Safest/Best way to disable phone line ringing

electron

Administrator
Staff member
Up until now, I used to turn off my cordless phones at night so we wouldn't be disturbed. However, battery aging is causing this to be a problem now, since the battery ends up dead after a few minutes of use.

So I would like to disable the ringing signal with my Elk M1 (either with the digital outputs, or the relay outputs). I know there are some circuits out there that can do this, but I am hoping someone else is already doing this, and can recommend a safe & reliable circuit to do this.

This would allow me to free up my UPB modules, and keep the phones turned on. Thanks!
 
Why not open the telephone line with a relay that is going to the base station on the wireless phones.
 
I totally forgot about the sandman site, thanks Wayne!

Spanky, which wire would I put through the relay, or do I have to use 2 relays?
 
Simply opening one of the phone wires with a relay will disable that phone. Opening both lines is more polite, but not required.

But keep in mind, that also disables outgoing calls from that phone, which may become a safety issue.
 
Well I am currently disabling the phone, but still being able to make outgoing calls would be the perfect solution for sure. I just wish that device was a little cheaper.
 
I have heard that all you need to do is add a bridge rectifier circuit to the phone line to prevent the AC ringing voltage from getting to the phone (it comes through as a DC voltage, which doesn't ring). Then use a double pole relay to bypass the diodes when you want the phone to be ringable. But I have also heard that the phone company frowns upon a user installing diodes on their circuit. I was unable to confirm with a Google search. Does anybody know?
 
WayneW said:
I have heard that all you need to do is add a bridge rectifier circuit to the phone line to prevent the AC ringing voltage from getting to the phone (it comes through as a DC voltage, which doesn't ring). Then use a double pole relay to bypass the diodes when you want the phone to be ringable. But I have also heard that the phone company frowns upon a user installing diodes on their circuit. I was unable to confirm with a Google search. Does anybody know?
i did just that when my kids were babies but i've since taken out the circuit (& re-used some of the parts) when they stopped napping. unfortunately, i can't find the circuit diagram anymore and i've come up empty googling for it.
 
Thanks Stuart, thats what I was looking for. The only obvious change I would make is to use a 12VDC coil on the relay so that it can be directly controlled from the elk or Ocelot easier.
 
Electron,
Put a normally closed relay contact on one side of the telephone line going into the M1 from the outside telephone line.

Write a Rule to open the relay contact which will disable the incoming telephone line from whatever method you want.

The M1 will now power the in house telephones.

Write other Rules so that if the alarm activates or you pick up an in house phone, the relay contacts close and re-establishes the telephone line.

This way you can have in coming call privacy and yet get to the telephone line upon an emergency.
 
Using Sandman's device or the diodes/relay should also allow you to get CID at each phone (assuming the phone has caller ID). Therefore if you happen to be awake or hear a phone ring in the distance, you can see who it is and decide if you want to answer.
 
It seems to me that a diode bridge on the telephone line will put 40 Hz (twice the original frequency), half ringing voltage to the telephones. Will the telephone's ringer turn on to those conditions?????

Most modern telephones have a diode bridge inside the telephone to put the proper polarity into the circuitry. I am not sure if the ringer sense comes before or after the bridge.
 
Back
Top