The use of hollow coil

Hollow coil primary used in inductive acceptance, focusing, magnetic card, magnetic head, large current coil, low-voltage electrical appliances,industrial control, home appliances, car electronics, mount SMT, mobile phone, wireless transceiver, electronic navigation device, power supply regulator, amplifier, supplies and filter etc.. The main parameters of air core coil

1, the inductance

L is a characteristic of inductance coil itself, has nothing to do with thecurrent size. Inductance is general with special names indicate.

2, inductance

The size of the current block effect of inductance coil inductance XL iscalled, is measured in ohms.

3, quality factor

The quality factor Q is that of a physical quantity coil quality, ratio of Q toXL resistance, inductance and equivalent is: Q=XL/R.

The higher the Q value of the coil, loop loss is smaller. Q value of the coilDC resistance of conductor and dielectric loss, the loss of skeleton,shield or the core of the high frequency, the influence of the skin effectand other factors related to. The Q value of the coil is generally tens to hundreds of.

4, the distributed capacitance

Capacitance between turns and turns of the coil, coil and sheet, coil and shield are called distributed capacitance. The distributed capacitance of the existence of the coil Q value decreases, poor stability, so the distribution of capacitance of the coil is as small as possible.

The effect of hollow coil

1 hollow coil, choke function

Self induced electromotive force in the coil and the coil is the current in the coil resistance change. Hollow coil of AC current block, block effectsize inductance XL, is measured in ohms. The relationship between it and the inductance L and the frequency of the alternating current of F PI was xl=2 fl.

2, tuning and frequency effect

Hollow coil and a capacitor in parallel to form an LC tuned circuit. Thenatural oscillation frequency of the F0 circuit and AC signal frequencyinductive and capacitive reactance of F flat, loop is flat, so theelectromagnetic energy in the inductance, capacitance and oscillationresonance imagery, the LC loop. Resonance circuit inductance andcapacitance equivalent and reverse current circuit inductance, the totalamount of current minimum, maximum (f= "F0" communication signal), the LC resonant circuit with frequency selective role, can convert the AC signal of a certain frequency of the selected F.

Equipment and the use of hollow coil care matters

Electronic equipment in any electronic equipment, is through theengineering and technical personnel according to the characteristics ofthe various components of the use function, carefully arranged, plan,plan out. As the air core coil by using equipment, pay attention to the following several problems on it.

(1) equipment range hollow coil shall comply with the project needs

Relative orientation equipment range air core coil and other componentsto comply with the program rules, otherwise it will affect the normal work.For example, high resistance semiconductor radio brief flow in the ring and the magnetic antenna azimuth must be appropriate and reasonable arrangement; antenna air core coil and oscillation of air core coils should be perpendicular to each other, this prevents the effect of mutual coupling.

(2) hollow coil at the front of the apparatus, a visual inspection must be carried out

Before use, should check the air core coil structure Shi Bushi robust, turnShi Bushi loose and loose surface, lead contact for loose core rotation,Shi Bushi loose, without slipping. These aspects are checked, then the equipment.

(3) hollow coil in use process need trimming, trimming method should be considered

Some hollow coil in the use process, need to be fine tuned, relying on thechange of hollow coil number is not easy, therefore, selection should consider to fine tune the method. For example, single coil can beremoved by endpoint method the number of trapped air core coil, theadvance in the end of hollow coil around the 3 laps to 4 ring, in the range of fine-tuning, the mobile can change the inductance. Practice has proved, the inductance this scheduling method can 2% end trimming + + 3%. The use of air core coil in HF and VHF circuits, often set aside halfcircle as a fine-tuning, remove or turn the half circle of the inductancechange, end trimming. Multi section air core coil tuning, you can move adistance relative to the end of the number of segments, mobile segmentring should be 20% - 30% of the total number of coils. Practice has proved: This fine-tuning programming up to 10% to 15%. Air core coil with magnetic core, magnetic core by scheduling in hollow coil pipe in therange, the end of an air core coil inductance tuning.

(4) the use of hollow coil shall be stick to the original hollow inductancecoil

Hollow coil in use, do not change the hollow coil of arbitrary shape. The size and the distance between the hollow coil, otherwise it will affect the original hollow coil inductance. Especially the higher the frequency, theless the hollow coil circle number. Therefore, the high frequency coil wasused in televisions, generally with the data of high wax or other medium issealed and fixed. Other, should pay attention to in the repair, do not arbitrarily change or adjust the original hollow coil position, to prevent themismatch problem.

(5) adjustable hollow coil device should be easy to adjust

Adjustable hollow coil shall be equipment in the machine is easy tooperation range, easy to adjust the inductance coil reaches the optimal working conditions.