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.
We found this circuit in an old American documentation. The table gives the values of the...
This circuit, from a 1978 publication, uses a germanium power PNP, but the BD135 can be used for 6...
This water-triggered relay circuit was found in a Radio Electronics from May 1959. The circuit has only...