What is the principle of the shunt The shunt is used to […]
What is the principle of the shunt
The shunt is used to measure DC current, and is mainly made based on the principle that a voltage will be generated across the resistor when the DC current passes through the resistor. The shunt is actually a resistor with a small resistance value. When a direct single phase meter shunt passes through, a voltage drop is generated for the direct current meter to display. The so-called shunt is to divide a small current to drive the meter indication. The smaller the ratio of the small current (mA) to the current in the large loop (1A-tens of A), the better the linearity and accuracy of the ammeter reading.
Shunts can be divided into two main categories: one is external shunts, and the other is internal shunts. There are many types of external shunts, for example; FL-2, FL-1, FL-27, FL-19, FL-13, FL-21, FL-29, FL-39 Type, Taiwan type, Russian type, Korean type, American type and so on. There are also many types of internal shunts, and the shape can be customized according to customer needs, but the shape of the internal shunt is much smaller than the external shunt.
A shunt is actually a resistor that can pass a very large current. Generally, the commonly used 15A or 20A and 35A ammeters require a shunt. The impedance of the shunt can be determined by the "meter head sign full-scale voltage/meter head full-scale current" To calculate. If you want to measure a large DC current, such as tens of amperes, or even greater, there is no such large range of ammeters for current measurement, what should you do? At this time, a shunt should be used. It is to use a short conductor, which can be any metal or alloy, and also connect the terminals; its DC resistance is strictly adjusted; when it is connected in series in a DC circuit, the DC current flows through the shunt, and the two ends of the shunt generate millivolts The DC voltage signal causes the pointer of the meter connected at both ends of the shunt to swing, and the reading is the current value in the DC circuit.