We found this circuit in an American 1980s documentation. Other comparators can be used and the transistors depend on the driven load. For LEDs the BC548 can be used.
![](/images/stories/cir/2101202023_140400_0001.gif)
We found this circuit in an American 1980s documentation. Other comparators can be used and the transistors depend on the driven load. For LEDs the BC548 can be used.