JPH08242596A - Dc brushless motor and its control circuit - Google Patents

Abstract

PURPOSE: To provide a DC brushless motor and its control circuit capable of increasing the maximum value of current being able to cause to flow in the coil, and increasing the torque too. CONSTITUTION: A DC brushless motor 1 having coils 10U, 10V, 10W separated from one another and independent, and a DC brushless motor control circuit 2 for controlling the drive of this motor 1 are provided. In this control circuit 2, control of selecting two out of coils 10U, 10V, 10W according to phase switching signals U1-U4, V1-V4, W1-W4 from a phase switching signal generating circuit 22, and causing current to flow into each selected coil independently is performed by an H bridged driver circuit 23, switching coils to be objects in a fixed order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC brushless motor and a DC brushless motor control circuit suitable for use in a magnetic disk device or the like.

[0002]

2. Description of the Related Art Conventionally, a DC brushless motor used for a spindle motor or the like of a magnetic disk drive and its control circuit have generally been constructed as shown in FIG. First, the DC brushless motors 3 are N, for example, 3
It is equipped with individual coils 30U, 30V and 30W. These three coils 30U, 30V and 30W are U
Phase, V phase, W phase, common contact point (common point) 31
Have. As a drive method of the motor 3, bipolar drive in which a current is passed between two phases is often used.

On the other hand, the DC brushless motor control circuit 4
Is a current source 41 for controlling the current flowing through the motor 3 and a phase switching signal for generating signals (phase switching signals) UT, UB, VT, VB, WT, WB for controlling the switching of the phases through which the current flows. A generation circuit 42 and an H-bridge type driver circuit 43 for switching current according to the phase switching signal.
And coils 30U, 30V, 3 depending on the rotation of the motor 3.
It has a phase detection circuit 44 for detecting the position of a rotor (not shown) by detecting the induced voltage generated at 0 W.

The driver circuit 43 includes the coil 3 of the motor 3.
Switching circuit 4 connected to 0U, 30V, 30W
It consists of 30U, 430V and 430W. The switching circuit 430U is driven by the signals UT and UB, the switching circuit 430V is driven by the signals VT and VB, and the switching circuit 430W is driven by the signals WT and WB.

The phase detection circuit 44 includes coils 30U and 30V.
, 30W phase voltage and coil 30U, 30V, 30W common point (contact point) 31 voltage (common voltage)
The comparators 440U, 440V, and 440W for comparing

In the configuration of FIG. 5, the current from the current source 41 is supplied to the phase switching signal UT, UB, VT from the phase switching signal generating circuit 42 by the H-bridge type driver circuit 430.
According to VB, WT, WB, as shown in FIG.
It flows through two coils (between two phases) of one coil 30U, 30V, 30W. Torque is generated in the motor 3 by this current, and if the motor 3 is applied to a disk device, the disk is driven.

When the current flow method (bipolar drive) as shown in FIG. 6 is applied, the maximum value of the current that can be passed through the motor 3 by the H-bridge type driver circuit 42 is a constant coil DC resistance (per phase). Assuming that the voltage required to configure the 5Ω current source 41 is 0.5V, the power supply voltage (Vcc) is 5V, the following calculation is performed.

Maximum current = (5 (V) −0.5 (V)) ÷ (2.5 (Ω) +2.5 (Ω)) = 0.9 (A) In the configuration of FIG. 2 of the current is flowing
For the two phases (coils), the phase voltage when the induced voltage (back electromotive force) is not considered is High as shown in FIG.
(Voltage VM lower than the power supply voltage Vcc by a voltage required to form the current source 41) / Low (ground G). On the other hand, the remaining one phase (one phase in which current is not drawn or drawn) is in a high-impedance state, so that the induced voltage generated by the rotation of the motor 3 directly appears. The center voltage of the generation of the induced voltage is the intermediate voltage (common voltage) COM of the two-phase coils in which current flows, as shown in FIG. Here, since the current is made to flow between the two phases, the induced voltage can always be detected in the one phase at any timing. Therefore, as described above, the common voltage COM and the coils 30U, 30V, 30W
By comparing the phase voltages of the above with the comparators 440U, 440V, 440W, the movement of the induced voltage can be detected and the position of the rotor can be known.

[0009]

By the way, in the DC brushless motor, the obtained torque is almost proportional to the current. Therefore, the larger the maximum value of the current that can flow, the larger the torque. However, the conventional DC brushless motor of the type in which a current is passed between the two phases is advantageous in terms of torque efficiency because six types of phase switching combinations are possible, but it is limited by the DC resistance of the coils for the two phases. It was difficult to increase the maximum value of the current that can be passed without increasing the power supply voltage and increase the torque.

On the other hand, when a DC brushless motor is applied to a magnetic disk device, it is expected that the magnetic disk device in the future will have a lower voltage and an increased number of disks. Is required.

However, the conventional DC brushless motor has not been able to meet such requirements as described above. The present invention has been made in view of the above circumstances, and an object thereof is to provide a DC brushless motor and a control circuit therefor capable of increasing the maximum value of the current that can flow in the coil and increasing the torque as compared with the conventional case. is there.

[0012]

A DC brushless motor (N-phase DC brushless motor) according to the present invention is provided with N coils which are separated and independent from each other, and each coil has a structure in which a current can flow independently. It is a feature.

The DC brushless motor control circuit of the present invention is for controlling the drive of a DC brushless motor having N coils which are separated and independent of each other.
A driver circuit for selecting two of the N coils of the brushless motor and individually controlling the flow of current to each of the selected coils while switching the target coils in a fixed order is provided. Characterize.

The DC brushless motor control circuit of the present invention compares a reference voltage source for supplying a reference voltage to one end of each of the N coils with a voltage on one end and a voltage on the other end of each coil. Therefore, a phase detection circuit for performing phase detection is further provided.

[0015]

In the DC brushless motor having the above structure, the N coils forming the N phase (unlike the conventional N phase DC brushless motor) do not have contacts (common point) and are separated and independent from each other. Therefore, each coil has a structure in which a current can flow independently. Therefore, unlike a conventional DC brushless motor in which N coils have a common point, in which a current is passed in series between two phases, the maximum current that can be passed through the coils can be increased. For example, by the DC brushless motor control circuit having the above-described configuration, a current is independently applied to two (two phases) of the N coils so that the direction of the current flowing through the coils is the same as that of the conventional motor. When the control is performed while switching the coils through which the currents are passed in a fixed order, the maximum current that can be passed through the coils can be doubled as compared with the conventional case under the same power supply voltage condition as the conventional case.

Further, in the DC brushless motor control circuit having the above-mentioned configuration, the common voltage generated at the common point of the conventional motor (the common point which is the middle point of the N coils) at each end of the N coils. Since the reference voltage corresponding to is supplied by the reference voltage source, even when the coil is in a high impedance state where no current flows, the phase detection circuit compares this reference voltage with the phase voltage generated in each coil, Since the movement of the induced voltage in the coil that is not related to driving can be detected, the rotor position can be detected (phase detection) while the N coils are cut off without having a common point.

[0017]

1 is a block diagram of a DC brushless motor and its control circuit according to an embodiment of the present invention. In FIG. 1, reference numeral 1 is a DC brushless motor that generates torque by flowing current, and 2 is a DC for driving and controlling the motor 1.
It is a brushless motor control circuit.

The DC brushless motor 1 has N, for example, three coils 10U (U phase), 10V (V phase), and 10W.
(W phase). This coil 10U, 10V, 1
Unlike the coils 30U, 30V, and 30W of the conventional DC brushless motor 3 shown in FIG. 5, 0W is independent of each other without having a contact point (common point), and each of them can independently carry current. It is characterized by

The DC brushless motor control circuit 2 has a current source 21, a phase switching signal generation circuit 22, an H-bridge type driver circuit 23, a phase detection circuit 24 and a reference voltage source 25.

The current source 21 controls the current flowing through the motor 1. The phase switching signal generation circuit 22 is based on the phase detection signals (rotor position signals) PU, PV, PW detected and output by the phase detection circuit 24, and the phase and current direction in which the current generated by the current source 21 flows. Signals (phase switching signals) U1 to U4, V1 to V4, W1 to W for controlling switching (switching between a phase for flowing current and a phase for drawing current)
4 is generated.

The H-bridge type driver circuit 23 has the phase switching signals U1 to U4 generated by the phase switching signal generating circuit 22.
From the current source 21 to the motor 1 according to V1 to V4 and W1 to W4
The switching of the current flowing through the coils 10U, 10V and 10W is performed.

The driver circuit 23 is a pair of switching circuits 230UA and 230UB for controlling the on / off and direction of the current flowing through the coil 10U at both ends of the coil 10U.
And a pair of switching circuits 230VA and 230VB for controlling the on / off and direction of the current flowing through the coil 10V at both ends of the coil 10V, and the on / off switching of the current flowing through the coil 10W at both ends of the coil 10W. It is composed of a pair of switching circuits 230WA and 230WB for controlling the direction.

Switching circuits 230UA, 230UB, 2
30VA, 230VB, 230WA, 230WB are each 1
Pair of switching transistors, eg driver FET
It consists of 231. The pair of FETs 231 forming the switching circuit 230UA is turned on / off by the phase switching signals U1 and U2.
A pair of FETs that are turned off and form the switching circuit 230UB
231 is turned on / off by the phase switching signals U3 and U4. A pair of FETs 23 forming a switching circuit 230VA
1 is turned on / off by the phase switching signals V1 and V2, and the pair of FETs 231 forming the switching circuit 230VB are turned on / off by the phase switching signals V3 and V4. The pair of FETs 231 forming the switching circuit 230WA are turned on / off by the phase switching signals W1 and W2, and the switching circuit 2
The pair of FETs 231 forming 30 WB are phase switching signals W3 and W.
Turn on / off by 4. Where the signals U1 and U4,
The signals U2 and U3, the signals V1 and V4, the signals V2 and V3, the signals W1 and W4, and the signals W2 and W3 are the same signals.

The switching circuit 230UA includes the coil 10
One end point 110UA of U is switched and connected to the current source 21 side when the signal U1 is High (on) and the signal U2 is Low (off), and the signal U1 is Low and the signal U2 is Hi.
When it is gh, it is switched to the ground G side and connected. The switching circuit 230UB is connected to the other end 11 of the coil 10U.
0UB, signal U3 (= U2) is High, signal U4 (=
When U1) is Low, the current source 21 side is switched and connected, the signal U3 (= U2) is Low, and the signal U4 (= U1)
Is High, the connection is switched to the ground G side.

The switching circuit 230VA includes the coil 10
One end point 110VA of V is switched and connected to the current source 21 side when the signal V1 is High and the signal V2 is Low,
When the signal V1 is Low and the signal V2 is High, the connection is switched to the ground G side. Switching circuit 230VB
Connects the other end point 110VB of the coil 10V to the signal V3
When (= V2) is High and the signal V4 (= V1) is Low, the connection is switched to the current source 21 side, and the signal V3 (= V
When 2) is Low and the signal V4 (= V1) is High, the connection is switched to the ground G side.

The switching circuit 230WA includes the coil 10
One end point 110WA of W is switched and connected to the current source 21 side when the signal W1 is High and the signal V2 is Low,
When the signal W1 is Low and the signal W2 is High, the connection is switched to the ground G side. Switching circuit 230WB
The signal W3 from the other end point 110WB of the coil 10W.
When (= W2) is High and the signal W4 (= W1) is Low, the current source 21 side is switched and connected, and the signal W3 (= W
When 2) is Low and the signal V4 (= W1) is High, the connection is switched to the ground G side.

The phase detection circuit 24 detects the position of the rotor (not shown) of the motor 1 by detecting the induced voltage (back electromotive force) generated in the coils 10U, 10V and 10W according to the rotation of the motor 1. To do. Phase detection circuit 24
Is a comparator 240U that compares the voltage (U-phase voltage) on one end point 110UA side of the coil 10U of the motor 1 with the voltage on the other end point 110UB side, and one end point 11 of the coil 10V.
A comparator 240V for comparing the voltage on the 0VB side (V phase voltage) and the voltage on the other end point 110VA side, the one end point 110W of the coil 10W on the WB side (W phase voltage) and the other end point 110.
It is composed of a comparator 240W for comparing the voltage on the WA side. The outputs of the comparators 240U, 240V, 240W are supplied to the phase switching signal generation circuit 22 as phase detection signals (rotor position signals) PU, PV, PW.

The reference voltage source 25 includes coils 10U and 10V.
, 10W end points 110UB, 110VA, 110WA are connected via a resistor Rc, and a reference voltage Vref is applied.

Next, a method of supplying a current to the DC brushless motor 1 in the configuration of FIG. 1 will be described with reference to FIGS. 2 and 3. In the configuration of FIG. 1, the directions of the currents flowing through the coils 10U, 10V and 10W of the motor 1 are the same as those of the bipolar drive system for the conventional DC brushless motor 3 as shown in FIG. The characteristic point of this embodiment is that the common point is cut off to allow the coil 10U,
It means that the current is not applied in series to the two coils (between the two phases) of 10V and 10W, but the current is applied independently to each of the two coils.

In the example of FIG. 2, one end 110UA of the coil 10U is connected to the current source 21 by the switching circuit 230UA.
By switching and connecting the other end point 110UB to the ground G side by the switching circuit 230UB, a current is supplied to the coil 10U in the direction of the arrow 2U, and one end point 110VA of the coil 10V is switched by the switching circuit 230VA. It is connected to the source 21 side by switching, and the other end point 110VB is connected to the switching circuit 230.
By switching and connecting to the ground G side by VB, a current is applied to the coil 10V in the direction of arrow 2V. At this time, the remaining switching circuits 230WA and 230WB do not connect the coil 10W to either the current source 21 or the ground G side. In the example of FIG. 2, the coil 10U corresponds to the phase for flowing a current in the conventional bipolar drive system, and the coil 10V also corresponds to the phase for drawing a current. The coil 10W corresponds to the phase in the high impedance state in the conventional bipolar drive system.

Due to the current flow method as shown in FIG. 2, the maximum current that can be passed through the coil can be increased as compared with the conventional bipolar drive, although the current flows in the two phases as in the conventional bipolar drive. Therefore, the torque of the motor 1 can be increased. The maximum current here is constant in the coil DC resistance (per phase) 2.5Ω, voltage required to configure the current source 21 0.5V Power supply voltage (Vcc) 5V Assuming the same value as the case, the following calculation is performed.

Maximum current = (5 (V) −0.5 (V)) ÷ 2.5 (Ω) = 1.8 (A) As a result, the maximum current is doubled and therefore the maximum torque is increased as compared with the conventional method. It can be seen that is almost doubled.

In the present embodiment, in order to realize the above-described current flow method (driving method), the phase switching signal generation circuit 22 causes the phase switching signals U1 and U1 at the timings shown in FIG.
U2, U3 (= U2), U4 (= U1), V1, V2
V3 (= V2), V4 (= V1), W1, W2, W3
By generating (= W2) and W4 (= W1), the switching circuit 230U in the H-bridge type driver circuit 23 is generated.
A, 230UB, 230VA, 230VB, 230WA, 230W
Controls B. In this case, the coil 10U of the motor 1
The phase voltages without considering the induced voltages of (U phase), 10V (V phase), and 10W (W phase) are as shown in FIG.

Next, phase detection (rotor position detection) and the like in the configuration of FIG. 1 will be described with reference to FIG. First,
Coil 1 of DC brushless motor 1 applied in this embodiment
0U, 10V, and 10W are independent of each other without a contact (common point). On the other hand, the coils 30U, 30V, 30 of the conventional DC brushless motor 3 shown in FIG.
W has a contact (common point). Therefore, in the conventional motor (3), the center voltage of the induced voltage generated in the coil due to the rotation of the motor (3) is, as described in the "Prior Art" section, the two-phase current It becomes the intermediate voltage (common voltage) of the coil. Since the current flows between the two phases,
The induced voltage can always be detected in one phase at any timing. Therefore, the position of the rotor can be known by detecting the movement of the induced voltage by comparing the common voltage with the phase voltage of each coil.

On the other hand, the present embodiment is similar to the conventional one in that currents are applied to the two phases, but since the coils 10U, 10V and 10W of the DC brushless motor 1 do not have contacts (common points), common voltage is used. No longer exists. That is, the common voltage that serves as a reference voltage for accurately detecting the induced voltage (phase voltage) does not exist. In this case, the conventional method of comparing the induced voltage (phase voltage) with the common voltage cannot be applied to the rotor position detection (phase detection).

Therefore, in this embodiment, in order to accurately detect the induced voltage (back electromotive force) as shown in FIG. 4 generated in the coils 10U, 10V and 10W of the DC brushless motor 1, as shown in FIG. Then, a reference voltage Vref corresponding to the common voltage is supplied from the reference voltage source 25 to the coils 10U, 1
The end points 110UB, 110VA, and 110WA of 0V and 10W are applied. However, each coil 10U, 10V,
Since 10 W has a role of passing current, its end point 110
The reference voltage source 25 cannot be directly connected to UB, 110VA, 110WA. Therefore, in this embodiment, the coil 1
Coil 10U, 10V through a resistor Rc having a resistance value high enough not to affect the current flowing in 0U, 10V, 10W
, 10W end points 110UB, 110VA, 110WA are connected to the reference voltage source 25. By doing this, coil 1
The reference voltage Vref (corresponding to the common voltage) can be applied at the time of high impedance without affecting the currents flowing in 0U, 10V and 10W. Here, as the resistance value of the resistor Rc, a high value such that a current does not flow into the reference voltage source 25 and a large current load is not applied to the reference voltage source 25, for example, the coil 10U.
, A value of several hundred times to several thousand times the resistance of 10V and 10W (1KΩ to 10KΩ if the resistance of the coils 10U, 10V and 10W is, for example, about 2.5Ω). Further, in the present embodiment, as the voltage value of the reference voltage Vref, a voltage value (Vcc / 2) that matches the center voltage of the induced voltage, that is, the intermediate voltage of the two coils through which the current is flowing, is used, but it is not always necessary. It need not be Vcc / 2.

Now, the comparator 240U in the phase detection circuit 24
, 240V, 240W are one end points 110UA, 110 of the coils 10U, 10V, 10W of the motor 1, respectively.
VB, 110WB each voltage (phase voltage), the other end 110U
B, 110VA, 110WA voltage comparison. Here, the end points 110UB, 1 of the coils 10U, 10V, 10W
A reference voltage Vref corresponding to the common voltage is applied to 10VA and 110WA by the reference voltage source 25. Therefore, comparators 240U, 240V, 240W
Is equivalent to comparing the phase voltage of the coils 10U, 10V, 10W with the common voltage (COM) as in the conventional method, even though the coils 10U, 10V, 10W have no common point. Will be done, coil 10U, 1
Of 0 V and 10 W, the induced voltage generated in the coil in the high impedance state (floating state) where current does not flow (not related to current driving) (induced voltage generated in one of the three phases) is accurate. Then, the position of the rotor can be detected.

As a result of the above comparison, the comparators 240U, 240V and 240W have a high level during which the phase voltage of the coils 10U, 10V and 10W is higher than the reference voltage Vref (corresponding to the common voltage), and low during a small period.
The phase detection signals (rotor position signals) PU, PV, PW as shown in FIG. This signal PU,
PV and PW themselves are the comparator 44 in the conventional configuration of FIG.
Same as 0U, 440V, 440W output. The signals PU, PV, PW (from the comparators 240U, 240V, 240W in the control circuit 2) are guided to the phase switching signal generation circuit 22.

The phase switching signal generation circuit 22 includes the phase detection circuit 2
Phase detection signals (rotor position signals) from 4 PU, PV, P
W is delayed by a certain time Δt, and the phase excitation timing is determined based on the delayed phase detection signals (rotor position signals) PU, PV, PW as shown in FIG. The signals U1 to U4, V1 to V4 and W1 to W4 are generated. The reason why the signals PU, PV, PW are delayed by the time Δt is that it is necessary to delay the phase excitation timing by a predetermined electrical angle (generally 30 °). The logic representing the timing of phase excitation in the present embodiment is based on the states ETU, ETV, E for each phase U, V, W.
It is shown in FIG. 4 as TW.

Here, the states ETU, ETV, ETW are H.
In the case of the high level, in the conventional bipolar drive, the switch state corresponds to the state in which the current is supplied from the current source 21 to the coils 10U, 10V, 10W, that is, the switching circuits 230UA, 230VB, 2 in the driver circuit 23.
30 WB current source 21 side FET231 is turned on, ground G
The side FET 231 is off, and the switching circuit 230UB,
The current source 21 side FET 231 of 230VA and 230WA is off, and the ground G side FET 231 is on.

The states ETU, ETV, ETW are low.
In the case of the level, a switch state corresponding to a state in which current is drawn from the coils 10U, 10V, 10W to the ground G in the conventional bipolar drive, that is, the driver circuit 2
Switching circuit 230UA, 230VB, 230WB in 3
Current source 21 side FET231 is off, ground G side FE
When T231 is on, the switching circuits 230UB, 230
The current source 21 side FET 231 of VA, 230WA is on, and the ground G side FET 231 is off.

The states ETU, ETV, ETW are High.
In the case of the state Z (referred to as the Z level) which is neither the h level nor the low level, the coils 10U, 10V and 10W are in the high impedance state, that is, the switching states 230UA and 230V in the driver circuit 23.
B, 230 WB current source 21 side and ground G side FET2
When both 31 are off, the switching circuits 230UB, 230
VA, 230WA current source 21 side and ground G side FET2
Both 31 also indicate an off state.

Therefore, the switching circuits 230UA, 230VB, generated by the phase switching signal generating circuit 22,
230WB (230UB, 230VA, 230WA) current source 2
Phase switching signals U1, V1, W1 (U for controlling ON / OFF of the 1-side FET 231 (ground G-side FET 231)
4, V4, W4) is on (High level),
The high level period of the states ETU, ETV, and ETW corresponds to the high level period, and the state ETU, ETU,
This coincides with a period (Low level or Z level period) where ETV and ETW are not at High level. Similarly, switching circuits 230UA, 230VB, 230WB (230U
B, 230VA, 230WA) ground G side FET231
Phase switching signals U2, V2, W2 (U3, V3, W3) for controlling on / off of (current source 21 side FET 231)
Is on (high level), the states ETU, ET
Matches the low level period of V and ETW, and turns off (Lo
(w level) period is L of states ETU, ETV, ETW
This coincides with the period that is not the ow level (the period of the Hihg level or the Z level).

Phase switching signals U1 to U4 and V1 generated by the phase switching signal generation circuit 22 based on the phase detection signals (rotor position signals) PU, PV and PW from the phase detection circuit 24.
~ V4, W1 to W4 are supplied to the H-bridge type driver circuit 23. Switching circuit 2 in driver circuit 23
30UA is based on the phase switching signals U1 and U2, the switching circuit 230UB is based on the phase switching signals U3 and U4, the switching circuit 230VA is based on the phase switching signals V1 and V2, the switching circuit 230VB is based on the phase switching signals V3 and V4, and the switching circuit 230WA is The phase switching signals W1 and W2 cause the switching circuit 230WB to switch the phase switching signal W1.
3 and W4, respectively. As a result, as described above, the motor 1 is driven so that the current flows in the two phases and the remaining one phase becomes high impedance, and the induced voltage (back electromotive force) of the coils 10U, 10V, 10W is taken into consideration. Phase voltage (phase voltage observed at the end points 110UA, 110VB, 110WB of coils 10U, 10V, 10W)
Becomes as shown in FIG. The comparators 240U, 240V and 240W in the phase detection circuit 24 convert the phase voltages of the coils 10U, 10V and 10W into the coils 10U and 1W, respectively.
As described above, the phase detection signals (rotor position signals) PU, PV, P are compared with the reference voltage Vref given to the 0V, 10W end points 110UB, 110VA, 110WA.
Output W. Although the three-phase DC brushless motor has been described above, the present invention can be similarly applied to a four-phase or more DC brushless motor.

[0045]

As described above in detail, according to the present invention, D
Since each coil (each phase) of the C brushless motor can be independently supplied with current, the maximum value of current that can be applied to the coil can be increased and torque can be increased as compared with the conventional case.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a DC brushless motor and its control circuit according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining how to pass a current to a motor in the embodiment.

FIG. 3 is a diagram for explaining a motor drive logic in the embodiment.

FIG. 4 is a view mainly for explaining phase detection in the embodiment.

FIG. 5 is a diagram showing a configuration of a conventional DC brushless motor and its control circuit.

FIG. 6 is a diagram for explaining how to pass a current through a conventional motor.

FIG. 7 is a diagram for explaining a conventional motor drive logic.

[Explanation of symbols]

1 ... DC brushless motor (3-phase DC brushless motor), 2 ... DC brushless motor control circuit, 10U, 1
0V, 10W ... Coil, 21 ... Current source, 22 ... Phase switching signal generating circuit, 23 ... H bridge type driver circuit, 24 ...
Phase detection circuit, 25 ... Reference voltage source, 230UA, 230UB,
230VA, 230VB, 230WA, 230WB ... Switching circuit, 231 ... FET, 240U, 240V, 240
W ... comparator.

Claims (4)

[Claims] 1. A DC brushless motor, comprising N (N is an integer of 3 or more) coils independent of each other, and having a structure in which a current can flow through each coil independently. 2. A DC brushless motor control circuit for driving and controlling a DC brushless motor comprising N (N is an integer of 3 or more) coils independent of each other. A driver circuit for selecting two of the coils and individually controlling the flow of current through the selected coils while switching the target coils in a fixed order.
C brushless motor control circuit. 3. A DC brushless motor control circuit for driving and controlling a DC brushless motor comprising N (N is an integer of 3 or more) coils independent of each other. A driver circuit that selects two of the coils and independently applies a current to each of the selected coils while switching the target coils in a certain order, and a driver circuit on one end side of the N coils. A D is provided with a reference voltage source for giving a reference voltage, and a phase detection circuit for performing phase detection by comparing the voltage on one end side and the voltage on the other end side of each coil.
C brushless motor control circuit. 4. A DC brushless motor having N (N is an integer of 3 or more) coils independent of each other, and a DC brushless motor control circuit for driving and controlling the DC brushless motor, wherein the DC A driver circuit for selecting two of the N coils of the brushless motor, and individually controlling the flow of current through each selected coil while switching the target coils in a fixed order, DC brushless including a reference voltage source for applying a reference voltage to one end of each coil, and a phase detection circuit for performing phase detection by comparing the voltage on one end of each coil with the voltage on the other end A DC brushless motor device comprising a motor control circuit.