Zero test (CB22304E)

This circuit, bridge type, was found in American documentation from the 60's. The transistor is germanium of the time.

Relaxation Oscillator using the 741 (CB485)
This circuit can produce signals up to 100 kHz depending on C1 and R1 adjustment. The output has a...
Shield for triac activation (CB7833E)
Found in Radio Electronics this circuit uses a fotodiac to drive a triac. The circuit can use...
Programmable Gain Operational (CB18630E)
This circuit was obtained in an American documentation translated in the 80's. The circuit can be...