I have three illuminated momentary buttons with a separate anode and cathode for the led.
(source of image)
I want a circuit that illuminates the LED of the button that was most recently pushed.
My initial idea has been to use three SR Latches created using NOR gates. Connect the S or Q of each latch to the reset of the two other latches. But then this creates the opportunity for HIGH on both S and R which is disallowed. Right?
I imagine there are other ways to accomplish this without latches too. Any help is greatly appreciated.
Best Answer
The circuit you're looking for is called a "flip-flap-flop". It is essentially a 3-state (rather than 2-state) flip-flop. It can be implemented using a single 74xx27. It is the circuit on the right below: