Digital volt meter circuit is simple and not much use of additional components. Volt meter circuit uses IC L7107 as a main actor. L7107 IC is an Analog to Digital Converter (ADC) which has been equipped with the viewer seven segment driver 3 1 / 2 digits. IC L7107 in the application of digital volt meter is in it has been equipped with an internal voltage reference circuit, analog switches, sequential control logic, and LED display driver. This digital meter volt circuit can be operated with a working voltage 5VDC. A full suite of digital volt meter can be seen in the following figure.
To set or Calibration to 0 Volt. done by adjusting the VR 2KOhm. then to test the display can be done by pressing the test switch, where to normal conditions when the switch is pressed then all the display lights up.
