This old circuit, from the 80's, uses an integrated circuit that is uncommon today. The circuit is intended for loads controlled by triac and the resistors depend on the desired control.
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...