The idea of this circuit found in a Radio Electronics from January 1966. The idea of the circuit is to improve the reception of audio signals, mainly telegraphy, working as a filter.
The integrated circuit used in this 1986 project is not very common today. The circuit uses few...
This circuit controls a relay causing it to open and close its contacts at a speed that depends on the...
The circuit is from the MC1539 manual, an operational one close to the 741. The transistor admits...