Applications for using a single pushbutton to advance a circuit to its next logical state are legion. Typically, there are just “on” and “off” states, but there can be more. The heart of the circuit ...

This circuit shows how a 4017 CMOS decade counter can be used to build a timer circuit. Push-button S1 will discharge capacitor C1 through resistor R2. This circuit shows how a 4017 CMOS decade ...

Here’s your useful and beautiful circuit for the day — [New Pew]’s vibration sensor takes manual control of the flip-flop inside a 555 timer and lights an LED in response. Use it to detect those ...