After continuous exploration and improvement, HANGZHI's HIT series--Hall-substituting current sensors have been well prepared and fully launched. Based on fluxgate technology and the application of closed-loop control in the electronic circuit, HIT series sensors introduced by HANGZHI achieved higher measurement accuracy than the Hall current sensors.
l Difference between Fluxgate Current Sensor and Hall Current Sensor
Bandwidth: The magnetic fluxgate measuring the magnetic field always changes near zero magnetic flux. In addition to the closed-loop control circuit, the magnetic field changes very little and the changing frequency can be very high. Therefore, the fluxgate current sensors have short response time, and the bandwidth can usually reach up to more than 500kHz. The bandwidth of open-loop Hall current sensors is usually narrow at around 3kHz. The bandwidth of closed-loop Hall current sensors can only reach 100kHz.
Accuracy: The output of the secondary side of the open-loop Hall current sensor is proportional to the magnetic induction intensity at the air gap of the magnetic core, and the magnetic core is made of high magnetic permeability material. Since the non-linear and hysteresis effects are inherent characteristics of all high magnetic permeability materials, open-loop Hall current sensors generally have poor linearity, and the output of the secondary side will be different during the rise and fall of the primary signal. The accuracy of open-loop Hall current sensors is usually less than 1%. Since the closed-loop Hall current sensor works in the state of zero magnetic flux, the nonlinearity and hysteresis effect of the magnetic core do not affect the output, and better linearity and higher accuracy can be obtained. The accuracy of the closed-loop Hall current sensor is up to 0.2%. HANGZHI Hall-substituting fluxgate current sensor adopts three key technologies with independent intellectual property to achieve accuracy of 0.05%.
Zero-drift Temperature Drift and Anti-Interference Ability: Among the various components for measuring magnetic field, the Hall element is not sensitive. Because the installation position of the Hall device is in the air gap of the magnetic core, the magnetic core needs to be disconnected, the sensitivity and the resolution is greatly reduced, resulting in relatively large zero drift and temperature drift, and poor anti-interference ability. HANGZHI Hall-substituting fluxgate current sensor adopts a complete magnetic core structure with no magnetic core cutout and no air gap, so it has strong anti-interference ability and its sensitivity is much higher than the Hall effect, which makes it has extremely low zero drift and temperature drift.
l Three Core Technologies of HIT Series Fluxgate Sensor
1. The excitation closed-loop control technology is adopted, which saves the complicated magnetic shielding system design compared with the traditional scheme.
2. The self-excited demagnetization technology is adopted, zero drift is small, and the measuring range is expanded. The problem solved with two sensors now only needs one sensor.
3. The multi-closed-loop control method is adopted to realize zero-flux closed-loop control of excitation magnetic flux, DC magnetic flux and AC magnetic flux, and the detection of high-frequency ripple is realized by constructing a high-frequency ripple induction channel, so that the sensor has high gain and measuring accuracy in the whole bandwidth.
HIT series fluxgate current sensor is a Hall-substituting fluxgate current sensor launched by HANGZHI. This series of products have the same function but better performance of closed-loop Hall current sensor, which can be used to perfectly replace Hall current sensor. The accuracy of the HIT series sensor can reach 0.05%, while the closed-loop Hall effect current sensor is only 0.2%; in terms of bandwidth, the HIT series sensor can reach more than 500kHz, which is at least 5 times higher than the closed-loop Hall current sensor. This series include the following models: HIT50, HIT100, HIT200, HIT300, HIT500 and HIT600, which can measure 50A to 600A DC, AC and pulse current.
In short, HIT series sensors are an excellent alternative to Hall-effect current sensors, the best choice for pursuing high cost performance, and at the same time, they can greatly help promote high-precision DC sensor popularization.