JPH04265691A - Cooling unit for electronic appliance - Google Patents

Abstract

PURPOSE:To ensure cooling in a battery drive electronic appliance mounting a cooling unit comprising a fan motor and to suppress battery power consumption. CONSTITUTION:A battery power supply E is connected with a DC/DC converter 1 connected through a first control circuit 5 with a fan motor 3. A second control circuit 7 is connected in parallel with the first control circuit 5 and a power supply voltage lower than that for the first control circuit 5 is fed from the DC/DC converter to the second control circuit 7. A selecting circuit 9 connected with the first and second control circuits 5, 7 operates the first control circuit 5 for a specific operation requiring sufficient cooling whereas operates the second control circuit 7 when the fan motor 3 is not fully rotated under stand-by mode, for example. Consequently, rotational speed of the fan motor 3 is controlled according to the operation of an electronic appliance resulting in saving of battery power.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for electronic equipment, and more particularly to an improvement in a cooling device installed in a portable electronic equipment having a built-in fan motor.

0002

2. Description of the Related Art In recent years, portable electronic devices such as laptop-type personal computers have become available. This type of electronic equipment is often driven by battery power, and some configurations do not include a cooling device consisting of a fan motor for cooling in order to reduce power consumption. In cases where the heat generated inside the housing is large and there is no place for the heat to escape, and the effects of the heat cannot be ignored, a cooling device is often installed out of necessity. Generally speaking, this type of cooling device for electronic equipment has a configuration in which the cooling fan motor is directly connected to a battery power source, and the fan motor is driven by the operation of a main switch that turns the battery power ON/OFF. It was a target.

0003

[Problems to be Solved by the Invention] However, in the cooling device having the above-mentioned configuration, since the drive voltage is automatically supplied from the battery power source and the fan motor rotates when the main switch is turned ON, the fan motor is rotated while the main switch is turned ON. It is difficult to control the rotation of the fan motor, and even when there is no need to rotate the fan motor very much, the power of the battery power source may be wasted.

[0004] The present invention has been made to solve these conventional drawbacks, and it automatically controls power supply from a battery power source according to the operating state of electronic equipment, thereby reducing wasted power consumption of the battery power source. The purpose is to provide a cooling device that can suppress the

[0005]

[Means for Solving the Problems] In order to solve such problems, the present invention has a battery power source disposed within an electronic device and a fan motor disposed in the electronic device, and a first
A first control circuit is arranged between the battery power source and the fan motor to control the power supplied from the battery power source so as to rotate the fan motor at a rotation speed of . A second control circuit for controlling the power supply to rotate the fan motor in parallel with the first control circuit, and controlling the first or second control circuit in response to the operation of the electronic device. The configuration is such that a selection circuit for selective control is connected to the first or second control circuit.

[0006]

[Operation] In the present invention equipped with such means, when the selection circuit selects the first control circuit in response to a certain operation of the electronic device, the first control circuit supplies power to the fan motor and Rotate at a rotation speed of 1. Further, when the selection circuit selects the second control circuit in response to another operation, the second control circuit supplies power to the fan motor to rotate the fan motor at a rotation speed lower than the first rotation speed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a block circuit diagram showing an embodiment of a cooling device for electronic equipment according to the present invention. In the figure, battery power source E
For example, 9V or 12V built-in or added to a portable laptop personal computer as an electronic device.
It can be charged to about V and is connected to the DC/DC converter 1. The DC/DC converter 1 is a well-known converter that converts the voltage of a battery power supply E to about -24V to +24V to supply a power supply voltage to each electronic circuit in the personal computer, and is connected to the emitter of a PNP transistor Tr1. ing.

The collector of the transistor Tr1 is connected to the power supply terminal of the fan motor 3 via the current limiting resistor R, the base is connected to the collector of the NPN transistor Tr2, and the emitter of the transistor Tr2 is grounded, so that it is not connected to the non-contact switch. A first control circuit 5 is formed. The DC/DC converter 1 includes a transistor T
PN via a low voltage line separate from the power supply line to r1
It is connected to the emitter of P transistor Tr3. Note that it is also possible to supply a low voltage to the PNP transistor Tr3 from the power supply line to the transistor Tr1 via a resistor or the like.

Similar to the collector of the transistor Tr1, the collector of the transistor Tr3 is connected to the power supply terminal of the fan motor 3 via the resistor R, the base is connected to the collector of the NPN transistor Tr4, and the emitter of the transistor Tr4 is connected to the ground. A second control circuit 7 consisting of a non-contact switch is formed. A selection circuit 9 is provided at the base of these transistors Tr2 and Tr4.
The output side of is connected.

The selection circuit 9 is an operation processing circuit (all not shown) comprised of a CPU, ROM, and RAM in the personal computer, and is a circuit that processes data according to a predetermined operation program. Then, the selection circuit 9 sends the first control signal to the first control circuit 5 during a specific operation in which it is necessary to rotate the fan motor 3 to sufficiently cool the inside of the device during the operation of the program. It has a function of setting the second control signal to "H" to operate the first control circuit 5 and setting the second control signal to the second control circuit 7 to "L" so that the second control circuit 7 does not operate.

Furthermore, during another operation process, such as standby mode, in which the fan motor 3 does not need to be rotated to the maximum, the second control signal to the second control circuit 7 is
At the same time, the first control signal to the first control circuit 5 is set to "H" to operate the second control circuit 7, and the first control signal to the first control circuit 5 is set to "L" to operate the second control circuit 7.
It has a function of not operating the control circuit 5 of.

Next, the operation of the cooling device having such a configuration will be briefly explained. When the main switch (not shown) is turned on and the voltage of the battery power source E is supplied to the DC/DC converter 1, a predetermined power supply voltage is supplied to the emitter of the transistor Tr1 of the first control circuit 5, and A power supply voltage lower than that power supply voltage is supplied to the emitter of the transistor Tr3 of the second control circuit 7. In this state, when the operation processing circuit executes a specific operation that requires the fan motor 3 to rotate to the maximum to sufficiently cool the inside of the device, the selection circuit 9 sends the first control signal to the base of the transistor Tr2. Since the transistor Tr2 is set to "H", the transistor Tr2 becomes conductive and the transistor Tr1 also becomes conductive, a high power supply voltage is supplied to the fan motor 3, and the fan motor 3 rotates at the maximum rotation speed.

Furthermore, during operation such as in standby mode where it is not necessary to rotate the fan motor 3 to the maximum, the selection circuit 9 sets the second control signal to the base of the transistor Tr4 to "H". becomes conductive, transistor Tr3 also becomes conductive, a power supply voltage lower than the power supply voltage to transistor Tr1 is supplied to fan motor 3, and fan motor 3 rotates at a reduced rotation speed. On the other hand, the main switch is turned OFF and the voltage of the battery power supply E becomes DC/DC.
No supply to converter 1 or main switch is ON
Even in the state where there is no need to rotate the fan motor 3, the selection circuit 9 does not operate the first and second control circuits 5 and 7, so the fan motor 3 does not rotate.

As described above, in the cooling device of the present invention, when it is necessary to sufficiently cool the inside of the device in response to the operation of the processing circuits such as the CPU, ROM, and RAM in the personal computer, the first control is performed. The power supply voltage that allows the maximum number of rotations to be obtained is supplied to the fan motor 3 via the circuit 5, while the power supply voltage that allows the maximum rotation speed to be obtained is supplied to the fan motor 3 through the circuit 5. During operation, such as in standby mode, when the fan motor 3 does not need to rotate to its maximum speed, the power supply voltage is supplied in parallel to the first control circuit 5. Since a power supply voltage that provides a low rotational speed is supplied to the fan motor 3 via the connected second control circuit 7, the rotational speed of the fan motor 3 is automatically controlled in accordance with the operation processing of the personal computer. Ru. Therefore, consumption of the battery power source E can be reduced while ensuring a good cooling condition inside the personal computer. Note that in the present invention, the first and second control circuits 5 and 7 that supply the power supply voltage to the fan motor 3 are not limited to the circuit configuration described above.

The first control circuit 5 may be configured to supply a power supply voltage or power supply current from a battery power source to the fan motor 3 so as to rotate the fan motor 3 at a certain rotation speed, and the second control circuit 7 may be configured to supply the power supply voltage or power supply current from the battery power source to the fan motor 3 so as to rotate the fan motor 3 at a rotation speed lower than the rotation speed. Furthermore, in the present invention, the second
A selection circuit 9 is provided with third and fourth control circuits that supply power from the battery power source to the fan motor 3 so as to sequentially control the rotation of the fan motor 3 at a rotation speed lower than that of the control circuit 7. A configuration that allows selection is also possible.

[0016]

Effects of the Invention As explained above, the cooling device of the present invention controls the power supply between the battery power source and the fan motor arranged in an electronic device so as to rotate the fan motor at the first rotation speed. A first control circuit that controls the fan motor and a second control circuit that controls the power supply to rotate the fan motor at a second rotation speed that is lower than the first rotation speed are arranged in parallel to control the operation of the electronic device. Correspondingly, by providing a selection circuit that selectively operates the first or second control circuit, the rotation speed of the fan motor is automatically controlled by switching the control signal from the selection circuit. The rotation speed of the fan motor can be variably controlled depending on the connection of the fan motor or specific processing operations using software. Therefore, in electronic devices equipped with fan motors, the power supplied from the battery power source is automatically adjusted according to the fan motor's operation, reducing wasteful consumption of power from the battery power source and extending the lifespan of the power source battery. It is possible to significantly extend the

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing an embodiment of a cooling device for electronic equipment according to the present invention.

[Explanation of symbols]

1 DC/DC converter 3 Fan motor 5 First control circuit 7 Second control circuit 9 Selection circuit E Battery power supply R resistance

Claims (1)

[Claims] 1. A battery power supply arranged in an electronic device, a fan motor rotated by power supplied from the battery power supply, and a fan motor arranged between the battery power supply and the fan motor and controlling the power supply to control the fan motor. a first control circuit that is disposed between the battery power source and the fan motor and controls the power supply to generate a second rotation speed of the fan motor that is lower than the first rotation speed; A cooling device for an electronic device, comprising: a second control circuit that generates a number; and a selection circuit that selectively controls the first or second control circuit in accordance with the operation of the electronic device. .