This circuit is from a publication from the 70s. The operational amplifier is from the period. Modern equivalents according to the motor current must be used.
This circuit was found in an English operational documentation from 1970. The circuit can be...
This circuit is from a 1974 publication. It generates a pulse with several sinusoidal cycles from...
This solar cell driven circuit makes 4 LEDs run at a speed given by capacitor C2. The circuit is...