Found in a documentation from the 90s, this circuit limits and amplifies a voice signal in the 800 to 3000 Hz range and is intended for transmission systems.
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...