This circuit was obtained from the Encyclopedia of Electronic Circuits volume 5 of 1995. The circuit uses the 4001 CMOS to obtain hysteresis in the sensor feedback.
This '80s circuit drives an infrared LED, producing a modulated signal. Modern higher power LEDs...
We found this circuit in the February 1987 issue of Radio Electronics magazine. It is based on an...
This simple 1 transistor circuit was found in an American documentation from the 60's. The...