Astable 555 (CB21101E)

This 50% duty cycle configuration was found in a Popular Electronics from the 1990s. The operating frequency is given by C1.

Relay and neon driver (CB8833E)
Found in a 1960s documentation, this circuit uses a transistor to drive a relay as well as a set...
Capacitive Alarm (CB12181E)
This approach alarm was found in Radio Electronics from July 1990. The circuit must be powered by a...
High Power Source (CB20214E)
This 75 W power supply was found in American documentation from the 1980s. Transistors can be...