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.
This circuit using an operational amplifier was found in old American documentation. It can be...
If the circuit oscillates, emitting sound, it is because the transistor is good. This simple...
Like the previous circuit, this is used in the analog part of the telephone lines. The same...