SU756470A1 - Device for magnetic recording and reproducing of information - Google Patents

Description

The invention relates to the field of instrumentation, namely, equipment magnetic recording and playback of digital information. five

A device for magnetic recording and playback of information, containing a recording-reproduction channel, is known through a control unit connected to a generator, the output of which is connected to a period measurement unit on a leading edge, the output of which is connected to an error recording unit connected to a mode control unit and a control unit a drive connected to a servomotor mechanically connected to the drive shaft and a position sensor connected to the period measurement unit on the leading edge of the signal.

The disadvantage of such devices is that the accuracy of stabilization of the speed of the drive shaft depends entirely on the accuracy of manufacturing the position sensor.

The position sensors or tachometric sensors of these devices actually have the ultimate resolution for a given class of devices and its increase is associated with

RECORDS AND REPRODUCTION

2

the technological difficulties of their preparation, and the difficulty of removing the signal from them Μ ·

The closest to the invention to the technical entity is a device for magnetic recording and playback of information, containing a recording channel - playback, connected through the mode control unit to the reference frequency generator, output connected to the period measurement unit on the leading edge, the output of which through the error recording unit is associated with a mode control unit and a drive control unit connected to a servomotor connected to the drive shaft and a position sensor connected to the measurement unit Heat-on the rising edge of the signal.

A disadvantage of this device is that the accuracy of stabilization of the speed of the drive shaft depends on the accuracy of manufacturing an inductive tachometer [2].

The aim of the invention is to improve the accuracy of work.

The goal is achieved by the fact that a block of 7 56470 is entered into the proposed device.

measuring the period on the falling edge, connected to the position sensor and simultaneously with the period measuring unit on the leading edge, as well as to the generator of the reference frequency.

The essence of the proposal is that the periods from the position sensor measured on the leading and trailing edges of the signal are measured and compared with periods of the reference frequency, in contrast to the prototype, in which measurements were taken only on one (front or rear) edge of the pulse.

In the device, the correction speed is made almost 2 times more often than in the prototype, which allows to increase the accuracy of maintaining its constancy.

The drawing shows a block diagram of a device for magnetic recording and reproduction of information. The diagrams show the measurement of the period T1 in the device described in the prototype, and the measurement of the periods T1 and T2 in this device.

The following notation is used in the drawing and in the text: 1 - mode control unit, 2 - channel for reproducing, 3 - reference frequency generator, 4 - period measurement unit on the leading edge, 5 - position sensor, 6 - period measurement unit on the rear front, 7 - error recording unit, 8 - drive control unit, 9 - servomotor,

10 - drive shaft.

The device for magnetic recording and playback of information contains a recording-playback channel 2, through the mode control unit 1 connected to the generator 3, the output of which is connected to the period measurement unit 4 on the leading edge, the output of which is connected to the error recording unit 7 connected to unit 1 mode control and the drive control unit 8 connected to the servo motor 9 mechanically connected to the drive shaft 10 and sen- ¹ Chick 5 positions, connected to the period measuring unit 4 at a leading edge signal. The period measurement unit 6 on the falling edge of the signal is connected to the generator 3, the sensor of 5 positions and the error recording unit 7.

The device works as follows.

When performing the process of recording or playback unit 2 of the block. 1 control modes through the drive control unit 8 to the servo motor 9, a start signal arrives, and the drive shaft 10 begins to accelerate. From the sensor 5 positions to the period measurement circuit 4 on the leading edge of the signal, measuring circuit 6, -period on the falling edge of the signal. for example bye

eannah on diagrams a, b (see figure 1)

Using a reference generator 3 which has a frequency significantly higher than the frequency of the pulses coming from sensor 5., continuous periods are measured on the leading edge of the signal T 1 and the falling edge of the signal T 2. The measurement results are recorded in the error recording unit 7, and after each the period measurement unit 8 controls the drive receives a signal that leads either to increase or decrease the speed of the servomotor 9, and hence the drive shaft 10.

The sequence of measurement of periods on the leading edge of the signal or on the falling edge of the signal can be arbitrary.

The technical advantage of the device is to increase the stability of the angular velocity of rotation of the servomotor by introducing into the device a period measurement unit at the falling edge of the signal, whereby the speed correction is performed almost 2 times more often than in the known devices.

Separate errors in the manufacture of a position sensor within a step lead to a smaller error in the speed stabilization, since the error acts on a shorter interval.

The proposal can be used not only for the digital method of maintaining the angular velocity, but also for the analog method.

Claims (1)

Claim A device for magnetic recording and reproduction of information containing a recording / reproducing channel connected via a mode control unit to a reference frequency generator, an output connected to a period measurement unit on a leading edge, the output of which is connected to a mode control unit and a drive control unit through the error recording unit, connected to a servomotor connected to a drive shaft and a position sensor connected to a period measurement unit on a leading edge of a signal, characterized in that to improve the accuracy of work, a unit for measuring the period on the falling edge, connected to the position sensor and simultaneously with the measuring unit on the leading edge, is entered into the device, as well as to the reference frequency generator.