This is a circuit of a digital ampere meter with 4 digit LED 7-segment display, the circuit capable of measuring the current consumption up to 10A with selected 100mA, 10mA and 1mA accuracy, and consumes only about 25mA of current. The ammeter is based on single ICL7107 chip and 3.5-digit seven segment LED displays. Due to a Relatively small number of components That the circuit is using it is possible to fit it on a small 3cm x 7cm printed circuit board.
Skema Rangkaian Ampere Meter Digital0.01 Ohm resistor should be made out of 1.5mm thick / 5cm long copper wire. 0.1 Ohm and 1 Ohm resistors should have 5W ratings.
For highest accuracy it is recommended that the ICL7107 ampere meter module should be supplied with its own voltage supply. If measurement of the current of the same supply is needed, ICL7107 ampere meter would have to sample negative not positive voltage supply.
Brightness of the LED displays can be varied by adding or removing 1N4148 small signal diodes that are connected in series. Use two 1N4148 diodes for higher brightness.
Also, the use of 7805 5V voltage regulator is highly recommended to prevent the damage of ICL7107 and 7660 ICs. .
For highest accuracy it is recommended that the ICL7107 ampere meter module should be supplied with its own voltage supply. If measurement of the current of the same supply is needed, ICL7107 ampere meter would have to sample negative not positive voltage supply.
Brightness of the LED displays can be varied by adding or removing 1N4148 small signal diodes that are connected in series. Use two 1N4148 diodes for higher brightness.
Also, the use of 7805 5V voltage regulator is highly recommended to prevent the damage of ICL7107 and 7660 ICs. .
Source: http://electronics-diy.com