We know that a current transformer is a product made according to the left-hand rule, in order to convert the large current on the primary side into a small current, or to convert the small current signal on the primary side into a large current. thatModel and specification of current transformerSo many, how can we classify them? Mainly distinguished by installation method and the material of the magnetic core inside, specifically manifested in the product, divided by installation method, closed and open.

Divided by magnetic core material:

1. For power frequency (silicon steel, generally mainly recycled silicon steel materials), measure 40-70HZ power frequency AC signals.

2. Medium to high frequency, 40-50KZH, magnetic materials mainly consist of amorphous, nanocrystalline and other materials, which are also commonly used in the current market for transformers.

3. Ferrite, measuring high frequency, 40-10MHz, mainly used for high-frequency power supply. The working principle of Hall sensors and transformers is fundamentally different. Transformers induce magnetic fields through coils, while Hall sensors are induced by materials such as gallium arsenide, indium antimonide, and indium arsenide. The common point is that the measurement method is the same, and the primary stage is highly isolated.

Isolate and convert the measured three-phase AC current into three standard DC voltages or DC currents output in linear proportion;

Excellent anti-interference ability and high precision (0.5%);

Perforated input, standard guide rail (35mm) installation;

Widely used in various industrial, automotive, military and other industries for online current detection systems;

There is no superiority or inferiority between transformers and Hall sensors for current sensors, only differences in usage conditions. The advantages of transformers are: 1. They have driving capability and generally output large currents; 2. They are low-cost; 3. They do not require auxiliary power supply for operation and are easy to use; 4. They can measure high-frequency AC signals that Hall sensors cannot reach. Disadvantages of transformers: 1. Due to their large output, secondary isolation is required for MCU acquisition in microcircuits to protect the device. 2. There is a difference between the primary and secondary edges, which needs to be compensated in the software during MCU acquisition, which is quite troublesome. 3. Measuring high current requires a large volume, which affects installation. The microcurrent we are talking about is a microcurrent testing solution based on industrial manufacturing that can be mass-produced and applied. The current ranges from 1mA The acquisition scheme for 100mA AC/DC signals.

Generally speaking, the most commonly used current sensor for collecting DC microcurrents is the magnetic modulation DC or DC leakage current testing scheme, which is also a commonly used testing scheme with low cost, strong anti-interference performance, and good practical application effect. It is widely used in DC screens and also belongs to the traditional DC microcurrent testing scheme. The disadvantage is that it can only measure DC, and there are many control process points in mass production, resulting in low product consistency and large volume. More importantly, the testing of microcurrents or DC leakage currents based on this principle has a contradictory parameter of corresponding time and zero point stability. If the corresponding time is less than 200MS, the zero point will be unstable, which is not convenient for situations where accuracy is required. If the corresponding time is greater than 200MS, it will be unstable. Around 500MS, the zero point is relatively stable, However, such a long response time is also unacceptable in many application scenarios. Currently, the DC leakage current sensors (magnetic modulation) on the current sensor market generally have a response time of around 500MS, and some even 1S.

A small current testing scheme based on the principle of magnetic flux gate, which is universal for both AC and DC, has been widely used in the field of low-voltage electrical appliances and is currently in the rising stage of the market. It almost fills all the functional disadvantages of the small current testing scheme of magnetic modulation principle, with small volume, fast response time, diverse output signals, and is suitable for convenient acquisition of various MCUs. The disadvantage is that although the principle has changed, the cost has slightly increased, and it still belongs to the category of modular sensors in structure. The process control still requires high requirements. Weikewei has started large-scale production, effectively solving the hidden danger of reliability.