This circuit is from a 90s American documentation. The circuit can use complementary pairs according to the power. The power voltage can be between 5 and 12 V.
This simple circuit was found in an English magazine that no longer exists, January 1970 issue. It is...
This circuit, suggested by a 1975 documentation, detects an electrical discharge in a storm by...
This circuit for timing small loads was found in a 1964 General Electric documentation....