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.
This experimental amplifier was found in the 1960 Mullard transistor reference manual. The...
This circuit from Motorola is from 1968, appearing elsewhere on this site. The transistors admit...
This circuit triggers the LED when the monitored battery voltage drops below 9 V for 12 V...