This circuit is from an 80's technical newsletter. The circuit can use any general purpose transistor and its power supply can be changed with a resistive divider to use a single 9V battery.
This circuit turns on your car's backlight when a vehicle coming from behind gets too close to it...
This circuit from the 90s, was found in an Electronic Design of the time. The components used are...
We found this circuit in documentation from Ferranti from 1968. The circuit uses transistors from that...