Institute Newton C. Braga

Circuit Bench

Vox or Sound Switch (CB13609E)
I found this circuit in a 1978 publication. The circuit can be assembled with a BD136 transistor to...
Signal Follower (CB12343E)
This sensitive 4-transistor signal follower can be used in both audio and RF circuits. P1 is a...
Five Transistor Superherodyne Receiver (CB960E)
This is a commercial circuit from the year 1958. Transistors are germanium types and transformers...