The shunt resistor is named according to its function. It is made according to the principle that a voltage is generated across the resistor when the DC current passes through the resistor. The shunt is widely used to expand the meter's measuring current range. It has a fixed-valued shunt and a precision alloy resistor. It can be used for current limiting of the instrument, communication system, electronic whole machine, and automatic control power supply. But how do shunts work? Let's take a closer look.
First, the shunt function of the shunt resistor
 We use the current statistics to have a maximum current value upper limit, but if we divide the shunt resistor in parallel with a resistor to separate a portion of the current, the current statistics can measure the total current in the circuit that exceeds its maximum value. Similarly, current statistics can measure larger currents, and shunt resistors can achieve shunting in this way.

 
Second, the partial pressure of the shunt
 
When measuring the voltage divider of the shunt resistor, a voltage measurement meter can be placed in the detection circuit and the converter circuit. We use the principle that the internal resistance of the voltmeter is infinite, and we pass the internal resistance of the voltmeter. The shunt resistor is tested for comparison. When we ignore the current through the voltmeter, we can know that the total current in the circuit is the current through the shunt resistor. We can calculate the voltage of the shunt resistor by Ohm's law.

 
Through the above two points, we know that the shunt can realize the function of shunting and step-down in the power supply. At present, the shunt is used in many circuits. In the new energy vehicle, the precision shunt is the most applied, and the new energy vehicle requires the shunt resistance precision. More than other industries, precision shunts are the most common in our battery management system BMS.