Doorbell Resistor?

Frank Hagan · Oct 29, 2009

I have a lighted doorbell I replaced, and have lost the old doorbell and resistor that was on it. The new lighted doorbell is lit, but pushing it doesn't activate the electronic chime. Sometimes, I can cause the chime to ring if I short the wires without the doorbell in place, but usually only once.

I tried a 1w 150 ohm resistor across the terminals, and the light goes out (and the doorbell still doesn't work). How do you calculate the size resistor that is needed? I suspect I just had too much resistance with that particular resistor. The chime unit itself doesn't have an electrical schematic, and the lighted doorbell doesn't include one on the packaging.

pipeman · Oct 29, 2009

Not many doorbell/chime setups that I know of require a resistor.
The light is parallel to the switch. When not in use, the current flows through the bulb and the chime circuit both. You have a voltage divider with enough voltage/current to light the bulb, but not activate the chime. When you push the button, the bulb is shorted out of the circuit, which supplies full voltage to the chime.
Sounds like your problem may be in the wiring, transformer or chime.

Frank Hagan · Oct 29, 2009

Thanks. The reason I thought it might need the resistor is that one was wired across the terminals on the old button (not sure how old it was, but the button failed due to dirt trapped between it and the bezel). I misplaced the old button with the resistor.

The wiring seems OK, as I'm getting voltage at the doorbell. But I'll check the resistance of the wiring and try a new chime.

pipeman · Oct 29, 2009

You could troubleshoot by checking the on/off voltage across the chime terminals with a helper to push the button.

arbware · Oct 29, 2009

Frank Hagan said:
Thanks. The reason I thought it might need the resistor is that one was wired across the terminals on the old button (not sure how old it was, but the button failed due to dirt trapped between it and the bezel). I misplaced the old button with the resistor.

Just a thought...
A lot of "electronic" doorbells (non mechanical... plays a melody/chime through a speaker) use a diode across the pushbutton..

This lets the chime have current to finish the chimes.. (westminster etc...) after the button is released.

If it was a diode instead of a resistor.. they are available at radioshack.. (1n2222 i think is the diode most commonly used.)

It's easy to mistake a diode for a resistor.. they both are the same size.. but diodes tend to be solid color (black) with a single stripe (Silver).. where resistors are typically tan... with several different colored bands.

My doorbell has a diode across the push button.. but it's not lighted.. so i'm not sure if it is the same as yours.

mustangcoupe · Oct 29, 2009

arbware said:
If it was a diode instead of a resistor.. they are available at radioshack.. (1n2222 i think is the diode most commonly used.)

and fyi there is a right and wrong way to put in a diode... they wont let current flow the wrong way

Frank Hagan · Oct 29, 2009

arbware said:
Just a thought...
A lot of "electronic" doorbells (non mechanical... plays a melody/chime through a speaker) use a diode across the pushbutton..

This lets the chime have current to finish the chimes.. (westminster etc...) after the button is released.

If it was a diode instead of a resistor.. they are available at radioshack.. (1n2222 i think is the diode most commonly used.)

It's easy to mistake a diode for a resistor.. they both are the same size.. but diodes tend to be solid color (black) with a single stripe (Silver).. where resistors are typically tan... with several different colored bands.

My doorbell has a diode across the push button.. but it's not lighted.. so i'm not sure if it is the same as yours.

Maybe it was ... I don't remember the color of it. I'll pick up a diode and see if that works.

The thing does play a distressingly large library of horrible sounding "tunes" that my wife enjoys. I would be happy with "ding dong", but sometimes get the "Song of the Volta Boat Men" instead (it gets changed frequently; the thing has something like 48 tunes). I have assured her I didn't sabotage it on purpose, which has stopped her from shopping for one with recordable content (I shudder to think of the possibilities that raises).

gatchel · Oct 29, 2009

A cut extension cord end to the two door bell wires at the button could solve all of your problems...maybe....

Doorbell Resistor?

Frank Hagan

Member

pipeman

Active Member

Frank Hagan

Member

pipeman

Active Member

arbware

Member

mustangcoupe

Senior Member

Frank Hagan

Member

gatchel

Senior Member

Similar threads