Improvement of a current measurement method with loop probes

A new structure of B-dot probes for the rail-gun speed measurement is introduced, which combines several separate loops together. It is benefit for the digital data storage equipments to control its cost. In the past, each B-dot used single channel of the data recording equipment. If there were ten B-dot probes, we used ten channels for the probes to record data. However, it is no need to use so many channels. Because the core output waveforms of B-dot probes distribute in different time, several probes can be connected together to form one new probe. Extremely speaking, it is possible to use only one channel to record the data, and all the probes are combined into only one B-dot probe. The new B-dot probes' data was used to improve the current waveform measurement method with loop probes. Loop probes in the breech measure the magnetic field decided by the main current. If the current's position is fixed, the waveform of current can be easily calculated by the measured magnetic field. The armature's speed information is brought to reduce the influence of the nominal current position which is always changing. The experiment results show that it works fine to measure the current in low cost.