This circuit also appears elsewhere on this site, obtained from other sources. This is an 80's American schematic book. Instead the lamp can be used white high-brightness LEDs.
The circuit presented uses the high-power operational amplifier LM12, which is currently not an...
Suggested by Philips documentation from 1968, this circuit uses components from the era that can...
This highly sensitive circuit causes one relay to be closed when the other is open or still...