Guitar Distorsion Pedal (CB18205E)

This simple circuit with two transistors was found in a 1985 publication. The power can come from batteries or battery, as consumption is very low.

| Clique na imagem para ampliar |

3-Range FET Voltmeter (CB25570E)
This circuit can work with almost any JFET. The circuit is from an Electronics Now from April...
Servo Control (CB5941E)
This physical line servo control uses components that are not currently common. The circuit is from...
Current Amplifier (CB6136E)
This circuit was found in a British documentation from 1969. It can be implemented with modern...