JFET VCO (CB21133E)

This circuit was found in a Popular Electronics from the 90's. The frequencies depend on the components indicated in the table next to the diagram.

| Clique na imagem para ampliar |

Bistable Multivibrator (CB9925E)
This circuit using an operational amplifier was found in old American documentation. It can be...
Simple transistor tester (CB23746E)
If the circuit oscillates, emitting sound, it is because the transistor is good. This simple...
Telephone Amplifier with TDA7052 (CB990E)
Like the previous circuit, this is used in the analog part of the telephone lines. The same...