This circuit was found in a Hughes manual of 1068 using a MOSFET of the time. The circuit can be adapted to use modern equivalent MOSFETs.
The interruption of the light incident on the phototransistor causes the trip of this circuit that can...
Found in a 1990s Popular Electronics, this circuit uses two transistors to boost the power of a...
This circuit activates a buzzer when the voltage applied to the input falls below a preset value in...