This circuit provides an audible signal when testing a TTL circuit. The circuit is from an old documentation, being fed with the 5V of the circuit under test.
This circuit generates signals from 0.01 Hz to 10 kHz, but uses unusual components today. The...
This 1969 Mullar circuit appears elsewhere on this site. The circuit uses germanium diodes and the...
This control circuit for direct current motors uses a 741 and an operational one of unusual power...