Transistor voltmeter (CB20582E)

This is a voltmeter with high input resistance. The transistor is germanium. We found it in an English publication from the 60s.

Sweep Generator (CB3955E)
In the figure we have the circuit of a sweep generator obtained in an old publication. The central...
1 Hz Oscillator with Quadrature Output (CB4841E)
This circuit is from an operating manual from the 1990s. The circuit generates sinusoidal and cosine...
Temperature Control (CB4666E)
This circuit was originally designed to maintain the temperature of a brooder at 41º C. However,...