Card works

Card works Residual magnetic flux density magnetic above Br in the magnetic work plays a crucial role. laptop battery Card with a certain speed through the work coil head, the external magnetic field lines cutting the coil, induced electromotive force generated in the coil, which transmit the signal to be recorded. Of course, it also requires the work be recorded in the magnetic signal has a wide frequency response, low distortion and high output level.

A very thin metal lines can be used as a simple playback devices. Metal line and the card close to the direction laptop battery perpendicular to the magnetic direction of running, card runs, metal line cutting magnetic field lines generated EMF, EMF and cutting the size is proportional to the magnetic field lines. When the card's speed is constant, the voltage induced metal line and the residual magnetic flux density is proportional to the surface, while the voltage induced in a conductor can be expressed as follows:

e = BrWv the formula Br-surface residual magnetic flux density;
W-recorded Road track width;
v-card playback speed.

In the case of Br = 2πf/vφrmcos2πft comprehensive Br and e the relationship, get e = 2πfWφrmcos2πft. Of course, with a magnetic wire for work equipment, the output is small, Guer is not practical.

The head is of high permeability soft magnetic material of core, windings wrapped around the top, head in front of a very narrow gap,Dell 312-0058 battery then head into the work of the magnetic flux is concerned, can be seen as two parallel effective reluctance, that gap reluctance and the reluctance core heads. Because the gap is much larger than the effective magnetoresistive head core of the reluctance of work, so the vast majority of card on the magnetic flux input to the head core, laptop battery and work on the coil winding heads crosslinking occurs, which induces a electromotive force, in this case , the single metal replay line EMF obtained by the formula is fully applicable to the work of annular magnetic head, just a different scale factor.

N number of turns for the coil set, m for the core work of the size and magnetic head-related factor, is the work of the head ring winding induced voltage is generated by: e = 2πfWmNφrmcos2πft

Because the work in the induced magnetic winding electromotive force is proportional to the rate of change of flux, that EMF eαByα frequency f. In the record i = Isinwt, longitudinal remanence density Bxαi (transfer curve of the straight part), so, Bx = K1Isinwt. As Byαdbx / dt, eαBy, therefore, e = K2Iwcoswt. Where K2 depends on the efficiency of the work of heads, number of turns, the tape material. The formula also shows that: Dell Latitude X200 battery the output voltage is proportional to the current record; output voltage proportional to signal frequency; the output voltage by 90 °, corresponding change (change from sine to cosine key items).

Card international standards

Card 1, ISO7810: 1985 Identification cards Physical characteristics
Provided the physical characteristics of the card, including card materials, construction, size.
Card size: Width 85.72mm ---- 85.47mm
Height 54.03mm ---- 53.92mm
Thickness of 0.76 ± 0.08mm
Card corner radius 3.18mm
Generally speaking card size: 85.5X54X0.76
2, ISO7811-1: 1985 Identification cards Recording technique Part 1: Embossing
dell 312-0625 battery Provides a card embossed character requirements (character sets, fonts, laptop battery character spacing and character height).
3, ISO7811-2: 1985 Identification cards Recording technique Part 2: Magnetic
Provides the characteristics of magnetic stripe cards, encoding and coded character sets.
4, ISO7811-3: 1985 Identification cards Recording technique Part 3: ID-1 type card embossed character position
5, ISO7811-4: 1985 Identification cards Recording technique Part 4: Read-only track the first 1,2-track position
6, ISO7811-5: 1985 Identification cards Recording technique Part 5: read and write the first three tracks here tracks

Use of magnetic

1 card, magnetic stripe cards in use will be subject to many external disturbances. Dell 8U443 battery
2, magnetic stripe cards in the wallet, wallet from Cikou too close, or even come into contact with the Cikou.
3, with Ms. handbags, men handbags Cikou too close or touch.
4, and contacts with a magnetic seal, notebook touch.
5, and put on the Cikou mobile phone, car keys and other magnetic objects in contact.
6, and mobile phones and other devices that can generate electromagnetic radiation a long time together.
7, and tape recorders, and other laptop battery effects of strong magnetic fields of household appliances too close.
8, when used in supermarkets, and supermarket security degaussing equipment used too close or even touch.
8, more than magnetic strip cards put together, the two magnetic stripe cards are in contact.
9 In addition, magnetic stripe cards under pressure, have been broken for a long time bump, exposure, high temperature, dirty, also will scratch the magnetic strip magnetic stripe card can not work properly. Meanwhile, in a swipe card reader on the card transaction process, the head of the cleaning, aging, data transmission interference, system error movements, Dell Latitude X200 battery cashier and so may result in improper operation can not be used magnetic stripe cards.

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