This circuit that we found in a 1990 documentation uses an LED as a sensor. The operational amplifier is equivalent to the 741 and the trigger adjustment is made in the potentiometer.
With this circuit you can control up to 3 A of LEDs in different sequences, using a PWM...
This is the typical circuit of a 60's tape recorder. The circuit uses only two transistors and has a...
This application is from a circuit manual from the 90s and only works with incandescent lamps. The triac...