This simple power supply circuit triggers when the light on the LDR reaches the level set on the potentiometer. The circuit is from an Electronics Now from July 1995.
This circuit that uses only discrete components (transistors) mimics the sound of an American...
The purpose of this simple configuration, found in old documentation, is to trigger a buzzer if...
The value of R1 given by I = R1 / 5 determines the load current of this circuit. The maximum...