JPH05251884A - Forced air cooling - Google Patents

Abstract

(57) [Abstract] [Purpose] Providing a forced air-cooling device capable of precise power control, which corresponds to low power consumption operation of the main body of the processing device, and further, small information processing capable of battery operation for a long time with low power consumption Provide the device. A means for inputting information such as an operation clock signal 16 of a central processing unit is provided, and a blower fan 11 is provided according to the information.
An electric power control unit 9 is provided to appropriately control the pulse or electric power supplied to the. [Effect] It is possible to realize a forced air-cooling device capable of fine power control that corresponds to the low power consumption operation of the processing device body, and further to provide a small information processing device that can be driven by a battery for a long time with low power consumption. I can.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced air cooling device for cooling heat generated by power consumption in a housing of an information processing device or the like by a flow of air, and particularly low consumption. The present invention relates to a forced air cooling device used in a battery-powered compact information device that needs to be powered.

[0002]

2. Description of the Related Art As described in Japanese Patent Application Laid-Open No. 3-128269, a conventional device controls the operation and stop of a forced air cooling device depending on whether the device is in an operating state or not.

[0003]

However, the above-mentioned prior art only controls the operation and stop of the forced air cooling device, and the detailed low power consumption operation corresponding to the power consumption states of several types or more. There was a problem such as not being able to do.

For example, in a battery-powered small-sized information processing apparatus, for the power control of the processing apparatus main body, a method such as frequently switching the operation clock or a method such as stopping the clock of the non-operation part in the operation mode is used. Despite various efforts have been made to reduce power consumption, proper control of power according to the power consumption state of the processor main body of the electric fan that is a forced air cooling device has not been performed.

An object of the present invention is to provide a forced air-cooling device capable of fine power control, which corresponds to a low power consumption operation of a main body of a processing device, and further, a small information processing which can be driven by a battery for a long time with low power consumption. To provide a device.

[0006]

The above object is to provide a means for inputting an operation clock signal of a processing device, a clock switching signal indicating a power consumption state if necessary, and a forced air cooling device according to information of these signals. Is provided with means for controlling electric power by controlling the number of revolutions of the motor for driving the fan of
This is achieved by controlling the power of the forced air cooling device corresponding to the low power consumption operation of the processing device body.

[0007]

The heat generated in the housing of the information processing device is proportional to the power consumed in the housing. If the power consumed in the housing is large, the flow rate of air for forced air cooling must be high, and if the power consumed in the housing is small, the flow rate of air for forced air cooling is small but sufficient cooling is achieved. It is possible. The air flow rate required to maintain the life and reliability of electrical parts depends on the degree of integration of individual parts (LSI), the type of element,
It varies depending on the mold material (of the LSI), operating state, and the like. However, in the information processing apparatus, the LSI that constitutes the CPU, which is generally the central part of the central processing unit, determines the maximum value of the flow velocity of air for forced air cooling.

In a battery-powered small-sized information processing apparatus or the like, this is one of the reasons for the power control of the processing apparatus main body (which is one of the reasons that the elements constituting the circuit are C-MS).
As can be inferred from the fact that the system which frequently changes the operation clock of the PU is adopted, when the clock frequency of the CPU changes, the maximum value of the flow velocity of air for forced air cooling also changes.

The forced air cooling device is provided with means for inputting an operation clock signal of the processing device, a clock switching signal indicating a power consumption state as necessary, and the like, so that information on the maximum value of the flow velocity of air for forced air cooling is obtained. Will be available. According to this information, the power control means for controlling the rotation speed of the motor for driving the fan, which is necessary to obtain the required air flow velocity, is provided and the power is controlled appropriately, so that the low power consumption and the long time are achieved. It is possible to realize a compact information processing device that can be driven by a battery for a time.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of the present invention in a compact information processing apparatus.
The functional block diagram of an Example is shown. In FIG. 1, 1 is a central processing unit (hereinafter abbreviated as CPU), 2 is a bus including address / data and control signals of the CPU 1, 3 is a register for setting information for selecting an operating clock of the CPU 1, address decoders and the like. Including circuits necessary for reading and writing from the bus 2 of 4 is an oscillator 1 having a specific natural frequency, 5 is an oscillator 2 having a specific natural frequency different from the oscillators 1 and 4, and 2 is an input having 1 output. Selector, 7 is a timing circuit for controlling the timing of clock switching, 8 is a memory, 9 is a power control unit for controlling the power of the forced air cooling device, 10 is a motor for powering the forced air cooling device, 11 is a forced air cooling device. A fan for blowing air, 12 is a register output signal of the register 3, 13 is a clock switching signal synchronized by the timing circuit 7, and 14 is an output of the oscillator 1. No., 15 oscillator 2 output signal, 16 is a clock signal supplied to the CPU1 and the power control unit 9, 17 is a motor feed line to the power of the forced air cooling system motors, 18
Is a shaft that transmits the rotation of the motor 10 to the fan 11. 1 to 3, the same parts are designated by the same reference numerals.

The processing state and the power consumption of the information processing device are the highest, and the operating state of the clock generated by the oscillators 1 and 4 shifts to the operating state of low power consumption of the clock generated by the oscillators 2.5. CPU1 to register 3
Need to be accessed to change the value set in the register. Here, it is assumed that the register 3 is allocated to a specific address, and that only one bit is allocated to the register value because there are two kinds of operation clocks in this embodiment. When the value of the register 3 is changed, the binary level of the register output signal 12 is inverted, and when it is transmitted to the timing circuit 7, the clock switching signal 13 is synchronized and output. The selector 6, which also serves as the clock driver that has been supplying the clock generated by the oscillators 1 and 4 to the clock signal 16 up to now, receives the clock generated by the oscillators 2 and 5 by inputting the synchronized clock switching signal 13. Is synchronized with the clock signal 16 to start the supply. In this way, oscillator 1
4 shifts from the operating state with the clock generated by the oscillator 4 to the operating state with low power consumption with the clock generated by the oscillator 2.5.

As the clock frequency supplied to the clock signal 16 decreases, the CPU 1 shifts to a low power consumption operation. The power control unit 9 that controls the power of the forced air cooling device is
Clock signal 16 and register output signal 1 of register 3
From 2, it can be recognized that the CPU 1 has shifted to the low power consumption operation. That is, the maximum value of the flow velocity of the air for the forced air cooling becomes low, so the power control unit 9 appropriately controls so as to reduce the power supplied to the motor 10 that is the power of the forced air cooling device, and the motor power supply line 17 is supplied. Through the motor 10
Supply power to.

The power control unit 9 which is an important part of the present invention will be described with reference to FIGS. 2 and 3. Figure 2
3 is a detailed block diagram of the vicinity of the power control unit 9 when the motor 10 is a DC motor, and 101 is a clock signal 16
To a fixed multiple or register output signal 12
Frequency division part that performs frequency division for multiples specified by the information of
Reference numeral 102 controls the length of the effective portion of the square wave with respect to the clock divided by the dividing unit 101 to a fixed length or, if necessary, to a length designated by the information of the register output signal 12 (duty control). One-shot pulse generator, 1
Reference numeral 03 is a drive transistor for driving the motor 10 with a signal from the one-shot pulse forming unit 102, and reference numeral 19 is a flywheel diode.

The rotation and power control of the DC motor shown in FIG. 2 is called a PWM (pulse width modulation) system, and when the clock is generated by the oscillators 1 and 4, the oscillators 1 and 4 generate it. Air velocity for forced air cooling required when operating with the clock, and air for forced air cooling required when operating with the clock generated by the oscillator 2.5 when operating with the clock generated by the oscillator 2.5 A power waveform is appropriately generated by the frequency dividing unit 101 and the one-shot pulsing unit 102 so that the flow velocity can be obtained. Also, with the clock generated by the oscillators 1 and 4,
The ratio of the clocks generated by the oscillators 2.5 is the oscillators 1.4
Of the flow velocity of the air for forced air cooling required when operating with the clock generated by and the flow velocity of the air for the forced air cooling required when operating with the clock generated by the oscillator 2.5. When the ratio is almost equal, the frequency division and the one-shot pulsing can be fixed, so that the information of the register output signal 12 becomes unnecessary.

FIG. 3 is a detailed block diagram of the vicinity of the power control unit 9 when the motor 10 is a pulse drive type motor, and 101 is a fixed multiple of the clock signal 16 or, if necessary, the information of the register output signal 12 A frequency dividing unit that performs frequency division by a designated multiple, 104 is a distributing unit that distributes the pulse supplied from the frequency dividing unit 101 according to the number of poles of the motor, and 105 is a driver unit that corresponds to the number of poles of the motor. ..

Also in FIG. 3, oscillators 1 and 4 are used as in FIG.
When operating with the clock generated by the oscillators 1 and 4, the flow velocity of the air for forced air cooling required when operating with the clock generated by the oscillators 1 and 4, and when operating with the clock generated by the oscillator 2.5 In order to obtain the flow velocity of the air for forced air cooling required when operating with the clock to be generated, a pulse is generated by the frequency dividing unit 101, and the pulse is appropriately distributed by the distributing unit 104 to operate the pulse motor. To drive. Also in this case, similarly to the case of FIG. 2, if it is possible to obtain the flow velocity of the air for the forced air cooling necessary for the operation at each clock by driving with the pulse proportional to the difference in the clock frequency. The information of the register output signal 12 is unnecessary.

In this embodiment, a PWM (pulse width modulation) method and a power control method using a pulse drive type motor are used, but the present invention is not limited to these methods, and DA It is also possible to use a method such as conversion (digital-analog conversion).

Further, in the present embodiment, only the operation modes of the CPU with the two kinds of clocks are supported, but the present invention is not limited to the two kinds of power consumption operation modes, and the operation modes are not limited. The present invention can be applied to any kind of power consumption operation mode only by changing the number of bits of the designated register and the functions such as the number of inputs of the selector accompanying this. In this embodiment, the power control of the forced air cooling device depending on the power consumption operation mode of the CPU is performed assuming a general small-sized information processing device, but the heat generation amount (power consumption) is large, and the forced air cooling is performed. A special input / output device that determines the maximum value of the flow velocity of the air (heat generation amount is larger than that of the CPU) is built in the chassis, and it is possible to control the operation and stop of this input / output device and to reduce the power consumption in several power consumption operation modes. When performing power consumption control, change the number of bits in the register that specifies the operation mode to control the operation and stop of this special I / O device, and to set several types of power consumption operation modes as conditions. It is also possible to control the power of the forced air cooling device.

Further, as a means for physically realizing the power control unit, inside (on the surface of) the printed circuit board including the central processing unit,
A part or all of it is mounted, a part or all of it is mounted separately from a printed circuit board that includes a central processing unit as a power control printed circuit board, and a fan and a motor (including a brushless motor) are integrated. It is conceivable that a part or all of the module is mounted in the module. Since the physical quantity can be realized on the order of several tens of gates, it does not cause a problem in a recent small-sized information processing apparatus which has a common sense to incorporate a custom LSI, and it does not cause an economical problem.

According to the present embodiment, it is possible to realize a forced air cooling device capable of fine power control corresponding to the low power consumption operation of the processing apparatus main body, and further, a small information capable of being driven by a battery for a long time with low power consumption. We can provide processing equipment.

[0021]

According to the present invention, a simple circuit of about several tens of gates, which does not cause a problem in terms of economy and space, enables fine power control corresponding to the low power consumption operation of the processing apparatus main body. It is possible to realize a forced air cooling device, and it is possible to provide a small information processing device that consumes low power and can be driven by a battery for a long time. Also, if the battery is driven for a certain period of time, it will be possible to drive with a battery with a smaller current capacity,
This has the effect of making it possible to reduce the size and weight of the small information processing device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram of a power control unit in a DC motor.

FIG. 3 is a block diagram of power control in a pulse motor.

[Explanation of symbols]

1 ... Central processing unit (abbreviated as CPU), 2 ... Bus, 3 ... Register, 4 ... Oscillator 1, 5 ... Oscillator 2, 6 ... Selector,
7 ... Timing circuit, 8 ... Memory, 9 ... Power control unit, 1
0 ... Motor, 11 ... Fan, 12 ... Register output signal, 13 ... Clock switching signal, 14 ... Oscillator 1 output signal, 15 ... Oscillator 2 output signal, 16 ... Clock signal,
Reference numeral 17 ... Motor power supply line, 18 ... Shaft, 19 ... Flywheel diode, 101 ... Dividing unit, 102 ... One-shot pulse converting unit, 103 ... Driving transistor, 104
… Distribution unit, 105… Driver unit.

Front page continuation (72) Inventor Takao Oba 1 Horiyamashita, Hadano City, Kanagawa Prefecture Hitachi, Ltd. Kanagawa Plant

Claims (4)

[Claims] 1. A forced air cooling device, comprising a means for controlling the amount of air blown in accordance with the consumed electric power in a system composed of electric power operated parts. 2. A digital system composed of parts that operate on electric power, comprising means for inputting information such as an operating clock of a central processing unit, and appropriately supplying a pulse or electric power to a blower fan according to the information. A forced air cooling device, which is provided with a control means. 3. An information processing apparatus comprising a forced air cooling device capable of appropriately controlling the amount of air blown according to the power consumption state. 4. A low power consumption type system device comprising means for appropriately controlling the power supplied to the forced air cooling device according to the power consumption state.