JPH0680397U - Motor rotation control circuit - Google Patents

Abstract

(57) [Summary] [Object] To provide a rotation control circuit of a motor capable of changing the rotation speed in two steps with a simple circuit configuration. [Configuration] Rotation is controlled by detecting the rotational position of the rotor,
In a rotation control circuit of a motor capable of switching between a low-speed rotation state and a high-speed rotation state, a switch means S is provided which drives only an arbitrary one-phase coil L2 of the multi-phase stator coils L1 and L2 during low-speed rotation. The number of turns of the one-phase coil L2 is larger than that of the other-phase coil L1, or the wire diameter of the one-phase coil L2 is smaller than that of the other-phase coil L1, or the one-phase coil L2 is wound. The tension at the time of rotation is made larger than that of the coil L1 of the other phase.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotation control circuit for a motor used for a fan for cooling OA (office automation) equipment, power supply equipment, and the like. More specifically, the invention relates to a motor rotation control circuit capable of switching between a low-speed rotation state and a high-speed rotation state. It relates to a rotation control circuit.

[0002]

[Prior art]

 In recent years, office automation equipment such as personal computers has been widely used, but in many of these equipment, a cooling fan is provided to prevent the equipment from overheating.

Some of such fans rotate at a low speed when the device is not driven and rotate at a high speed when the device is driven to enhance the cooling effect.

As a motor rotation control circuit for such a two-speed fan, for example, as shown in FIG. 3, a current is caused to flow through the stator coils L1 and L2 through a resistor R1, and both ends of this resistor R1 are semiconductor switches. The switch S1 is connected, and the switch S1 is turned off and on according to a low-speed / high-speed switching signal.

That is, when the switch S1 is off, the current flowing through the stator coils L1 and L2 becomes small, so that the magnetic driving force acting between the stator and the rotor including the magnet rotor decreases, The rotor rotates at a low speed, and when the switch S1 is turned on, the current increases and the rotor rotates at a high speed.

In the figure, HIC is a Hall element, DIC is an integrated circuit that constitutes the drive circuit DO1, and the current flowing through the coils L1 and L2 is supplied to the output transistors Q1 and Q2 based on the rotor rotation signal from the Hall element HIC. Switching control is performed through to obtain stable rotation of the rotor.

Further, as another rotation control circuit, as shown in FIG. 4, there is one in which a semiconductor switch S2 is connected to the base of the output transistor Q1 of one stator coil L1 in the two-phase motor.

According to this, by turning the switch S2 off and on according to the switching signal of low speed and high speed, when the switch S2 is off, the transistor Q1 is fixed to off and only the other stator coil L2 is driven. When the switch S2 is on, both the stator coils L1 and L2 are driven together.

[0009]

[Problems to be solved by the device]

 However, in the conventional rotation control circuit shown in FIG. 3, a resistor R1 having a large power consumption, that is, a large resistance capacity is required in order to reduce the current flowing through the stator coils L1 and L2 at low speed rotation. There is a problem with.

Further, in the case of the one shown in FIG. 4, there is a drawback that the rotation speed does not decrease so much even if only one phase is driven at low speed rotation.

Here, it is possible to combine the resistance insertion method shown in FIG. 3 and the one-phase drive method shown in FIG. That is, as shown in FIG. 5, a resistor R2 is connected in series to the stator coils L1 and L2, both ends of this resistor R2 are connected by a semiconductor switch S1, and the base of the output transistor Q1 of one stator coil L1 is further connected. The semiconductor switch S2 is connected.

When both the switches S1 and S2 are turned off in response to the low-speed and high-speed switching signals, only the stator coil L2 is driven, and the current flowing through the stator coil L2 is small, so that the rotor is When the switches rotate at low speed and both switches S1 and S2 are turned on, both stator coils L1 and L2 are driven by a large current, and the rotor rotates at high speed.

According to this, since the coil current can be reduced during one-phase driving at low speed rotation, the rotation speed can be greatly reduced, and the current limiting resistor R2 is connected to the one-phase stator coil L2. Since it is sufficient to reduce the current, there is an advantage that a resistor with low power consumption is enough.

However, this structure has a drawback that the circuit structure becomes complicated.

The present invention has been made in view of the above problems of the conventional technique, and an object of the present invention is to change the rotation speed in two steps with a simple circuit configuration. It is to provide a rotation control circuit of a motor capable of performing.

[0016]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the motor rotation control circuit of the present invention, the rotation position of the rotor is detected to control the rotation, and the rotation of the motor can be switched between a low speed rotation state and a high speed rotation state. In the control circuit, there is provided a switch means for setting only one arbitrary phase coil among the multiphase stator coils in a driving state at low speed rotation, and the number of turns of the one phase coil is larger than that of the other phase coils, or The wire diameter of the coil of one phase is made smaller than that of the coils of the other phases, or the winding tension of the coil of the one phase is made larger than that of the coils of the other phases.

In the rotation control circuit of the motor of the present invention, the rotation position of the rotor is detected to control the rotation, and the rotation control circuit of the motor capable of switching between the low-speed rotation state and the high-speed rotation state has a low speed. Switch means is provided for driving only any one-phase coil of the multi-phase stator coil during rotation, and a resistor is connected in series only to the one-phase coil.

[0018]

[Action]

 In the rotation control circuit of the motor having the above-described configuration, in the case where the number of turns of any one-phase coil is larger than that of the coils of other phases, this one-phase coil is If the electric resistance increases more than the attractive force increases and only one phase coil of the multi-phase stator coil is driven at low speed rotation, the current flowing through this coil is small and the rotor speed Is reduced.

When the wire diameter of an arbitrary one-phase coil is smaller than that of the coils of other phases, the resistance of this one-phase coil becomes large, and the resistance of any one of the multi-phase stator coils during low-speed rotation is increased. When only the one-phase coil is in a driving state, the current flowing through this coil is small, so that the rotational speed of the rotor decreases.

Further, in the case where the winding tension of an arbitrary one-phase coil is made larger than that of the coils of the other phases, this one-phase coil is pulled in the lengthwise direction to reduce its wire diameter. As a result, the resistance increases, and when only one of the multiphase stator coils is driven during low speed rotation, the current flowing through this coil is small and the rotor speed decreases.

Next, in the case where a resistor is connected in series only to an arbitrary one-phase coil, when only one arbitrary one-phase coil of the multi-phase stator coils is driven during low-speed rotation, this coil Since the flowing current is small, the rotation speed of the rotor is reduced.

[0022]

【Example】

 An example will be described with reference to FIGS. 1 and 2. In these drawings, the same reference numerals as those used in the related art denote the same or corresponding ones.

First, the first embodiment will be described with reference to FIG. FIG. 1 shows a drive circuit of a brushless two-phase motor used for a cooling fan or the like, in which two-phase stator coils L1 and L2 are connected to a DC power supply terminal VCC, and these coils L1 and L2 are output transistors Q1 and It is connected to the ground terminal GND through Q2.

The transistors Q1 and Q2 control switching of currents flowing through the coils L1 and L2, and the transistors L1 and L2 switch according to a signal from the motor driving integrated circuit DIC input to the base.

Further, a hall element HIC that magnetically detects the position of the rotor and outputs a signal is connected to the integrated circuit DIC.

A semiconductor switch S is connected to the base of a transistor Q1 connected to one coil L1 of the coils L1 and L2. The switch S is turned on / off in response to a low speed / high speed switching signal, and during low speed rotation, the transistor Q1 is fixed to be off to form a driving state by only the other coil Q2.

Further, the winding factor of the one coil L1 is different from that of the other coil L2. That is, the number of turns of the coil L2 is larger than that of the coil L1.

Here, when the number of turns of the coil L2 increases, the magnetic attraction force generated during energization increases, but the increase in the number of turns also causes an increase in resistance, and the current flowing through the coil L2 exceeds the magnetic attraction force. Decrease.

Therefore, at low speed rotation, the switch S is turned off to drive only the other coil L2 having a large resistance, and the current flowing through the coil L2 is small, so that the rotor rotates at a low speed.

Further, at the time of high speed rotation, both coils L1 and L2 are energized. In this case, the current flowing through the other coil L2 is still small, but a large current flows through one coil L1. Rotates at high speed.

In the above embodiment, the number of turns is increased in order to make the winding factor of the other coil L2 different from that of the one coil L1, but the number of turns is not limited to this, and the wire diameter of the coil L2 may be changed to the coil L1. It may be made smaller to increase the resistance of the coil L2.

Alternatively, the tension at the time of winding the coil L2 may be made higher than that of the coil L1. When the tension of the winding is increased, the winding is pulled in the length direction, the wire diameter is reduced, and the resistance of the coil L2 is increased.

As described above, in the configuration in which the coil L2 has a large resistance by changing the winding factor of the other coil L2 with respect to the one coil L1, not only the conventional resistance becomes unnecessary, but the circuit is not required. The configuration is simple.

Next, a second embodiment will be described with reference to FIG. In this embodiment, the resistor R is connected in series only to the coil L2 that is driven at low speed rotation by turning the semiconductor switch S on and off.

Therefore, as in the case of the first embodiment, at the time of low speed rotation, the current flowing through the coil L2 can be limited by the resistor R, so that the rotor can be rotated at low speed. Moreover, since the resistor R only needs to limit the current of the other coil L2, it is not necessary to use a resistor that consumes a large amount of power as in the conventional case.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and it is obvious that the present invention can be modified without departing from the gist of the present invention.

[0037]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. In the rotation control circuit for a motor according to any one of claims 1 to 3, the number of turns of a coil of one phase driven at low speed rotation is made larger than that of coils of other phases, or the coil wire of the one phase is The diameter can be made smaller than the coils of other phases, or the winding tension of the one-phase coil can be made larger than that of the coils of other phases, and the current flowing through the one-phase coils can be made smaller to rotate the rotor at low speed. As a result, the conventional resistance can be eliminated and the circuit configuration can be greatly simplified.

Further, in the motor rotation control circuit according to the fourth aspect, since the resistor is connected in series only to the one-phase coil driven at the low speed rotation, the one-phase coil has a simple circuit configuration. It is possible to reduce the current flowing through the rotor to rotate the rotor at low speed, and it is not necessary to use a resistor that consumes a large amount of power as in the conventional case.

[Brief description of drawings]

FIG. 1 is a first embodiment of a motor rotation control circuit according to the present invention.
It is a circuit diagram showing.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a conventional rotation control circuit.

FIG. 4 is a circuit diagram showing another conventional rotation control circuit.

FIG. 5 is a circuit diagram showing still another conventional rotation control circuit.

[Explanation of symbols]

 L1, L2 Stator coil Q1, Q2 Output transistor S Semiconductor switch R Resistance

Claims (4)

[Scope of utility model registration request] 1. A rotation control circuit for a motor, which detects rotation position of a rotor and controls rotation to switch between a low-speed rotation state and a high-speed rotation state. A rotation control circuit for a motor, characterized in that a switch means for setting only a phase coil to a driving state is provided, and the number of turns of the one phase coil is larger than that of the coils of other phases. 2. A rotation control circuit for a motor capable of detecting rotation position of a rotor and controlling rotation to switch between a low speed rotation state and a high speed rotation state. A rotation control circuit for a motor, characterized in that a switch means for setting only a phase coil to a driving state is provided, and a wire diameter of the one phase coil is made smaller than coils of other phases. 3. A rotation control circuit for a motor capable of detecting rotation position of a rotor to control rotation and switching between a low speed rotation state and a high speed rotation state. A rotation control circuit for a motor, characterized in that a switching means for driving only a phase coil is provided, and a tension at the time of winding the one phase coil is made larger than that of coils of other phases. 4. A rotation control circuit for a motor capable of detecting rotation position of a rotor and controlling rotation to switch between a low speed rotation state and a high speed rotation state. A rotation control circuit for a motor, characterized in that a switch means for driving only a phase coil is provided and a resistor is connected in series only to the phase 1 coil.