MOSFET Amplifier Stage (CB26315E)

Found in a 1990s Popular Electronics, this circuit uses a small transformer matched to the impedance of the speaker being driven.

| Clique na imagem para ampliar |

Telegraph manipulator (CB7038E)
This circuit was found in an American magazine 73 for radio amateurs of the 80s. It is an...
Sound activated switch (CB9087E)
Found in American documentation from the 1980s, this circuit can be designed with equivalent...
TTL Logic Probe (CB1461E )
This circuit is from a 1977 documentation. It is powered by the power supply of the circuit under...