| 摘要 |
PROBLEM TO BE SOLVED: To enhance current sensing accuracy of a shunt resistor based current sensor by accurately detecting bus bar temperature on which a resistance value is based.SOLUTION: Use of infrared temperature detection means as a temperature sensor 60 allows the temperature sensor 60 to directly detect temperature of a shunt resistor portion SR by detecting infrared rays radiated from the shunt resistor portion SR. Such a detection method can reduce deviation of detected temperature from the temperature of the shunt resistor portion SR because the method is less susceptible to heat loss compared to a method with which temperature is detected in the process of sequential heat transfer from a bus bar 10 to a circuit board 20. Also, directly detecting temperature of the shunt resistor portion SR and avoiding heat transfer paths that are susceptible to heat loss, such as the circuit board 20, allows temperature variations to be quickly captured. As such, the method allows accurate detection of bus bar temperature on which a resistance value is based. |
