This circuit can function as both a light alarm and a shadow alarm. The components are common. The circuit includes the power supply. Output transistors must be mounted on heatsinks.
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...