The 555 is really only a few comparators, a voltage divider, one or two transistors, a flip flop and an inverter. The idea is you use a capacitor to charge and the comparators can set or reset the ...

With a 555 on the BOM, you never know what you ... which only requires a little persuasion to become a JK flip flop. His initial design for the flip flop that would form the core of the circuit ...