My house came with a non-working 1960’s doorbell. It’s a quite nice retro one with large bell rods.
This doorbell functioned by a simple linear solenoid. When the doorbell button was pushed, it would apply power to the solenoid striking one bell. The button was then released and a spring would pull the striker back with enough force to hit the other bell, before returning to a middle resting position.
It appeared to be ceased as applying power did nothing and I couldn’t get it to move.
As with most of my projects, it was put away in a box and not looked at for years.
After finally pulling it out again I connected the relay to my new bench supply. I stuck 24v through it and it moved! It turns out that I was not using enough power. It also used lots of amps and got really hot.
I decided it was best to use new lower power relays for the rebuild rather than sticking with the old one. I couldn’t find any that would match, but I figured two small ones would work fine.
Little Bird Electronics sold some that would be perfect, two small 3v ones.
- Arduino Uno
- Ethernet Shield
- Relay Shield
- Power Supply
This part was fairly simple, but I did have power issues. At first, when the relays triggered the solenoids, it would reset the Arduino. After some tweaks with higher power and a capacitor, it was fixed.
- Arduino Code
The Arduino code used a prepackaged LIB for network requests. When the button is pressed it triggers the relays in a sequence to produce a “song” from the two bells. After the sequence is finished, it sends a push notification to my phone using Prowl. This system allows me to know someone has pushed the doorbell anywhere, even not at home.
To do a proper restoration, I had to replace the old label, and layers of paint.
I recreated the old label and printed it off on some sticker paper before cutting it to size.
The next part was sanding back the back plate to bare metal and spray painting.
The last part was to scrub the copper tubular bells with steel wool and Braso.