What is non inductive resistance? Non inductance resistor; It means that the inductive reactance value on the resistance is very small, which can be said to be negligible. It should be noted that although it is said to be negligible, it can not be said to be completely absent. The non inductive resistor is usually used for load, to absorb unnecessary power generated in the process of product use, or buffer and brake. This kind of resistance is usually called brake resistance and load resistance. In addition, for high-precision resistors, products are not allowed to have high impedance, which requires the selection of high-quality materials and high requirements of the process. Common non inductive resistors include: metal film resistance, winding resistance, TO-220 high power load resistance. In some precision instruments and meters, electronic industrial equipment usually needs to use this kind of non inductive resistance, because ordinary high inductive resistance is easy to produce vibration in use and damage other equipment in the circuit.
Non inductive resistance action
Non inductive resistance only needs the resistance on the wire or coil, not the voltage caused by inductance or induction. The common non inductive resistance is composed of two insulated wires, the terminal is short circuited, and the head end is external power supply and application wire. The current direction of these two insulated wires is opposite, and there is no external mutual inductance. They can be wound into coils and only play the role of resistance. For example, non inductive resistance is embedded in stator slot of large AC motor for temperature measurement.
Characteristics and advantages of non inductive resistance
The inductance value of the resistor is very small (only a few micro Heng) and the frequency response characteristic is excellent. Besides being widely used in AC and DC circuits, it is also suitable for medium and high frequency circuits;
The volt ampere characteristic is linear, the electrical performance is stable, high voltage resistance and good insulation performance;
It is especially suitable for intermittent power supply and high pulse current circuit;
The resistance has good temperature characteristics and wide temperature range;
High mechanical strength, cold and heat shock resistance;
Application of non inductive resistor
Starting, braking or speed regulating for high-power AC and DC motor control, electric traction locomotives and elevators for subway and road light rail, lifting equipment, medium and high frequency equipment, industrial electric furnace, electric pulse equipment, loads of various power devices, power control cabinet, converter devices, etc., voltage reduction in various high-voltage power output circuits, central air conditioners, AC and DC inverter welding machines, etc Current limiting and absorption, resistance and capacitance absorption of thyristor protection circuit, switching shunt resistance of high voltage switch, overvoltage protection in high voltage equipment, neutral point grounding of transformer or generator in high voltage distribution network, various electronic and power devices requiring high power, high resistance and no inductance, etc.
Selection of non inductive resistance
(1) The non inductive resistance pays more attention to the induction value and the consistency and stability of the equipment;
(2) As a load, non inductive resistance produces a lot of heat, and good heat dissipation is also one of the important parameters;
(3) If the equipment requires a high volume, it is not suitable to select the non inductive resistance with a large volume such as winding resistance;