The magnetic parts of an apparatus in circuit

 

Magnetic inductor of yuan of — of parts of an apparatus and transformer and other and electric element are different, the person that use purchases the inductance that accords with his to ask and transformer very hard. Because of the parameter of the standardization with current inside formulary limits neither one, and the most parameter of token magnetism component (inductance quantity, voltage, electric current, handle energy, frequency, v/LIT all over the ground than, leakage feeling, loss) be not know what to do to manufacturer.

 

 

The analysis of magnetic component and design are more complex than circuit design much, want to get only solution is difficult. Because want to involve a lot of elements, because this designs a result,not be exclusive and reasonable absolutely. Of the consideration is the minorrest volume not only, lowermost cost, or highest efficiency, contain structure, technology even, medicinal powder the design such as heat and interference. A lot of troubles of power source of high frequency switch are caused.

 

 

Inductor is principle of basis electromagnetism induction, circle by lead make and become. The effect that knows dc, block communication is had in circuit. Express with symbolic L in circuit graph, main parameter is inductance quantity, the unit is henry, express with H. According to electromagnetism induction principle, inductor derive gives a lot of kinds of parts of an apparatus.

 

 Z=R+jX      R=ωL0μ’’    X=ωL0μ’

 

 

Inductor sort

 

1 Small-sized and fixed inductor

 

Small-sized and fixed inductor is to use enamel-insulated wire to be circled directly on magnetic core normally make and become, basically use in the circuit such as wave of filter wave, oscillation, defect, defer, it has sealed type and blame sealed type encloses a form two kinds, two kinds of forms have vertical and horizontal again structure of two kinds of appearances.

 

1, horizontal is sealed and fixed inductor

 

Sealed and fixed inductor uses horizontal axial cite a base, have the series such as LG1, LGA, LPH. The inductance of LG1 series inductor measures limits to be 0.1~100000μH, cent of rated electric current is 50mA, 150mA, 300mA, 700mA and 1.6A 5 kinds of norms. LGA series inductor is used exceed small-sized structure, appearance and resistor of 1/2W lubricious annulus are similar, its inductance measures limits to be 0.22~1000μH, rated electric current is 0.04~1.4A. LPH series inductor also is small-sized enclose a structure, its inductance measures limits to be 3.9~18000μH. Error limits is ±5%~±20% .

 

2, vertical is sealed and fixed sealed and fixed inductor uses inductor vertical with to model cite a base, have the series such as LG2P, LG2S, LPV. Inductance measures limits to be 0.1~100000μH, rated job electric current is 0.05~2.0A, error limits is ±5%~±20% .

 

2 adjustable inductor

 

Its are exterior overspread for metallic screen, in-house by nylon cap of magnetic core of line wearing, I-shaped, magnetism is reached cite a base etc form, enamel-insulated wire of useful on labour word magnetic core high strenth circles the winding that make. Magnetism cap installs the nylon inside screen cover to wear, can get on next whirl move, will change the inductance volume of coil through changing the distance of it and coil.

 

3 block shed inductor

 

Block shedding inductor is point to the inductance coil in access of alternating current of block of the in order to in circuit, its cent sheds coil and circle of streamline of low frequency block for high frequency block.

 

1, circle of streamline of high frequency block: Group of streamline of high frequency block also says high frequency clutch streamline to encircle, it is used prevent high frequency alternating current to pass. Streamline of V high frequency block encircles the job to be in high frequency circuit, multi-purpose collect hollow or ferrite is high frequency magnetic core, framework uses data of pottery and porcelain or plastic make, coil uses apiary style section to circle make or multilayer smooth circle section make.

   

2, circle of streamline of low frequency block: Group of streamline of low frequency block also calls low frequency choke, it applies at the circuit such as voltaic circuit, frequency circuit or field output, its action is to prevent low frequency alternating current to pass.

 

4 by application the principle is classified

 

Store can kind: Include to rise store can of action store can inductor, syntonic inductor; Inductor of switch power source (the) such as BUCK inductance, BOOST inductance.

 

EMI filter wave kind: Include to differ modular inductor; In all modular inductor;  Passive PFC inductor; Inductor of LC filter wave. The electromagnetism that communicate since and electromagnetism restrains to disturb action since the; of filter wave inductor of action of straight wave drifting filter disturbs filter wave inductor, aiguille restrains inductor; The; of inductor of noise filter wave that noise function controls since removes those who absorb effect of surge electric current to absorb inductor, remove the amortize inductor; of rate of change of slow down electric current

 

Other kind: Step aside closes the magnetic switch inductor of action; Remove the inverting inductor that helps action of semiconductor switch inverting; Adjust since of inductance action can accuse inductor and saturated inductor.

 

5 by enclose structural classification

 

Metallic carapace is sealed kind: The metal is sealed housing comes forward of what make alone and terminals, this category does not include to cross the inductor of metallic carapace with insulation down-lead.

 

Fill seals kind: Include to the model notes fill to seal or cover structure, and include to have metallic case, one aspect of the matter the inductor that two end are opened wide and perhaps seals stuff stuff with fill, perhaps use the inductor that crosses metallic carapace with insulation down-lead.

 

Open kind: Open kind divide metallic case namely kind, fill seals kind of inductor beyond, include to carry the inductor of the structure that seal formula.

 

 

The main parameter of inductor

 

1, inductance quantity

 

Reaction inductance stores magnetic field can competence, dimension of the v/LIT all over the ground number of its size and inductance coil, geometry, have without magnetic core (core) , of magnetic core guide magnetism rate is concerned. Below coequal condition, amount of much inductance of v/LIT all over the ground number is large, amount of coil diameter big inductance is large, magnetic core is measured than doing not have magnetic core inductance big. The inductance amount that is used at high frequency circuit is relatively lesser, the inductance amount that is used at low frequency circuit is opposite bigger. The unit that inductance measures is henry (H)

 

 

L=Ψ/I=NAeB/I=N2AeB/Hle

=μ0μeN2Ae/le

 

2, nominal voltaic value

   

Inductor works for a long time not to damage place allows the biggest electricity that carry. It is high frequency, the important parameter that low frequency clutchs streamline circle and high-power resonance coil. Often express respectively with alphabetical A, B, C, D, E nominal voltaic value 50mA, 150mA, 300mA, 700mA, 1600mA. The carries inductor actually electricity when application is unfavorable exceed nominal voltaic value.

 

More detailed content:

 

Why does the rated electric current of power inductor have two kinds?

 

3, quality factor (Q is worth) :

 

Store in inductance coil energy and the ratio of disappear energy consumption call quality factor. Call Q the value again. Or it is the inductance that coil place presents and coil dc the ratio of block, q=wL/R. The Q value of inductor is 50-300 commonly, the structure of Q value and coil (lead degree of finish, much or odd, circle law, magnetic core) about, q cost is higher, the loss of circuit is smaller. In harmonious loop, requirement Q is taller, in order to reduce the loss with coil loop; In filter wave loop, q value is unfavorable and exorbitant, lest make its and filter wave capacitance make syntonic return circuit, produce an effect to circuit, do not make a demand to high frequency choke and low frequency choke.

 

4 accuracy class

 

Tolerance is the permission that points to the nominal inductance amount on inductor and actual inductance error value.

 

The inductor claimed accuracy that is used in the circuit such as oscillation or filter wave commonly is taller, tolerance is ±0.5% ; And use at coupling, high frequency block to shed the precision that waits for coil the demand is not high, tolerance is ±10%~20% .

 

5, distributinging capacitance: Show coil is v/LIT all over the ground with v/LIT all over the ground between formation distributinging capacitance, it reduced the quality factor Q of coil, also make the working frequency of coil is restricted. High frequency coil is used reduce coil framework diameter, use thin lead to circle make, apiary type or section type wind a way is to reduce distributinging electric capacity.

 

6, lead from harmonics: Inductance is when its SRF, the distributinging capacitance of inductance and inductance value produce resonance, right now inductance value and capacitance are worth equal and mutual countervail. The Q value of inductance is when resonance frequency, q=0, XL=0, reason right now inductance appears a tall impedance value. Inductance exceeds this frequency criterion invalidation becomes capacitance sex product, cause is common question mark can order SRFmin with inductance

    

We know syntonic frequency F=1/ (2π√LC) , there are 2 parameters to decide F in this type, it is L and C. By type knowable, LC is smaller, frequency is taller. In capacitance particular case falls, can consider to reduce inductance, rise from syntonic frequency; If inductance is certain, be about to consider how to reduce distributinging electric capacity, and the formula of capacitance is C=ε·S/4πkd, here has 3 variable, ε , s and D, dielectric constant ε namely the stuff stuff inside inductance, look to whether optional material reduces dielectric constant, another is S, reduce interface to accumulate namely, namely each inside inductance contact area that winds a string is reduced, the 3rd is D, can consider a line each rounds scanty circle. Perhaps use the magnetism core of tall U, decrease circle coil number to wait.

 

The influence with characteristic to magnetism air gap

 

 

The effective magnetism conductance of magnetism club

 

 

The stress influence to magnetism function

 

 

Transformer

 

 

1 transformer can be divided by working frequency for high frequency transformer, intermediate frequency transformer and low frequency transformer.

 

2 transformer can be divided by its utility for power source transformer, frequency transformer, intermediate frequency transformer, high frequency transformer, pulse transformer, constant voltage transformer, coupling transformer, wait from Ou transformer, segregation transformer a variety of.

 

3 transformer press core (magnetic core) appearance can be divided for “E” transformer, “C” transformer and annulus transformer.

 

The loss of transformer and magnetism leak

 

 

The magnetism of magnetism material transmits character

 

 

The leakage move impact to character

 

Leakage feels formulary: Ls=μ0N2dg/h

 

N is primary v/LIT all over the ground number, h circles line width, d is height of two coil clearance, the average circumference C=2πr between two coil of G.

 

1, decrease primary v/LIT all over the ground number can drop leakage move. N reduces Ls.

2, increase the breadth that wind a string, h increases Ls to reduce.

3, reduce insulation thickness, d reduces Ls.

4, reduce winding number of plies, g reduces Ls.

5, the winding choice of malcontent layer is scanty bypass full layer, h increases Ls to reduce.

6, winding is circled close and distributing even, reduce G to reduce Ls.

7, reduce breath, drop leakage move.

8, increase coupling to reduce leakage feeling, wind a way with sandwich.

 

Transformer parameter

 

1, rated power

  

Show in the regulation frequency and voltage fall, transformer permanent worker is made and do not exceed the power of the biggest output of formulary temperature rise, the meeting in rated power has a part not to have result power, reason unit is VA. It is commonly under hundreds volt-ampere.

 

2, transformation ratio N

  

It is to point to transformer one, pressure ratio of 2 winding report. If oversight this value is equal to the loss of core, coil approximately one, 2 times the v/LIT all over the ground number of winding is compared, this parameter showed this transformer is step-up transformer or step-down transformer.

             

N=U1/U2=N1/N2

 

3, the relation of electric current and voltage

 

If take no account of the loss of transformer, criterion U1.I1=U2.I2 or U1/U2=I2/I1

 

4, impedance commutation concerns

  

The relation of Z1 of primary input impedance and Z2 of sub and laden impedance can be derived by Ohm’s law.

  

U1/Z1=I1 U2/Z2=I2 takes the place of to go up type gets 

 

Z1/Z2=(U1/U2)2=n2  Z1=n2Z2

  

So transformer has the effect of commutation impedance.

 

5, efficiency η :

     

When rated load, transformer outputs power to hold the percentage of power input. η ＝ (Po/Pi)×100%

  

It and design parameter, material, workmanship and power are concerned. Normally efficiency is 70%-80% under 20VA, and 100VA above efficiency can amount to 95% above. Transformer of common power source, frequency considers efficiency, intermediate frequency, high frequency transformer takes no account of efficiency.

 

6, insulation resistance and compression intensity

   

It is the important parameter that transformer safety works

 

Insulation resistance: Between transformer coil, between coil and core and the resistor between down-lead.

 

Combat electric strength: Inside formulary time (be like １ minute) transformer but susceptive voltage.

 

Insulation resistance of transformer of small-sized power source is not less than 500MW, the intensity that fight report is more than 2000V.

 

Magnetic core choice

 

 

Copper cash choice

 

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: of collect skin deepness? ℃ of?0 of chair of straight Qu miscellaneous κ and ℃ of temperature 100, haveδ= 6.6 /√F and δ= 7.65/√F two formula, eventuate Cm. Choose the diameter of cupreous wire or ply according to collect skin deepness.

 

The collect skin deepness of cupreous conductor: (20 ℃ )

 

 

The influence of collect skin effect exists in high frequency circuit, effect of higher volume skin jumps over frequency serious, be in like effect of 1MHz collect skin 60μm thick level, effect of 500MHz collect skin is in 3.0μm thick level, effect of 1GHz collect skin is in 2.1μm thick level, effect of 10GHz collect skin is in 0.7μm thick level. Signal along lead surface (include 4 side) flow, hope lead surface is flowing, because rough surface is met,defer signal transmits time. Printed board uses Copper Foil now thick changing a face is 2μm ～ 3μm, concave and convex outline still is shown big, the demand is lower the transmission of outline Copper Foil with contented and high frequency electric current.