I don't know what the eFF i'm doing

Thread Starter


Joined Jul 19, 2007
I have a doorbell button that is working as a contact. I want to use this contact button to operate a doorbell chime and a DoorFon system. If i connect just the doorbell to the button, the door chime works fine. If i connect just the DoorFon system to the button, the phones ring and operate just the way they are supposed to. If I parallel the doorbell and the DoorFon to the button, the system goes haywire and doesn't work at all...it just keeps ringing the DoorFon. What i want to do is use ONE button to operate TWO systems. I'm getting about 9-10.5V DC from the two wires from the doorbell AND, i'm getting about 2.5V DC from the DoorFon wires. What do i need to do to make these two systems work off of one button? Someone told me i need a zener diode or something to isolate the two voltages.... Please help! Thanks.



Joined May 19, 2004
as gadget mentioned, signal isolation is required here. a set of contacts for the chime circuit (9-10.5vdc) and a set of contacts for the doorfon circuit (2.5vdc). a momentary pushbutton with 2 sets of n.o. contacts would be perfect if it could cosmetically look like a doorbell. but the 2-spst n.o. (minimum) relay will work also.


Joined Jul 17, 2007
A suitable relay gets my vote.

Otherwise, you'll have to run more wiring through the walls and replace the doorbell switch as well. With the relay, you just put it in the circuit near your doorbell chime and DoorFon - and each has their own enable circuit.