The principle and application of Holzer effect

2015-12-14
The essence of the Hall effect is: solid material carrier in the external magnetic field, due to the Lorentz force and the track shift, and on both sides of the materials to produce electric charge accumulation, formation of vertical to the current direction of electric field, the final carrier by the Lorentz Lorentz force and electric repulsion phase equilibrium, and on both sides establish a stable potential, namely, Hall voltage. The ratio of the product of the perpendicular electric field and the electric current intensity to the magnetic field strength is the Holzer coefficient. The ratio of the parallel electric field and the current intensity is the resistivity. A lot of research reveals that in the conductive process not only have negatively charged electrons and positively charged holes.

在导体上外加与电流方向垂直的磁场,会使得导线中的电子与电洞受到不同方向的劳伦兹力而往不同方向上聚集,在聚集起来的电子与电洞之间会产生电场,此一电场将会使后来的电子电洞受到电力作用而平衡掉磁场造成的劳伦兹力,使得后来的电子电洞能顺利通过  ,不会偏移,此称为霍尔效应。而产生的内建电压称为霍尔电压。

The applied magnetic field perpendicular to the direction of the flow of electric current in the conductor, the conductor of the electrons and holes by different directions of the Lorentz force and different directions to gather, between the aggregation of electrons and holes will generate an electric field, the electric field will be the later electrons and holes by power function and balance out the magnetic field caused by the Lorentz force and the subsequent electron hole can smoothly through the, will not be offset, and this is called as the Hall effect. And the built - in voltage is called the Holzer voltage.

方便起见,假设导体为一个长方体,长度分别为a,b,d,磁场垂直ab平面。电流经过ad,电流I = nqv(ad),n为电荷密度。设霍尔电压为VH,导体沿霍尔电压方向的电场为VH / a。设磁场强度为B。   Fe = Fm   qVH / a = qvB   VH / a = BI / (nqad)   VH = BI / (nqd) 编辑本段相关反应  量子霍尔效应   热霍尔效应:垂直磁场的导体会有温度差。   Corbino效应:垂直磁场的薄圆碟会产生一个圆周方向的电流。   自旋霍尔效应 编辑本段本质  固体材料中的载流子在外加磁场中运动时,因为受到洛仑兹力的作用而使轨迹发生偏移,并在材料两侧产生电荷积累,形成垂直于电流方向的电场,最终使载流子受到的洛仑兹力与电场斥力相平衡,从而在两侧建立起一个稳定的电势差即霍尔电压。正交电场和电流强度与磁场强度的乘积之比就是霍尔系数。平行电场和电流强度之比就是电阻率。大量的研究揭示:参加材料导电过程的不仅有带负电的电子,还有带正电的空穴。 编辑本段应用  霍尔效应在应用技术中特别重要。霍尔发现,如果对位于磁场(B)中的导体(d)施加一个电压(Iv),该磁场的方向垂直于所施加电压的方向,那么则在既与磁场垂直又和所施加电流方向垂直的方向上会产生另一个电压(UH),人们将这个电压叫做霍尔电压,产生这种现象被称为霍尔效应。好比一条路, 本来大家是均匀的分布在路面上, 往前移动. 当有磁场时, 大家可能会被推到靠路的右边行走. 故路 (导体) 的两侧, 就会产生电压差. 这个就叫“霍尔效应”。根据霍尔效应做成的霍尔器件,就是以磁场为工作媒体,将物体的运动参量转变为数字电压的形式输出,使之具备传感和开关的功能。   讫今为止,已在现代汽车上广泛应用的霍尔器件有:在分电器上作信号传感器、ABS系统中的速度传感器、汽车速度表和里程表、液体物理量检测器、各种用电负载的电流检测及工作状态诊断、发动机转速及曲轴角度传感器、各种开关,等等。   例如汽车点火系统,设计者将霍尔传感器放在分电器内取代机械断电器,用作点火脉冲发生器。这种霍尔式点火脉冲发生器随着转速变化的磁场在带电的半导体层内产生脉冲电压,控制电控单元(ECU)的初级电流。相对于机械断电器而言,霍尔式点火脉冲发生器无磨损免维护,能够适应恶劣的工作环境,还能精确地控制点火正时,能够较大幅度提高发动机的性能,具有明显的优势。   用作汽车开关电路上的功率霍尔电路,具有抑制电磁干扰的作用。许多人都知道,轿车的自动化程度越高,微电子电路越多,就越怕电磁干扰。而在汽车上有许多灯具和电器件,尤其是功率较大的前照灯、空调电机和雨刮器电机在开关时会产生浪涌电流,使机械式开关触点产生电弧,产生较大的电磁干扰信号。采用功率霍尔开关电路可以减小这些现象。   霍尔器件通过检测磁场变化,转变为电信号输出,可用于监视和测量汽车各部件运行参数的变化。例如位置、位移、角度、角速度、转速等等,并可将这些变量进行二次变换;可测量压力、质量、液位、流速、流量等。霍尔器件输出量直接与电控单元接口,可实现自动检测。目前的霍尔器件都可承受一定的振动,可在零下40摄氏度到零上150摄氏度范围内工作,全部密封不受水油污染,完全能够适应汽车的恶劣工作环境。

For convenience, assuming that the conductor is a rectangular, the length is a, B, D, and magnetic field perpendicular to the ab plane. Current through AD, current I = NQV (AD), n for charge density. The electric field in the direction of Holzer's voltage is a / VH, which is located at the Holzer voltage of VH. The magnetic field intensity is B. Fe = qVH Fm / a = VH qvB / a = BI / (nqad) VH = = BI / (NQD) edit this section related reaction quantum Holzer effect thermal Holzer effect: the conductor of the vertical magnetic field will have temperature difference. Corbino effect: the vertical magnetic field of the thin circular plate will produce a circumferential direction of the current. Spin Hall effect of editing the essence of solid material carrier in the external magnetic field, because by the Lorentz force and the track offset, and on both sides of the materials to produce electric charge accumulation, formation of vertical to the current direction of electric field, the final carrier by the Lorentz force and electric repulsion phase equilibrium, thus on both sides established a stable potential, namely, Hall voltage. The ratio of the product of the perpendicular electric field and the electric current intensity to the magnetic field strength is the Holzer coefficient. The ratio of the parallel electric field and the current intensity is the resistivity. A lot of research reveals that in the conductive process not only have negatively charged electrons and positively charged holes. The application of Holzer effect in the application of this section is particularly important in the application of technology. Hall, if applying a voltage (IV) in magnetic field (b) in the conductor (d), the magnetic field perpendicular to the direction of in the direction of the applied voltage, then in and perpendicular to the magnetic field and the applied voltage of another (Uh) generated on the current in a direction perpendicular to the direction, people will this voltage is called the Hall voltage, this phenomenon is known as the Hall effect. Like a road, we would have to be uniformly distributed on the road, move forward. When the magnetic field, we may be pushed to walk on the right side of the road. On both sides of road accidents (conductor), it will produce a voltage difference. This has been called the "Hall effect". According to the Holzer effect of the Holzer device, is the magnetic field as the working media, the motion parameters of the object into the form of digital voltage output, so that it has the function of sensing and switching. Up to now now, has been widely used in modern automobile Hall devices: at the distributor for signal sensor, ABS speed sensor, automobile speedometer and odometer, liquid physical quantity detector, electricity load current detection and working condition diagnosis, motivation speed and crankshaft angle sensor, switch, and so on. For example, the car ignition system, the designer will be placed in the Holzer sensor sensor to replace the mechanical broken appliances, used as an ignition pulse generator. This Holzer ignition pulse generator with the speed change of the magnetic field in the charged semiconductor layer generated pulse voltage, control of electronic control unit (ECU) of the primary current. With respect to the mechanical broken appliances, hall type ignition pulse generator wear free maintenance free, can adapt to the harsh working environment, but also accurately control ignition timing can greatly improve engine performance, has obvious advantages. The Holzer circuit, which is used as the power of the automobile switch circuit, has the function of restraining the electromagnetic interference. Many people know that the higher the degree of automation of the car, the more microelectronic circuit, the more afraid of electromagnetic interference. And in the car has many of the lighting and electrical parts, especially more powerful front lights, air conditioner motor and wiper motor at the switch will produce surge current, the mechanical switch contact arc, larger electromagnetic interference signal. These phenomena can be reduced by using power Holzer switching circuit. Holzer device can be used to monitor and measure the variation of operating parameters of various components of a vehicle by detecting the change of the magnetic field and transforming to the electrical signal output. For example, position, displacement, angle, angular velocity, speed, etc., and these variables can be transformed into two times; can measure the pressure, quality, liquid level, flow rate, flow rate, etc.. The output of Holzer device is directly related to the electronic control unit, which can realize automatic detection. Current Holzer devices can withstand a certain vibration, can be in - 40 degrees Celsius to 150 degrees Celsius on the scope of work, all sealed by water and oil pollution, completely able to adapt to the harsh working environment of the car.