JPH0576093U - Cooling fan controller - Google Patents

Abstract

(57) [Summary] [PROBLEMS] The present invention relates to a cooling fan control device, and an object thereof is to provide a cooling fan control device with excellent efficiency in which the cooling capacity changes according to the heat generation state of a cooling target. is there. [Composition] A cooling fan attached to a device having a heat generating part, a temperature sensor for detecting a temperature change of the heat generating part according to an output to a load, and a rotation of the cooling fan based on an output signal of the temperature sensor. A rotation control circuit for controlling the number and a protection circuit for turning off the output to the load when the output signal of the temperature sensor exceeds a set value.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cooling fan control device incorporated in an electronic device or the like, and more particularly to improving efficiency.

[0002]

[Prior Art]

 Electronic devices, which may generate a relatively large amount of heat inside the device, often include a cooling fan as a cooling device.

For example, a cooling fan is also incorporated in the voltage / current generator. Further, the cooling fan incorporated in the conventional voltage / current generator is configured to always rotate at a constant rotation speed in conjunction with the power-on of the voltage / current generator.

[0004]

[Problems to be solved by the device]

 However, the cooling fan in such a conventional configuration operates at the same cooling capacity as in the high power output state in which the heat generation amount is considerably large even in the low power output state in which the heat generation amount is relatively small. , Power consumption is wasteful and efficiency is poor.

The present invention has been made in view of the above problems, and an object thereof is to provide a highly efficient cooling fan control device in which a cooling capacity is changed according to a heat generation state of a cooling target. Especially.

[0006]

[Means for Solving the Problems]

 A cooling fan control device according to the present invention includes a cooling fan attached to a device having a heat generating part, a temperature sensor for detecting a temperature change of the heat generating part according to an output to a load, and an output signal of the temperature sensor. It is composed of a rotation control circuit that controls the rotation speed of the cooling fan based on the above, and a protection circuit that turns off the output to the load when the output signal of the temperature sensor exceeds a set value. It is what

[0007]

[Action]

 The rotation speed of the cooling fan increases as the temperature of the heat generating portion increases, and decreases as the temperature of the heat generating portion decreases. That is, the cooling capacity of the cooling fan also changes according to the heat generation state of the heat generating portion, and efficient cooling can be performed.

[0008]

【Example】

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention. In the figure, reference numeral 1 denotes a heat radiating plate which is thermally coupled to a heat generating portion (not shown), and a temperature sensor 2 is attached to the heat radiating plate 1. The output signal v of the temperature sensor 2 is input to the non-inverting input terminal of the operational amplifier U1 and also to the non-inverting input terminal of the operational amplifier U2. The output terminal of the operational amplifier U1 is connected to the base of the transistor Q1 via the resistor R1. A voltage V _P is applied to the collector of the transistor Q1, and a cooling fan 3 is connected to the emitter and an earth is connected through a series circuit of resistors R2 and R3. The midpoint of connection between the resistors R2 and R3 is connected to the inverting input terminal of the operational amplifier U1. The base of the transistor Q2 is connected to the output terminal of the operational amplifier U2 via the resistor R4, and the DC voltage source 4 for outputting the set voltage V _th is connected to the inverting input terminal. A voltage V _P is applied to the collector of the transistor Q2 via a relay RL functioning as a protection circuit, and the emitter is connected to the ground.

FIG. 2 is a connection example diagram of a protection circuit, showing an example applied to a voltage / current generator. In the figure, a D / A converter 5 converts digital data input from a control unit (not shown) to set output voltage or output current into an analog signal. The analog signal is output to the output terminal 7 via the changeover contact switch SW of the relay RL and the amplifier 6. The switching contact switch SW switches and connects the input terminal of the amplifier 6 to the output terminal of the D / A converter 5 or ground.

FIG. 3 is a timing chart for explaining the operation of FIGS. 1 and 2. When the temperature T of the heat sink 1 changes as shown in (A), the output v of the temperature sensor 2 also changes as shown in (B) as in (A). The output v of the temperature sensor 2 is amplified by the operational amplifier U1 as shown in (C) and applied to the fan 3 as the drive voltage V. As a result, the rotation speed N of the fan 3 also changes according to the change of the drive voltage V as shown in (D). That is, when the temperature T of the heat sink 1 increases, the rotation speed N of the fan 3 increases and the cooling capacity increases, and when the temperature T of the heat sink 1 decreases, the rotation speed N of the fan 3 decreases and the cooling capacity increases. Will be lower.

On the other hand, the changeover contact switch SW of the relay RL is usually connected to the output terminal side of the D / A converter 5. Then, for example, when the fan 3 fails and does not rotate, the temperature T of the heat sink 1 becomes abnormally high and the output v of the temperature sensor 2 exceeds the set voltage V _th , the relay RL is excited and driven, and the changeover contact switch SW is switched to ground and connected. As a result, when the temperature T of the heat sink 1 becomes abnormally high, the output can be turned off, and an accident due to abnormal overheating can be prevented.

Although the temperature sensor is attached to the heat dissipation plate in the above-described embodiment, other members thermally coupled to the heat generating portion may be used. Further, the device is not limited to the voltage / current generator, and it is obvious that the device can be applied to various electronic devices having a built-in cooling fan.

[0013]

[Effect of the device]

 According to the present invention described in detail above, the following effects can be obtained. Since the cooling capacity of the cooling fan also changes according to the heat generation state of the heat generating part, the overall power consumption of the equipment can be saved.

Further, when abnormal overheating of the heat generating portion occurs when the fan is stopped, the output can be turned off, and the occurrence of an accident due to the abnormal overheating can be prevented.

[Brief description of drawings]

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

FIG. 2 is a connection example diagram of a protection circuit.

FIG. 3 is a timing chart illustrating the operation of FIGS. 1 and 2.

[Explanation of symbols]

 1 Heat sink 2 Temperature sensor 3 Cooling fan 4 DC power supply 5 D / A converter 6 Amplifier 7 Output terminal

Claims (1)

[Scope of utility model registration request] 1. A cooling fan attached to a device having a heat generating section, a temperature sensor for detecting a temperature change of the heat generating section according to an output to a load, and a cooling fan based on an output signal of the temperature sensor. A cooling fan control device, comprising: a rotation control circuit for controlling the number of rotations of the temperature sensor; and a protection circuit for turning off the output to the load when the output signal of the temperature sensor exceeds a set value.