DC ammeter

The floating DC ammeter circuit composed of an operational amplifier and a DC milliammeter is shown in the figure.     In the figure, the operational amplifier uses LM324.     In current measurement, the measurement of floating current is common. For example, if the measured current has no grounding point, this is the case. For this reason, the power supply of the operational amplifier should also be floated to ground. The ammeter constructed in this way can be connected in series in any current path to measure the current like a conventional ammeter.     Change the resistance ratio (R, /R2). The current flowing through the ammeter can be adjusted to improve sensitivity. If the measured current is large, a shunt resistor should be connected in parallel to the ammeter head.