This circuit was found in an English magazine from 1977. Signal inputs and outputs must be shielded, and the circuit can be powered by battery, since its consumption is low.
The circuit we present is that of a good power ultrasound generator, as it uses a transistorized output...
Two of the four gates of a 4011 is used in this biestable touch circuit. Do not use a power source...
This encoded lock circuit with alarm for use in homes was found in a publication from the 90s. The...