K7,
I got to thinking about your idea, and I like the simplicity of it a lot.
Yes, all of the switches in the house are momentary contact.
In doing some looking at DigiKey catalog, I thought of some questions...
You had recommended 2400Ω resistors, which (excluding the diode effects) would limit current to approx 50mA. Most of the cheaper LEDs are 20mA rated, so I was thinking about a 10kΩ resistor to limit to 12mA, as I don't need them to be super bright. Any concern with this?
I was confused by the ½ Watt resistor selection. discounting again the effects of the diode, in the 2400 case, isn't the power 6W peak? (V*I is 120*50mA). If you took the rms value for the voltage, I see it dropping to 4W peak, but how does it get to fit in the ½W resistor? Even with my 10kΩ case, P=V²/R, I get peak power of 1.44W, and if I took RMS voltage and used that in the equation, I'd still get 0.72W. What am I missing here?
I'm thinking of not board mounting this, rather a parasite soldered on the end of the 12AWG wire that screws into the relay lug. the connections are so simple that with some shrinksleeving for isolation and hiding what's underneath(except the LED poking out), I could almost make it look like an intentional design, with the only obvious add is a white wire from under the shrink sleeve up to the neutral terminal strip.
Appreciate if you can straighten me out on the resistor!
thanks!