This circuit synchronized by the power grid can be used as a shield. We found it in an 80's Electronic Engineering. R1 can typically be 4k7.
The current of this voltage regulator depends on the transistor which can be a TIP31 for 2 or 3 A....
This electronic car lock was found in a 1988 magazine. It uses a code key that must be activated to...
This circuit was found in 80's Popular Electronics. The components used are common and the number of...