Found in a 90s Siliconix documentation, this high voltage power supply uses components from that time. MOSFETs can be current equivalents.
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...