9V power source (CB21164E)

This simple circuit with a 5V regulator was found in an American documentation from the 90's. The output voltage is adjusted in a trimpot.

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1 kHz oscillator (CB21934E)
This circuit was taken from the 1960's Mullard Transistor Manual. Information about the coils is...
LM386 Bridge Amplifier (CB25300E)
This bridge circuit is designed for 8-ohm speakers delivering a few watts of power. The circuit is from...
Rain Alarm (CB15108E)
This alarm, from a 1996 magazine, can be fitted with two BC548s in the original configuration...