This circuit was obtained in a General Electric documentation from the 80's, and can be used as a shield. The circuit supports current equivalent components.
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...