This is a commercial circuit from the year 1958. Transistors are germanium types and transformers and coils are hard to fild today. The circuit is destinated to the reception of medium wave stations.
This circuit was found in a 90s Popular Electronics. The sensors can be common speakers that reach...
This circuit indicates when a 28 V lamp burns, lighting a neon lamp with higher voltage. The...
This circuit was obtained from an American 80's documentation. The operational ones can be...