This circuit was found in a documentation of the 80s, having didactic purpose. For R1 values between 10k to 1M can be used. Transistors are general purpose types.
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...