We found this circuit in a 1966 documentation. The circuit is intended for a door opening system by the headlight of a car. The sensor is a photo-FET, an uncommon component today.
Unlike the previous circuit, this circuit from Electronics Now, October 1993, has the load...
For the component values used in thisf this circuit, the frequency can be adjusted between 740 Hz and...
We found this circuit in the 1982 Selezione Radio magazine in Italy. The circuit uses an...