SU836662A1 - Device for reproducing multichannel magnetic record - Google Patents

Description

(54) DEVICE FOR PLAYING MULTICHANNEL MAGNETIC RECORDING

Claims (2)

The invention relates to the field of instrumentation and can be used in equipment intended for the entry of magnetic records into a digital electronic computer. The usual operations performed when inputting analog signals recorded on a magnetic tape into a computer, in particular, the time-pulse modulation (VIM) method, are demodulation and analog-to-digital conversion of signals. This leads to the fact that the distortions introduced into the signal by demodulators and analog noise-correction devices of tape-carrying mechanisms are completely transferred to the copied signal. / Recording and reproducing analog signals using time-pulse modulation are known, in the paths of which the generators (sources) of linearly varying voltage are introduced, which turn on and off at the instants of the signal and clock pulses the peak detectors and filters. l. The disadvantages of these devices include phase and amplitude distortions of the reproduced signals, especially for the frequency components of signals that are close to the upper limit of the passband, and the need to use an analog-digital converter to input signals into a digital electronic computer. The closest technical solution is a device for multi-channel magnetic recording and playback, which contains a magnetic recording head of information pulses in the recording path, connected to the input terminals of information channels via corresponding keys, a comparator unit connected via a linear-variable voltage generator with a 38 generator clock pulses connected to the inputs of the recording keys through the recording distributor, and the information recording amplifier, and the magnetic recording head of the clock pulses, connected to the output of the clock pulse generator through the delay element and the amplifier, and in the playback path, the magnetic head of the playback of information pulses connected to the output terminals of the information channels through the corresponding playback keys, interconnected linear-and-linear-voltage generators and the playback amplifier information pulses and a magnetic head for reproducing information pulses and a magnetic head for reproducing clock pulses Bits connected to the control inputs of the playback keys via the playback distributor, the delay element associated with the reset inputs of the line-ramp and line-drop generators, and the clock reproduction amplifier associated with the start input of the linear-drop voltage generator and input stopping the linear-increasing voltage generator iz j. The disadvantages of this device are the dependence of the accuracy of reproduction of signals and distortions of the time scale from the oscillations of instantaneous speed of the recording medium, phase and amplitude distortions of the reproduced signals, especially near the upper boundary of the recorded band, and the need to use an analog-to-digital converter for inputting signals into a digital machine. The efficiency of using analog devices for correcting distortions of a reproduced signal based on measuring the velocity of a carrier and regulating the measured change in the output voltage of a linearly falling and linearly increasing voltage generators on the results of measuring the carrier velocity in the next time interval can be used for correction purposes no earlier than in the next time interval (almost, a little later), when the true The shutter speed different from the already measured. 2 The aim of the invention is to reduce the amplitude distortion and eliminate the distortion of the time scale associated with fluctuations in the instantaneous speed of the recording medium. This goal is achieved by the fact that a device for reproducing a multichannel magnetic recording, containing a magnetic head for reproducing information pulses and a magnetic head for reproducing clock pulses, connected to the input of the distributor via serially connected clock reproducing amplifier and delay element, as well as a separate generator and output bar of the device, equipped with serially connected to the output of the playback amplifier information synchronous pulses an accelerator, a speed code generator, a dividing unit and a buffer register unit, the second input of which is associated with the distributor output, as well as a sign code generator and an information code generator that are connected to the second and third inputs of the dividing unit, respectively, the fourth input connected to the delay element , at the same time, the latter is connected with the second inputs of the synchronizer and the character code generator, the third input of which is connected to the first output of the synchronizer, and the second input of the code generator the speed is connected to the generator and to the first input of the information code generator, the second input of which is connected to the second output of the synchronizer. FIG. 1 is a functional block diagram of the proposed device; in fig. 2 - the synchronizer circuit is functional; in fig. 3 is a functional diagram of a character code generator; in fig. 4 is a functional diagram of a driver, an information code and a speed code; in fig. 5 - timing charts of the device. A device for reproducing a multichannel magnetic (Fig. I) contains magnetic carrier 1, magnetic reproduction head of information pulses 2, magnetic reproducing head of clock pulses 3, playback amplifier of information pulses 4, clock reproducing amplifier 5, synchronizer 6, reference frequency generator 7 element delays 8, a character code generator 9, a speed code generator 10, an information code 11 generator, a division block 12, a distributor 13 and an output register block trO1v 14, the synchronization unit 6 may be constructed in accordance with hydrochloric functional diagram (FIG. 2). It contains a delay element 15, a coincidence circuit (s) 16, a combination circuit (or) 17 and 18, and a counting trigger with a setting of 1 - 19. The sign code 9 generating unit (FIG. 3) contains the trigger 20 and 21, the delay element 22 and the matching scheme 23. The blocks for forming the speed code 10 and the information code 11 may have an identical structure (Fig. 4) and differ in the mode of operation. The block contains (FIG. 4) a discharge counter 24, an P-discharge register 25, an inverter .26, a coincidence circuit 27, a pulse shaper 28, and a delay element 29. The device operates as follows. The signals from the two tracks of magnetic carrier 1 (Fig. 1) combine magnesium, the playback head of information pulses 2 and the magnetic head reproduction of clock pulses 3 and are amplified by the corresponding playback amplifiers 4 and 5, Playback information and clock pulses (Fig. 5, a and b) nocTynajot to the inputs of the synchronizer 6 and the formation of the character code 9 (Fig. L). In the initial state on the first course of the synchronizer 6, the potential of a logical zero is held, on the second output - a logical unit. In the process of operation, a control pulse (at the logic zero level) is formed in the second output (Fig. 5e), the duration of which is different from the time of occurrence of the information and clock pulses, and a short pulse appears at the first output (at the level of logical unit), delayed relative to the clock by the value of T / 2 .5-T, where T is the period of the following clock pulses and (Y-T ct 0.05-0.08 T (Fig. 5, d}). Pulses from the first output synchronizer is fed to the third code setting the sign code generator 9 and to the control first input The speed code is set to 10. 62. The synchronizer 6 (FIG. 2) works as follows: Trigger 19 in its initial position is in state 1. The information and clock pulses following each other in any order through the OR circuit 17 are turned over twice. trigger 19, forming a zero-level pulse at the second output, the duration of which is equal to the difference in the times of occurrence of information and clock pulses. In case the input pulses coincide, the AND 16 circuit generates a pulse that, through the OR 18 circuit, keeps the trigger 19 in the state I. Delayed the delay element 15 at time T / 2 - (the rt clock pulse arrives at the first output and sets the trigger 19 to the initial state through the circuit OR 18. At the output of the character code generator 9 in the initial state, the potential of a logical zero is held. The output of block 9 does not change its state, signaling a negative value of the signal if the information pulse is delayed relative to the clock and takes the state of a logical one at the time of the appearance of the clock pulse and holds this state for a time interval T / 2 + T, after it (Fig. 5, e), a signal is signaled about a positive signal if the information pulse is ahead of the clock one at the inputs of block 9. The output signals of block 9 are fed to the input sign register 2 of division unit 12. The shaper of the code of the sign 9 is working t follow the order. Triggers 20 and 21 in the home position are in the state O. If the signal PULSE appears at the first input before the clock one at the second input, it, entering input S of the trigger 20, reverses the trigger. Giving on one of the inputs of the coincidence circuit And 23 is the potential of a logical unit. The next clock pulse passes through an AND 23 circuit, enters input S of flip-flop 21 and transfers the flip-flop to state 1. The output signal of flip-flop 21 is fed to the output of block 9. The initial state of lok 9 is transferred by a setting signal that is supplied through the third input and drag the element 22 at a time of 2 T (Fig. 5, e). In the case when the signal pulse is delayed relative to the clock, the latter cannot pass through the AND 23 circuit, since at its second input the level of logic zero is maintained and the output of block 9 does not change its state (Fig. 5, e). The pulses with the synchronizer output (Fig. 1) are fed to the first and second control inputs of drivers 10 and 1 1, respectively, of the speed and information codes, the second and first counting inputs of which receive pulses from the generator output 7 of the reference frequency. The second input of block 11 receives control pulses from the second output of block 6. At the output of block 11, a number is generated in code form corresponding to the duration of the control pulse and, consequently, the value of the reproduced signal value, and is fed to the first input register 1 of the division block 12. For the second the input of block 10 receives control pulses from the first output of block 6. At the output of block 10, a number is formed in code form corresponding to the duration of the interval between control pulses and, consequently, the reciprocal of the instant hydrochloric magnetic carrier movement speed during reproduction, and is supplied to the third input register 12. The block division information code generator 11 operates as follows. In the initial state, the counter 24 is in the position O, the output number 25 is recorded in the output register 25. The high-frequency reference pulses are constantly received at the first input; On the second IDOM of the output, a potential corresponding to logic level 1 is maintained and, through the inverter, maintains in a closed state an AND 27 coincidence circuit. When a control signal appears at the second input, the AND circuit 27 opens and the pulses from the first input go to the counting stroke of counter 2 (FIG. . 5, g). By the end of the control pulse, a number is formed in the counter, equal to the number of pulses transmitted through circuit 27 during the duration of the control pulse, which corresponds to the instantaneous value of the registered signal. On the falling edge of the control pulse, Lenin in the driver 28 generates a short pulse, which opens the information inputs of the output registers of the recorder 25 through the synchronization inputs, records the state of the counter 24 and records the delay element 29 to a small time interval through the delay element 29 The reader 24. Block 10 according to the functional diagram and principle of operation is similar to block 1I. The delayed delay elements 8 approximately by half of the next T / 2 period of the clock pulses (Fig.5, c) arrive at the fourth synchronization input of the division unit 12 and to the input of the distributor 13 (Fig. 1). These pulses are command pulses for block 12, by which it rewrites the information code from block II and the speed code from block 10 into its input registers and performs the division of the information code by the speed code, recording the quotient on its output register . This operation allows with sufficiently high accuracy to eliminate from the measurement results the errors generated by the non-uniformity of motion of the magnetic carrier 1, both during playback and during recording. The division results from the output register of block 12 are sent to the first information input of the block of output registers 14, in which they are distributed to output registers or buffer storage devices having numbers corresponding to the numbers of input signals during recording, according to commands received through the second input from the distributor 13 A positive effect, which consists in reducing amplitude distortion, is achieved by simultaneous (synchronized) measurement with high accuracy available for digital duration gauges. time intervals, instantaneous values of the reproduced signal and speed of carrying (l and correcting the instantaneous values of the reproduced signal by dividing them by instantaneous values of carrier speed. At the same time, the time distortions are completely eliminated, since the synchronization of measurements is performed from the clock pulses reproduced from the magnetic carrier simultaneously with the information ones. Claims An apparatus for reproducing a multi-channel magnetic recording comprising a reproducing magnetic head days of information pulses, connected to an amplifier to reproduce informational pulses, and a magnetic head for reproducing clock pulses, connected to the input of the distributor through serially connected amplifier of reproducing clock pulses and a delay element, as well as a separate generator and output bus of the device, characterized in that, in order to reduce distortions of signals during reproduction, the device is supplied with serially connected to the output of the playback amplifier information pulses by a synchronizer, a speed code generator, a dividing unit and a buffer register block, the second input of which is connected to the output of the distributor, as well as a character code generator and 8 shape Figure 1 is an information code rover connected respectively to the second and third inputs of a dividing unit, the fourth input of which is connected to the output of the delay element, the input of the latter being connected to the second inputs of the synchronizer and the sign code generator, the third input of which is connected to the first output of the synchronizer and the second input of the speed code generator is connected to the generator and to the first input of the information code generator, the second input of which is connected with the second synchronizer output. Sources of information taken into account during the examination 1. USSR author's certificate No. 343294, cl. G 11 B 5/00, 08/31/67. 2. USSR author's certificate according to application No. 2633753 / 18-10, class G 11 В 5/00, 06.23.78 (prototype). FIG. five 23 hell F. four C T Hl .. F .MIL Score