Making a phone ring - Community Theatre

[DavePEI]

It's been 20 years or so since I worked on 1A2 but I seem to recall the motor keeps running once A and A1 are shorted to indicate an answered call, but the flashing lamp and ringing stop because they are overridden by the A/A1 answer leads being shorted. If the motor simply followed the ringing then the lights would stop flashing during the silent interval

That is the case when it is used in its original application, but when used individually, it behaves as I said. We are talking about a completely different application of the interruptor. There are two options, neither of which makes much difference, leave the 10 volts solidly on the motor leads and switch the output, or switch the motor and  don't switch the output.

In either case, there are going to be times where the hump in the cam is between the contacts, so there will be a second or two before the ring will begin.Theoretically, it could also start out with the contacts on the hump in the cam, and it could theoretically start out with a short ring. This is the same effect one could get with an old exchange motor driven interruptor. As soon as the cam closes the contacts, you will get your first ring. All rings after that will match the expected cadence.

Dave

[TelePlay]

A simple circuit that acts like an interrupter but can be programmed or manually used to generate the exact ring cadence on cue is below.

The transformer cost me $1.95. The relay about $1.50. I already had a Tellabs unit and a phone.

I hooked this circuit up tonight and it worked just fine. I plugged an 8101 into an outlet and left it powered up. One of the leads went directly to the phone, the other to the Normally Open terminal of a relay SPDT switch rated at 120 VAC and 10 Amps. The relay common terminal was connected to the phone. The phone did not ring.

I then attached the leads from a 6 VDC transformer to the two coil terminals on the relay. I plugged the transformer into a switched outlet when the outlet was off. The phone did not ring.

I powered up the outlet and the phone rang until I powered off the outlet, the ring then stopped.

This circuit can be used to ways. The transformer can be plugged into a light board controlled outlet on stage and the light board can power the circuit on and off in a 2 second 4 second cycle.

Or, the transformer can be plugged into a normal powered outlet and a momentary SPST switch be placed in one of the 6 VDC leads to the terminal and the relay coil can then be powered by pushing the switch by a stage hand to complete the circuit and ring the phone.

A momentary switch could simply be put in the Tellabs line instead of the relay and pressed to ring the phone. The purpose of the relay is to provide the ability to control the circuit from a programmable light board. A programmable light board would be programmed to power up the circuit for 2 seconds (the length of the power up cue may have to be about 1.5 or 1.75 seconds because on power down it took a portion of a second for the transformed to drop the voltage below that at which the relay coil would deactivate), then off for 4 seconds, or whatever cadence is wanted, for as long as the light board cycle continued. The light board cycle would be stopped by one additional light cue which would stop the cycle right after the phone is picked up.

I was using a 6 VDC transformer with a 300 mA rating. A 100 mA transformer or adding a 200 mA load to the 300 mA transformer circuit may solve the power down issue.

The theater LD can best advise you if this can be done. Some smaller theaters may still be using manual/analog light boards.

[winkydink]

A simple circuit that acts like an interrupter but can be programmed or manually used to generate the exact ring cadence on cue is below.

The transformer cost me $1.95. The relay about $1.50. I already had a Tellabs unit and a phone.

This looks great.  So simple, even I can probably do it [LOL].  I am going to purchase a Tellabs unit and also the relay and transformer.  I will let every one know how it goes.

Thanks again !

[winkydink]

I just purchased (ebay) Tellabs 8101 unit.

I need to go and purchase and spdt relay and spdt switch

I am a little confused by your terminology regarding the relay and switch

You say " Open terminal of a relay SPDT switch rated at 120 VAC and 10 Amps"

Is the switch rated 120 VAC/10Amps or is it the relay ?

If I could get some clarification, it will save me a bit of trouble so I don't purchase the incorrect item.

Thanks again !

[DavePEI]

I just purchased (ebay) Tellabs 8101 unit.

I need to go and purchase and spdt relay and spdt switch

I am a little confused by your terminology regarding the relay and switch

You say " Open terminal of a relay SPDT switch rated at 120 VAC and 10 Amps"

Is the switch rated 120 VAC/10Amps or is it the relay ?

If I could get some clarification, it will save me a bit of trouble so I don't purchase the incorrect item.

Thanks again !

I would imagine he is referring to the rating of the contacts - that they will survive the near 100 volts of ring voltage. The primary in his configuration needs to match the output of the power supply - in this case 6 volts..

Dave.

[TelePlay]

Yes, Dave is correct. The coil is 6 VDC and needs at least 60 mAmps. The switch in the relay has contacts rated at 120 VAC and 10 amps, more than enough to handle the Tellabs power when ringing a phone.

I sent you a PM about the relay.

[TelePlay]

I have a play coming up in February 2013 where a candlestick rings once at the very end of the show.

With no dialing out or conversation required, I see no need to set up a full POTS Teltone system so am building one of these circuits.

I am going to put one additional switch in the circuit, a miniature SPST slide switch that will when closed allow the 6 VDC to bypass the momentary push button switch. That way, the transformer can be plugged into a light board switched outlet and the ring controlled by the programmable light board.

With the slide switch open, the transformer can be plugged into a powered outlet and then the momentary push button switch can be used to operate the relay and make the phone ring.

Am using a 3x2x1 ABS project box from Radio Shack and will use a terminal strip for the Tellabs line in, a modular wall plug for the phone line cord out and then hard wire the transformer line into the box.

[TelePlay]

I am building one of these circuits.

I am going to put one additional switch in the circuit, a miniature SPST slide switch that will when closed allow the 6 VDC to bypass the momentary push button switch. That way, the transformer can be plugged into a light board switched outlet and the ring controlled by the programmable light board.

With the slide switch open, the transformer can be plugged into a powered outlet and then the momentary push button switch can be used to operate the relay and make the phone ring.

Here's the circuit with a SPST mini-slide switch inserted in the 6 VDC line which when closed will take the momentary push button SPST out of the circuit. This will allow operating the relay with a switch outlet (a light board circuit on stage). With the mini-slide switch open, the transformer can be plugged into a standard outlet and the phone will ring when the button is pushed by a stage hand in the wings.

[winkydink]

OK

So I purchased a used Tellabs 8101 off ebay (with "free" shipping) and it arrived today.

I want to test it out to make sure that the unit works before I go any further.

I have a know WE 302 phone that rings.  Can I just hook the red and green wires to the two screws on the unit an plug it in for a second to see if it rings or is it not as simple as that ?

Just trying to do first things first.

Thanks again for the help.

[winkydink]

Well I found the manual on line and the instructions say that either ringer lead can be connected to either screw.

So I tried this with red/green leads.

Then I plugged the unit in.

Results:  Nothing

Picked up handset:  Heard a buzz

Hung up and unplugged Tellabs unit.

Do I have a bumb unit or do I need to do something more ?

[DavePEI]

Picked up handset:  Heard a buzz

Hung up and unplugged Tellabs unit.

Do I have a bumb unit or do I need to do something more ?

Won't ring unless the handset is on hook. However, there is a possibility you have a bum unit. Check the fuse...

Dave

[winkydink]

Won't ring unless the handset is on hook. However, there is a possibility you have a bum unit. Check the fuse...

Dave

Yeah, well the handset was on the hook.  Went and plugged phone back into wall, call the home number and it rung, so ....

I will see if it is the fuse, but since I heard a buzzing when I picked up the receiver I am going to assume that the fuse is not bad. 

As the saying goes, "Nothing is ever easy ...."  Oh well.

[winkydink]

OK,

I am going to get a new fuse and also find a different phone, and try this again.  If no luck then, the unit gets shipped back, as it did have a 14 day return policy.

If certainly is frustrating when some thing easy becomes something complicated.

Oh well.....

[winkydink]

Well the tale of the Tellabs unit is a sad one.

I replaced the fuse, still no ring.  Checked the output voltage for both the electrical outlets and output connectors.  The outlets were fine but there was no voltage registered for the output connectors.

The unit is defective and is being shipped back. 

stay tuned ....