The idea of this circuit is that when the device in SO1 is turned on, the device connected to SO2 automatically receives power. The circuit is from Radio Electronics from January 1985.
We found this circuit in a technical documentation on the National Semiconductor LM3909. The...
The LEDs act as diodes, so if good they will show the same characteristic curve. Arrangment shown...
This circuit is from an old English publication from 1968. We can implement it with TIP32...