Phone Ringer

[timmiddleton]

hi

I need a way of ringing a normal UK landline phone on stage. I've read about phone ringers but the only one I found on the net was £200 so I could do with something a little cheaper!

 

tim

[ChrisD]

Try Sparks www.everythinglighting.co.uk

[J Pearce]

Maplins sell or did sell a kit to do this.

We built one to ring a phone in Annie.

[Andrew C]

Maplins sell or did sell a kit to do this.

We built one to ring a phone in Annie.

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Did. I do have the instructions/schematics. PM if you want a copy.

[Malcolm Gordon]

I built the Maplins kit ringer about 9 years ago and have been using it for plays ever since. It has the option to make a UK or US style ring.

 

One proviso - the instructions state that the circuit does not have sufficient output to drive an old-fashioned phone with bells e.g. bakelite model.

[Andrew C]

One proviso - the instructions state that the circuit does not have sufficient output to drive an old-fashioned phone with bells e.g. bakelite model.

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And it is also unfortunately correct. The one I have was modified to increase the available current, but I don't remember how.

[Jivemaster]

They are trade out of Gradav in N London chose the ring in accordance with the setting of the play. they may even hire!!!!

[Ellis]

The actual ring signal used for telephones is 50v AC (modern ones will work with less). I have seen (in my student days) a lethal implementation using a relay channel and several wire-wound resistors - DO NOT TRY - I am not telling anyone the forrect

 

I have an old ringer that came from a theatre in the 70's which is just a GPO transformer, a bell push and a BT Master socket (recent mod). Any ~50V isolating transformer would do in a suitable enclosure.

 

The hardest part is to teach the operator what a telephone ring sounds like (listen to a normal land-lne)

[Lamplighter]

The actual ring signal used for telephones is 50v AC the forrect

 

I have an old ringer that came from a theatre in the 70's which is just a GPO transformer, a bell push and a BT Master socket (recent mod). Any ~50V isolating transformer would do in a suitable enclosure.

 

 

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The correct supply for ringing current was 16.6666 cycles per second, 100v nominal supplied via barretta (sort of filament lamp) to provide current limiting and protect the generator. When the first private automatic exchanges appeared they used a saturated transformer to provide 25 Hertz 50volt ringing. This is now the standard in newer telephone exchanges. The correct ringing cycle is 400mS on 200mS off 400mS on 2 seconds off. Most bell type phones will not respond to 50 Hertz.

 

Brian

[Penny]

Is is not possible just to run a long extension lead from the nearest phone socket to the stage? You can get extension leads about 25m long for about a fiver.

[Andrew C]

Getting it to ring on cue becomes rather hit-and-miss. You are at the whim of the system timing, and the crew tying up the line dialing out for a pizza!

[TomLyall]

Getting it to ring on cue becomes rather hit-and-miss.  You are at the whim of the system timing, and the crew tying up the line dialing out for a pizza!

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Or worse, someone else phoning it mid-show...

[Penny]

Then you just leave it unplugged except when it's being used.

[paulears]

never use a real phone circuit, the time delay before it rings is variable enough to make cueing difficult. As previous posters have said - get a proper ringer that works when you push the button - well worth it.

[danburns]

Is is not possible just to run a long extension lead from the nearest phone socket to the stage? You can get extension leads about 25m long for about a fiver.

 

 

Also, not everywhere has

A) A nearby phone socket

B) More than one phoneline.

 

In our venue, it's impossible to get to a phone jack without going throughthe back wall of the stage, into the lighting store and then swapping it out for the backstage phone. Then we only have one phone line for the building...so it's not a viable option in some venues