The purpose of this circuit is to cut off the high voltage when the bias voltage fails. The circuit is from a 1975 documentation and can be adapted for other purposes.
The figure shows how to implement an alarm buzzer in an LM3914 to warn about crossing the scale...
This circuit can act as a shield being controlled by a microcontroller by pin 1 or 2. The...
This circuit was obtained from a 1980's QST magazine. The circuit can generate 1 to 15 MHz signals...