This circuit is from documentation from 1965 but can be easily implemented today using modern transistors. We can use BD136 for Q1 and TIP42 for Q2. The TIP must be equipped with a heat sink.
In this circuit the LED lights up when the voltage drops below the value set in the trimpot. The...
This circuit was obtained from a Linear Technology manual from the 90's. The integrated circuits are...
Found in a 1995 documentation, this circuit is an alternative output to the previous circuits. The MOSFETs...