This audio-driven relay was published in the July 1977 issue of Radio Electronics magazine. The circuit uses CMOS components, and the relay must be a sensitive type.
Found in Mullard's 1960s transistor manual, this circuit has components that depend on the...
This signal injector uses a single integrated circuit as an oscillator, producing rectangular...
This second amplifier is based on the integrated LM108 and has a differential input. The resistor...