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.
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...