Found in a Hands On Electronics from the 80's, this circuit activates a relay with alternating touches on the push-button. The relay depends on the supply voltage.
This circuit for a decorative robot was found in the April 1988 Radio Electronics magazine. The...
This circuit has a very traditional configuration that can be found elsewhere on the site. R2 and...
Indicated by Texas Instruments, this 1968 circuit measures the duration of a light pulse captured...