SU1434489A1 - Apparatus for reading information off magnetic carriers and measuring magnetic values - Google Patents

Abstract

The invention relates to the automatic collection of information from vehicles and to magnetic measurements and can be used in enterprises of the industry related to the transportation of cargo and in measuring equipment. The invention improves the accuracy of reading information and measuring magnetic quantities. At the moment when the carrier is located, the information and the read and measure zone measure the frequency of the electromagnetic oscillator 2, which changes as a result of the inductance of the oscillating circuit of the oscillator 2 under the influence of the magnetic field of the information carrier. Then, the measured frequency is compared with the specified one and the magnitude and direction of the magnetic field of the information carrier is determined from the deviation of the measured frequency from the specified one. 1 il. (L with 4ii F bo

Description

The invention relates to the automatic collection of information from vehicles and magnetic measurements and can be used in enterprises of all branches of industry related to the transportation of cargo and in measuring equipment.

The purpose of the invention is to improve the accuracy of the device.

The drawing shows the functional diagram of the device

The device contains an oscillating circuit 1 of the generator 2, connected to the automatic frequency tuning unit (AFC) 3 and the comparison unit 4, which is connected to the master oscillator 5 and the switch 6 connected to the indicator 7, the information carrier detection sensor 8 and the discriminator 9 connected through integrator 10 to block 3

AFC;

The device works as follows.

The signals of oscillator 2, whose frequency is determined by the parameters L and C of circuit 1 and equal to the frequency of signals of master oscillator 5, are fed to block 4 of the comparison. The second input of block 4 is supplied with signals of the master oscillator 5. The output signal of block 4 through the switch 6 is fed either to the input of the indicator 7 or to the input of the discriminator 9. At the same time, the switch 6 connects the output of the block 4 to the indicator 7 only when the storage medium is in the read zone, i.e. on the control input of the switch 6 there is a signal carrier detection sensor 8 In the absence of the information carrier in the readout zone, the switch 6 connects unit 4 to the discriminator

Before entering the readout area of the information carrier, the compensation of the magnetic field interference is carried out as follows.

The magnetic field of interference, acting on the electromagnetic field of circuit 1, changes the frequency of the signals of generator 2, since the inductance L of circuit 1 o changes

Therefore, the frequency of the generator 2 signals differs from the frequency of the signals of the master oscillator 5. In block 4, the frequency of the generator 2 is subtracted

from the frequency of the master oscillator 5. The output signal of block 4, whose frequency is equal to the frequency difference of the master oscillator 5 and generator 2, through the switch 6 is fed to the input of the discriminator 9, the discriminator 9 in accordance with the output signal of the block 4 generates a signal

voltage, the magnitude and direction of which is unambiguously determined by the magnitude and direction of the deviation of the frequency of the generator 2 from the frequency of the master generator 5. The output voltage of the discriminator 9 through the integrator, 10 arrives; to the input of block 3 of the AFC, which

affects generator 2, change

its frequency until it

, becomes equal to the frequency of the master oscillator 5.

Thus, before the information carrier enters the readout zone, the frequency of the signal from generator 2 is equal to the frequency of master oscillator 5, i.e.,

the magnetic field of interference acting in the readout zone is compensated. When a carrier appears in the readout zone, the magnetic field of the carrier affects the electromagnetic field of circuit 1 changes the inductance L of this circuit 1, and depending on the direction of the magnetic field of the carrier, the inductance L either increases, or

decreases as a result of which the frequency of the electromagnetic oscillations of the generator 2 changes,

Comparison unit 4 determines the magnitude of the oscillator frequency deviation.

2 from the frequency of the oscillator 5. Switch 6 is connected to the output of block 4 by the signal of sensor 4 for detecting media 8. The output signal of block 4 through switch 6 is fed to the input of indicator 7 ,. which produces a signal, the magnitude and sign corresponding to the frequency deviation of the generator 5, i.e. the magnitude and direction of the magnetic field of the information carrier.

Claims (1)

Invention Formula A device for reading information from magnetic media and measuring magnetic quantities, containing an oscillatory circuit, sets the generator and indicator, which is, in order to increase the value of the U34489. . . . ,, accuracy of the device, in it and in the discriminator, the outputs are inputted to the sensor for detecting the carrier of the carrier, respectively -information, automatic sub- unit with oscillatory circuit and from the first frequency tuning, generator, unit. the input of the comparison unit, the second input comparison, the switch, the discriminator of which is connected to the back-end integrator, and the outputs of the sensor generator, the output of discrimination and detection of the information carrier and connected through the series of the comparison unit are connected to the inputs of the integrator and the automatic a switch whose outputs are connected to the junction of the frequency control connected to the input not correspondingly with the inputs of the indie generator.