This circuit uses two relays that switch when the voltage exceeds the value given by zener D2. The circuit is from a Radio Electronics magazine from April 1975.
This circuit generates sinusoidal and cosine signals of 2 kHz given basically by the values of C1...
This circuit was found in a Dutch documentation from 1970. The circuit makes use of semiconductors that...
This circuit has both frequency and duty cycle control. We found it in the October 1992 Radio...