This circuit, suggested by an Electronics World of 1969, keeps a blinking LED for a while when a power outage occurs. Time depends on capacitor C1.
This amplification stage circuit with a germanium transistor was found in a 1980s documentation. The...
This circuit was originally used in a 1989 documentation presence simulator. The circuit activates...
This circuit is from a Popular Electronics from July 1990. The magazine no longer exists, but the...