Classic Rotary Phones Forum

Telephone Switching => Magneto & Manual (Cord Boards etc) => Topic started by: rglenn on July 04, 2020, 08:06:17 AM

Title: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 04, 2020, 08:06:17 AM
Is the Western Electric 20B2 Power Unit an appropriate power supply for the WE 555 PBX?

Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 04, 2020, 11:01:59 AM
Well, that looks like a 24v power supply.
So, if your board has 24v bulbs, that part should work. but that's not all...
I don't know all the variations of power supplys,
The Sig output seems to be 24v??? maybe should be 90v??
I found this...
555 power supply info short version
The Tellabs 8050.  It's a switched mode unit, standby power is low if you choose to leave it powered up.  Switches between 24 or 48VDC and the ringing source to 20 or 30 Hz.  Switchboards always use 20Hz.  And a 10VAC 60Hz output for key telephone systems.

The 101G use saturated core devices to produce the ringing current which have much higher standby power consumption, heat production and are much larger.  The 101G versions which provide ringing provide 20Hz
-24VDC connects to CENT OFF BAT.
The + side of the 24VDC source connects to CENT OFF GRD.
The high side of the 90VAC 20Hz ringing source connects to GEN +/-.
The return side of the 90VAC 20Hz ringing source connects to GEN G.

I'm not sure whether there is an internal connection within the swbd between the DC GRD and the ringing GRD.  It would be good to check for continuity before making these terminals before making connections. 
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 04, 2020, 02:34:34 PM
I can't seem to find a Tellabs 8050 or 101g for less than $150.  Anything else that's less expensive and available that would work?
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: Jim Stettler on July 04, 2020, 03:04:36 PM
Basically, you need a filtered 24 or 48 volt DC power supply.
The key is filtered to simulate talk battery.
Talk battery was battery, a power supply can cause hum, That is why you need filtered to simulate talk battery.



If you have a 48V board, running it on 24 is fine and your lamps will last much longer.
I think you can find a cheap key system power supply that will satisfy your needs.
You could probably use a printer power supply, these are popular among the telephone switchers .
You could use actual battery.  AGM 12 volt batteries (alarm system batteries)  is another method of providing talk battery. Even if your charger isn't well filtered, you could  charge up the batteries when the system is idle.
Just some work around thoughts,
Jim.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 04, 2020, 04:27:45 PM
The 12 0r 24v DC power supply is easy...
most anything will get you goin. "per Jim's recommendations".
The 90v 20 hz ringer power is the killer.
That's why you need a good supply.
Nuthin runs on 20 hz today.
So, supply is limited.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: Jim Stettler on July 04, 2020, 05:00:30 PM
There are old wall warts that provide 48VDC filtered (Wescom comes to mind)  for telephone systems, you can find the 24 volt DC as well.
 There are also telephone system wall warts and small power supplies that can provide ring power.

You can also get ring signal from powerdesign type  ringer modules.
You would need to home brew a circuit to interject the ring signal, I think this could be a very simple circuit. Basically a relay based circuit interjecting a ring frequency.



The power-design type modules can also do frequency ringing, most are designed for 1 specific  frequency.

Black magic is one brand and I think they are sometimes on the forum
http://affon.narod.ru/Phoneline/Telecom.pdf
Jim
 I could control the world given enough relays and proper interface components, that is the design power of relays.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: Babybearjs on July 04, 2020, 07:17:14 PM
A 20B2 will work fine.... except for the 48 volt side, that will have to be on a seperate PSU.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 05, 2020, 08:00:08 AM
Could I use this?  Will the ringing @ 110V and 30Hz be a problem?
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: poplar1 on July 05, 2020, 08:46:00 AM
A 20B2 will work fine.... except for the 48 volt side, that will have to be on a seperate PSU.

I don't understand this statement. The 555 PBX will work on a variety of DC voltages, including 24 VDC *or* 48 VDC. You don't need both on the same PBX. (As others have stated, you do need lamps rated for 48 VDC if your power supply is 48 V output.)
E
110 VAC @ 30 Hertz is OK for ringing.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 05, 2020, 08:48:52 AM
The ring voltage is maybe a little high?
Don't know if that will be an issue.
The 30hz will make the station phone ring funny, won't sound as clean. but it would work.
Just read pops post, guess it would be ok.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 15, 2020, 12:09:38 PM
OK, I found a power supply mentioned a few times in the forum for use on a 555 PBX.  As I have no idea what I am doing, I was hoping to get confirmation or corrections to the way I think it is to be wired before I blow everything sky high.

On the MISC terminal strip
Power supply 24v Talk - (A) goes to terms (1-4) should be strapped together
Power supply 24v Talk - (G) goes to term (45-48) should be strapped together

Power supply 110v ring (+/-) goes to term 21 (21-22) should be strapped together
Power supply 110v ring (G) goes to term 24

Where would the power supply GRD be connected?
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 15, 2020, 05:32:06 PM
If it is indeed a ground, "not the neg side of power", then it should be tied to the frame. imho
may not be needed.
Are there going to be any outside extensions connected?
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: HarrySmith on July 15, 2020, 06:08:29 PM
I have a ton of 555 documents on Google Drive here:
https://drive.google.com/drive/folders/0B6eDAxemj1VHZjk2NTgwNWItMGUzNy00YzhhLWI4NGQtNzc3MTU4OGE5MjRh
You can also find documents at the TCI library.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: Key2871 on July 15, 2020, 07:26:20 PM
Those power units are positive ground, not negitive.
So you have to remember that when using those.
And yes when your connecting to a key system or a box you must make sure your connections are correct before powering up.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 15, 2020, 08:30:28 PM
Thanks everyone.  I do plan to have 2 extensions and a trunk assuming I can get anything to work.
 
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: Jim Stettler on July 15, 2020, 09:42:29 PM
From looking at the photo:
The ground terminal is an electrical ground. It should be connected (bonded) to the frame of the switchboard.
 This ground the metal components  to your electrical ground thru the power supply cord. It helps keep you safe.
----------------------------------------------------------------------------------------------------------------------
Telephone systems  were wired  positive ground. 
------------------
Telephone tidbit:

I had a very old Bell report about "The deterioration of underground lead sheathed cables".
It said a negative ground would deteriorate the lead sheath. A positive ground would increase the thickness of the lead sheath.
This is the basis for cathodic protection of buried metal pipe.

Jim

Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 15, 2020, 09:53:18 PM
Well, I wired it up, and will add the power supply ground to the frame based on Jim's note.  Unfortunately, I got absolutely nothing.  No lights, no buzz, no sparks no smoke.  Any ideas on the first places to look would be appreciated.  Pictures below in case they are helpful.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 15, 2020, 09:56:19 PM
The ringer was just hanging by its wires in the back of the cabinet.  I suspect it is not original equipment.  The buzzer knob on the front panel is currently a bridge to nowhere, it is not connected to anything.  I expect the large cable with a plethora of wires at the bottom of the unit is the cut extension lines.  I'm  not sure if the other bundle of cut cables (picture above) is an issue.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 15, 2020, 10:00:06 PM
one more pic.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: Jim Stettler on July 15, 2020, 10:18:56 PM
Have you verified that you have output voltage from the power supply?


Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 16, 2020, 08:08:33 AM
I assume you turned the BATT switch to ON???
Also, you won't get any activity until you connect a station phone, and lift the handset.
Do you have any trunk connections active?
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 16, 2020, 10:47:23 AM
Well, something must have happened to the "talk" fuse after I tested the power supply voltage.  When I again checked the talk output voltage, I got nothing.  I replaced the fuse and stuff starting happening.  When I turn on the BATT switch, a single light from one of the plug pairs comes on.  Encouraged, I hooked up one of the trunks and called its extension. To my surprise, the trunk light lit up and buzzed briefly.  I installed an extension phone and was able to pass the trunk call to the extension....  well, at least it rang.   More testing coming up.  I am curious why the single plug pair light comes on when I power up the unit.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 16, 2020, 10:52:08 AM
what state is the talk switch in?
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 16, 2020, 11:41:34 AM
It stays on in either position.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 16, 2020, 12:28:49 PM
pushed or pulled also?
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 16, 2020, 01:58:59 PM
Glad you asked.  Now the behavior seems to have changed.  The light is off when the lever is pulled,  When pushed in and to the right, the light is on, When pushed in and to the left, it flashes briefly and buzzes.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 16, 2020, 03:33:40 PM
I think you are close to working???
try the same steps on another cord set, and see if the result is the same
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 16, 2020, 03:38:45 PM
I'll do that.  I'm currently creating a shelf for the bottom of the unit to more permanently position my power supply, voip ata and wap.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 16, 2020, 06:32:36 PM
I added a wooden shelf to the bottom of the unit for my power supply and voip equipment.  I imagine I may have touched some of the station wires when installing the shelf.  So now when I turn the BATT switch on, I have (5) seemingly random extension lights come on and stay on.  My trunk still works and the (2) extensions I actually have installed both work.  None of the (5) lights are the installed trunk or extensions.  Any ideas on why these lamps would be lit?
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 16, 2020, 09:11:10 PM
First, check the condition of all the cord set switches.
Make them all the same.
2nd, chk the condition of the ENDS of both the grey cut cable, and the bundle in the pic.
Fan out the ends of these bundles, so no shorts can happen.
You got some loose wires in there. Clean them all up.
Then read this... Enjoy
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 16, 2020, 10:10:12 PM
Awesome, thanks.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 17, 2020, 01:58:48 PM
RB was right!  Fanning out the wires at the end of the cut gray cable corrected the random extension light issue.  I think the PBX is about 80% working. 
Next I want to see if the dial and operator station can be restored to functionality.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 17, 2020, 03:43:49 PM
Plug in OP set. Make sure SPLIT switch is turned to LEFT
Plug in a Right cord from one of the sets to a station.
Turn switch to Right. "they should all be in the OUT and UP position when not used".
Pick up station Rec, and talk. OP should be on line, and can hear and talk to Station.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 20, 2020, 03:59:40 PM
I was unable to hear the station following these instructions -
Plug in OP set. Make sure SPLIT switch is turned to LEFT
Plug in a Right cord from one of the sets to a station.
Turn switch to Right. "they should all be in the OUT and UP position when not used".
Pick up station Rec, and talk. OP should be on line, and can hear and talk to Station.

I was able to dial out once using left cord into trunk.  The dial tone was very faint in the operator headset.  I could not get it to work a second time.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: Babybearjs on July 20, 2020, 04:09:16 PM
make sure you research the schematic.... it took me forever to understand the wiring of some of the 1A1 system parts.... just study the schematics and you should be able to trace the problems....
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 24, 2020, 05:19:43 PM
Ok.  I've made progress.  Now the trunk works, the extensions work, the operator station works, and the dial works.  The only improvement I would like to make is to the volume on the receiver for the operator headset is very low.  I can hear the dial tone and callers speaking but not very loudly.  The transmitter is loud and clear.  I have tried (2) headsets to rule that out as the issue.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 24, 2020, 06:28:40 PM
Glad to hear you are making progress!
What did you have to do to get it working?
Also, what do the op sets look like?
Are they both identical?
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: rglenn on July 24, 2020, 06:37:58 PM
I found one of the wires disconnected on the operator headset input box.  I soldered it.  One headset is a type #53 and the other is type #52.
Title: Re: WE 555 PBX - just flew one in last weekend, hoping to get working
Post by: RB on July 24, 2020, 10:39:46 PM
A couple things.
By headset input box, I assume you mean a matchbox sized box mounted under the deck, with 2 holes in it?
How did the other wires look? I assume there were 4 total?
Did you try wiggling the plug while listening?
Also, have you tried the test with another cord set?
Also, try switching the SPLIT switch a few times while listening.
and check its wires too.
If you can check the dial wires and the switch adjustments.
Last, for now... there are a couple relays associated with the op pack.
There could be dirty/misadjusted switches in them too.
They are not easy to get too.
A gentle tap on the housing while listening, may produce a different result, but be careful.