ولت متر  ۰ to 199.9V
آمپر متر up to 10A
ICL7107 / ICL7106 – DIGITAL VOLTMETER
About this Circuit

This digital voltmeter is ideal to use for measuring the output voltage of your DC power supply. It includes a 3.5-digit LED display with a negative voltage indicator. It measures DC voltages from 0 to 199.9V with a resolution of 0.1V. The voltmeter is based on single ICL7107 chip and may be fitted on a small 3cm x 7cm printed circuit board. The circuit should be supplied with a 5V voltage supply and consumes only around 25mA.

Construction Notes

Brightness of the LED display segments can be varied by adding or removing 1N4148 small signal diodes that are connected in series. Use two 1N4148 diodes for higher LED display brightness.

The use of 7805 5V voltage regulator is highly recommended to prevent the damage of ICL7107, 7660 ICs and to extend the operating voltages.

۲۲۰ Ohm resistor should be connected to the PIN 4 on the first LED display.

The voltmeter can also be configured to measure different voltage ranges and display higher voltage resolution. Replacing 1M with 100K resistor will allow to measure 0 – 19.99V voltages with 0.01V (10mV) accuracy.Construction Notes

Brightness of the LED display segments can be varied by adding or removing 1N4148 small signal diodes that are connected in series. Use two 1N4148 diodes for higher LED display brightness.

The use of 7805 5V voltage regulator is highly recommended to prevent the damage of ICL7107, 7660 ICs and to extend the operating voltages.

۲۲۰ Ohm resistor should be connected to the PIN 4 on the first LED display.

The voltmeter can also be configured to measure different voltage ranges and display higher voltage resolution. Replacing 1M with 100K resistor will allow to measure 0 – 19.99V voltages with 0.01V (10mV) accuracy.