This “people detector” with pyroelectric sensor was found in the April 1991 issue of Radio Electronics magazine. The circuit is based on an LM324 and a sensor from that time.
This circuit consists of a simplified Hartley oscillator that changes the frequency according to...
This circuit was obtained in a 1994 documentation. The assembly is very critical, and the circuit...
This circuit for analog TV was found in a 90s EDN. The integrated circuits used are from that time...