JP2689166B2 - Motor control method - Google Patents

Description

The present invention relates to a motor control method, and more particularly to a fan motor control method.

[Problems to be solved by conventional technology and invention]

Generally, in an electronic device or the like in which electronic components are mounted inside a housing, it is necessary to cool the electronic components, and therefore a cooling fan is attached.

In the early stage of driving the electronic device, the amount of heat generated by each electronic component is not large and the electronic component does not need to be cooled so much. Therefore, it is not necessary to drive the fan, but if the electronic device is driven for a long time, , Each electronic component gradually becomes hot and needs to be cooled.

Therefore, if the fan is driven together with the driving of the electronic device, the current consumption becomes large, and if the fan is rotated at a high speed after the driving of the electronic device, noise becomes a problem.

Therefore, it is an object of the present invention to provide a motor control method that can save power and that does not easily generate noise.

Another object of the present invention is to provide a motor control method capable of easily switching between the case where the fan rotation control is controlled according to the temperature and the case where it is not.

[Means for solving the problem]

In order to achieve the above-mentioned object, the motor control method of the present invention is such that when the connector provided in the housing of the fan is in the open state, the impeller of the fan is rated by the motor winding excitation circuit provided in the housing. It is characterized in that the impeller is rotated according to the temperature detected by the temperature sensor when it is driven by rotation and a temperature control unit body having a temperature sensor is connected to the connector.

In this case, when the temperature detected by the temperature sensor is equal to or higher than a predetermined high temperature, control by the unit body is performed by supplying a continuous DC current to the motor winding excitation circuit to rotate the impeller at a constant high speed. When the detected temperature is equal to or lower than the predetermined low temperature, a pulse signal having a constant duty is input to the motor winding excitation circuit to rotate the impeller at a constant low speed, and the detected temperature is equal to or higher than the predetermined low temperature and the predetermined high temperature. In the following conditions, PWM control is performed so that the current supplied to the motor winding excitation circuit becomes continuous from the constant duty as the detected temperature rises from the predetermined low temperature to the predetermined high temperature. It is desirable to have the impeller rotation variable with temperature.

[Action]

In the motor control method of the present invention described above, in the state where the temperature control unit body is connected to the connector of the housing, the ambient temperature is detected by the temperature sensor of the unit body, and according to the detected temperature, the inside of the housing is moved from the unit body. A signal for controlling the number of revolutions is sent to the motor winding exciting circuit, for example, the impeller is controlled to rotate at a low speed when the ambient temperature is low, and the impeller is controlled to rotate at a high speed when the ambient temperature is high.

When the unit body is removed from the connector of the housing, the impeller of the fan is rotated at the rated rotation by the original control of the motor winding excitation circuit.

Further, in the control by the unit body, if the upper and lower limits are set for the ambient temperature, when the ambient temperature is below the predetermined low temperature, the impeller of the fan is rotated at a constant low speed, and when the ambient temperature rises above the predetermined low temperature, It is possible to control the impeller to rotate at a constant speed from a low speed constant rotation to a high speed gradually as the temperature rises, and further to rotate the impeller at a high speed constant rotation when the ambient temperature rises above a predetermined high temperature.

Even when the ambient temperature is lower than the predetermined low temperature, the fan is rotating at a low speed, and it is felt that the noise is smaller than when the fan suddenly starts rotating from the stopped state.
Also, when the ambient temperature is equal to or higher than the predetermined low temperature and equal to or lower than the predetermined high temperature, the fan rotates at a rotation speed according to the ambient temperature, and even if the fan rotates at high speed, noise is not bothered. Optimal cooling without waste is achieved. Further, when the ambient temperature becomes higher than or equal to a predetermined high temperature, the fan enters a high-speed constant rotation state, which is the upper limit, so that the fan does not have so-called runaway.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings showing examples.

FIG. 1 shows an embodiment of an electric circuit used in the motor control method according to the present invention. As shown in the block diagram of FIG. 2, this circuit includes a temperature sensor 1 such as a thermistor and a voltage comparator. 2 and a multi-valvator 3, which are mounted on a fan 4 as shown in FIG.

Here, as shown in FIG. 7, the fan 4 includes a motor unit 5, an impeller 6, and a housing 7, and a motor winding exciting circuit 8 is mounted on the fan 4.

The temperature sensor 1 uses a thermistor having a positive characteristic, and its resistance value increases as the temperature rises. The temperature characteristic of the voltage Va at the portion 9 is as shown in the graph of FIG. Become.

Further, the voltage comparator 2 is provided with an operational amplifier 10 and compares it with the reference voltage Vref to set the signal B at the portion 11 to a low level 12 if the temperature is below a predetermined temperature, as shown in FIG. If it is higher than the above, it is set to High level 13. That is, as shown in FIG. 3, at the point 14 where the reference voltage Vref (broken line) and the voltage Va (solid line) match, the signal at the part 11 switches from the low level 12 to the high level 13. In this embodiment, the switching point 14
Is 40 ° C.

Next, the multivibrator 3 includes an operational amplifier 15,
As shown in FIG. 5I, if the voltage Vb at the portion 11 is at the low level, the voltage at the portion 16 outputs the waveform signal as shown in FIG. 5II, and as shown in FIG. 6I. , Voltage Vb at part 11 is Hi
At the gh level, the voltage at the portion 16 outputs a waveform signal as shown in FIG.

Therefore, when the temperature detected by the temperature sensor 1 is below the predetermined temperature, the PWM signal is input to the motor winding excitation circuit 8, the impeller 6 of the fan 4 rotates at a constant low speed, and the detected temperature is above the predetermined temperature. Then, a continuous DC current is applied to the motor winding exciting circuit 8, and the impeller 6 rotates at a constant speed at a high speed.

Next, FIG. 8 shows a circuit diagram of another embodiment. In this case, the temperature sensor 1, the limiter circuit 17, the multivibrator 18, the integrating circuit 19, and the voltage comparator 20 are provided. . The temperature sensor 1 is a thermistor having a positive characteristic even in this case, and the limiter circuit 17 includes the operational amplifier 2
1, 22, the multivibrator 18 includes an operational amplifier 23, and the voltage comparator 20 includes an operational amplifier 24. That is,
As shown in FIG. 9, this circuit includes the temperature sensor 1, the limiter 17, the triangular wave generator 33, and the voltage comparator 20.

Therefore, the temperature characteristic of the voltage Vd at the portion 25 becomes a graph as shown in FIG. 10, and the voltage Vd rises as the temperature rises. Further, the temperature characteristic of the voltage Ve at the portion 26 becomes a graph as shown in FIG. That is, the limiter circuit 17 keeps a constant voltage value (5 V in the embodiment) below a predetermined low temperature (10 ° C. in the embodiment).

Then, the voltage Vf at the portion 27 becomes a triangular wave as shown in FIG. 12I, this triangular wave signal is input to the voltage comparator 20, and the voltage Vg at the portion 28 becomes a waveform as shown in FIG. 12 II. .
Note that in FIG. 12 II, the high state is the ON state, and the low level is the OFF state.

Therefore, when the temperature detected by the temperature sensor 1 is below a predetermined low temperature (10 ° C. in the embodiment), a constant PWM signal is input to the motor winding exciting circuit 8 and the impeller 6 of the fan 4 rotates at a low speed and a constant speed. When the temperature rises above the predetermined low temperature, the exciting circuit 8 is PWM-driven, and the speed increases in sequence as the temperature rises.

In this circuit, as shown in FIG. 11, the voltage value of the voltage Ve is not held at a constant voltage value even when it reaches a predetermined high temperature (50 ° C. in the embodiment), but the triangular wave of FIG. Since the thermistor voltage exceeding the voltage is input and excitation is performed in the whole section ON, the upper limit is set as a result. The DC current is applied, and the impeller 6 rotates at high speed and constantly.

That is, as shown in FIG. 13, the rotation speed is 1000 [rpm] at a predetermined low temperature (10 ° C) or lower, and the rotation speed is 2000 [rpm] at a predetermined high temperature (50 ° C) or higher, 10 ° C to Up to 50 ° C, the rotation speed is 1000 [rpm] to 2000 [rpm]
To rise.

Then, as shown in FIG. 14, the motor winding excitation circuit 8
It is also preferable to form a unit body 29 in which circuits other than the above are incorporated and attach the unit body 29 to the fan 4 in a detachable manner.

That is, the connector 30 is provided on the housing 7 of the fan 4, and the connector 31 provided on the cable 32 from the unit body 29 is detachably connected to the connector 30. In the connected state, the rotation speed of the impeller 6 is increased. Has an upper limit and a lower limit to its rotation speed when the temperature sensor 1 rises as the temperature rises. Also, if the connector 31 is removed, the rotation speed does not increase or decrease due to temperature changes, and the normal rated rotation Become.

Next, FIG. 15 shows a case where a thermistor having a negative characteristic is used as the temperature sensor 1.
As shown in the figure, the resistance value R _T decreases as the temperature rises.

In this case, therefore, the sensor 1 is connected in parallel with the temperature lower limit reference Zener diode 34. Therefore, the voltage Vo at the portion 35 has a waveform as shown in FIG. 17, and the lower limit of the rotational speed is determined as in the embodiment shown in FIG. The voltage V _Z represents the Zener voltage, and the voltage Vcc ′
Indicates the voltage at site 36.

It should be noted that the present invention is not limited to the above-described embodiment, and can be freely changed in design without departing from the gist of the present invention.
In the embodiment of the circuit diagram shown in FIG. 1, low level 12
The switching point of High level 13 can be freely set to a temperature other than 40 ° C., and in the embodiment of the circuit diagram shown in FIG. 8, the predetermined low temperature and the predetermined high temperature can be changed freely, and the predetermined low temperature can be changed. The rotation speed at a predetermined high temperature can be changed freely. Furthermore, in FIG. 8, it is also preferable to provide an upper limiter circuit.

〔The invention's effect〕

Since the motor control method according to the present invention is configured as described above, it has the following effects.

According to the motor control method of the first aspect, the temperature control unit can be attached to and detached from the connector provided on the housing of the fan to switch between the rated operation state and the temperature control state. The rotation speed control can be selectively used, and optimum fan operation, that is, cooling, can be performed according to the place of use and the application.

According to the motor control method of the second aspect, when the ambient temperature is a low temperature equal to or lower than the predetermined low temperature, the fan rotates at a low speed, so that the noise is felt to be smaller than when the fan suddenly starts rotating from the stopped state. . In addition, since the lower limit of the number of rotations (the number of rotations in the low speed rotation state) is provided, if the fan is a brushless motor type, it can be started reliably. In other words, if the duty ratio of the pulse signal supplied to the motor winding excitation circuit becomes small (shortening the ON time), the starting current required to start this motor cannot be supplied, so the duty ratio of the pulse signal The lower limit is set to ensure the start.

Also, when the ambient temperature is equal to or higher than the predetermined low temperature and equal to or lower than the predetermined high temperature, the fan rotates at a rotation speed according to the ambient temperature. Not only does this not occur, but also optimal cooling with no waste according to the ambient temperature is realized.

Further, when the ambient temperature becomes equal to or higher than a predetermined high temperature, the fan enters a high speed constant rotation state, which is the upper limit of the rotation speed of the fan, so that the fan does not run out.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing an embodiment used in a motor control method according to the present invention, FIG. 2 is a block diagram, and FIG. 3 is a voltage diagram.
FIG. 4 is a graph showing the temperature characteristic of Va, FIG. 4 is a graph showing the temperature characteristic of voltage Vb, FIG. 5 is a voltage waveform, and FIG.
Is a waveform diagram of voltage Vb, FIG. 5 is a waveform diagram of voltage Vc, FIG. 6 is a waveform diagram of voltage, and FIG. 6I is a waveform diagram of voltage Vb, FIG.
II is a waveform diagram showing the voltage Vc, FIG. 7 is a simplified perspective view of the fan, FIG. 8 is a circuit diagram showing another embodiment used in the motor control method, FIG. 9 is a block diagram, and FIG. FIG. 11 is a graph showing the temperature characteristic of the voltage Vd, FIG. 11 is a graph showing the temperature characteristic of the voltage Ve, FIG. 12 is a voltage waveform, and FIG.
Waveform diagram of Vf, FIG. 12 is a waveform diagram of voltage Vg, FIG. 13 is a graph diagram showing temperature characteristics of rotation speed, FIG. 14 is a simplified perspective view of a fan, and FIG. 15 is a modification of an electric circuit. The main circuit diagram shown,
Figure 16 is a graph showing the temperature characteristics of the resistance value of the temperature sensor.
FIG. 17 is a graph showing the temperature characteristics of the voltage Vo. 1 ... Temperature sensor, 4 ... Fan, 6 ... Impeller, 8 ... Motor winding excitation circuit.

Claims (2)

(57) [Claims] 1. When the connector 30 provided in the housing 7 of the fan 4 is in the released state, the motor winding excitation circuit provided in the housing 7 operates the impeller 6 of the fan 4 at the rated rotation, and A motor control method characterized in that when the temperature control unit body 29 having the temperature sensor 1 is connected to the connector 30, the rotation of the impeller 6 is changed according to the temperature detected by the temperature sensor 1. 2. The control by the unit body 29 is performed when the temperature detected by the temperature sensor 1 is higher than a predetermined high temperature.
When a continuous DC current is supplied to the motor winding excitation circuit 8 to rotate the impeller 6 at a high speed and a constant speed, and the detected temperature is equal to or lower than a predetermined low temperature, the motor winding excitation circuit 8 is pulsed with a constant duty. When a signal is input to rotate the impeller 6 at a constant low speed and the detected temperature is equal to or higher than the predetermined low temperature and equal to or lower than the predetermined high temperature, the detected temperature rises from the predetermined low temperature to the predetermined high temperature. 2. The rotation of the impeller 6 of the fan 4 is variable according to the temperature by performing PWM control so that the current supplied to the motor winding excitation circuit 8 becomes continuous from the constant duty in accordance with the above. Motor control method.