SU972298A2 - Device for measuring non-uniformity of data medium speed - Google Patents

Description

(54) DEVICE FOR MEASURING THE NEGNOMANITY OF THE SPEED OF THE MEDIA INFORMATION

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The invention relates to instrumentation and can be used in the construction of equipment for the study of the dynamics of the movement of a magnetic carrier in the transport mechanism.

According to the main author. St. No. 416615, a device for measuring the unevenness of the speed of the information carrier is known, which contains a block for determining the sign of the period deviation from the average value, consisting of a counter whose input through valve 0 is connected to a generator of reference pulses, a trigger connected to the input bus through a valve , the unit of integration and determination of the sign of the product of deviations, made in the form of two connected to each other through the valves of the reversible counter and modulo-adder on the trigger, and bl to control a timer, associated with the sign determination unit and deflection unit integration and scaling circuit, the input 20 is connected to the integration unit, and output - with an inlet valve 1.

A disadvantage of the known device is its narrow functionality, since it allows to determine only the autocorrelation function of uneven carrier speed, which in many practical cases is insufficient when assessing the movement dynamics of the carrier in the transport mechanism.

The purpose of the invention is to extend the functionality by providing a measurement of the mutual correlation function of speed and carrier unevenness.

The goal is achieved by introducing a skew sign detection unit into the device for measuring the unevenness of the carrier speed, consisting of an OR circuit, a valve and two flip-flops, whose inputs are connected to the input valves directly and through the OR circuit, and the outputs through the gate to the input of the integration unit and the definition of the sign of the product of the period deviations, while the output of the control unit is connected to the input of the valve of the skew sign determination unit.

The drawing shows a functional diagram of the proposed device.

The device contains input terminals I and 2, connected through playback amplifiers to magnetic playback heads (not shown) and to input valves 3 and 4 devices, the second inputs of which are connected to trigger 5. The device also contains a pulse counter b, valve 7, generator 8 reference pulses, trigger 9, drivers 10 and II pulses and valve 12, which make up the period deviation sign from the mean value, the OR circuit 13, the modulo two on trigger 14, valves 15 and 16 and the reversible counter 17, which are form a block integration and determining the sign of the product of the period and skew variance, an OR gate 18, flip-flops 19 and 20 and valve 21, which constitute the unit for determining the skew mark. In addition, the device includes triggers 22 and 23, valves 24 and 25, scaling circuit 26 and time relay 27, which form the control unit. The output of the device is the output indicator display 28 of the reversible counter 17.

The device works as follows.

Input pulses formed from signals reproduced from parallel tracks are inputted on input terminals 1 and 2 to valves 3 and 4 that are open at the time of measurement by trigger 5. From the outputs of these valves, pulses go to blocks determining the sign of the period deviation from the mean value and determining the sign of a skew . During the first period of the input signal, the pulse counter 6, the capacitance of which corresponds to the average period, counts the reference pulses of the generator 8 coming through the valve 7. At the end of the period, the pulse of the driver 11 through the gate 24 opened by the trigger 22 interrogates the gate 12 and overturns the trigger 22. The output pulse of the valve 12 corresponding to the sign of the period deviation according to the state of the most significant bit of the counter 6, through the OR circuit 13, goes to the unit for integrating and determining the sign of the deviations. This pulse from the output of the valve 24 starts the time relay 27. The output pulse of the time relay 27 changes the trigger 23, so the first incoming pulse from the driver 11 passes the valve 25 and triggers the skew sign definition unit, consisting of the flip-flops 19 and 20, the OR circuit 8 and the valve 21. In the case of a positive sign skew triggers 19 and 20 are in one state, and in case of negative - in zero. Therefore, the pulse in the presence of a positive sign from the output of the valve 21 through the scheme OR 13

enters the adder input modulo two on trigger 14. The same pulse from the output of valve 25 transmits the code of the adder on trigger 14 through gates 15 and 16 to the reversible counter 17, overturns the triggers 22, 23 and enters the scaling circuit 26. When the scaling circuit triggers 26, the trigger 5 is tilted, and the passage of the input pulses through the gates 3 and 4 is terminated. This ends one measurement cycle, which is repeated the number of times specified by scaling circuit 26. Thus, on the input indicator board 28 of the reversible counter 17, one estimate of the mutual correlation function of velocity non-uniformity and carrier skew is obtained. Values of other points of the correlation function

measured in the manner described with the corresponding delay times set by time relay 27.

The device can be used in the study of the dynamics of the magnetic carrier in a variety of multi-track magnetic recording systems.

Claims (1)

Invention Formula A device for measuring the uneven speed of the information carrier according to the ed. St. No. 416615, characterized in that, in order to expand its functionality by providing a measurement of the mutual correlation function of velocity unevenness and carrier skew, a skew sign definition unit is inserted into it, consisting of an OR circuit, a valve and two triggers whose inputs connected to the input valves directly and through the OR circuit, and the outputs through the valve to the input of the integration unit and determining the sign of the product of the period deviations, while the output of the control unit is connected to the input of the valve of the op unit edeleni skew the mark. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 416615, cl. G 01 R 15/00, 1971.