Summary:The principle of the shunt
The shunt is made according to the principle of generating a voltage acro...
The principle of the shunt
The shunt is made according to the principle of generating a voltage across the resistor when the DC current passes through the resistor. The shunt is actually a resistor with a small resistance value. It is a voltmeter. Generally, the range of this voltmeter is 75mV, 150mV, and 300mV. Use a voltmeter to measure this voltage, and then convert this voltage into current to complete the measurement of a large current.
There are two types of shunts: slot type and non-slot type. The rated current of the slot type is 5A, 10A, 15A, 20A, and 25A, and the rated current of the non-slot type is from 30A to 15KA at standard intervals.
The role of the shunt
The shunt is widely used to expand the measuring current range of the instrument. It is widely used to expand the measuring current range of the instrument. There are fixed value shunts and precision alloy resistors, which can be used in communication systems, electronic complete machines, automatic control power supplies, and other circuits. Current limiting, current sharing sampling detection.
Limitations of Current Shunts for Measuring AC Signals
Generally, we apply shunts to the measurement of DC current. In fact, for the measurement of some AC signals, the shunt is also a measurement scheme, but it has many limitations.
1. The shunt must be connected in series in the circuit, and two direct access points are inevitable. Unlike the transformer, which can avoid connection points in the circuit, the safety performance is relatively poor;
2. The shunt generates a lot of heat in the state of high current (for example, more than 100A). The shunt should take more measures to ensure stability, and the thermal stability is insufficient;
3. At high frequency, the skin effect and proximity effect have a great influence on the accurate measurement of current, and the influence at power frequency and low frequency is relatively small.
China Manganin Shunts Manufacturers
English