JPS59154671A - Data protection system of magnetic disk device - Google Patents

Abstract

PURPOSE:To find out earlier an abnormal magnetic head having a grounding fault by providing independently respectively a constant voltage driving circuit giving a potential to a center tap of a magnetic head at each magnetic head so as to provide a potential only to an accessed magnetic head. CONSTITUTION:Constant voltage driving circuits 9, 10 giving a voltage of a constant voltage power supply 1 to magentic heads 5, 6, 7 and 8 are provided by the number of magentic heads. Further, circuits consisting each of a transistor TR3 are provided by the number of plural heads IC3 and 4. When the magnetic head 5 is selected for example and write is started, even if the magnetic head 8 has a grounding fault, since the magnetic head 8 has no potential, no problem is arisen. If a grounding fault takes place in the magnetic head 5, a voltage drop of the constant voltage power supply 1 due to a short-circuit current is detected by a comparator 2 and a detecting signal is transmitted to AND circuits 12, 13. Thus, the destruction of data after recording because of a magnetic head producing the grounding fault is prevented in this way, and the magnetic head causing the grounding fault is detected suitably.

Description

DETAILED DESCRIPTION OF THE INVENTION (4) Technical field of the invention The present invention relates to an arm on which a magnetic disk 1 is mounted, and a magnetic node amplifying section (II) mounted thereon. Prevent the recorded data from being destroyed in the event of a ground fault in the device, especially in the case of a ground fault in the magnetic heme 1, and perform rewriting according to the ground fault situation. This invention relates to a data protection method for magnetic disk drives that determines whether

(1)) Prior Art and Problems In a magnetic disk drive equipped with a magnetic head amplification unit formed into an IC on an arm on which a conventional magnetic head is mounted, when a write state is entered, a constant voltage for write drive is applied. Since the center taps of all magnetic nodes are connected in parallel to the power supply, all magnetic heads have the same potential, and the write current flows only to the accessed magnetic nodes. Therefore, even if the accessed (d air-\nod) is normal, if another magnetic head has a ground fault, it will be detected as an abnormal magnetic head. What is being accessed is the accessed magnetic head 1.Furthermore, ground faults in magnetic heads are generally intermittent faults, so recovery may be possible, so rewriting is often performed.However, r
Even if iT writing is performed, it is carried out on the normal magnetic head, and no action is taken on the paramagnetic heso F of H, y3, and the normal termination is repeated in a group.

The frequency of repeating the destruction of recorded data increases, and even if a read command is attempted and the data cannot be reproduced, the cause is There are drawbacks such as making it difficult to investigate).

Figure 1 does not accept the conventional method of 11 harakku. When in the write state, the terminal is connected to the terminal through the resistor R1 and then to the terminal T1.
The metering selection signal that turns on is input, and the voltage of source 1 for constant voltage is set to W S 1. , through the line, the magnetic node 5°Ei
, added to the 7.8 center tap. Next r/l
Suppose that 3 is selected, and a plurality of chip selection signals are input, for example, an IC, and a magnetic node amplifying section (-. 4
A plurality of magnetic heads 15, 6 and 7, 8 are provided in (), and are selected by a magnetic head jx selection signal input from () or [). When the selection signal υ is entered from 111 end C, Henno I IC3 is selected, so magnetic - So 15
is selected and the payment process begins. At this time, magnetism - No. 1
8, when a ground fault occurs as shown in FIG. 2, a short-circuit current flows to the ground via the line and through the coil at the magnetic node as indicated by the arrow.

Therefore, the comparator 2 monitoring the voltage of the constant voltage power supply 1 detects the ground fault. Although the signal at terminal A is blocked and the transistor 'T' R1 is turned off to bring the voltage of the WSi-line to zero, it is inevitable that the recorded data will be destroyed during this time.

(C) Object of the Invention The object of the present invention is to eliminate the above-mentioned disadvantages by providing a constant voltage drive circuit for each node of the magnetic head independently to provide two potentials, and to provide access to the The discovery of the J7+ period of an abnormal magnetic head that caused a ground fault by applying a potential only to the saw magnetic head, and the connection to the abnormal magnetic head.
In order to determine whether rewriting is possible for 11J, the object of the present invention is to provide a data protection force formula for a magnetic disk device that detects a ground fault in the magnetic field 71 based on a combination of remaining time intervals.

(d) Structure of the Invention The structure of the present invention uses a constant voltage that changes a potential to the center tap of the magnetic head during data writing in a magnetic TiSF device in which a magnetic head amplifier is mounted on an arm carrying a magnetic head. A drive circuit is installed independently for each magnetic node. Also, data writing 11) Q each magnetic - so 1
Means is provided for detecting ground faults in the magnetic head at predetermined intervals of 114 for each ζ.

It is designed to determine whether internal writing is appropriate.

CQ) Embodiment of the Invention FIG. 3 is a block diagram of a circuit showing an embodiment of the invention. The voltage of the constant voltage power supply 1 is changed to a plurality of θi values F'5. G
, 7.8, the constant voltage drive J circuit 9゜10 is magnetically...
Provide as many as No.1. In addition, the circuit of the transistor 'I''R3 is provided with a plurality of ・\ノ(・J in terms of the number of ICs 3 and 4. When the separate state occurs, the magnetic field accessed is =/F5.6.7
．． 8) In 11.1 completed △ again (j', : A write selection signal is input from the 1st child F to t, input is input from terminal Δ)
In this case, the I-transistor T in 1 is turned on through the resistor R1, and the magnetic field is turned on through the WSl, 1 line.
Change the voltage of constant voltage power supply 1 to the center tap of . If it enters from the terminal I5, it turns on the transistor 'I''R2 through the resistor 1 and 2, and changes the voltage of the magnetic head [set at the center tap of j?Li voltage power supply 10)' through the WSL2 line. A write selection signal is also input to terminal G.

Chip selection signal (No. 4 is input from terminal) 3 or terminal 13, and FIC3 or 4 is selected. At the same time, the chip selection signal is also input to terminal) ■, so NA, ND circuit 11 passes through resistor R3. I-Run Sister 1' Turn on R3 and apply constant voltage' voltage of power supply 1 to 2゜-・SoF IC3! j-Eh, I'll operate the active elements such as the I'C3 amplifier.
Uru. When a write selection signal is input to the terminal; 1 end completed 0
When the write selection IR signal is input to 171:+F, the magnetic hexagonal 1- selection signal is input to the terminal 1, and the magnetic hexagonal 1' selection signal is input to the terminal 2.
Select 5 or 6. For example, when Magnetic "No I" 5 is selected and writing starts, at 62 o'clock, 7+" 8 becomes Earth 1.
Even if a 181i chiffon is produced, there is no problem because there is no potential in the magnetic throat 8.

If the magnetic field F' 5 causes a ground fault, the comparator 2 detects a drop in the constant voltage power supply 1 due to the short circuit current, and the AND circuit 12. 1.3, send out the detection signal.

Figure 4 is a diagram explaining the timing for determining whether reseparation is possible.
The number N is +j. A signal is given to the terminal 4J, which is obtained by turning the circuit 12 to A for a certain period of time immediately after J and 1j and 2 knee-in states. From slave 1 and comparator 2, XG is obtained at this timing.
, - When a ground fault is detected in the magnetic field 1-5 as shown, the on-candy is sent to I'lj:l 71-1. Do not allow i-store inclusion. Evening as shown in 7Y (Mink-ζ
111! If a contact fault occurs, i'lit'' [(
niI〈not shown〉
N I) It is possible to turn on the circuit 13.

Together with the detection signal of the comparator 2, the A N D circuit 13 is turned on to send out a signal to the terminal M that allows input 11i-. This is due to the fact that the 101 path failure of magnetic / The ground fault is a complete ground fault G (1 rate or 111□
Because of that, jfi Furukomi, /! , and if it is detected at other timings, it may result in a mountain damage, so 11th write and 7th are allowed to be 11iJ.

(f) Invention glue no ψ! As explained, the present invention originates from the ancient times.
L.

Saw magnetic... So1. 1. In order to prevent the destruction of the data in Q'/d and to accurately detect the magnetic node caused by the ground fault fault, it is possible to prevent the damage caused by the occurrence of the ground fault fault. Since it becomes possible to determine whether or not to perform a write operation, the effect is significant.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a conventional system, Fig. 2 is a diagram explaining a ground fault, and Fig. 3 shows an embodiment of the present invention.
The block diagram and FIG. 4 are diagrams for explaining the timing for determining whether rewriting is possible. lGJ constant voltage power supply, 2+:, i comparator, 3.4 - Soto IC, 5, 6, 7, 8 magnetic node, 9.1. O is a constant voltage drive circuit.

Claims (1)

[Claims] 1) In a magnetic disk drive in which a magnetic head amplifier is mounted on an arm on which a magnetic head is mounted, a constant voltage drive circuit that applies a potential to the center tap of the magnetic head 1 at the time of data writing is provided in each case. A data protection system for a magnetic disk device characterized by the fact that each magnetic disk is provided with an independent disk. 2) In the magnetic disk device described in 1-1, when writing data, a means is provided for each magnetic head 4σ to detect a ground fault in the magnetic head at a predetermined time interval, and rewriting is possible.
Data of a magnetic disk device characterized by determining the
Stunned expression.