The signals from this circuit obtained from the 1965 Radio Shack documentation are picked up from a medium wave receiver. L1 and L2 have 80 to 100 turns of yarn 28 on a ferrite rod.
If the input voltage falls below 12 V the LED glows up. Other voltages can be monitored by...
ON Semconductor FFSP0665B 650V 6A SiC Schottky Diodes Available through Mouser Electronics, these...
This adjustable circuit from 0 to 200 nA was found in a 90's EDN. The components can still be...