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.
This circuit was found in General Electric documentation from 1964. It makes use of a PUT, called the...
This circuit uses a diode to generate white noise for various applications. One involves the...
This circuit is a reminder for drivers who leave the headlights on and the car does not have the...