Found in na 1969 Electronics World, this circuit makes use of transistors of the time. Equivalent transistors can be used. The diodes can be 1N4004.
Taiwan Semiconductor Dual N Channel MOSFET Taiwan semiconductor makes available through Mouser...
This circuit was obtained from my Mechatronics Sourcebook, published in the United States. In it...
This combination key or code key was found in old documentation. The consumption is very low, and...