1 Introduction With the deepening of economic reforms, energy conservation and consumption reduction has become one of the important means to reduce production costs and improve product quality. The frequency conversion speed regulation technology is in line with the requirements of industrial production automation development, creating a new era of intelligent motors. . At present, the technology has been practically applied in electric drive equipment of various industries such as electric power, metallurgy, chemical industry, papermaking, food, textile, etc., and has become a major development direction of modern electric drive technology. Using the inverter to control the motor to achieve speed regulation can save more than 10% of electrical energy. Hall current sensors Due to their excellent characteristics, more and more inverter manufacturers choose it as a component for power monitoring. 2. Working principle The Hall current sensor is a magnetic field sensor fabricated according to the Hall effect. It works in two ways, open loop (direct release) and closed loop (magnetic balance). The advantage of the direct-release Hall sensor is that the circuit form is simple and the cost is relatively low; the disadvantages are poor accuracy, linearity, slow response time, and large temperature drift. In order to overcome its shortcomings, a closed-loop (magnetic balance) Hall current sensor has emerged. The closed-loop Hall current sensor, also known as the zero-magnet-type Hall current sensor, is composed of a primary side circuit, a magnetic collecting ring, a Hall element secondary coil, an amplifier, and the like, as shown in FIG. When the magnetic flux generated by the primary current IP is concentrated in the magnetic circuit through the high-quality magnetic core, the Hall element is fixed in the air gap to detect the magnetic flux, and the reverse compensation current is output through the multi-turn coil wound around the magnetic core. In order to cancel the magnetic flux generated by the primary side IP, the magnetic flux in the magnetic circuit is always kept at zero. After special circuit processing, the output of the sensor can output a current change that accurately reflects the primary current. figure 1 3. Product introduction 3.1 Product selection The closed-loop Hall current sensor has many advantages such as short response time, high operating frequency, strong overload capability, and high isolation. In general, the Hall current sensor is selected according to the input signal, shape, and inner hole size. In the sensor industry, Jiangsu Ankerui Hall current sensor is strictly in accordance with the requirements of JB/T 7490-2007 "Hall Current Transformer Industry Standard", and it is green instead of the pin type wiring. Plug and unplug the terminals for convenient and reliable field wiring. Common brand products are shown in Table 1. Table 1 3.2 Product appearance Model: AHBC-LTA Physical map size chart 3.3 Technical Specifications ◠Response time: ≤1us ◠Bandwidth: 100kHz ◠Offset current: 0.1mA ◠Working temperature: -25 ~ 70 ° C ◠Storage temperature: -40 to 80 ° C ◠Output load: according to different auxiliary power, input signal, output signal ◠Input overload capability: 2 times the input range maximum can resume normal operation. ◠Withstand voltage: 3.5kV/50Hz/1min 4. Application 4.1 Sensor application in variable frequency speed control loop Figure 2 The variable frequency speed control circuit Y is the Hall current sensor Ø Figure 1 is used to detect the DC current of the bus. When an abnormal pulse is detected in the main circuit, or the effective value exceeds the standard, the trigger pulse of the inverter trigger circuit is quickly cut off to protect the inverter and rectifier module. Ø 2 in Figure 2 is used to detect the current difference between the two bridge arms. Because the commutation failure is easy, the IBGT module in the upper and lower arms of one phase is damaged due to overcurrent. At this time, the short-circuit current protection is required to be short-circuited. The door drive circuit is cut off within 10us. This inverter must use a fast overcurrent protection device. The Hall current sensor can be used to detect the current in each bridge arm. If the upper and lower arms are simultaneously conducting due to the commutation failure, then The corresponding two sensors simultaneously detect the current signal, and after being converted into a square wave by comparison with the reference voltage, all the inverter trigger pulses are blocked by the gate circuit control, the short circuit path is cut off, and the expensive IBGT module is protected; Ø In Figure 2, 3 is used to detect the waveform of the output current. It is connected to the output loop of the inverter to detect the AC current changing with frequency. It can better control the trigger pulse and also provide the overload signal of the powered device. 4.2 Precautions for use 1. In order to obtain better dynamic characteristics and sensitivity, it is necessary to pay attention to the coupling of the primary coil and the secondary coil. To be well coupled, it is better to use a single conductor and the conductor completely fills the aperture of the Hall sensor module; 2. When the large DC current flows through the primary coil of the sensor, and the secondary circuit is not connected to the power supply | the regulator or the secondary side is open, the magnetic circuit is magnetized, and residual magnetism is generated, which affects the measurement accuracy (so When using, first turn on the power and measurement terminal M). When this happens, demagnetize the first. The method is that the secondary circuit does not supply power, but passes the same level of alternating current in the primary coil and gradually reduces its value; 3. In most cases, the Hall sensor has a strong resistance to external magnetic field interference. Generally, a magnetic field interference generated by a current twice the working current Ip between the modules 5-10 cm is negligible. However, when there is a stronger magnetic field interference, take appropriate measures to solve it. The usual methods are: 1 Adjust the direction of the module to minimize the influence of the external magnetic field on the module; 2 Shield the module with a metal shield that is resistant to magnetic fields; 3 Select modules with dual Hall elements or multiple Hall elements; 4 The best accuracy of the measurement is obtained at the rated value. When the measured current is much lower than the rated value, to obtain the best accuracy, the primary side can use multiple turns, namely: IpNp=rated ampere-turns. In addition, the primary feeder temperature should not exceed 80 °C. 5. Conclusion Due to its many advantages, Hall current sensor ensures accurate and reliable operation of the inverter by accurately detecting and controlling large currents, so that the inverter can process abnormal conditions in time while outputting normally. Improve the reliability of the inverter and improve the safety quality of the inverter. Therefore, the advantages of the Hall current sensor in the inverter are becoming more and more obvious, and it has become an indispensable part of the inverter industry.
LED Garden spot Light with High quality Brigelux & Osran LED chips ,304 Stainless Steel and Aluminum housing ,standard IP68 protection ,tempered glass mask. option color. Garden Spot Light with IP68 rated.widely use for garden landsape lighting
Classify:Construcion light/Commercial light/City lighting project/Industrial lighting/Urban light.
Install Garden,Courtyard, musical fountain and city landscape etc.
Light Feature:
1.OEM&ODM service available .
Our other products range:Led underground Light, LED Underwater Light , LED Wall Washer Light, LED Linear Light , LED Outdoor Flood Light, LED Garden Light , LED Landscape Light , LED Strip Light , Led Step Light etc.
For any inquiry, please feel free to contact us. We will follow up and come back to you ASAP.
Garden Spot Light,water proof spot light.outdoor spot light. SHENGYA LIGHTING TECHNOLOGY CO., LTD. , https://www.syalighting.com
2.CE &RoHS certificate approve.
3. More LED avaliable.
4. Waterproof IP68.
5. 304 Stainless steel, efficient heat dissipation
6.Lens or reflector are available for perfect light effect
7. Power range: 3W-36W
