The Development Of The Current Control And Measurement System In A Low-frequency Electro-magnetic Field

This paper mainly introduces the development of the Current Measurement and Control System in a Low-frequency Magnetic Field. The design method of the system is expounded in detail and some improvement in the task is emphasized.The Current Measurement and Control System in a Low-frequency Magnetic Field is a comprehensive system of hardware and software, including two parts: current measurement and computer control. The system hardware design consists of current and voltage sensors, CPU interface, data sampling circuit and current, frequency control parts. The system software comprises the display of waveform, number of frequency and amplitude and the control of current parameters. What's more, some study of variable parameters waves are displayed in the paper.The improvement of this system is made in following aspects. A new type sensor is employed to transfer the current to appropriate voltage, which can be sampled by the computer. The operating system of PC Bus industrial computer software has changed from DOS to Windows. The sampling frequency is determined on the basis of spectrum analysis and the arithmetic design for control is discussed. Also, three kinds of wave is output through computer programming. It may simplify system hardware design and after amplified, the wave can be used as signal source.Furthermore, the low-frequency magnetic field generator, computer interface and data transmission method, square wave frequency spectrum are also discussed in this paper.