This circuit with its light source was found in American documentation two years 70. Or transformer of the type found in small transistor radios of the time. The transistors are general-purpose.
This well-known siren configuration using complementary transistors is from a 1980s documentation. The...
This circuit was found in an old American magazine and could make use of more modern components...
This circuit is from the Philips integrated circuits manual of 1990. It is intended for magnetic...