SU1327165A1 - Apparatus for playback of digital information signals erom magnetic medium - Google Patents

Abstract

This invention relates to magnetic recording. The purpose of the invention is to improve the noise immunity of the device. The result of reproduction from reproducing magnetic heads 1 and 2 passes through amplifiers 3 and 4 of reproduction to shapers 5 and 6 pulses, which produce ffly bands corresponding to the moments of change of polarity of magnetization of the recording medium. Element OR 7, through element 15, sets counter 23 to the initial state and transfers trigger 13, which opens element 14, through which generator 20 pulses pass to counter 23. When the contents of counter 23 have reached, there is no value corresponding to half the clock period of the playback signal , the decoder 24 is triggered, which generates a pulse, overturning the trigger 13, and the counter 23 is reset to the initial state via the element OR 16. The pulses of the decoder 24 arrive at the elements AND 17 and 18. Pr and reproducing the logical unit from the carrier, the pulse of the decoder 24. passes through the element And 17 to the output bus 21. When playing the logical zero, the pulse passes through the element And 18 to the output bus 22. Gil. from 9 (L 00 to Od el

Description

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The invention relates to magnetic recording, in particular, to devices for reproducing digital information signals from a magnetic recording medium.

The aim of the invention is to improve the noise immunity of the device,

The drawing shows a device for reproducing digital information signals from a magnetic recording medium.

The proposed device contains first and second reproducing magnetic heads 1 and 2, connected respectively via the first and second reproduction amplifiers 3 and 4 with the inputs of the first and second formers of 5 and 6 pulses, respectively. The first and second outputs of the first driver 5 pulses are connected to the first and second inputs of the first element 11LI 7 and to the first and second inputs of the first trigger 8. The first and second outputs of the second Amplifier 6 pulses are connected to the third and fourth inputs of the first element OR 7 and the first and second inputs of the second trigger 9, the first and second

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the outputs of the first trigger 8 are connected to the first inputs of the first and second elements AND 1C) and 11, respectively, and the first and second outputs of the second trigger 9 are connected to the second inputs of the first and second elements 10 and 1, respectively. Outputs of the first and second elements 10 and 1 connected to the inputs of the second element OR 12.

The device also contains a trigger trigger 13 connected by the first and second outputs respectively to the first input of the third element AND 14 and to the first input of the fourth element AND 15 connected by an output to the first input of the third element OR 6, five and sixth elements And 17 and 18, the element NOT 19 and generator 20 pulses. At the same time, the fifth and sixth elements And 17 and 18 are connected by outputs to the output bus of 21 logical units and to the output bus of 22 logical zeros, respectively.

The device also contains a counter 23, connected by a setup input to the output of the third element OR 16 and a connected counting input to the output of the third element I 14 connected to the output of the pulse generator 20 by a second input, and a decoder 24. The output of the decoder 24 is connected to

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the second input of the third element OR 16, with the first input of the third trigger 13, with the first input of the fifth element AND 17 and with the first input of the sixth element And 18. The second input of the sixth element And-18 is connected through the element NOT 19 to the output of the second element OR 12 connected to the second input of the fifth element And 17. At the same time, the output of the first element of EPI 7 is connected to the second input of the fourth element 15, connected by an output to the second input of the third trigger 13, and the inputs of the decoder 24 are connected to the outputs of the counter 23.

The reproduction of digital information signals from a magnetic recording medium by means of the device proposed is as follows.

The first and second reproducing magnetic heads 1 and 2 are reproduced from a magnetic recording medium being moved relative to them, in which the logical unit is represented as sections of magnetization of the same polarity on two parallel recording tracks within the clock recording period, and logical zero — as sections magnetization of different polarity. The result of reproducing from the first and second reproducing magnetic heads passes through the first and second amplifiers 3 and 4 of reproduction to the first and second formers 5 and 6 pulses, which produce pulses corresponding to the moments of change in the magnetization of the magnetic recording carrier. The pulses of the first and second formers 5 and 6 pulses arrive at the first and second triggers 8 and 9, developing potentials that follow the shape of the magnetization of the magnetic recording carrier along the parallel recording tracks, and onto the first element OR 7. The last element through the fourth And 15 sets the score; the first trigger 23 and returns the third trigger 13. The third trigger 13 opens the third element 14, through which the pulses of the generator 20 pulses pass to the counter 23. When the contents of the counter 23 reaches the value corresponding to guide half a clock period of the reproduction signal occurs srabatgoanie decoder 24 which

generates a pulse that overturns the third trigger 13. At the same time, the pulse generator of the pulse generator 20 is counted and the counter 23 is set to its original state through the third element OR 16. The puller of the decoder 24 enters the fifth and sixth elements And 17 and 18. The fifth element AND 17 also affects the second element OR 12, which through the third and fourth elements And 10 and 11 are applied to the potentials of the first and second triggers 8 and 9. The sixth element And 18 is the second element OR 12 operates through the element NOT 19. When playing back a logical units with n CITEL magnetic recording pulse decoder 24 passes through the fifth AND gate 17 to output line 21 a unified logical faces. When playing the logical zero from the magnetic recording medium, the pulse of the decoder 24 passes through the sixth element 18 to the output bus 22 logical zeros.

Claims (1)

Invention Formula A device for reproducing digital information signals from magnetic recording carriers, comprising first and second reproducing magnetic heads connected respectively via the first and second reproduction amplifiers to the inputs of the first and second pulse shapers, respectively, connected by outputs to the inputs of the first OR element and to the inputs of the redo L.Povkhan Compiled by Yu.-K.Royenkrantz Tekhred L.Oliynyk Order 3395/48 Circulation 589 VNISh State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 I Production and Printing Enterprise, Uzhgorod, Projecto st., 4 65 first and second triggers whose outputs are connected to the inputs of the first and second AND elements connected by outputs to the inputs of the second OR element, the third trigger connected to the first and second outputs respectively to the first input of the third And element, and to the first input of the fourth And element connected the output to the first input of the third element OR, the fifth and the sixth elements AND, connected by the outputs respectively to the output bus of logical units and to the output bus of logical zeros, the element NOT and the pulse generator, characterized by o, in order to increase the noise immunity of the device, a counter is inserted into it, connected by a setup input to the output of the third OR element and connected by a counting input to the output of the third AND element connected by a second input to the output of the pulse generator, and a decoder, the decoder being connected to the outputs of the counter and connected to the output of the second input of the third element OR, with the first input of the third trigger, with the first input of the fifth element And with the first input of the sixth element And, the second input of which is connected via ele NOT to the output of the second element OR connected to the second input of the fifth AND element, and the output of the first element OR connected to the second input of the fourth AND element connected by the output to the second input of the third trigger. Proofreader S.Shekmar Subscription