In fact, this circuit from the 60's applies to photographic printers of the time, timing the lighting of a 20 W lamp. The components are from the period.
Found in National Semiconductor documentation from the 1990s, this circuit corrects the curvature of...
Developed by Philips this 60's circuit uses a transistor of the time, but the configuration holds true for...
We found this circuit in an American 1980s documentation. The transistors can be equivalent as BC548...