SU1509989A1 - Device for playback of information from magnetic carrier - Google Patents

Abstract

The invention relates to instrumentation, in particular to a magnetic recording technique, and can be used in information processing and recording systems. The purpose of the invention is to expand the frequency range of the playback signals in the low frequency region, achieved by tracking the positive feedback of the target's magnetomotive force. The device contains an induction reproducing magnetic head 1, the winding 2 of which is connected to a non-inverting converter 3 short-circuit current - voltage, the output of the reproduced information connected to the output bus. Magnetic head 1 is also made with a flow-sensitive converter 5 connected to the positive feedback circuit of the non-inverting converter 3 short-circuit current - voltage. Such switching-on of a flow-sensitive converter, which ensures the formation of a positive feedback current (summed with a short circuit current) in the region of zero and infra-low frequencies, provides a more complete compensation for the magnetic flux and core loss of the magnetic head in the low-frequency region and thereby expanding the frequency range of reproducible signals. information. 3 il.

Description

SL

ABOUT

with so

00 WITH

The invention relates to instrumentation, in particular to a magnetic recording technique, and can be used in information recording and processing systems.

The purpose of the invention is to expand the frequency range in the lower frequency range by providing a positive feedback circuit following the magnetomotive force of the carrier,

Fig. 1 is a schematic diagram of the device; Fig 2 is a block diagram of the device; Fig. 3 shows a positive feedback block.

The device (FIG. 1) contains an induction magnetic head with a winding 2 and a flow-sensitive converter 3, containing, for example, a magnetoresistive current-voltage converter 4 and a voltage-current converter 5, in combination with winding 2, representing a voltage generator magnetomobile si

Lou (MDS).

Q

where the approximate equality is valid for the loop gain Is determined by the choice of the value of the voltage-to-current conversion coefficient, which is significantly larger than one.

Thus, the system converting the SLM current characterized by relation (3) is determined by the inversely proportional dependence on the number of turns of the winding 2, as in the known device, however, the flow compensation in the core is due to the use of a flow-sensitive 5 converter VAT compensation due to the absence of the resultant flow does not lead to a decrease in the constant time of the head due to the increase in the value of the magnetic resistance, which significantly affects the low-frequency part of the spectrum signal produced,

A positive feedback device block can be performed

0

25 (fig, 3) in the form of four adders

and

In accordance with the block diagram (FIG. 2), the device can be represented as an adder 6 formed by a magnetic head, in which, in combination with a carrier, MDS of carrier F and MDS of winding 2 of head FQ are balanced due to the effect of voltage converter in DPT, which is characterized by a conversion factor

TO

F I and V

(one)

where and is the output voltage of the converter 4;

W is the number of turns of the winding 2. The flow-sensitive converter 8 in accordance with the block diagram (FIG. 2) is characterized by the conversion factor.

K - U g

where and is the output voltage of the converter 4 at the output terminal of the device (not indicated);

-: K, j is the conversion factor for flow 0 to voltage, for example, magnetoresistive converter 3, the transfer coefficient of the structural

schemes for MDS (Fig, 2) is characterized by 55

by ratio

tracking a system with a physical model in a positive feedback current circuit.

The equations of the elements of the system (FIG. 3) have the form

e (p) F (p) —Fo (p); FO (P) KI (P) Y (P); Y (p) K, (p) 0 (p) + Z, (p); Z, (p) K, (p) x

45 x04p) + Za (p); e ,, (p) Y (p) -Z (p); (4) (2) Zi (p) K2 (p) e, (p); e, (p) Z, (p) - Z., (P),

where F (P), FO (P),

Y (p), e (p) Z, (p), Z (p), ®Z, (P), 6 (p)

images no Lap-las signals in the system, respectively, of the MDS of the carrier and winding 2, the output value and error (non-compensation signal) of the system;

one

to

Kv

w

(3)

two communication elements connected in a definite way and representing the model 9 of the system, followed by the MDS, B1 switched off by means of the adder 10 into the positive feedback circuit on the short-circuit current of the winding 2,

The positive feedback circuit consists of an adder 11 simulating a magnetic head 1, a feedback element 12 imitating elements 2, 4, 5 (FIG. 1), adders 13 and 14, and also a communication element 15

images no Lap-las signals in the system, respectively, of the MDS of the carrier and winding 2, the output value and error (non-compensation signal) of the system;

Laplace images of the corresponding signals in the system model;

К Хр), К (р) -transfer functions, respectively

formers 7 and 8; 5 neny (A) is the ratio

F (p)

in (p), (5)

1 + K, (p) Kj (p)) 1 + K. (P) J

. „I I

determining the value of the follow-up error, depending on the result of the conversion of the flow-sensitive transducer, allows for a magnetic flux in the core of the head without reducing the time constant of the magnetic head, limiting the loop gain value in the system, and in combination with limiting the positive reverse 20

system.

From the expression (5) it follows that when the equivalence conditions are realized

KZ, (P) 1,

K: .. (P) K, (p) K, (p),

IT is converted to expression

(6)

(7)

and F (}

p) to, (p)

That is, the system is characterized by a higher order of astatism while maintaining stability determined by the invariance of the roots of the characteristic equation, as a result the system reduces the error in the derived signal.

When implementing the conditions

25

Due to the short circuit current, the circuit of which contains the model of the tracking system, the frequency range of the reproduced signals can be significantly extended.

Claims (3)

1. A device for reproducing information from a magnetic recording medium, one (p) .K2iEL 1 + K, (p) Kj (p) Kg / p) | fl, KZ) -K, (p) discharge (5) takes the form Q (p) EM. (9) H-K (p) Kj (p) l + K ,, (p) In this case, the characteristic equation of the system is the equation 1 + K (p) Ki (p) 1 + K (p) 0. (10) If the roots of the equations that have multipliers, 1 + K, (p) K (p) O (11) IHK, (P) 0, 1. A device for reproducing information from a magnetic recording medium, 30 containing an induction reproducing magnetic head, the winding of which is connected to one input of a short-circuit current-to-voltage converter, a positive feedback unit with a head-to-magnetomotive force signal converter connected between the input of a short-circuit current-voltage converter and the output terminal of the repro 40 information, characterized in that, in order to expand the frequency range output signals, the positive feedback block is made in the form of are complex conjugated, then the 4E converter that implements the physics system becomes a broadband model that follows along a magnetized frequency independent minimum carrier of the playback system, an error signal, i.e., none. 2. The device according to claim 1, wherein the positive feedback block is made in the form of four adders and two communication elements, while the output of the first adder is connected through the second sum allows to optimize the trace - 55 the first communication element and the third conductor of the carrier for the VAT according to the Criter- adder with its other input and with the other minimal tracking error. The input of the second adder, as well as The formation of a short circuit current with one input of the fourth adder, the test, by forming it in the winding, the other input of which is connected to the other, is characterized by the expansion of the spectrum of signals in the high frequency region. Thus, the formation of a positive current of positive communication by turning on the model of the reproduction system. (p),) are the transfer functions of the communication elements 12 and 15, respectively. The joint solution of the urn system (6) cabbage (7) depending on the result of the conversion of the flow-sensitive converter, it allows to realize the magnetic flux in the core core without reducing the time constant of the magnetic head, limiting the loop gain value in the system, and in combination with the limiting of the positive reverse Due to the short circuit current, the circuit of which contains the model of the tracking system, the frequency range of the reproduced signals can be significantly extended. Invention Formula 1. A device for reproducing information from a magnetic recording medium. 30 containing an induction reproducing magnetic head, the winding of which is connected to one input of a short-circuit current-to-voltage converter, a positive feedback unit with a head-to-magnetomotive force signal converter connected between the input of a short-circuit current-voltage converter and the output terminal of the repro 40 information, characterized in that, in order to expand the frequency range output signals, the positive feedback block is made in the form of that input of the third adder and is connected via the second communication element with the output of the fourth adder, and the head-to-magnitude moving signal converter is connected between the output of the first adder and the other input of the short-circuit current to voltage converter. Fie.2 3. A device according to claim 1, characterized in that the short-circuit current converter is applied to the voltage in the form of a compensating tracking system, in the negative feedback circuit of which a magnetic flux converter is introduced into a magnetomotive force. Fi.Z