Detailed explanation of shunt circuit wiring method

In electronic circuit design and application, shunt circuit is a common and important circuit type. It is mainly used to measure current, distribute current or control current paths, and is widely used in power systems, electronic instruments, industrial automation and other fields. The correct shunt circuit wiring method is not only related to the normal operation of the circuit, but also directly affects the accuracy of measurement and the safety of the equipment. This article will introduce the wiring method of the shunt circuit in detail to help readers master the core skills and improve the level of circuit design and maintenance.

1. Basic concepts of shunt circuit

A shunt circuit usually refers to a low-resistance circuit connected in parallel to the main circuit.resistancecomponent, and the current is deduced by measuring the voltage drop across the resistor. Since the shunt resistor has a very small resistance and will not have a significant impact on the main circuit current, it is widely used as an auxiliary component for current measurement. Understanding its working principle is the prerequisite for mastering wiring methods.

2. Select the appropriate shunt resistor

Before wiring, you need to select an appropriate shunt resistor based on the circuit's rated current and measurement accuracy. The resistance of the shunt resistor is generally small (such as a few milliohms), and the power level needs to meet the heating requirements when the current passes through. A resistance value that is too large may affect the normal operation of the circuit, and a resistance value that is too small may make it difficult to obtain an accurate voltage signal.

3. Determine the connection position of the shunt resistor

Shunt resistors are generally connected to the current path of the circuit. Common locations are the power supply end and the load end. When connected to the power supply end, the current measurement is more accurate, but installation space and safety need to be considered; when connected to the load end, maintenance is more convenient, but it may be affected by load voltage fluctuations.

4. Connect strictly according to polarity

The voltage measurement terminals at both ends of the shunt resistor should be connected strictly according to the polarity. Usually the positive terminal is connected to the current inflow terminal and the negative terminal is connected to the current outflow terminal. This can ensure the accuracy of the measured voltage signal and avoid measurement errors or equipment damage caused by reverse polarity.

5. Use shielded wires and secure connectors

Since the voltage signal measured by the shunt resistor is small and susceptible to external interference, it is recommended to use a shielded wire to connect the measuring instrument end to reduce electromagnetic interference. At the same time, ensure that the wiring terminals are stable and in good contact to prevent signal fluctuations caused by poor contact.

6. Avoid overheating of shunt resistor

The shunt resistor will generate a certain amount of heat when working. Sufficient space for heat dissipation should be reserved when wiring. If necessary, a heat sink or fan should be installed to prevent excessive temperature from affecting the stability of the resistance value and thus affecting the measurement accuracy.

7. Regularly check and maintain wiring

During the long-term operation of the shunt circuit, poor contact may occur at the wiring due to vibration, oxidation and other reasons. The wiring status should be checked regularly and the oxide layer should be cleaned to ensure reliable circuit connections and ensure the accuracy of measurement data and the safety of the equipment.

8. Pay attention to safety protection measures

Shunt circuits are mostly used in high-current environments. The power supply must be cut off during wiring to prevent the risk of electric shock. After the wiring is completed, it should be confirmed to be correct before powering on for testing. If necessary, install fuses and overcurrent protection devices to ensure the safety of the circuit and personnel.

The shunt circuit wiring method seems simple, but the details determine success or failure. Selecting the appropriate shunt resistor, determining the correct access location, strictly connecting with polarity, using shielded wires, ensuring good contact, and doing heat dissipation and safety protection are all keys to ensuring stable and reliable operation of the shunt circuit. Through the introduction of this article, readers can systematically master the wiring skills of shunt circuits, improve their practical operation capabilities, and ensure the accuracy of circuit measurements and the safety of equipment.