This circuit was found in a Philips documentation from 19678. The transistors are from the period with emphasis on the married pair. Modern equivalents can be used.
This circuit visually indicates that a high voltage is present in an outlet or other point. The...
This circuit found in a 1988 documentation consists of a timer or sequential timer controller. The...
Using a 4017 as a base, this circuit from a 1990s Popular Electronics generates low-frequency...