Found in old documentation as permanent security lighting, this circuit uses common components. The lamps can be replaced by fluorescent inverters or LEDs with appropriate series resistors.
Found in a 1970 EEE, this circuit uses general-purpose transistors of the time. Transistors support...
This simple source using fixed voltage regulators can supply currents up to 1 A at the voltages...
Originally suggested by Harris in the 1990s, this circuit uses an optical tachometer. The circuit is...