Detecting 36 12v lamps on/off

I have a vintage roll down game that has 36 12v lamps that I would like to detect when they are on/off with an Arduino Mega. Should I use 36 of these? or is there a better way to detect these lamps turning on/off?

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shacomm:
I have a vintage roll down game that has 36 12v lamps that I would like to detect when they are on/off with an Arduino Mega. Should I use 36 of these? or is there a better way to detect these lamps turning on/off?

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You could, or just use the voltage divider resistor pair they specify and make your own, 36 times. They are going to an A/D pin to measure the voltage, but you don't care, so use a digital pin. Need 36 available pins, though.

Paul

Could use simple NPN transistors and a resistor.
12V turns on transistor, open collector pulls down INPUT_PULLUP pins, 0 indicates 12V light is on.

cd74HC4050 powered from 5V would do the same for 8 channels at once. 5 chips would handle all the inputs.

Firstly are the 12V lamps all referenced to the same ground?
Are they DC or AC?

I'm thinking of optocouplers in parallel to the existing lights (or if they all share either the 12V or GND lines a single wire per lamp is enough).

I also like the open collector scheme.