from normal to reversed.
2.   Wait for a short time.
3.   Change the line voltage back to normal.
This is a fleeting reversal.

Quote
Another point is the video that I make. When I showed you how collecting works, a couldn't make a call, dial or anything, because the phone was connected with polarity reversed, and for each token I connected and disconnected the phone from the current, so the coil could do the movements it should do while collecting. But as I explained before, if you have connected the phone with reversed current, you neither have dial tone nor able to dial.

As I understand it, when the line voltage is not reversed (that is, when it is normal), you can make a phone call normally. Are you saying that you can't make a fleeting reversal (that is normal --> reverse --> normal) to collect a coin without losing the connection? The fleeting reversal should only take about a second.

Quote
The, in the steps you described, apart from the kind of fleeting it does, it goes wrong in step 4: 3 goes perfectly, collects the first token, but after is collected, I have a busy signal or kind of, maybe is a waiting call signal, because beeping is faster, then if I collect another token, call is reestablished. Really strange. That happens if you reverse polarity just the time to permit the coil to collect the token, if you reverse less time, nothing happens, phone does not collect the token and call continuous.

OK, it sounds like you have the timing right but the exchange line is doing something I don't expect. Does your phone line accept a hook flash or similar? If it does, can you turn it off?

I need help from someone here with some European/Spanish telco experience. Dsk (or anyone), what is happening when the coin collection occurs? Assuming the button and relay are being used to generate the reversals, the exchange should see a brief increase in loop impedance to 5k1 ohms plus the loop resistance. Is this being interpreted as a flash of some sort? Without telco experience, logic only takes me so far...

If that is the problem, the actual phone impedance during collection will have to be hidden from the exchange by the controller – no big deal. It looks like this procedure will work.

Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: poplar1 on December 13, 2013, 10:14:03 AM
Quote from: dsk on December 13, 2013, 02:27:37 AM
I guess I have to focus a little on the line intended to use for this.

Could you please describe the line:

Volts?
max current?
Does it accept rotary?
Do it deliver reverse polarity, and if yes, when?
Does it accept flash or recall pulse? If yes what kind?

dsk


"Flash" is a timed interrupt button, usually 600* milliseconds, for accessing call waiting, transferring calls, etc.

EDIT: *600 ms in US. Some Cortelco sets are programmable for 300 ms/600 ms. Some sets also have additionally "positive disconnect" that hangs up for long enough to terminate a call.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 13, 2013, 11:13:58 AM
The European variant of flash are the R or Recall button. This is a short break.
According to this page: http://tinyurl.com/qdo9s79   about 75 milliseconds. (I would have said 80-120 mS)
The voltage reversal might be misunderstood as this short pulse.

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 13, 2013, 02:18:08 PM
I guess I have the idea to a working solution.  :D

We have to trust some timers, just as the payphone controllers made for the North American 3-slots.

The Relay R will draw after you lift the receiver, it starts the timer 1 and after the time its set on ( a little more than the time needed for dialing) , it moves the contacts W, X an Z. It is important to close X before y opens.

When this happens, the vice path will go trough the line transformer, (or alternative 2 coils and a capacitor) A small transformer with a center tapped 230V primary will do (or 2x 115V) Leave other windings open. The battery or noiseless power supply of 40-50V (30 milliamps are enough or 5x 9V batteries?) are put in opposite polarity of the exchange. This will give a collect of the first token, The relay R with a capacitor C of suitable size will remain engaged long enough to let the 5000 ohms winding be shunted, and the circuit remains in operation.

Timer 1 has to start the timer 2 who gives a short 1/2 second? pulse to T2 contact let us say every 3 minutes to collect a new token.

When you hang up, the relay R returns to normal position (after a delay of e.g. 1 sec) and we are back to normal.
(The remaining tokens are returned.)

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 13, 2013, 07:03:02 PM
Quote from: dsk on December 13, 2013, 11:13:58 AM
The European variant of flash are the R or Recall button. This is a short break.
According to this page: http://tinyurl.com/qdo9s79   about 75 milliseconds. (I would have said 80-120 mS)
The voltage reversal might be misunderstood as this short pulse.

dsk

Dsk,

This is where I think the accidental "flash" is (attachment). If the controller is based on using an ATA (for the answer supervision) this might not happen but if it does, it can be masked. I think a controller is now straight forward but not trivial because of the need to detect no coin and terminate the call.

The alternative is to use the approach that many of the US three slot controllers use and that is to forget the exchange coin collection and answer supervision. Some just execute a delay after detecting payphone off hook and assume that the called party answered.

I would prefer an accurate controller myself but I'll leave the details to you guys so as not to confuse the issue.

Regards
Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 14, 2013, 03:29:10 AM
Jack I think you are right. (Except for 100 ohms would probably be 700 if the phone itself are 600) The 600 ohms value are more or less impedance, and will be pretty much lower as seen as DC resistance. maybe less than 300, but this will not change what you have figured out in your drawing.

Since we have no answer detection, we have to use a timer.  (timer 1, long enough to finish dialing, but not long enough to not needing to pay at all)

When no more coins in the phone, the resistance will be constant at the 5000+ ohms level, and the voice quality will be hopeless, but the R will either er keep holding, or have a great delay before the the timer circuits stops working, so the call will be understood as broken.

dsk

Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 14, 2013, 06:59:19 AM
Quote from: dsk on December 14, 2013, 03:29:10 AM
Jack I think you are right. (Except for 100 ohms would probably be 700 if the phone itself are 600) The 600 ohms value are more or less impedance, and will be pretty much lower as seen as DC resistance. maybe less than 300, but this will not change what you have figured out in your drawing.

Yes, I forgot to add the telephone component resistances – oops.

Quote
Since we have no answer detection, we have to use a timer.  (timer 1, long enough to finish dialing, but not long enough to not needing to pay at all)

If you want the controller to work on the PSTN you don't have much choice but to use a timer. You could use voice detection but it is quite difficult to implement a DSP with relays.

How are you going to start the answer timer? Will you detect loop current when the handset is lifted? With suitable pulse width filtering, you could use the same loop current detection circuit to detect no token.

Quote
When no more coins in the phone, the resistance will be constant at the 5000+ ohms level, and the voice quality will be hopeless, but the R will either er keep holding, or have a great delay before the the timer circuits stops working, so the call will be understood as broken.

That would be the simplest solution. Again, you could detect the 5k loop resistance and terminate the call but that just adds complexity.

I look forward to seeing it all come together.

Regards
Jack
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 14, 2013, 12:32:45 PM
OMG! I think the one who's lost now!

I'm not the greatest at English as you can see, that's why I get confused sometimes, because I misunderstand some things

The main problem is that is I do fleeting reversals, call is ended, and I have no information about how central used to control payphones.
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on December 14, 2013, 04:52:44 PM
 :) We take it a little bit slowly, my English are not perfect either.

It looks like you have a regular European line. It may be smaller variations, like ring cadences, (length and rhythm of ringing) Ringing frequency, and voltage, but not more than it should be almost equal.

I guess I want you to try to dig out what you hide in the basement, or wherever you hide old things who could be of interest. Please look for a transformer of any size who has 2 almost equal windings, or/and some coils, relays.... Things you may use to build the circuit in the drawing.  we may start with manual timing, and later build/buy timers.

A power-supply are probably the most difficult part, 5  9 volts batteries for testing are OK, but they will not last for hours.  4 old car batteries could probably be found for free, but are huge and heavy. the capacitors, and rectifier (diodes) are probably available on a garbage printed circuit.  etc. etc.

By the way, its not just to test on your phone every time I get an idea, but it might be just working (in your existing setup) with a resistor in parallel with the 5000 ohms winding. The resistor should be as low ohmic value as possible ,but still not so great that the relay not will move.  (I would tried with about 5000 ohms as a start.)

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Jack Ryan on December 16, 2013, 06:27:21 PM
Iñaki,

Quote from: Spanish_phones on December 14, 2013, 12:32:45 PM
The main problem is that is I do fleeting reversals, call is ended, and I have no information about how central used to control payphones.

I am fairly certain that your phone works as I described. The problem is that your phone line is not meant for (old) payphones AND it accepts a "flash". A flash is used, for example, to get dial tone within (during) a call to make a conference call or an enquiry. Your modern phones may have a "flash button" that you press for special exchange services.

When you do a fleeting reversal to collect a token, there is a brief moment where the line resistance is quite high and the exchange (incorrectly) interprets this as a flash and you are presented with tone from the exchange. When you collect the next token, the exchange sees a second flash and restores the original call.

The controller will have to mask this effect so that you can continue the call between all token collections. I think this is what Dsk is looking at.

I hope this is a bit clearer.

Regards
Jack

Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on January 30, 2014, 03:03:46 PM
 :) I have had some time for thinking and fettling. (And eBay shopping)
My payphone are simpler, so I have to deposit a coin when I hear party answers, and then again every 2-1/2 min.

The relay are so extremely sensitive so did not work with only one shunting diode, the other series diode had to be put in.
It will only be a short line so I skipped the possibility of making a balanced line.


This works  here.

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: dsk on February 06, 2014, 09:49:03 AM
If you in Linksys/Sipura use this dial tone  200@-10,233@-10; 30(*/0/1+2) you get a purring sound.
The ATA setup could be like this:

dsk
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Kimball321 on November 04, 2015, 07:24:31 PM
Even though this topic is a little old I think I just found something that may work as a controller for this payphone.  I think the Japanese payphones this is designed to work with work the same way as this Spanish one, ie one quick polarity reversal equals one coin collected.

http://www.idknet.co.jp/product/5235/

May be able to buy one second hand from a Japanese auction website and if they wont ship internationally there are services you can purchase it through that will.

http://www.noppin.com/
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Spanish_phones on December 05, 2016, 07:22:07 AM
Well... after one year of delay, I'm back jajaja

Thank you Kimball for the links... buf I don't know japanese... :(

My payphone still doesn't have a controller....
Title: Re: Spanish Payphone, I need help to make a controller
Post by: Kimball321 on December 11, 2016, 05:25:41 PM
That's what Google translate is for.  ;D