SU1601638A1 - Device for shaping signal of speed of movement of magnetic heads - Google Patents

Abstract

The invention relates to a magnetic recording technique, in particular, to devices for positioning magnetic heads in magnetic disk drives having a tracking system. The purpose of the invention is to expand the functionality of the device. After counting the number of step pulses, the processor extracts from the internal memory a digital code corresponding to the number of steps, and outputs it to port P1. The first D / A converter 2 converts the code into a voltage level, which, through amplifier 3, controls the servo drive. The magnetic heads are moved by the drive. One of them (servo-head) reads magnetic marks recorded on the service surface (servo-surfaces) and converts them into position signals P and Q. Comparative circuit 4 generates logical position signals of magnetic heads to control the smoothing circuit 6. Of the same signals, 5 cross pulse generator Magnetic tracks form counting pulses, which are fed to the input of processor 1, causing with each step from the ROM a new value of the digital code corresponding to the specified velocity profile.

Description

Phage. 7

The invention relates to a magnetic recording technique, in particular, to devices for positioning magnetic heads in magnetic disk drives.

The purpose of the invention is to expand the functional capabilities of the device by allowing the formation of a smoothed velocity signal for any phase path,

FIG. 1 shows a functional diagram of the device; in fig. 2 - time diagrams that show his work.

The device contains a microprocessor 1, the port of which is connected to the bit inputs of the first digital-to-analog converter (DAC) 2, the output of which is connected to the first input of summing amplifier 3, the output of which is the output of the device. The buses of the position signals of the magnetic heads P and Q are connected to the inputs of the comparator circuit 4, the outputs of which are connected to the inputs of the shaper of the intersection pulses of the magnetic tracks and the control inputs of the smoothing circuit 6, the analog inputs of which are connected to the position signal buses. Port P2 is connected to the input of the second DAC 7, Output of the second DAC 7 is connected to the second input of summing amplifier 3, and the input voltage of the second DAC 7 is connected to the output of smoothing circuit 6.

The device works as follows.

After counting the pulses received through the accumulator interface into microprocessor 1 (the interface and communication with the microprocessor are not shown in Fig. 1), the code value corresponding to the initial speed of movement along a given phase trajectory is extracted from the processor memory. This value is in the form of a digital code of the type Ki ViT (where Ki is a proportionality factor; n is the number of step pulses received from the interface) is fed to the bit inputs of the first DAC 2, where it is converted into a voltage level that through the summing amplifier 3 It follows the drive. When moving, one of the magnetic heads counts the pulses from the magnetic marks on the service surface, from which the position signals P and Q are formed, out of phase relative to each other by 90 °. Comparator circuit 4 generates logical signals for the position of the magnetic heads on the track, with the help of which the driver 5 count pulses of the traversed tracks produce counting pulses.

the output of the imaging unit 5 pulses arrive at the input of microprocessor 1 and call a new code value from the processor's memory, corresponding to the value Ki vn - 1, etc., in general, KiVn - 1, where 1 is the number of tracks passed or the number of count pulses. The smoothing circuit 6, controlled by the signals from the comparator circuit 4, generates from the linear sections inverted and non-inverted position signals P and Q sawtooth voltage supplied to the input voltage reference voltage of the DAC 7. The digital inputs of the DAC 7c of processor 1 are digitized. derivative (finite difference) from a function describing the change in the speed of movement of the magnetic heads from the remaining distance to the required

tracks of type K2 (- i - Vn - i - 1), where K2 is the proportionality coefficient; n is the number of steps from the interface; I - the number of tracks traveled. From the output of the DAC 7, the summing amplifier 3 receives a sawtooth smoothing voltage, the amplitude of which is proportional to the derivative of the function of the velocity of movement at this step. Thus, smoothing of the step voltage of the DAC 2, which changes according to a complex law, is achieved.

Claims (1)

Claims An apparatus for generating a signal of a moving speed of magnetic heads, comprising a digital-to-analog converter whose output is connected to the first input of a summing amplifier, a comparatory circuit for generating logical signals of the position of magnetic heads, inputs connected to tires of the position signals of magnetic heads, outputs connected to a pulse shaper the intersection of the magnetic tracks and the control inputs of the smoothing circuit, the analog inputs of which are connected to the signal buses by Magnetic heads are characterized in that, in order to expand functionality by providing the ability to form a smoothed velocity signal for any phase trajectory, a second digital-to-analog converter and a microprocessor are introduced into it, and the microprocessor input is connected to the output of the intersection pulse generator of magnetic tracks, the first port the microprocessor is connected to the bit inputs of the first digital-analog converter; the second port of the microprocessor is connected to the bit inputs and second digital to analog converter, input oporno516016386 The first voltage of which is connected to is connected to the second input of the summing the output of the smoothing circuit, and the output of the amplifier. R . five I I I I I t "NNNNK rj jN-jv K J FIG. g