Found in a 90s Popular Electronics, this sensor operates by infrared reflection. The components are modern, and the phototransistor can be of almost any type.
This circuit consists of a simplified Hartley oscillator that changes the frequency according to...
This circuit activates the horn if the door is opened with the headlights on. The circuit is for...
This linear characteristic circuit is based on a junction field effect transistor. The FI and BFO...