This circuit was suggested by an Electronic Design from the 90s. Its purpose is to detect resistance relationships in circuits with resistive sensors for control purposes, by firing a relay.
This circuit was found in a Popular Electronics of the 90s. The operational amplifier admits...
This is the typical circuit of a local oscillator for a superheterodyne FM receiver. The circuit...
Found in a 1968 Motorola publication, this circuit generates a high-powered audio tone when...