This circuit was found in a 90s Radio Electronics. It is intended to amplify the sound channel of analog televisions of the time. The integrated circuit used is uncommon today.
The base of this circuit is one of the four Norton amplifiers existing in an LM3900 integrated circuit....
This simple CMOS metronome circuit can be mounted in a small box, providing both sound and light...
This circuit of an old American publication uses RF transistors to obtain unit voltage gain, but...