SU142054A1 - Method for accurate magnetic recording of functions - Google Patents

Description

The known methods for precise magnetic function with compensation of the effect of carrier motion instability by isolating the error signal and then using it to restore the undistorted signal have a rather complicated scheme and require additional lowering of the reference signal to a separate carrier track.

In the proposed method, thanks to the use of one-sided pulse-width modulation, in which the position of the trailing edge contains information about the useful signal, and the relative position of the leading fronts gives information about temporal instability, it became possible to improve the accuracy of compensation and simplify the recording circuit.

The drawing shows a block diagram of an apparatus for performing accurate magnetic recording according to the proposed method.

Using a magnetic recording head / output signal amplified by an amplifier 2, the modulator 3 modulates the position of the falling edge of pulses coming from the 4 clock generator. The leading edge of the reproduced pulses from the playback head 5 through the amplifier 6 causes the transfer of the flip-flops 7 and S, which by means of the communication element 9 are in different stable states. Repeated voltages from the triggers are differentiated into the respective differentiating chains x 10, T1 and positive pulses trigger the Kipp relay 12 and 13. The duration of the pulses is equal to the period of the clock frequency of the generator 4.

Positive-polarity pulses from triggers 7, 5 and pulse-relay relays 12, 13 fall on mismatch schemes 14, 15, at the outputs of which pulses are formed with a duration determined by the reproduction rate ratio l / i to the recording speed V. Pulses Carriers containing information about the change in speed are fed to one of the inputs of the forming unit 16, 17. The other inputs of these blocks are fed with the number 142054-2 to the signal of the lock (locks 18, 19, controlled by the same pulses that trigger the Kipp-relay 12 and id Thus, at one input of the block forming exists a signal proportional ognoV, .., sheniyu -, ana A (5ugom input - a signal proportional proizvede1 / 2,

I / ny - on t, where / - duration of the corresponding impulse at

records

In blocks 16 and 17, a logical division operation is performed, as a result of which the pulse duration at the output of the block will exactly correspond to the length of the write pulse. A feature of the circuit is the implementation of the division operation only at the time of arrival of the clock pulses from the generator 4, which automatically ensures the absence of distortions of the time scales. The locking circuits 20 and 21 are necessary to ensure the operation of the formation blocks 16 and 17 only after the end of the work of the KIPP-relay. The rising edge of the pulse at the output of the generating unit is the reset of the blocking circuit and the preparation of the circuit for the next cycle of operation. Blocking circuits can be performed on triggers that control the diode array, and the formation blocks can be executed on fadrons or Kipp relays controlled by logic circuits.

The proposed method can be applied when recording signals in electronic modeling installations, phototelegraphy, software devices, etc.

Subject invention

A method of accurate magnetic recording of functions with compensation for the effect of carrier motion instability by extracting a signal from the bend and then using it to restore an undistorted signal, characterized in that, in order to simplify the method and improve the accuracy of compensation, one-sided pulse-width modulation is used in recording, in which the full front of the trailing edge contains information about the useful signal, and the relative position of the leading fronts gives information about the temporal instability.