Found in documentation from the 90s, this circuit triggers a relay with inductive signals applied to a link. The sensitivity depends on the frequency and the power supply depends on the relay used.
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...