This circuit indicates when the voltage of a 12 V battery is low. With changes, for example, the zener, the circuit can be used to monitor other voltages.
This operational filter configuration was obtained in a 1980s publication. The calculation is made by the...
The sensor in this simple circuit is a NTC (Negative Temperature Coefficient) resistor. NTCs with...
This circuit is from a high voltage tube source. It does not include the filament voltage that must...