SU458018A1 - A device for reproducing signals with relative phase shift keying. - Google Patents

Description

one

This invention relates to a magnetic recording technique, namely, devices for reproducing phase-shifted signals.

The known devices for reproducing signals with relative phase manipulation from a magnetic recording medium, comprising a magnetic head, a reproduction amplifier, a unit for differentiating the reproduced signals, and a summation unit connected to it through two integrators, whose output is connected to a voltage driver, is characterized noise immunity.

The purpose of the invention is to increase the noise immunity.

For this, a generator of phase-shifted voltages is introduced into the proposed device, the outputs of which are connected to the generators.

FIG. 1 shows one of the possible variants of the proposed device; in fig. 2 - timing charts characterizing his work.

The device contains a magnetic head 1, a playback amplifier 2, a unit 3 of differentiation of the reproduced signals with the integrators 4 and 5 connected to it. The inputs of the summation unit 6 are connected to the outputs of the integrators 4 and 5, and the output is connected to the driver 7 for voltage pulses. Generator 8 phase-shifted voltages are connected to integrators. The device works as follows. The reproduced and amplified signal from 5 magnetic head 1 after differentiation in block 3 enters the inputs of two integrators 4 and 5. The integration intervals are determined by the generator 8, from the outputs of which two series of the input signal are received.

0 The pulses of one series are in-phase t by the beginning of the symbol, the pulses of the second series are shifted by half the period. The signals from the integrators are summed up in block 6. The sum signal is the voltage whose sign changes only at intervals where the phase of the reproduced signal changed from the previous premise. From each differential by shaper 7, a signal is generated corresponding to a unit (zero) of the reproduced information.

The operation of the proposed device is illustrated by the timing diagrams depicted in FIG. 2. Here in FIG. 2a shows reproducible signals; in fig. 26 - signal

5 at the output of amplifier 2; in fig. 2c - at the output of block 3; in fig. 2g and d - at the outputs of the generator 8; in fig. 2e and g - at the outputs of integrators 4 and 5, respectively; in fig. 2h - exit 6; in fig. 2i - at the output of the mold 7.

Subject invention

A device for reproducing signals with relative phase manipulation from a magnetic recording medium, comprising a magnetic head, a reproduction amplifier, a unit for differentiating the reproduced signals and a summation unit connected to it via two integrators, the output of which is connected to a voltage driver, different in that, in order to increase the noise immunity, the generator of phase-shifted voltages was introduced into it, the outputs of which are connected to the integrators.

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