I'm trying to build a simple circuit to control a church lampadary for an escape room game. I don't know if you've seen these but they're fairly common in catholic churches where I live: You input donations and a fake candle lights up for each coin.
And powered it up with a 12V, 1A adapter. At the same time I'm using a car usb phone charger as converter (12V to 5V) to power my logic.
This acceptor has a NC signal configurable to output 100ms, 50ms or 22ms square pulses whenever a coin is inserted. To adapt this signal I used a couple of 10M resistors in series and a parallel 5V Zener diode in reverse connected to my 7474's ¬PRESET pin. Two ANDed flip-flops catch this signal and send a "clock pulse" to a 74164 which puts one bit up and lights a candle.
(Sorry for this, newbies can't post more than two links) All ICs in the picture are pointing west. Pin #1 is on the south west corner.
Still, when I input a coin in my acceptor, nothing happens. I've also tried to simulate acceptor output with a switch, and I saw two consecutive bits light up at the same time at each switch push. Maybe switch bouncing, which I thought I could solve with my flip-flops? Or maybe it isn't a good idea to use gate output as a clock signal for another IC?
Acceptor output gives 2.56V in my multimeter, which according to the datasheet should be enough to activate the latch.
This being the case, my question is: Is this a/the proper way to interface my 12V acceptor with my circuit? Am I missing something?
Thank you for reading. Any help would be appreciated!
I implemented the voltage converter using the IRF530 as proposed in this answer. Still the circuit wasn't responsive. I suspected the coin acceptors so I tried to test them connecting a couple of LEDs to N.O. and N.C. outputs through a 10K resistor. None of the LEDs lights up but they aren't burnt. Are the acceptors definately broken or is there something I'm missing?