This simple tester was found in a Popular Electronics from the 90s. The circuit is powered by two 9 V batteries since it requires a symmetrical source.
This circuit can be used to test zener diodes up to 25 V using a standard multimeter. The voltage...
This circuit without any capacitor operates based in the time the transistor need to turn on. The...
This circuit is suitable for recovering vinyl media, having been found in an old sound magazine from...