Elaborate solution for doorbell chime ring and hum issues
I have had hum and “ding-without-dong” issues with my current 3-door Nutone chime (as well as with another 2-door chime) that are not fixed with chime connectors. The hum was silenced most of the time but the ring problem persisted.
A hardware engineer friend made what he calls a Rube Goldberg machine solution. It’s all what you see on the white board under my electric panel.
The VDP and chime circuits are entirely separated with the cameras having their own 16v30va transformer (on the side of the electric panel) and the doorbell having a separate 16v10va transformer at the bottom of the board.
At the top of the board are 3 Hall effect sensors (one for each VDP) that detect current changes when the button on the VDP is pressed. Next to them are resistors that take the place of the resistance of the chime coils through which the VDP would normally be drawing power.
In the middle is a green Arduino processor that analyzes the current changes and activate the relay for the door button being pressed. These relays are at the bottom of the board and one looks different because it’s mechanical whereas the other two are solid state.