9V power source (CB21164E)

This simple circuit with a 5V regulator was found in an American documentation from the 90's. The output voltage is adjusted in a trimpot.

| Clique na imagem para ampliar |

12 V Regulator with Operational Amplifier (CB24824E)
This circuit is from a Radio Electronics magazine from July 1984. The transistor determines the...
Dial Signal Detector (CB21274E)
This circuit was found at Electronics Now. It can be used as a shield detector for dial signals in an...
Universal Battery Test (CB21347E)
This circuit was obtained from an English circuit manual. Components are common and LEDs can be 3...