How do u connect 2 302's (not 301's) to use as an intercom with ringing?

[Penn0920]

I know you can wire the two phones with a 9V battery, and a 300ohm resistor to get audio, but the ringing is more involved since it requires 90v ac at 20 hertz?

There was a DIY yourself article in Octobers Popular Science on how to do it, but the parts list was not specific, and there was no schematic.  The instructions were just general, which I will summarize.

To make the phones ring use a 555 timer circuit to produce 2 sec's on 4 sec's off ring, and an amp and transformer to bump up for the ring voltage.

Parts list
-----------
Stated to use a solder breadboard, I would prefer solder-less, for better trouble shooting.
12V Diode.
Caps and Resistors (no further info on how many or values)
12V-24V power supply.

Can anyone provide the specific parts needed list and schematic for this?

Thanks

[rdelius]

A  WE 301 set is a wooden magneto fiddleback  set and would just need 2 d cells to  replace the old battery.the Crank should ring the other set .Connect L1 and L2 to the same terminals on other set
Robby

[Bill Cahill]

Hi, guys. I got a message from the poster that they made a mistake, and, asked for information on the 301. They meant to say they need it on the 302. I feel it's in-appropriate to delete that information, but, if you guys don't mind, please help again, this time on the 302/ I might even be able to use that information myself. Manny thanks.
Bill Cahill

[TelePlay]

What I use was a product made by Teletone Company which has been recently purchased by Industrial Defender.

I have several Teletone 3 and Teletone 4 plain old telephone simulators that I use to make phones ring on stage for theatrical productions.

The TLS 3 has only 2 ports so two phones can be connected from anywhere to anywhere you want to run the cable. I use that if I have one phone on stage and it needs to be rung from the tech booth.

There are several for sale on eBay now and prices are all over the place, paid less than $100 for some and a bit more for the others. Here's the link to a current TLS auction:

http://tinyurl.com/7vkmzrr

The TLS 4 and TLS 5 have 4 ports and by putting a touchtone into port one, you can program all 4 lines to any number you may want. The TLS 3 have fixed 2 digit numbers. I find these work great for up to three phones on stage and one in the booth. The phones on the stage, say a home and a store area of the set are to call each other and carry on a conversation.

When hooked up, you get a dial tone when off hook, dial the number, you get a ring signal and the phone you are calling is getting the 20 Hz 90 VAC ring signal from the simulator.

With the 4 and 5, you get a busy signal if the line being called is off hook. I think you can also change the ring frequency and have an alternate ring pattern with the 4's and 5's but have never needed that so can't say exactly. The 5 is the same as the 4 but with added features like music on hold and some other stuff.

The simulators plug into a standard 120 VAC outlet and work as long as the unit is powered on. It is fused. If a person didn't know a simulator was being used, they would think it was a real telephone line. Nice units but pricey but they are POTS simulators so would make two 302 work like a real phone system. Any phone of any era works on these as long it would work on a modern POTS copper wire line in you home.

They may be other ways creative people have done. This is the "throw money at it if you don't want to deal with the time and cost of building something" solution.

There are other brand name simulators out there and quite a few at a wide range of prices on eBay right now. Do an eBay search for "telephone simulator" and you'll get all of them. Also, you can do a Google search for "Teletone telephone simulator" and you'll find other places that sell them.

[Penn0920]

Thx, but I already knew about those line simulators.  what I am looking for it to build a timer switch to emulate the ringing a transformer, and amp, etc.  As outlined in my question.

[TelePlay]

You may already know this and I'm not sure what you're looking for. I do know that two 10K resistors with a 290 uF capacitor and a 555 chip will give you 4 seconds high and 2 seconds low but the output of pin 3 on the 555 is 200 ma DC max and about 1.5 volts lower than the Vcc DC voltage running the chip which is below 15 VDC. I've set up 555's but have had to use pin 3 to run a micro relay with a coil load of 50 ma to switch 10 VAC at 1 Hz to flash a lamp on a 565 phone.

I'm sure there is something out there but someone much more advance in electronics than I would have to come up with the circuit to turn 120 VAC 60 Hz into 90 VAC at 20 Hz.

Good luck and if you do find out how to do it, I know more than a few others who would like that circuit.

[dsk]

I have tried to figure out that for years, and I'm always ending up with to complex diagrams, so I have never built that.
My simplest solution was a 25Hz powersupply , a rectifier, two relays and two capacitors.  When lifting the handset Relay one energies, and charges a capacitor, When going on hook the capacitor energies the other relay and sends ring voltage to both telephones until the capacitor is empty.

So to ring, I had to lift handset, and replace it, Then one ring in both phones, The same signal as a ring off signal. This works to let an CB telephone to be connected to a LB exchange too.

dsk

[G-Man]

Thx, but I already knew about those line simulators.  what I am looking for it to build a timer switch to emulate the ringing a transformer, and amp, etc.  As outlined in my question.

I've been unable to find the article you cited in the October, 2011 edition of Popular Science however the use of a 555 (or similar) timer as a 20-cycle oscillator driving a couple of transistors with a step-up transformer is an old concept.

I don't understand why they would print a dyi project without a complete parts list.

I will look to see if I still have another schematic for this circuit. But since it is so archaic, most enthusiast prefer an off-the-shelf approach by searching ebay for an affordable solution.

Last week, a compact talk-battery and ringing generator offered for under 10-dollars failed to attract any bidders.

But I assume you would rather build it yourself so I will see if I can dig it up.      

[G-Man]

Thx, but I already knew about those line simulators.  what I am looking for it to build a timer switch to emulate the ringing a transformer, and amp, etc.  As outlined in my question.

I've been unable to find the article you cited in the October, 2011 edition of Popular Science however the use of a 555 (or similar) timer as a 20-cycle oscillator driving a couple of transistors with a step-up transformer is an old concept.

I don't understand why they would print a dyi project without a complete parts list.

I will look to see if I still have another schematic for this circuit. But since it is so archaic, most enthusiast prefer an off-the-shelf approach by searching ebay for an affordable solution.

Last week, a compact talk-battery and ringing generator offered for under 10-dollars failed to attract any bidders.

But I assume you would rather build it yourself so I will see if I can dig it up.      

A quick Google search has revealed two circuits for generating ringing voltages...

http://tinyurl.com/7ooujyf

[Penn0920]

The article in popsci was on the front inside cover.  It was under the heading Great Create. Which is like an instructable article that radio shack inserts.  Since they then push their parts to make the project.  It was written by Vin Marshall. 

This is the parts list they posted.

12v-24v wall wart power supply
12v Zener diode 276-563
Various Capacitors and Resistors
Telephone cable
RJ12 Jacks
Circuit board

[dsk]

This works at 50 hz. (But not nicely)  50 Hz ring when you go on hook. You call by going off hook, and on hook and both (all) phones rings.  When you have finished, and the last phone goes on hook it rings again.  Just the simplest way I found to make an intercom.  Electronic ringers copes with the mains frequency old ringers has to be tuned to give a kind of a ring.

[dsk]

I really miss a good circuit drawing software. Tested several, but...