SU672642A1 - Device for self-synchronisable digital magnetic recording - Google Patents

Description

(54) DEVICE FOR SELF-SYNCHRONIZED DIGITAL MAGNETIC RECORDING

The invention relates to automation and computing, in particular to magnetic recording of digital information on a moving magnetic medium, for example, on magnetic tapes, discs, drums, and is intended to record electrical signals represented in digital form.

A device for self-synchronizing digital magnetic recording is known, which uses a signal containing three time intervals between adjacent zero-intersections related to each other as 1: 2: 3 1.

The principle of operation of this device is based on transcoding every two characters of the INPUT BINARY sequence by three characters, followed by their recording on magnetic media using the method without returning to zero. The use of such a device allows a 1.33-fold increase in the longitudinal recording density compared to phase-modulated recording devices.

However, this device has a low noise immunity. This is because when passing through

The magnetic recording-reproduction path of the signal undergoes amplitude and phase distortions, which are expressed in changes in the ratio between the lengths of the intervals.

The closest in technical essence is a device for self-synchronizing digital magnetic recording, containing information and synchronization wounds and a counting trigger, to the unit input of which are connected in series the first element AND, the element OR, the output trigger n the magnetic recording unit 2.

The disadvantage of such a device is its complexity due to the presence of a large number of logical elements.

The aim of the invention is to simplify the device.

The goal is achieved by the fact that In the INPUT device and the zero output of the above-mentioned counting trigger, as well as the information and timing of the device are combined by the second AND element, the OUT of which is connected to the free input of the OR element, and the frequency multiplier is connected to the synchronization bus by three, the output of which is connected in parallel to the input of the counting trigger and to the free input of said first element I. In FIG. 1 shows a block diagram of the device; in fig. 2 - time diagrams of his work. A device for self-synchronizing digital magnetic recording contains a series-connected multiplier of 1 frequency by three and a counting trigger 2. The input and single output of the trigger are combined by the first element And 3, and the input and zero output of the trigger 2 are combined by two inputs of the second element And 4. Free inputs of the element And 4 connected to syncplay and information buses. The outputs of the elements And 3, 4 combined element OR 5. To the output of the element OR 5 connected in series connected output trigger 6 and block 7 magnetic recording. The input clock sequence Ucu. representing a rectangular oscillation with a frequency of 1 / T, goes to a multiplier of 1 I frequency by three, where the voltage U j is formed from it. Voltage Ui is divided by the following frequency by two using flip-flop 2. Voltage Ui taken from the single output of flip-flop 2 is multiplied with voltage Ui, at the two-input element And 3, as a result of which a pulse sequence Uj is formed at its output. At the same time, the voltage and r taken from the zero output of flip-flop 2 is multiplied by element 4 with an input information signal in which the units correspond to a high level and zero to a low, and the clock sequence UCH and the tripled clock frequency Ui. From the output of the AND 4 element, a sequence of pulses U4 is removed, which is then biased on the element OR 5 with pulses

Claims (2)

 fffff uj. Pulses and 5, taken from the output of the element OR 5, arrive at the counting trigger 6, which forms from them the recording signal Ue. The signal Ue enters the magnetic recording unit 7, with which it is recorded onto a moving magnetic medium. After reproducing the signal from the magnetic carrier, it acquires the form shown in the diagram Uy, in which the time intervals between the zero-intersections are not distorted and are related to each other as 1: 2: 3. The structure of the device and the algorithm of its operation is much simpler, and it contains only 7 functional elements instead of 12 in the known device. Apparatus of the Invention A self-synchronizing digital magnetic recording device containing informational and synchronizing currents and a counting trigger, to the unit output of which are connected in series the first AND element, the OR element, the output trigger and the magnetic recording unit, characterized in that, to simplify the device, the input and the zero output of the aforementioned counting trigger, as well as the information and synchronization devices of the device are combined by a second AND element, the output of which is connected to the free input of the of said OR gate, and connected to the synchronizing schine frequency multiplier for GRK whose output is connected in parallel to the input of the flip-flop and counting to the free entry of said first member I. Sources of information received note in the examination 1.Patent № US 3609684, cl. 340-146 ES, published. 1971. 2. USSR Author's Certificate No. 574747 Cl. G AND B 5/09 1976 001 10011 101 1Я1Ж1ЖШЯШЛШЛШЯ1ЖШЯШЯШASHYASHYA and,  G1 LJ1 LJl L 1L L L Gu U-, and,. w l iTL w ui g / /