This 1967 modeling circuit mimics the whistle of a locomotive. The steam-shrieking wheezing is set in a 2k2 potentiometer.
This UHV generator circuit or ultra-high voltage was found in a 90s Electronic Engineering 90s. The triac...
When the sensor is activated the relay turns on powering na external load such as a buzzer siren...
This transistorized receiver was manufactured in the 1960s and distributed worldwide. The diagram is...