Microphone preamp (CB22043E)

This preamp was found in an old English publication. Any usage JFET can be employed. The output is high impedance.

High stability thermocouple amplifier (CB20684E)
This circuit was found in an American documentation from the 90s. It can be implemented with...
100 mA regulator (CB21168E)
This 2-terminal regulator was obtained from a 1990s National Semiconductor manual. The components admit...
Light Activated Relay (CB948E)
This circuit uses a photocell as sensor and a sensitive relay according the power supply voltage....