Adapting a telephone answering machine?

Question

a bit of a crazy idea but I have this oldish (tapeless) telephone answering machine hanging around and what I want to try and do with it is try and utilise it as a 'door announcement system' I suppose would be the best way to describe it so that if someone calls to the front door of my house I want them to press a doorbell and for it to announce 'I am sorry I cannot get to answer the door at the moment please leave a message of who called and what was it in connection with?' and then they can leave a message and when I get home I can see if someone has called to front door and what they wanted - also useful if someone calls to the front door early in the morning and I am asleep in bed (happened a few times) and I don't know whose called.

Now the thing is what I really want to know is how to tap into the ringing mechanism of the answering machine or can I somehow emulate the ringing circuit so that when people press the doorbell it sets the answer machine in action if anyone knows? thanks

Answer 1

wow what a novel idea, it could probably be done. dont know exactly how though, would require a bit of research into what exactly activates the answering machine and how it works.off the top of my head it would probably require a plc (programmable logic controller) between the doorbell and the answering machine. this is basically like a small computer which you write a simple program for. this would control when the machine activates, like after so many rings of the bell or could act as a timer to start the machine after so many seconds

the programming for a plc is very simple, you could prob find info on the internet or any first year engineering student could do it for you

Answer 2

Nice idea.

However, whilst I can see that it is possible to make it playback a message and sound the bell when someone operates the doorpush, it would require that a microphone be fitted outside the door.

If you already have a door intercom, it seems quite possible, but someone is going to have to trace out the wiring and connect it up, and that is not so easy from a distance and without being able to see all the hardware!

Answer 3

It's funny, I was experimenting with something similar recently but using the Asterisk PBX to record the messages - this was for warehouse deliverys out of hours though.

You can get doorphones that simulate a regular telephone, or you can modify an existing speakerphone to connect to a doorphone, then use this with a cheap old PBX (as someone else has mentioned) from ebay or similar to "speed dial" the anserphone when the button is pressed. A bit messy and you'll need a bit of electronics knowledge, but quite possible.

Edit: If you want to simulate ringing, you'll need 50v AC at very low current. This can be generated from a battery with a 555 timer chip and a transistor, or I think Maplin have/had a ring generater circuit that was intended for making phones on stage in a theatre ring - that would do the job.

Be careful when electricity is involved of course and don't go messing with anthing mains unless you're qualified.

Answer 4

The easiest way would be to get a small phone system which has a doorphone and then route the call from the doorphone to the extension with the answering machine. Job done

Answer 5

um... ok so you want to build a device to announce to people that you are not home, so they can break in and rob the place...

you are going to need to find a way to send 90VAC (ringing current) to the phone jack of the answering machine with VERY low amount of amps, on the center 2 pins of the jack (green/red) then find a way to feed 9VDC to the phone jack after the "ringing cycle" and send the person at the doors voice down the same wire so the device can record...

you better be pretty talented with electronics  to pull this off, it is unlikely that it is even remotely possible...

Answer 6

I have absolutely no flippin idea. But i think the idea is brilliant. if you get it up and running I would buy one!

Answer 7

Viking electronics and Wheellock chimes both have small devices that generate ringing current and provide conditioning for the line. Conveniently they both offer door-phones too because the Answering machine will not like rain. I have a tel labs 8101 Power supply I am using for a similar application at the office, but you can't have it its mine.