This circuit was found in a Popular Electronics of the 1990s. The sensor is a rotating mechanical system with a propeller-driven magnet to count pulses with a reedswitch.
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...