Logic test with sound (CB25389E)

This circuit has visual and audible status indication using an oscillator. The circuit is from a Radio Electronics magazine from June 1991.

| Clique na imagem para ampliar |

Intermittent Timer (CB1348E )
We find this circuit in an old American documentation, but it is perfectly current by its...
12V Regulator (CB21178E)
Found in an American documentation, this regulator supplies a current according to the integrated...
LM390 gain 20 amplifier (CB25307E)
This audio circuit has an output power of 1 W. We found it in the Radio Electronics magazine of...