This circuit was found in an American documentation from 1968. The circuit generates ladder-shaped signals adjusted in a potentiometer. Equivalent transistors can be used.
This second-order filter was found in American documentation and can be applied to almost any...
This circuit is based on documentation from the 1980s. It can be designed with modern operational...
This circuit is from an English magazine from 1978. The circuit can be assembled with BC557, BC547...