外文翻译-环形线圈检测原理.doc

英 文 翻 译 系 别 专 业 班 级 学生姓名 学 号 指导教师  The principle of toroidal coil detection Toroidal coil length is 2 m, width depends on the lane width, usually covering a lane of 50% ~ 60%, should not be less than 0.5 m. Know by electromagnetic field theory, any current-carrying conductor will be produced in the surrounding magnetic field, for the length of l type, number of turns for the N of solenoid coil, coil in the magnetic field strength. The self inductance is: L = LSL0N2Al (1)Type: the relative permeability of LS is medium, air LS to 1; L0 = 4 x 10-7 hm - 1; A. to coil around the area. Because of toroidal coil can not completely equal to solenoid, considering the nonuniform? 1.Design principle and the hardware of the system The system design principle and hardware system design principle as shown in figure 1. Toroidal coil through feeder connection to the isolation transformer, on the other side of the isolation transformer and a capacitance in parallel, LC parallel resonance of this LC parallel resonant frequency can be obtained according to the formula (1) [1]. F = 12 PLC (1) : L))) for the circular coil and the total inductance of feeder; C))) for parallel capacitor; F))) as the resonance frequency. Can be seen by the formula, the factors influencing the frequency f only L and C, so in certain cases, C ring coil and the total inductance of feeder determines the frequency of oscillation. The numerical values of similar products at home and abroad for reference, at the same time, to determine the vehicle detector coil oscillation frequency is between 20 ~ 100 KHZ range. Circular coil inductance is 80 ~ 120 lh, feeder inductance for 019 H# m - 1, plus the influence of other factors, the length of the feeder in within 300 m, in order to make the total inductance is less than 1 000 lh. Isolation transformer primary coil and secondary coil number of turns for the 1 b1, it makes the total inductance coil and feeder truthfully from pri