Remember that voltage is measured across a pair of wires, so you can’t power the chime with only a single wire. That’s part of what makes this difficult – these doorbell systems only have the bare minimum of wiring in them. Powering the camera and the chime in series with each other is quite difficult. I think a lot of these things just accept the short circuit, and use a battery to power the camera while the button is being held.
Here is what I was proposing, and I think what ch00f was also proposing. Replace “5VDC power supply” in this diagram with “a full bridge rectifier and a bunch of caps” in their description, and also note that your camera probably requires a well regulated 5VDC supply.
ch00f@lemmy.world 4 months ago
Your drawing is a little confusing. Here’s what you need:
Image
There’s nothing special about a setup with a light in the button. It’s literally just an incandescent bulb across the button. If you connect your circuit across the button terminals, it’ll work fine.
The 4 diodes in a loop is a “full bridge rectifier” that gives you DC from AC. The 5V regulator could be something like an LM7805.
The “large capacitor” is to keep power applied while the button is pressed, though you might be better off in that case with some small onboard battery. You just have to make sure that your battery charging circuit doesn’t draw too much power.