The Characteristics and Connection Method of Hall Sensor

Hall sensors are widely used in variable frequency speed regulation devices, inverter devices, UPS power supplies, inverters due to their high accuracy, good linearity, wide frequency bandwidth, fast response, strong overload capability and no loss of the energy of the circuit under test. Welding machines, substations, electrolytic plating, CNC machine tools, microcomputer monitoring systems, power grid monitoring systems and various fields that need to isolate and detect large currents and voltages. In power electronic products, accurate detection and control of large current is also the fundamental guarantee for the safe and reliable operation of the product.

1. The performance characteristics of the Hall sensor

The open-loop Hall sensor has superior electrical performance and is an advanced electrical detection element that can isolate the main circuit loop and the electronic control circuit. It combines all the advantages of transformers and shunts, while overcoming the shortcomings of transformers and shunts. The same Hall current sensor can detect both AC and DC, and even detect transient peaks, so it is a new generation of products to replace transformers and shunts. Hall current sensor has the following characteristics: it can measure the current of arbitrary waveform. Hall current sensors can measure current parameters of arbitrary waveforms, such as DC, AC and pulse waveforms. The transient peak parameters can also be measured, and the secondary circuit can faithfully reflect the waveform of the primary current. This point cannot be compared with ordinary transformers, because ordinary transformers are generally only suitable for 50Hz sine waves; the precision is high. The accuracy of the general Hall current sensor in the working area is better than 1%, which is suitable for the measurement of any waveform, while the accuracy of ordinary transformers is generally 3% to 5%, and is only suitable for 50Hz sinusoidal waveform; The linearity is better than 0.5%; the dynamic performance is good.

Open-loop Hall sensors provide the key basis (inductive elements) for improving the performance of modern control systems with their excellent dynamic performance. Generally, the dynamic response time of ordinary transformers is 10-20μs, which obviously does not meet the needs of the development of industrial control systems (inductive components). working frequency bandwidth. It can work well in the frequency range of 0 ~ 20kHz; strong overload capacity, large measurement range, high reliability, average trouble-free operation is more than 5 × 10000 hours; small size, light weight, easy to install and will not bring any problems to the system loss.

2. The connection method of the Hall sensor

The current sensor only needs to be connected with positive and negative DC power supplies. The measured current bus generally passes through the Hall sensor or is connected to the primary side terminal, and then makes some simple connections at the secondary side to complete the isolation detection of the main control circuit. The circuit design is very simple. If used in conjunction with the transmitter, after A/D conversion, it can be easily interfaced with a computer or various instruments, and can perform long-distance transmission.