SU1316032A1 - Device for reproducing frequency-modulated signal from magnetic record medium - Google Patents

Abstract

This invention relates to magnetic recording. The purpose of the invention is to reduce the error in reproducing a frequency-modulated signal from a magnetic recording medium. The device contains magnetic head 1, splitter 2 channels, amplifier-limiter 3, synchronization unit 4, counter 3, register 6, phase detector 7, low-pass filter 8, controlled oscillator 9, frequency divider 10, bus 11, digital width -impulse modulator 12, key 13, master oscillator 14, block 13 comparing pulse durations and transducer 16 period - code. The introduction of new elements and the formation of new connections between the elements of the device as a result of counting the filling pulses from the output of the rebuilt controlled oscillator 9 by the counter 3 produces a code proportional only to the deviation of the frequency modulated information signal. The resulting code is overwritten in register 6., from the digital outputs of which the code is sent to the 11 bus. 1 il. (L with O5 about 00 to

Description

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The invention relates to magnetic recording, namely, devices for reproducing a frequency-modulated signal from a magnetic recording medium,

The aim of the invention is to reduce the error in reproducing a frequency-modulated signal from a magnetic recording medium.

The drawing shows one of the possible variants of the proposed device for reproducing a frequency-modulated signal from a magnetic recording medium.

The device contains a reproducing magnetic head 1 connected to the input of the separator 2 channels the first output of which is connected through the amplifier-organizer 3 to the information input of the synchronization unit 4 counter 5. connected by digital outputs to the setup inputs of the register 6, and connected in series with the phase detector 7, filter 8 low frequencies and controlled oscillator 9. Bbi controlled oscillator 9 is connected through a frequency divider 10 to the first input of the phase detector 7. Digital outputs of register 6 are connected to the first output ne Ishna 11 numbers.

The device also contains a digital pulse / pulse modulator 12, connected by an information input to the first output of synchronization unit 4, a key 13 connected between the output of the controlled generator 9 and the clock input of the counter 5, the specifying generator 14 connected to the clock input of the synchronization unit 4, the unit 15 comparison of pulse durations and transducer 16 period - code. The latter is connected by a signal input to the second output of the 2-channel splitter and connected by an analog output to the second input of the phase detector 7. The first, second and third outputs of the synchronization unit 4 are connected respectively to the first input of the pulse width comparison unit 15, to the setup input of the counter 5 and to the overwriting input register 6. The output of the master oscillator 14 is connected to the clock input of a digital pulse-width modulator 12 and to the clock input of the converter 16 period -.code connected by digital outputs to Ora output line number n and to the control inputs

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digital ip pulse modulator 12. The output of the latter is connected to the second input of the pulse width comparison unit 15 connected by an information output to the control key input 13. In this case, the output of the symbol of the pulse width comparison block 15 is connected to the line included in the first output bus

10 11 numbers, and the second output of the splitter 2 channels - with the output line 18 of the reference signal.

 The reproduction of the frequency-modulated signal from the carrier of the magnetic recording by means of the device proposed is as follows.

The result of the playback comes from the reproducing magnetic head 1 on the 2-channel separator. From the second output of the splitter 2 channels to the converter 16, the period code receives a reference signal, the variable distortions of which correspond to the temporal distortions of the reproduced information frequency-modulated signal. Frequency Modulated Signal Information

30 comes from the first output of the splitter 2 channels to the amplifier-limiter 3, which converts it into rectangular pulses. The rectangular pulses of the information of the first frequency-modulated signal are fed to

information input unit 4 sync

Formations, the clock input of which receives the pulses of the master oscillator 14, are also fed to the clock inputs of the digital pulse-width modulator 12 and the converter 16, the period is the code. From the first output of the synchronization unit 4, the information input of the digital pulse-width modulator 12 provides pulses of the information frequency-modulated signal with a double follow-up period and synchronization with the pulses of the master oscillator 14. From

0 of the second and third outputs of the synchronization unit 4 to the installation input of the counter 5 and to the overwriting input of the register 6 receives the first and second short pulses generated by

5 the front of the pulse information frequency-modulated signal. From the output of the digital pulse-width modulator 12 to the second input of the unit 15 comparing the pulse durations

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impulses are received that follow the period of the reproduced information frequency-modulated signal. From the first output of the synchronization unit A, the first input of the unit 15 for the comparison of the pulse durations receives synchronized pulses of the information frequency-modulated signal. The difference signal obtained as a result of the comparison, from the information output of the comparison pulse duration unit 13, is fed to the control input of the key 13. Filling pulses pass through the key 13 from the output of the controlled generator 9 to the clock input of the counter 5. These pulses from the output of the controlled oscillator 9 are also transmitted after dividing the frequency divider 10 to the first input of the phase detector 7, to the second input of which pulses are received from the 16 period converter - code. The matching signal from the output of the phase detector 7, passing through the low-pass filter 8 to the input of the controlled oscillator 9, tunes its frequency during the time required for the signal to zero to zero. Counter 5 generates a code proportional only to the deviation of the information frequency-modulated signal. The resulting code is rewritten into output register 6, from the digital outputs of which the code goes to the first output bus of the 11th number.

Claims (1)

Invention Formula A dp playback device of a frequency-modulated signal from a magnetic recording medium containing a reproducing magnetic head connected to the input section. Editor L. Langazo Order 2369/54 Compiled by Y.-K. V. Roenecrantz Tehred L.OliynykKorrektor, Iekmar Circulation 589 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 24 channel bodies, the first output of which is connected via the limiting amplifier to the information input of the synchronization unit, a counter connected by digital outputs to the register setup inputs, and a phase detector connected in series, a low-pass filter and a controlled oscillator whose output is connected via a frequency divider with a first input of a phase detector, characterized in that, in order to reduce the reproduction error of the frequency-modulated signal, into it a digital pulse-width modulator connected by an information input to the first output of the synchronization unit, a key connected between the output of the controlled oscillator and the clock input of the counter, the master oscillator connected by the output with the clock input of the synchronization unit, transform the period - the code connected by the signal input to the second the output of the channel separator and the analog output connected to the second input of the phase detector, and a pulse duration comparison unit, the first, second and third outputs of the synchronization unit are connected respectively to the first input of the pulse width comparison unit, to the installation input of the counter and to the register overwriting input, and the output the master oscillator is connected to the clock input of the digital pulse-width modulator and with the clock input of the converter the period is the code connected by the digital outputs to control inputs of the digital pulse-width modulator, the output of which is connected to the second input of the pulse width comparison unit connected by the information output to the key control input.