Micro amplifier (CB23672E)

This three-transistor circuit was found in Radio Electronics magazine from May 1969. The circuit is for hearing aids and has earphone listening.

| Clique na imagem para ampliar |

Precision Limiter (CB15883E)
The circuit in the figure is based on an LM101A; diodes can be replaced with equivalents. The...
Transistorized tachometer (CB9355E)
This circuit, with magnetic sensor, uses an operational amplifier of the time. The circuit is from...
Remote control analyzer (CB7812E)
Found in a 90s Popular Electronics, this circuit checks if a remote-control transmitter is...