The selected circuit was found in GE's 1977 semiconductor manual. 3N84 is a controlled silicon switch and SCRs support equivalents. The transistor can be a BC558, depending on the supply voltage.
The circuit we have just described has been mounted in the car of the author of the project for...
This circuit was found in an old European publication, but it can be implemented with more modern...
This circuit is based on a PLL 566 and generates positive ramps. The frequency depends on Rx and C...