Breaker Conductive Loop Resistance Intelligence Test

Circuit resistance of breaker is one of the most important parameters which determine the quality of breaker. It can directly affect the temperature rising when the rated current passes through breaker and the moving thermal stability at the over loading moment. The resistance mostly lies on the contact resistance between moving and static contact of breaker. The value of the contact resistance is very small with micro ohm scalar. Micro ohm meter has been used to measure the contact resistance commonly at present. Since the constant-current source is used, the volume and weight of micro ohm meter is very large.In this design, a new instrument using pulse power supply is introduced to measure the contact resistance. The volume and weight of the new instrument is minished and it can be used expediently. In the new instrument a system of MCU is applied to control charging or discharging the pulse power supply, collects convert and operate data, and then display the value of the contract resistance and the peak value of discharging circuit current with LED.In the instrument the measurement of voltage and current adopt the technology of four-terminal connection which is used usually in engineering practice to reduce the system error on collecting signals. In the hardware instrument amplifiers are used to amplify the signals, at the same time Phototubes relay and filter circuit are adopted to reduce interference. In software program of digital filter can be compiled to reduce the measure error.It has been proved by experiments that the new intelligent instrument has a favorable interface, can be handled simply Eind has low cost.