Doorbell Expansion - help needed

[hardy16]

Doorbell Expansion

I have a hard-wired two button, two chime doorbell system installed in my home. I need to install a third chime/bell, but am unable to access the attic/wall to extend the wiring to the needed location.
Is there a way to add a wireless chime/bell which would activate when either of the existing buttons are pushed? If so, I would need the circuitry, needed components and instructions.

 

[karesz]

Doorbell Expansion

Hi Hardy16,
you can buy simple "wireless doorbell switches_with a small batery_ you must buy so one and apply in their switch(input) as "trigger" the output of your normal doorbell system.
Be care with "interfacing", may be you must apply a relay !
K.

 

[svhb]

Re: Doorbell Expansion

I suppose you have at least 3 wires to the buttons, then you can expand by using 2 diodes and two relays like in the picture.

The voltage source on the button size must be matched to the relays coil voltage and must be DC (otherwise the diode trick will not work).

The voltage for the bells can be anything, but must be the same for all bells, otherwise you need to use some extra relays as slave switches.