Phone ringers

[Dom Bell]

Hi just a quick question

 

is there any way of making a new style phone ring on stage. I can get an old style one thats easy enough it's the new type I'm having trouble with. it's a tour so I cant plug it in to the phone system or anything like that Any ideas

 

Many thanks Dominic Bell

[scarr]

You can probably buy something like a Tele-Q to generate the ring voltage, or just make something to generate the required voltage (something like 75V AC at 25Hz) and connect that to the correct wires of the phone when you want it to ring.

[Malcolm Gordon]

Have a look at this thread.

[Yogi Bear]

Appropriate surname for this post.

 

I'd be interested to know what method you use to get the old style phones to ring. I built a budget box for another drama group with a 20-0-20 v.a.c. (3 watt) transformer and that worked fine on old phones (although twice as fast) wired to pins 2 and 5 on the BT socket. It didn't work on a new phone of their's and from memory, I had to link pin 5 to 6. I'm sure my new phone was alright. They were quite happy with the sound which was more realistic than recorded sound.

 

I did think of using some op amps, one as an astable at around 25 Hz and a couple of L272 power op-amps in push-pull to drive the bell but temporarily shelved the idea as I also had a telephone ringer transformer which came from J. Bull Electrical about 20 years ago that I used for my own group.

 

Hope this helps.

 

 

Yogi Bear

[Simon Lyall]

as ive said on another post somwhere, I use an old style army field telephone that will ring the old style phones no problemn , on que becuase the ringer in a slide button thing, the other advantage is that when/if they pick it up, you can talk to them, and they can talk back, ie instant prompting!!

 

this I also use with a door bell as well, hwen there is no telephone as such and its off stage, gives you a realistic effect, beucase its real!

[Smallsy]

I've recently been looking into making my own phone ringer as opposed to buying one from - http://www.precisiovision.freeuk.com/index.html

 

I recently stumbled across http://www.epemag3.com

 

If you look at June 2006 issue there's a guide on making a Telephone Ringer Tester.

You can also buy the PCB board from them aswell as a back issue from their on-line store.

 

I hope this helps anyone who is looking to make one.

I hope it'll do the job.

Good luck.

[ramdram]

We use an old BT private exchange, PABX (about 6"x10"x2"), it supports tone or pulse dialling and had been tricked up with new type BT skts.

 

We know the time delay so it is not too difficult to judge the ring to hit the cue.

 

It was donated so no idea of cost. Possibly a trip to eBay?

[KevinE]

Most modern tonecaller phones are 2-wire and most will ring properly on a 50-75VAC 50Hz supply; though in reality it's just under 25Hz at 75VAC, meaning some bell-phones wont ring unless the gongs are adjusted.

 

For 2-wire phones, the bt socket connection is 2 and 5, no other wires are usually connected in the line cord.

 

For 3-wire 700 series bell phones that have a retro-fitted BT line cord, apply the ring volts to 3 and 5. This is because the no.3 wire is the 'bell' wire wrt no.5. although the speech loop is on 2-5. A master socket contains bell capacitor between 2 and 3 which passes only the AC to terminal 3. Modern IC-based phones usually have circuitry built in to suppress both bell tinkle and DC ringing (or built in capacitor!) which is why they work ok on 2-wire.

 

On the old 'bar of soap' skirting board GPO junction box, the bell wire was strapped across to the speech circuit and the bell capacitor present in the phone itself . This was to allow a bedroom phone to be connected and allowed the dial contacts of one phone to suppress the bell tinkle in both phones, before the introduction of the 'inphone' system as we have today.

 

The conversion of the old fixed wiring plan to the new inphone system required adapting the old type phones to high-impedance ringing as well, since plug-in phones would have to have parallel-connected ringers but still be able to suppress bell tinkle at the same time as being freely pluggable in or out.

 

So, in a nutshell, if you can ring an old phone by whatever method you're using, there's no reason why you shouldnt be able to ring a new one as they are much simpler to connect!

[J Pearce]

25Hz 75VAC should be easily achievable from a decent audio amp. Might want to check the impedance on the ringer first though.

[KevinE]

1K on a non-converted GPO wired phone, generally 4K on an approved plug-in phone of REN 1.

[themadhippy]

The ringing voltage and frequency aint normally a problem,_{dont mention that a center tapped site tranny gives 55 volts.}Its the patteren of the ring tone thats a bugger to get right every time on a bell push.

[J Pearce]

That was my point, if fed from an audio amp you could make a track with the right ring pattern and play it back.

[Don Allen]

The ring pattern is called the cadence, ITU-T Tones, I use a microcontroller to produce the ten most common ring tones and have off hook detection so the actor is not caught holding up a receiver while the phone continues to ring. Although the frequency is specified, it is easier to use 60 volts ac 50 hertz, as most audience members would not pick the difference.