SU1691886A1 - Pulse driver for counting information tracks in magnetic disk drives - Google Patents

Abstract

This invention relates to instrumentation engineering and is intended for use in magnetic disk drives having a tracking positioning system. In order to ensure high noise immunity and reliable operation in the conditions of defects in the position sensor and interference, a controlled current generator connected to the time of the one-time reference circuit and controlled by the speed of the positioner is introduced into the reference circuit of the magnetic tracks. The shaper consists of comparators 1 and 2, the inputs of which are connected to the position signal buses A, B, A. The comparators analyze the position signals and form logical signals from which the shaper on elements 3 and 4 generates pulses on the fronts to trigger the lockable one-shot vibrator 5, during the driver circuit of which is switched on the current generator, controlled by the signal of the speed V, of the current 6. 4 Il. cl

Description

This invention relates to instrumentation engineering and is intended for use in magnetic disk drives having a tracking positioning system.

The purpose of the invention is to improve the reliability of reading information tracks in magnetic disk drives.

FIG. 1 shows a functional diagram of the proposed device; figure 2 - timing charts of the proposed device:

a) position signals A, B with an example of interference and bounce;

b) signals at the outputs of comparators 1 and 2;

c) signals at the shaper output (output of element 4);

d) signals at the output of the one-shot 5;

in fig. 3 shows the dependences of the duration of the signal at the output of the one-vibrator or the level of the control signal V at the input of the controlled current generator; in FIG. 4, diagrams explaining the operation of the device at different speeds of movement of the positioner.

The device contains comparators 1 and 2, the inputs of which are connected to the signal buses of position A., B, A (inverted A). The outputs of the comparators are connected to the inputs of element 3 (EXCLUSIVE OR), the output of which is connected to the inputs of element 4 (EXCLUSIVE OR) directly and through an integrating circuit, the output of element 4 is connected to the start input of a single vibrator 5, the output of which is the output of the device. During driving circuit

ABOUT

Yu

00

Ltd

The one-shot 5 includes a controlled current generator 6, the control input of which is connected to the signal line of the positioner movement speed.

The shaper works as follows.

At the inputs of Comparators 1 and 2 signals of position A and B are received, having a square dependence. Comparators analyze the signals A and B, converting them into logical signals. On the fronts of the JTHX signals, a shaper on elements 3 and 4 generates short pulses arriving at the input of the one-shot 5. At the time of forming a given duration, the input of the single-vibrator is blocked and does not react to the pulses arriving during this period. The duration of the signal from the output of the one-shot 5 is determined by the current controlled by the current generator 6, which is controlled by the positioning speed signal V. The relationship between the current and the speed signal is proportional, and between the duration and the speed signal is inversely proportional. The generated signal from the output of the one-shot 5 covers almost the entire interval before the arrival of the next pulse. The occupancy of the interval is determined before the arrival of the next pulse. The occupancy of the interval is determined by the practically achievable linearity of the velocity / current conversion (actually, 2-5%). Thus, high immunity against false alarms and interference from the positioner position sensor is achieved.

The device can be implemented on the elements of the series: K140SAZ-comparators, K555LP5-shaper, K555AGS-single-vibrator, controlled current generator on transistors and discrete elements.

Claims (1)

Invention Formula The shaper of the counting pulses of information tracks in magnetic disk drives contains two comparators, whose inputs are connected to the positioner position signal buses, the positioner movement speed signal bus, and a one-shot, the output of which is connected to the pulse generator output, characterized in that, in order to improve reliability of reference information tracks, it contains two elements EXCLUSIVE OR, an integrating circuit and a controlled current generator, the control input of which is connected to the signal bus speed of the positioner, and the output is connected to the time by the master input of the one-shot, the start input of which is connected to the output of the first element EXCLUSIVE OR, the first input of which is connected to the output of the integrating circuit, the input of which is connected and simultaneously with the second input of the first element EXCLUSIVE OR or the output of the second element EXCLUSIVE OR, the inputs of which are connected to the outputs of the first and second comparators. AT but ° ri T figure 1 A A A8 eleven hnnnni ii II | 1m I I I II Tpaks Tnin (250 “Rig. 2 4S