Manganese-bronze shunt is a precision resistance element used to make high-level measurement voltage, current, bridge, potentiometer and other instruments and meters, and it is more suitable for making standard resistor elements for reference. The manganese-copper shunt (manganese-copper sampling resistor) of the electric energy meter is widely used as a power metering element in various digital electric energy meters. It is made of manganese-copper precision resistance alloy material. Manganin shunts are generally used together with ammeters, which are connected in parallel at both ends of the shunt. The main parameters of the shunt are the rated current to be measured and the corresponding number of millivolts. In the electric energy meter industry, manganese-copper shunts are generally used together with electric energy metering chips. At present, the positive and negative analog input pins of the current channels of the metering chips of major manufacturers adopt a fully differential input mode, and the maximum input voltage Vpp for normal operation is ±1000mV. The maximum withstand voltage is ±6V.
The manganin shunt
is an important part of electric energy meter sampling. Most current shunts in the industry are basically square or long strips. The manganese-bronze sheet temporarily uses a small area in the middle, and the signal sampling pin is generally directly welded to the manganese-bronze. At the connection with the red copper, the signal sampling pin often falls off due to unstable welding. In addition, the signal sampling pin is welded by argon welding, which requires a lot of labor costs. At the same time, the solder joints will be generated during welding. Strong light, long-term operation will cause damage to human skin, especially eyes, and it is difficult to guarantee the consistency of the resistance value of the manganese-bronze shunt. Mass production of manganese-bronze shunt is difficult to guarantee the error consistency, and the scrap rate is relatively high. It seriously affects the measurement accuracy on the electric energy meter. In addition, most of the existing shunts are reinforced with screws on the terminal. If the screws are loose and lead to a poor combination of the manganese-bronze shunt and the terminal, it will cause serious heat when the current is large, which will reduce the resistance of the manganese-bronze shunt. This results in meter measurement accuracy.