JPH01303511A - Cooling device for electronic equipment - Google Patents

Abstract

PURPOSE:To decrease the useless power consumption due to the excessive forcible air cooling together with reduction of the fan noises and also to increase the lifetime of the cooling fan by controlling the voltage applied to the fan based on the power consumption calculated by a power consumption calculating means. CONSTITUTION:A cooling fan 6 revolves at a speed corresponding to the applied voltage and a power consumption calculating means 18 calculates the power consumption of an electronic equipment. Then an applied voltage control means 17 controls the voltage applied to the fan 6 based on the power consumption calculated by the means 18. The means 17 controls the voltage applied to the fan 6 based on the power consumption calculated by the power consumption calculating means R1-Rn. Thus it is possible to decrease the useless power consumption, to reduce the fan noises and to increase the lifetime of the fan 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a cooling device for an electronic device such as a laptop type personal computer.

(Prior Art) Electronic devices such as laptop-type personal computers have heretofore generally been equipped with a cooling device in order to prevent functional failures caused by increases in internal temperature.

As this cooling device, a cooling fan for forced air cooling is widely used.

Incidentally, the rotational speed, that is, the cooling capacity of this cooling fan is set in accordance with the case where each drive unit in the electronic device, such as a floppy disk drive or a keyboard, operates at full capacity and generates the maximum amount of heat.

However, each drive unit in an electronic device is not always in full operation, and there is usually considerable variation over time.

Therefore, the conventional system in which the cooling fan is always rotated at a constant speed has the problem of wasting a lot of power and generating a high degree of noise.

(Problems to be Solved by the Invention) The present invention is intended to solve the above-mentioned problems with conventional cooling devices in electronic devices, and it is an object of the present invention to control the voltage applied to the cooling fan based on the power consumption of the electronic device. According to
The present invention aims to provide a cooling device for electronic equipment that can reduce wasteful power consumption, reduce noise, and extend the life of a cooling fan.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the cooling device for an electronic device of the present invention provides a cooling device that performs forced air cooling inside the electronic device at a speed corresponding to an applied voltage. a cooling fan that rotates, a power consumption calculation means that calculates the power consumption of the electronic device, and an applied voltage control means that controls the voltage applied to the cooling fan based on the power consumption calculated by the power consumption calculation means. It is equipped with

(Function) In the cooling device for electronic equipment of the present invention, the applied voltage control means controls the voltage applied to the cooling fan based on the power consumption calculated by the power consumption calculation means, so that unnecessary power consumption is avoided. Furthermore, fan noise can be reduced and the life of the cooling fan can be extended.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a perspective view showing the external appearance of a laptop type information processing device equipped with a cooling device according to an embodiment of the present invention, and FIG. 2 is a plan view showing the internal configuration of FIG. 1.

As shown in the figure, inside the information processing device 100, there is a power supply device 1 for obtaining a constant voltage such as +5V or +12V used in the device from a commercial ACIGOV power source.
, a floppy disk device 2 and a hard disk device 3 for writing/reading and storing information, a CPU board 4 equipped with various integrated circuits such as a storage device and a microcomputer, a keyboard 5, and each of the above driving units. A cooling fan 6 is provided to perform forced air cooling.

Further, 7a and 7b indicate an intake port and an exhaust port, respectively, and these intake lower a and exhaust lower b are respectively i!
The SR device a is provided facing the side wall of the main body of the information processing device 100 so as to sandwich the device component 1 position therebetween. The cooling fan 6 is installed facing the exhaust lower b.

Further, a blower deflecting plate 8 is arranged near the intake lower a. A part of the air sucked in from the intake lower a is deflected by the air deflection plate 8 and is sent to the floppy disk device 2,
It is designed to be sent to the hard disk device 3, CPU board 4, and keyboard 5 side.

With the above configuration, forced air cooling inside this information processing device 100 is performed.

Next, the configuration of the power supply device 1 described above will be explained.

FIG. 3 is a circuit diagram for explaining the configuration of this power supply device 1. As shown in FIG.

In the figure, 11 is a filter, 12 is a rectifier that rectifies the AC 100V that has passed through the filter 11, 13 is a smoothing capacitor that stores the charge after rectification, 14 is a switching transistor, 15 is a single-input multi-output type transformer,
16 is a snubber circuit that consumes energy stored in a part of the coil of the transformer 15 when the transistor 14 is turned off;
17 is a control circuit unit for controlling the switching of the transistor 14 and controlling the rotation speed of the cooling fan 6 based on fluctuations in power consumption; Rp is the transistor 1;
This is a resistor connected to the emitter side of 4.

Also D 11. D12, Dnl, and Dn2 are rectifier diodes connected to the secondary side of the transformer 15, respectively;
LL...Ln and C1...Cn are choke coils and smoothing capacitors that constitute a smoothing circuit for compressing input current ripples, and R1...Rn are resistors of about 0.1Ω for calculating power consumption. be.

Furthermore, RFI...RPn each represents a load resistance.

The control circuit unit 17 described above also includes a microcomputer 18, a ROM 19 storing control programs executed by the microcombiator 18, and an RA used as a work processing area of the microcomputer 18.
M20, an A/D converter 21 that A/D converts the voltage at two points across the resistors R1...Rn for power consumption calculation in each constant voltage output section, and the A/D converter 21 a first 8-bit register 22 that holds converted data as 8-bit data; a driver 23 that outputs a drive pulse to the base of the switching transistor 14;
It is configured to include a second 8-bit register 24 that holds signals sent to this driver 23 and signals sent to a voltage control transistor to be described later.

Note that the driver 23 described above is connected to the least significant bit (LSB) of the second 8-bit register 24.

Further, reference numeral 25 denotes voltage control transistors RA and RB for controlling the voltage applied to the fan motor 26.

Rc are first to third resistors connected to the base side of the voltage control transistor 25, respectively.

Further, the second resistor RB is connected to the O-th bit of the second 8-bit register 24, and the third resistor Re is connected to the first bit.

FIG. 4 is a circuit diagram for specifically explaining the action of the voltage applied to the cooling fan 6.

Here, RA is lkΩ, RB is 2.2Ω, RC is 2.2
Ω, the resistance RD of the 0th bit output section 24a and the 1st bit output section 24b in the second 8-bit register 24
%RD is 330Ω.

As shown in the figure, in this applied voltage control section, the 0th
When the second bit is set to "1", +12V is output from the corresponding bit output section 24a, 24b, and when it is set to "0", it is connected to ground. It looks like this. In the figure, the above-mentioned effect is expressed by the first to fourth transistors Ql-04.

Here, rlJ is set to the TSO bit and "1" is set to the ml bit.
are set respectively, the first transistor Q1
is ON, second transistor Q2 is op%, third transistor Q3 is ON, fourth transistor Q4 is opp
become.

FIG. 5 shows an equivalent circuit in this case, and as shown in the figure, in this case, sufficient current flows to the base to saturate the voltage control transistor 25, so the voltage control transistor 25 Emitter voltage is approximately +12V
becomes.

Furthermore, in FIG. 4, when the 0th bit is set to "1" and the 1st bit is set to "0", the first transistor Ql is turned ON and the second transistor Q2 is turned OP.
, the third transistor Q3 is opp.

The fourth transistor Q4 is turned on.

Therefore, the equivalent circuit in this case is as shown in FIG.

In this case, the base voltage V of the voltage control transistor 25
B is 1/(1/RA +
1/2RD) +RC: RC■12:VB From the formula, VB -12RC+ 1/ (1/RA + 1/
2RD)+RC-9,1V.

Furthermore, since the emitter voltage VE is VB-VBB, if VBE (base-emitter voltage) is about 0.7V, then VE-9, lV-0, 7V-8, 4V.

Hereinafter, this emitter voltage VB will be referred to as +9v.

Furthermore, in FIG. 4, when the 0th bit is set to "0" and the 1st bit is set to "0", the first transistor Ql is OFF and the second transistor Q2 is OFF.
Transistor Q3 of F, m3 is opp.

Transistor Q4 of IA4 is turned on.

Therefore, the equivalent circuit in this case is as shown in FIG.

In this case, the base voltage V of the voltage control transistor 25
B is 1/(l/RB +
l/RC) +RA :1/ [l/RB +
1/RC) -12: From the formula VB, VB -12/ l 1/RB + l/RC) ÷
1/ (1/RB + l/RC)+RA-6,6V
becomes.

As a result, the emitter voltage VE' is VE becomes -6,6V-0,7V-5,9V.

Hereinafter, this emitter voltage VE will be set to +6v.

In this way, in this example device, +12V, +9V
1. It is possible to apply a constant voltage of +ev to the fan motor 26.

Next, the operation of this embodiment device will be explained.

First, when a commercial AC 100V power source is applied to the human power section of the power supply device 1, the current is inputted to the rectifier 12 via the filter 11, where it is full-wave rectified, and the smoothing capacitor 13
A charge for about 140V is accumulated.

Here, by setting the least significant bit of the second 8-bit register 24 to "0", a predetermined drive voltage is applied from the driver 23 to the base of the switching transistor 14.

As a result, the switching transistor 14 is turned on, and the charge accumulated in the smoothing capacitor 13 flows as a current to the primary coil of the transformer 15, and each secondary coil of the transformer 15 is connected to the first rectifier diode Dll.
...A current flows in the direction of conduction through Dnl.

Thereafter, the least significant bit of the second 8-bit register 24 is set to "1", thereby turning off the switching transistor 14.

As a result, the energy stored in the primary coil of the transformer 15 is consumed by the snubber circuit 16, and at the same time, a second rectifier diode D is connected to each secondary coil of the transformer 15.
A current flows in a direction that makes I2...Dn2 conductive.

Then, after the ripples of the current that continuously flowed to each constant voltage output section through the above operation are compressed by a smoothing circuit composed of choke coils L1...Ln and smoothing capacitors C1...Cn, the constant voltage is given to the load.

The above is the normal operation of the power supply device 1.

Next, the operation of the control circuit section 17 will be explained.

The control operation in this control circuit section 17 is performed by the power supply device 1
This is done by finding the power consumption from the difference in voltage between two points across the resistors R1...Rn, that is, point A and point B, and point C and point 0.

That is, here, the voltage at point A is VA, and the voltage at point B is VB.
, the voltage at point C is VCSD, and the voltage at point VD.

If the resistance value of the resistor R1 is R1, and the resistance value of the resistor Rn is Rn, the power consumption WAB in the +5V output section is WAB-5 (V) is WCD-
It can be calculated as 12(V)X(VA-VB)/R1.

That is, the microcomputer 18 of the control circuit section 17 first converts the voltages at points A and B, and points C and 0 into an A/D converter.
The data is taken in by converting it into digital data using the converter 21 and sequentially setting it in the first 8-bit register 22, and then by performing the above calculation, the power consumption in each constant voltage output section is calculated.

Then, the pulse width of the ON time of the switching transistor 14 is determined according to the power consumption of each constant voltage output section,
Controls the switching of signal sets in the least significant bit.

As a result, the voltage applied to each secondary coil of the transformer 15 is controlled, and the output voltage of each constant voltage output section is maintained.

On the other hand, the microcomputer 18 calculates the total power consumption in each constant voltage output section, and controls the rotational speed of the cooling fan 6 based on the result as follows.

FIG. 8 is a flowchart showing the flow of controlling the rotational speed of the cooling fan 6 according to power consumption, and FIG. 9 is a diagram showing the relationship between the voltage applied to the fan motor 26 and the fan rotational speed.

First, the microcomputer 18 calculates the total power consumption in each constant voltage output section using the method described above (step 80), and checks whether the maximum power consumption is 80% or more of the power consumption during full operation (step 81). ).

If it is determined that it is 80% or more, the 0th bit of the second 8-bit register 24 is set to "1" and the first bit is set to "1" (step 82).

As a result, a voltage of approximately +12V is applied to the fan 26, and the cooling fan 6 rotates at a speed of 2500 revolutions/rotation (step 83).

On the other hand, in step 81, the power consumption is 8 at full operation.
It is determined that it is less than 0%, and in step 84 it is determined that it is less than 60%.
If it is determined that the above is the case, the 0th bit of the second 8-bit register 24 is set to "1", and the 1st bit is set to "1".
0" (step 85).

As a result, the voltage applied to the fan motor 26 is controlled from +12V to approximately +9V, and as a result, the cooling fan 6 is
000 revolutions/rotation speed (step 86).

Furthermore, if it is determined in step 84 that the power consumption is 60% or less of the full operation, the 0th bit of the 8-bit register is set to "0" and the 1st bit is set to rOJ (step 87).

This increases the voltage applied to the fan motor 26 by +9
As a result, the cooling fan rotates at 1500 revolutions/rotation speed (step 88).

FIG. 10 shows the relationship between the rotational speed of the cooling fan 6 and the generated noise.

As shown in the figure, the rotation speed of the cooling fan 6 is 250.
When the rotation speed is reduced from 0 rotations/minute to 2000 rotations/minute, the fan noise becomes about half, and when the rotation speed is further reduced by 1500 rotations/minute, it becomes about 174.

Thus, according to the device of this embodiment, fan noise can be effectively reduced by controlling the rotational speed of the cooling fan 6 in stages according to the power consumption.

Furthermore, this embodiment can save energy.

The following tables are +12V, +9V, +6V, +G
The power consumed by the voltage control transistor (TR) 25 and the cooling fan 6 when V is used is shown.

(Hereafter, blank space) As is clear from this table, the voltage control transistor (T
R) The power consumption of 25 increases as the rotation speed of the cooling fan 6 becomes slower, but the power consumption of the cooling fan 6 decreases as the fan rotation speed becomes slower, and in total, the slower the fan rotation speed becomes, the more the power consumption of the cooling fan 6 decreases. Power consumption is reduced. Therefore, energy savings can be achieved.

In the embodiment described above, the microcomputer 18 controlling the power supply device 1 controls the voltage applied to the cooling fan 6 based on power consumption, but the CPU controlling the entire information processing device controls the voltage applied to the cooling fan 6 based on the power consumption. A microcomputer on the board 4 checks power consumption in the floppy disk device 2, hard disk device 3, CPU board 4, and keyboard 5, and based on the results, controls the cooling fan 6.
The applied voltage may be controlled. In this case, it is preferable to perform control based on the recognition results of whether the floppy disk drive 12, the hard disk drive 3, the CPU board 4, and the keyboard 5 are active or inactive.

In addition, although this embodiment adopted a method of switching the fan rotation speed into three stages, it is possible to further reduce fan noise and power consumption by subdividing control into a larger number of stages. can.

Furthermore, a temperature sensor may be installed in the main body of the apparatus, and the voltage applied to the cooling fan 6 may be controlled based on the temperature detected by the temperature sensor.

Regarding the timing of switching the fan rotation speed, it is not only effective to change the fan rotation speed immediately according to a change in power consumption, but also to change the fan rotation speed after a period of, for example, about 5 minutes has elapsed.

If this method is used, fluctuations in power consumption within a short period of time can be ignored.

[Effects of the Invention] As explained above, according to the cooling device for electronic equipment of the present invention, the voltage to be applied to the cooling fan is controlled based on the power consumption calculated by the power consumption calculation means, so that no unnecessary force is applied to the cooling fan. It is possible to reduce wasteful power consumption due to air cooling, and furthermore, it is possible to reduce fan noise and extend the life of the cooling fan.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the external appearance of a laptop-type information processing device equipped with a cooling device according to an embodiment of the present invention, FIG. 2 is a plan view showing the internal configuration of FIG. 1, and FIG. FIG. 4 is a circuit diagram for explaining the configuration of the power supply device built into the information processing device shown in FIG. 7 to 7 are circuit diagrams showing the equivalent circuit of FIG. 4, and FIG.
The figure is a flowchart for explaining the flow of cooling fan rotation speed control according to the present invention, FIG. 9 is a diagram showing the relationship between the voltage applied to the cooling fan and the fan rotation speed according to the present invention, and FIG. 10 is a fan FIG. 3 is a diagram showing the relationship between rotation speed and generated noise. 1...Power supply device, 2...Floppy disk device,
3...Hard disk device, 4...CPU board, 5
... Keyboard, 6... Cooling fan, 17... Control circuit section, 18... Microcomputer, 19...
・ROM. 25... Voltage control transistor, 100... Information processing device. Applicant: Toshiba Corporation Patent Attorney Satoshi Suyama - Figure 4 Figure 5 Figure 6 ↓ Figure 7 Figure 92

Claims (1)

[Claims] (1) In a cooling device that performs forced air cooling inside an electronic device, a cooling fan rotates at a speed according to an applied voltage, a power consumption calculation means for calculating power consumption in the electronic device, and calculation by the power consumption calculation means. 1. A cooling device for an electronic device, comprising applied voltage control means for controlling a voltage applied to the cooling fan based on the calculated power consumption.