Wednesday, January 5, 2011
【 Weak current College 】 inductance of the classification, main characteristics of the inductance coil parameters, common coil 】
Inductance coil is a wire around a circle around the insulation pipe, the insulation wire each other, and the insulated pipe can be hollow, can also contain iron or magnetic core, hereinafter referred to as inductance. Use l, units have Henry (H), filiform Henry (mH), micro-Henry (uH), 1H = 10 ^ 10 ^ 6uH 3mH =.
First, the inductance of classification
By inductance form classification: fixed inductors, variable inductance.
Classification according to the conductive properties: air core coils, ferrite coil, coil core coil, copper conductor.
Classification according to the nature of work: antenna coil, oscillation coil, choke coil, notch coil, deflection coil.
Classification by winding structure: single-layer, multi-layer winding coil, hive-coil. 2. main characteristics of the inductance coil parameters
1, inductance L
Inductance L represents the inherent characteristics of the coil, and the current size. In addition to specialized inductance coils (inductors color-coded), inductance is generally not specifically labeled online circle, to a specific name.
2, inductive reactance XL
Inductance coil on AC current blocking effect called inductive reactance XL, unit is ohm. It and inductance L and AC frequency f relationship to XL = 2 π f L
3, quality factor Q
Quality factor Q is a physical quantity of the quality of a coil, Q for inductive reactance XL and its equivalent resistance ratio, i.e.: Q = XL/R. Coil q value higher, the more small loop of loss. Coil q value and conductor DC resistance, skeleton of dielectric loss, shielding enclosures or core loss caused by the high-frequency effect of skin effect and other factors. Coil Q value usually dozens to hundreds.
Coil turn to turn and turn, coil and shielding enclosures, coil and capacitor plate there is called distributed capacitance. The existence of distribution capacity so that the coil of the q-value decreases, stability, and thus the coil of distributed capacitance as small as possible. III. common coil
1, single coil
Single-coil is a circle of insulated wires get a ring around the on paper tubes or bakelite skeleton. Such as transistor radio wave antenna coil.
If the wound coil, the plane is parallel with the surface of revolution, but rather the intersection into a certain angle, the coil is called honeycomb-coil. While the rotation for a week, the wire bent back and forth many times, often referred to as folding points. Hive-around method has the advantage of small volume, capacitance and inductance. Honeycomb coil were using the hive winding machine for winding, discount points, the smaller the distribution capacity
3, ferrite cores and iron core coils
Coil inductance size and there is no magnetic core. In the Insert air core coils ferrite cores to increase inductance and improve the quality of the coil.
4. copper coil
Copper coils in the FM range applications more, use a swirling copper coil position of inductance, this convenient, durable.
5, color code inductors
Color code inductor is a fixed amount of inductor inductance, the inductance method with the same logo to color ring for electrical resistance.
6, choke coil (choke)
Limit by coil that AC power choke coils, HF choke ring and low frequency choke ring.
7, deflection coil
Deflection coil is TV scan circuit output level of load and deflection coil requirements: deflection of sensitivity high, uniform magnetic field, high Q value, small size, low price.