We found this circuit in the Linear Applications Handbook of the 1994 National Semiconductor. The transistor must be a high voltage type and the LM3900 power supply must be symmetrical.
This setting appears elsewhere in this section. This is found in an American documentation from...
Found in a 90s Popular Electronics, this circuit is intended for amplifying analog video signals....
This is one of many possible circuits for the LM3914 IC as an audio indicator. The trim pot has...