This circuit was obtained from the February 1992 Radio Electronics magazine. In it, a bar of 4 LEDs flashes continuously at a speed given by C1 and the setting of R3.
This simple logic level tester was found in Radio Electronics from the 90s. The inverters are of...
This circuit was found in a 1980s documentation. The circuit uses common components having an...
This circuit was found in a 2001 documentation. It is a test of zener diodes that uses a voltmeter or...