Found in 1968 Mullard documentation, this circuit uses period components. The transistors are matched pairs and the sensor is an Indian photocell of the time.
Found in a 90s Popular Electronics, this circuit is based on a common CMOS component. The circuit...
Taken from an Electronics Now from the 90s, this circuit generates signals whose frequency depends on...
This power supply uses a single-winding transformer. We found it in July 1984 Radio Electronics magazine....