This high-powered battery powered flasher was found in General Electric documentation from the 1980s. The circuit can control loads up to 3 A and has a sensor that triggers it in the absence of light.
Using SCRs, this circuit from a 1967 General Electric manual allows full wave load control with SCRs....
This interesting circuit from a publication from the 1970s, measures the intensity of the sound...
This simple NPN and PNP transistor tester configuration can use the low current range of a common...