Solid state relay (CB8518E)

This circuit was found in a 90s Popular Electronics. Both the coupler and the MOSFET can be of any type.

Neon Fuse Blown Monitor (CB24104E)
This circuit was found in the January 1971 Radio Electronics magazine. It keeps the light flashing if...
Infrared detector (CB7108E)
This circuit was found in a Philips documentation from 1967. The circuit uses components from the...
Power Cut-off Protector (CB17463E)
This circuit, from 1999 documentation, prevents the powered device from receiving power when it...