SU419961A1 - DEVICE FOR REPRODUCTION OF PHASOMODULATED SIGNALS - Google Patents

Description

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The invention relates to the field of instrumentation, in particular to magnetic recording equipment, intended to reproduce digital information signals recorded by the phase modulation method.

Phase-modulated signal reproducing devices are known based on two main blocks: a pulse shaping unit and a synchronization unit. In known circuits, in both blocks, logic elements are used, and in a synchronization unit, as a rule, a reference pulse generator with a counter and a decoder is used. The Io circuit construction of the known playback devices does not allow to obtain a sufficiently high noise immunity and reliability of operation in the playback device itself.

To improve the noise immunity and reliability of the proposed device, the generator of reference signals (pulses) is connected to the decoder via serially connected additional AND schemes and a pulse counter, between which and one of the AND schemes included the OR circuit of the synchronization unit , while the other inputs of the circuits " of the same unit are connected to the common one, to it by the " OR circuit of the pulse formation unit.

The drawing shows a block diagram of the device described, consisting of it from a block of forming pulses, which includes a linear amplifier 1, a detector 2, drivers of 3 and 4 pulses, And 5 and 6 circuits, as well as from a synchronization block, in which enter t schemes

"And 7, 8 and 9. The scheme" OR 10, which was common to the schemes "AND the forming unit, can also be conditionally assigned to this block, and the scheme" OR 11, together with the pulse counter 12, the decoder 13 and the generator

The 14 reference pulses relate to the sync block.

The signals reproduced from the magnetic amplifier (not shown) after amplification and detection are formed in the formers 3 and 4. The formation occurs from the positive and negative half-waves of the signal. The generated pulses go to the “And 5 and 6” circuits, which are unlocked by signals coming from the block

sync. In this block, when the first reproduced clock pulse arrives through the initial start-up terminal 15, the pulse counter 12 is reset to the initial state corresponding to zero through the circuit OR 11. The counter counts the pulses from the generator 14, which generates pulses with a frequency higher than the repetition frequency of the reproduced signals. The output signals from the counter are decrypted by the decoder 13, which forms

corresponding unlocking signals. Information pulses from a single 16 and zero 17 output clips collected by the OR 10 circuit pass through one of the open AND 7, 8 or 9 circuits and set the counter 12 to one of the initial states.

Thus, the adjustment of the period of the clock signals is carried out by setting the different initial conditions of the counter, depending on the moment of arrival of the reproduced signal to the synchronization unit.

Subject invention

A device for reproducing phase-modulated signals recorded on a magnetic carrier comprising a pulse shaping unit consisting of a series-connected linear amplifier and a detector loaded into two identical channels.

each of which includes in series a pulse shaper and an AND circuit, associated with single and zero output terminals and a common OR circuit, as well as a synchronization unit consisting of a pulse counter, an OR circuit, a reference pulse generator, a descrambler, circuits "And and clamping the start-up signal, which is the fact that, in order to poke

noise immunity and reliability of operation, the reference pulse is connected to the deschiftorator through the series-connected additional circuits “And the pulse counter, between which and one of the circuits“ And

The "OR synchronization block" circuit is connected to the initial start terminal, while the other inputs of the "AND the same block circuits are connected to the general" OR pulse formation block circuit.

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