Found in documentation two years 80, this toy instrument uses an integrated circuit little commonly. As notes are given the values of key series resistors on the keyboard.
This circuit was found in an American documentation from 1968. The circuit generates ladder-shaped...
This circuit keeps an LED on briefly when S1 is pressed. The time depends on C1. The circuit is...
This circuit was found in old documentation, but it adapts perfectly to modern applications with...