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 is from an old English documentation. It uses a common milliammeter to indicate the...
This circuit was obtained from an English magazine from 1976. The circuit operates two LEDs and...
This is a common oscillator configuration that generates rectangular signals in phase opposition. This...