JPS6244094A - Brushless dc motor control circuit - Google Patents

Abstract

PURPOSE:To enable the normal or reverse rotation of a motor by controlling a switching circuit in response to a position detection signal from a Hall element to control the polarity of a current flowing to an armature coil, and providing a full-wave rectifier between a switching circuit and a drive power source. CONSTITUTION:An armature coil 22-1 is disposed oppositely to a field pole. A Hall element 25 is applied with a power from a drive power source 1 to detect the position of the field pole and to generate a position detection signal. A switching circuit 24 controls the polarity of a current flowing the an armature coil 22-1 from the power source 1 in response to the signal from the element 25. A full-wave rectifier Br is provided between the power source 1 and the circuit 24.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a brushless DC motor control circuit, and particularly to a brushless DC motor control circuit that enables forward and reverse rotation of the motor by reversing the polarity of the drive 74H. .

[Technical background of the invention] Conventionally, the 21st! A brushless DC motor as shown in I is known. This DC motor includes field magnetic poles 18-1 to 18-8, which serve as the rotor 18, and these field magnetic poles 1.
Armature coil 2 arranged opposite to 8-1 to 18-8
2-1 to 22-3 and drive power supply terminals 12-1 to 12-1.
2-2 provides power to the field magnetic poles 18-1 to 1B-.
Hall elements 25, 26, and 27 which perform position detection of 8 and generate position detection signals, and armature coils 22-1 to 22- from the drive power supply element according to the position detection signals from the Hall elements 25.2G and 27. 3 and a switching circuit 24 that controls the polarity of the current flowing through the circuit.

In this operation, in response to the Hall elements 25, 26, 27 detecting the position of the field magnetic pole 1B-1-18-8 and generating a position detection signal, the armature is connected from the drive power source +- through the switching circuit 24. Current flows through the coils 22-1 to 22-3 to generate rotational torque. The polarity of this current is controlled according to the position detection signal from the Hall elements 25, 26, 27 based on the alternating NS poles of the field magnetic poles 18-1 to 18-8, so that a subsequent rotational torque is generated. The rotor rotates in one direction. Note that this circuit configuration and its operation are well known, so a detailed explanation will be omitted.Also, this DC motor has a configuration of 8F [t3 coils, but the number of field magnetic poles and coils that make up the motor will be omitted. Any other number can be used.

As an example of the switching circuit 24, as shown in FIG. 3, NPN) transistors Tr1, Tr3, Tr4,
Tr6, PNP There is a bridge system in which transistors Tr2 and Tr5 are combined.The driving power supply + is connected to the emitters and bases of transistors Tr2 and Tr5 through the resistors, and the drive IIR- is connected to the bases of transistors Tr3 and Tr6. The emitter is connected to the base via a resistor. The bases of the transistor Tr2 and the transistor Tr5 are respectively the transistor Tr.
1, is connected to the collector of transistor Tr4, and the collectors of transistor Tr2 and transistor Tr5 are connected to the collectors of transistor Tr6 and transistor Tr3, respectively. An armature coil 22-1 is connected between the collectors of the transistor Tr3 and the transistor Tr(3).The transistor Tri and the transistor Tr4
The emitters of are connected to the bases of the transistor Tr3 and the transistor Tr6, respectively. The drive sources 1 and 2 are connected to the power supply terminal of the Hall element 25 through resistors r1 and 2, respectively, to form a power supply circuit that supplies power to the Hall element.
．． 29 are transistor Tri and transistor T, respectively.
Connected to the base of r4.

Now, when the transistor Tri is turned on in response to the position detection signal from one output terminal 28 of the Hall element 25, and therefore the transistors Tr2, Tr3 are turned on, the transistors Tr4, Tr5, . Tr6 is turned off, and current flows in one direction through the armature coil 22-1, causing the motor to rotate forward.

On the other hand, when the transistor Tr4 is turned on/off in response to the position detection signal from the other output terminal 29 of the Hall element 26, and therefore the transistors Tr5 and Tr6 are turned on, the transistors Trl, Tr2, and Tr3 are turned off, and the armature coil 22-1 Current flows in the opposite direction and the motor reverses.

In this way, the switching circuit 24
This controls the polarity of the current flowing from the drive power supply +- to the armature coil 22-1. Although the Hall element 25 and the switching circuit 24 for the armature coil 22-1 are shown in FIG. 3, other armature coils 22-2
．． The configurations of the Hall elements 26 and 27 and the switching circuit for 22-3 are also similar to this.

Further, in the above example, a bridge system was used as the switching circuit, but a bush-pull system using two power supplies or the like may also be used.

By the way, the control circuit shown in Fig. 3 controls the normal rotation of the remote motor.
To perform the reversal, there is a method of switching the polarity of the Hall element and reversing the operations of the transistors Tri and Tr4. For this purpose, as shown in FIG. 4(a), the transistor Tr
7. A bridge system can be used in which Tr8, Tr9°TrlO and the power supply circuit terminal of the Hall element 25 are connected through resistors r1 and r2. 28 and 29 are output terminals. Also,
As shown in FIG. 4(b), transistors Tri, Tr
2 and the power supply circuit terminal of the Hall element 25 are connected with a resistor 2.
A bush-pull method using a power source or the like may also be used. Although FIG. 4 shows the power supply circuit for the Hall element 25,
The configuration of the power supply circuit of the Hall elements 26 and 27 is also similar to this.

[Problems with Background Art] In such a brushless DC motor control circuit, a 2Wi source is required to rotate the motor forward or reverse. Therefore, if these power sources are used as a common power source, there is a problem that when the power source is switched, the polarity of the power source for the Hall element and the armature coil is changed at the same time, making it impossible to rotate the remoter forward or reverse.

[Object of the Invention] The present invention has been made in view of the above-mentioned conventional difficulties, and it is an object of the present invention to provide a brushless DC motor control circuit that is equipped with one drive power source and that enables forward and reverse rotation of the motor by reversing the polarity of the drive power source. .

[Summary of the Invention] In order to achieve such an object, the brushless DC motor control circuit of the present invention has a field magnetic pole, an armature coil disposed opposite to the field 8i magnetic pole, and a drive power source. A Hall element to which power is applied detects the position of the field magnetic pole and generates a position detection signal, and controls the polarity of the N current flowing from the drive power source to the armature coil in accordance with the position detection signal from the Hall element. A full wave interposed between the driving power source and the switching circuit! 1 current path.

[Embodiments of the invention] Preferred embodiments of the present invention will be described below with reference to the drawings.

First, as already described in FIG.
-8, these field 81 magnetic poles 18-1 to 18-8, armature coils 22-1 to 22-3, and drive 'RR+- terminals 12-1-12-2. Hall element 25, 26, 27 which detects the position of field magnetic poles 18-1 to 18-8 and generates position detection No. 13.
It consists of Further, although this DC motor has a configuration of 8 poles and 3 coils, the number of field magnetic poles and coils can be set to other numbers that can configure the motor.

As shown in FIG. 1, the brushless DC motor control circuit of the present invention operates from a driving power source 1 to an armature coil 2 in response to position detection signals from Hall elements 25, 26, and 27 (FIG. 2).
2-1 to 22-3 (FIG. 2), the switching circuit 24 controls the polarity of the current flowing through each of the switching circuits 2-1 to 22-3 (FIG. 2), and a full-wave rectifier circuit Br interposed between the drive type R1 and the switching circuit 24. Further, an operational amplifier A M P is interposed between the drive type R1 and the Hall element 25. That is, one pole 2 of the drive power supply 1 is applied via the resistor R1, and the other pole 3 is directly applied to the operational amplifier AMP, and the input section and output section of the operational amplifier AMP connected to the resistor R1 are connected to the resistor. Connected by R2. This operational amplifier AMP
The gain of is R2/R1.

This output section is connected to one terminal 5 of a power supply circuit that supplies power to the Hall element 25, and the other terminal 6 of the power supply circuit is connected to a drive 11.
1 is connected to the other ■3.

In addition, the first [! 1 shows the Hall element 25 and switching circuit 24 for the armature coil 22-1, but the configurations of the Hall element 26, 27 and the switching circuit for the other 1i armature coils 22-2, 22-3 are also the same. It is similar to

The switching circuit 24 includes transistors (NPN) Tri, Tr3, Tr4, Tr, similar to those shown in FIG. 3, for example.
O, PNP) A bridge system combining transistors Tr2 and Tr5 can be adopted.

One pole 3 obtained from the driving power supply l via the full-wave rectifier circuit Br is connected to the emitters of transistors Tr2 and Tr5 and their bases via resistors R3 and R5, and is connected to the full-wave rectifier circuit Br from the drive type R1. The other pole 4 obtained through the transistor Tr3 and the transistor Tr6
The emitter is connected to the base via resistors R4 and R6.

Transistor T r 2. , the bases of transistor Tr5 are transistor Tri and transistor Tr4, respectively.
The collectors of the transistors T'2 and Tr5 are connected to the collectors of the transistors Tr6 and Tr5, respectively.
It is connected to the collector of transistor Tr3. A ii armature coil 22-1 is connected between the collectors of the transistor Tr3 and the transistor Tr6. The emitters of the transistors Tri and Tr4 are connected to the bases of the transistors Tr3 and Tr(3), respectively.The output terminals A of the Hall elements 250 and
B are transistor Tri and transistor Tr4, respectively.
connected to the base of.

Now, when the transistor Tri is turned on in response to the position detection signal from one output terminal A of the Hall element 25, and therefore the transistors Tr2 and Tr3 are turned on, the transistors Tr4, Tr5, and TrO are turned off, and the armature coil 22-1 is turned on. Current flows in one direction and the motor rotates in the normal direction. On the other hand, if the output polarity of drive IR1 is reversed, full wave! Although the polarity of the switching circuit 24 does not change due to the current path Br, the transistor Tr4 turns on in response to the position detection signal from the other output terminal B of the Hall element 25, and therefore the transistors Tr5 and Tr6 turn on. Tr
l, Tr2, and Tr3 are turned off, and the armature coil 22
-1, current flows in the opposite direction and the motor reverses. In this way, the switching circuit 24 controls the polarity of the current flowing from the drive type R1 to the armature coil 22-1 using the Hall element 25. Incidentally, in order to switch the polarity 2.3 of the Hall element II in order to rotate the motor in the forward direction or in the reverse direction, it is preferable to provide a changeover switch (not shown) in the drive power source I to change the output polarity.

Further, in the above example, a Britno type was used as the switching circuit, but a bush-pull type using two power supplies or the like may also be used.

Further, an operational amplifier AMP is interposed between the drive type R1 and the Hall element 25. When the motor is operated at low speed,
Naturally, there are times when the specified current does not flow through the Hall element and it does not operate. However, the drive type R1 by the amplifier AMP
Even if is a constant voltage, a specified current can flow through the Hall element. The higher the gain (R2/R1) of the amplifier AMP, the better, and it is preferable that the gain be such that the output is saturated even at a very small voltage.

[Effects of the Invention] As is clear from the above embodiments, according to the brushless DC motor control circuit of the present invention, power is provided by the armature coil disposed facing the field magnetic pole and one drive power source. a Hall element that detects the position of the 81 field poles and generates a position detection signal; and a switching circuit that controls the polarity of the current flowing from the drive power source to the armature coil in response to the position detection signal from the Hall element. , a full wave interposed between the driving NR and the switching circuit! Since the A flow path is provided, switching the polarity of the drive power supply for forward and reverse rotation of the motor does not affect the polarity of the switching circuit where the current flows through one punch coil, and only the R polarity of the Hall element is reversed. This allows the motor to rotate forward and reverse.

In addition, since the operational amplifier AMP is interposed between the drive type R1 and the 25 Hall elements, when the motor is operated at low speed, the amplifier AMP allows a specified current to flow through the Hall elements even when the drive power source is at a constant voltage. .

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a brushless DC motor control circuit according to the present invention, Fig. 2 is an exploded view of a conventional brushless DC motor, Fig. 3 is a circuit diagram of a switching circuit in the brushless DC motor of Fig. 2, and Fig. 4 (a) and (b) are circuit diagrams of a power supply circuit that provides power to the Hall element in the brushless DC motor of FIG. 2; 18-1 to 18-8... Field magnetic poles 22-1 to 22-3... Armature coilt... Drive power supply 25 to 27... Hall element 24... Switching circuit Br... Full wave Rectifier circuit AMP...Amplifier 2...One face agent Patent attorney Moritani - Yuwara 1 Figure 3 Figure

Claims (1)

[Claims] 1. A field magnetic pole, an armature coil disposed opposite to the field magnetic pole, and a drive power source that supplies power to detect the position of the field magnetic pole and generate a position detection signal. a switching circuit that controls the polarity of a current flowing from the drive power source to the armature coil in accordance with a position detection signal from the Hall element, and a full wave interposed between the drive power source and the switching circuit. A brushless DC motor control circuit comprising a rectifier circuit. 2. The brushless DC motor control circuit according to claim 1, wherein an amplifier is interposed between the drive power source and the Hall element.