Voltage Monitor (CB21505E)

This fail-safe circuit was found in a 1967 Electronic Design. Transistors admit modern equivalents. The potentiometer adjusts the trigger level.

MW radio TBA820M (CB15214E)
This low-cost MW receiver is from the SGS linear integrated circuit manual. The coil wire can be...
Alarm with Timed Shutdown (CB4801E)
This circuit was found in a former Popular Electronics. The timing is given by R1 and C1, R4 and...
Maxim MAX25612 High Voltage LED Controller
Maxim MAX25612 High Voltage LED Controller In stock from Mouser Electronics, this high voltage...