This simple three-LED sensor uses an NTC at the input. The circuit is based on an uncommon integrated component today. We found it in documentation from the 80s.
This simple strobe light is from an article in 1982. Its complete circuit, very simple, appears in the...
This power step for relay activation was found in the 1964 RCA transistors manual. The circuit is of the...
This circuit, bridge type, was found in American documentation from the 60's. The transistor is...