JPS6212974A - Compact fixed magnetic disk device - Google Patents

Abstract

PURPOSE:To protect the recording information for breaking of a power source by providing a capacitor in parallel with the power source, and returning a writing and reading head to a standby position when a power source voltage monitor circuit detects the lowering of the power source voltage. CONSTITUTION:When the voltage applied between terminals 11, 12 and terminals 13, 14 is removed due to the breaking of a power source, the stop of the electric current or the like, capacitors 5-7 disposed in parallel with the power source operate instead of the power source. A power source voltage monitor circuit 1 connected to both ends of a resistance 19 monitors the power source voltage between the terminals 11, 12 and when it goes below a fixed voltage, the circuit outputs a pulse signal to an interruption terminal 2 of a central processing unit 3. The central processing unit 3 receives the interruption by this pulse signal, it runs an interruption software, feeds a command for returning a writing and reading head to a standby position to a control part 4 and returns the writing and reading head to the standby position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a small fixed magnetic disk device used in a burner computer or the like.

[Conventional technology]

A solenoid coil with a spring is used in a Herd Disk device (hereinafter abbreviated as H and D),
The built-in device uses the spring force of this solenoid coil to quickly return the information writing/reading head from the H and D information recording surfaces to the predetermined standby position when the power is cut off, thereby protecting the recorded information. are doing.

However, since this protection device has a mechanical mechanism, it is large and cannot be used with small H
, D vr-this protection@fold Rt-cannot be incorporated.

[Two problems solved by the invention]

Conventional H and D for personal computers, etc. use solenoid coils as described above, but are too large to be incorporated into the next protection device, and are not provided with any protection against power disconnection. However, if there is an accident such as a momentary power outage or power outage while the head is running on the information recording surface, there is a risk that the information recording surface may be damaged by the head.

An object of the present invention is to provide a small fixed magnetic disk device capable of protecting recorded information by returning a read head to a standby value of 11ivr.

[Means for solving problems]

The small-sized fixed magnetic disk device of the present invention includes a capacitor provided in parallel with the power source, a blind power source monitoring circuit for detecting a voltage drop of the 11r source, and a 1c source monitoring circuit for detecting a voltage drop of the 11r source, and a 1c subtraction readout when the voltage of the power source decreases. and a return means for returning the head to the standby position.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a circuit diagram showing a power supply section of an embodiment of the present invention in a first embodiment. A voltage of 5V is applied between terminals 11 and 12 of a normal power supply, and a voltage of 12V is applied between terminals 13 and 14. Terminals 15 and 16 are terminals for powering the small H and D single-child circuits, and terminals 17 and 18 are terminals for supplying power to the small H and D motors. Connected in series to terminal 11 and connected to terminal 15 through constant resistor 19.20, connected in series to terminal 13 and connected to terminal 17 through constant resistor 21.22, connected to terminal 12, connected to terminal 16, and connected to terminal 14. It is connected to terminal 18. The connection point VC of a resistor 19.20 is connected to the connection point of terminals 12.16 via a small and large capacity capacitor (for example, a super capacitor manufactured by NEC Corporation) 5', and the connection point of terminals 14 and 18 is connected to a small and large capacity capacitor 5'. It is connected to the connection point of the resistor 19.20 via a capacitor 6.7.

Due to momentary power outage, power outage, etc., terminal 11 or 12 may be repaired.Terminal 1
When the voltage applied between 3.14 and 14 is removed, the capacitors 5 to 7 provided in parallel with the power supply take over as the power supply. A power supply voltage monitoring circuit (with VC connected to both ends of resistor 19)
For example, Texas Instruments' TL7705C
(Using P)) Monitor the power supply back pressure between terminals 11 and 12, and when the voltage falls below a certain level, output the full pulse signal to the interrupt terminal 2 of the central processing unit 3. When the central processing unit 3 receives an error interrupt from this pulse signal, it runs the interrupt software H-, sends a command to the control unit 4 to return the read/write head to the standby position, and returns the write/read head to the standby position. let it go back

FIG. 2 is a flowchart of interrupt software executed by the central processing unit 3 after receiving a pulse VC processing interrupt from the power supply voltage monitoring circuit 1.

〔Effect of the invention〕

As explained above, the present invention has a capacitor in parallel with the power supply, and when the power supply voltage monitoring circuit detects a decrease in the power supply snow pressure, the writing/reading node is returned to the standby position (1).・Small H for computers, etc.
D also has the effect of being able to return the throat to the standby position for writing and reading against VC in unexpected situations (HoIJ [J17+ in progress, suizothioff, instantaneous power outage/power outage from commercial 1, etc.).

[Brief explanation of the drawing]

FIG. 1 shows an example of the present invention, and FIG. 2 shows the central processing unit 3 shown in FIG. It is a flowchart of an example of interrupt software executed when a pulse is received from the source lightning voltage monitoring path. 1...Power supply voltage monitoring circuit, 2...Interrupt terminal, 3...Central processing unit, 4...
Suppression part, 5.6.7...Small large capacity capacitor. Agent Patent Attorney Shinka Uchihara 10

Claims (1)

[Claims] The present invention is characterized by comprising a capacitor provided in parallel with the power supply, a power supply voltage monitoring circuit for detecting a voltage drop in the power supply, and a return means for returning the write/read head to a standby position when the voltage of the power supply drops. A small fixed magnetic disk device.