Two sensors are used in this simple remote-control circuit, one to switch on and one to switch off the relay. The circuit is from 1986 documentation. The transformer has 12 V of secondary.
Found in European documentation from the 1980s, this circuit was originally designed for computer...
This circuit, from a 303 Circuits from the 90s, uses a telephone pickup coil as a sensor to...
This circuit allows to increase the output power of a 741 as an amplifier. The circuit is from a...