JPH01255496A - Dc brushless motor - Google Patents

Abstract

PURPOSE:To need no rotor pole position detecting means, by controlling feed current using rectangular wave voltage due to a CR charge or discharge voltage detecting circuit at the time of starting, and by using induced voltage automatically with its generation to control the feed current. CONSTITUTION:A DC brushless motor 4 has two-phase armature windings 2, 3 forming a stator, and the rotor 1 of a permanent magnet. The armature winding 2 is connected to a power line +V via a transistor(Tr)5, and the armature winding 3 is connected to the line +V via a Tr6, respectively. By the Tr5, a switching driving section 55 is formed, and by the Tr6, the switching driving section 55 is formed, mid current is fed to the respective windings 2, 3. In this case, at the time of starting, from a CR charge or discharge detecting circuit 54, starting signal is obtained, and the current is fed to the windings 2-3. After the starting, with induced voltage detected by induced voltage detecting circuits 18, 28, via resistors 7, 8, Trs 6, 7 are respectively driven and are rotated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a DC brushless motor used in fan motors for cooling various heat sources, etc. The present invention relates to a DC brushless motor used for fan motors for cooling various heat sources. , relates to a sensorless DC brushless morph that accurately rotates its rotor.

Conventional technology In a drive circuit that supplies current to the armature winding of a DC brushless motor to drive the armature winding, the current flowing through the armature winding is switched in accordance with the rotor's magnetic pole position. It is common to use a rotor magnetic pole position detecting means arranged to detect the position. For example, in the case of a relatively small DC brushless two-phase motor, a two-phase armature winding is provided as a stator for a permanent magnet rotor, but in the drive circuit for this, A drive unit composed of a switching transistor or the like is connected to each of the two-phase armature windings to intermittently supply current thereto, and a Hall element, for example, installed near the rotor is provided. A rotor magnetic pole position detecting means is provided using a magnetically sensitive element such as the above. The output of the rotor magnetic pole position detection means controls the drive unit by, for example, turning on and off switching transistors that form the drive unit connected to each of the two-phase armature windings. ,Thereby,
Current is selectively supplied to the armature windings depending on the appropriate position of the magnetic poles of the rotor, thereby sustaining the rotation of the rotor.

Problems to be Solved by the Invention However, when a DC brushless motor is provided with a conventional drive circuit in which a rotor magnetic pole position detection means is set near the rotor, the DC brushless motor is A space is required for the rotor magnetic pole position detection means in the motor, and this space must be specified, which increases the restrictions on the configuration and characteristics of the DC brushless motor.
When installing the rotor magnetic pole position detecting means, there is a problem in that high installation accuracy is required based on delicate installation position setting. Furthermore, the detection operation of rotor magnetic pole position detection means is usually affected by environmental conditions such as temperature and humidity, making it difficult to drive a DC brushless motor stably under various environments. There is also the inconvenience of being considered.

The present invention relates to a DC brushless motor drive circuit that can properly rotate the rotor without providing a rotor magnetic pole position detection means therein, and a rotational torque at the time of startup. The purpose is to obtain a starting circuit to give .

Means for Solving the Problems In order to achieve the above-mentioned objects, a DC brushless motor according to the present invention includes a first phase and a second phase armature winding. A rectangular structure that alternately sends out rectangular wave voltages based on signals from the second switching drive unit and the potential detection circuit of the CR charge/discharge circuit, and sends out first and second rectangular wave voltages that have opposite polarities to each other. a wave voltage generator, and a first unit that combines the first and second rectangular wave voltages and the induced voltages obtained in the armature windings of the first and second phases.
and a second waveform synthesis section, and the first and second waveform synthesis sections at the time of startup.
The first and second switching drive units are operated by supplying a rectangular wave voltage from a rectangular wave voltage generation unit of
If an induced voltage is generated in the armature winding of the phase, the first and second induced voltage detection circuits operate the first and second switching drive sections by the first and second waveform synthesis sections. , and an induced voltage synthesis circuit that controls the CR charge/discharge detection circuit using signals from the first and second induced voltage detection circuits.

In the DC brushless motor according to the present invention configured as described above, current is intermittently supplied to the first and second armature windings of the DC brushless motor by the first and second switching drive units. The induced voltage generated in each is the first
and a second waveform synthesizer, and these first and second waveform synthesizers
The waveform synthesizing section includes a rectangular wave voltage generating section that simultaneously sends out rectangular wave voltages alternately based on the signal of the CR charge/discharge detection circuit, and sends out first and second rectangular wave voltages having opposite polarities to each other. The signal is supplied to the first and second waveform synthesizers. The signals of the first and second waveform synthesis sections are
and a second induced voltage detection circuit, and the signals from the first and second induced voltage detection circuits are supplied to a switching drive section to perform a switching operation by them. It also supplies the first and second induced voltages to an induced voltage synthesis circuit that synthesizes them, and supplies the signal of the induced voltage synthesis circuit to the CR charge/discharge detection circuit to control the signal of the rectangular wave voltage generation section.

Thus, at startup, the first and second switching drive sections are controlled by the CR charge/discharge detection circuit. The signal from the rectangular wave voltage generator is supplied to the first and second waveform synthesizers, the signals from the first and second waveform synthesizers are supplied to the first and second induced voltage detection circuits, and the signals from the first and second waveform synthesizers are supplied to the first and second induced voltage detection circuits. Based on the signal from the induced voltage detection circuit, current is supplied to each of the first and second phase armature windings to start the rotor, which further rotates to start the first and second phase electric machines. If an induced voltage is generated in each of the child windings, the induced voltage will be
and a second waveform synthesis section, and a combined output of the signals of the rectangular wave voltage and the induced voltage is output from the first and second waveform synthesis sections, and the signal of the first and second induced voltage is outputted from the first and second waveform synthesis sections. The current is supplied to a detection circuit, and current is supplied to each of the first and second phase armature windings based on the signal from the induced voltage detection circuit, thereby intermittent rotation of the rotor.

Further, the induced voltage is supplied to an induced voltage synthesis circuit, and a signal from the induced voltage synthesis circuit controls charging and discharging of the CR, thereby controlling the rectangular wave voltage.

In this way, the DC brushless motor starting circuit according to the present invention does not require any rotor magnetic pole position detection means.
It can be driven properly.

Example Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of a DC brushless motor starting circuit according to the present invention, FIG. 1 is a block diagram thereof, and FIG. 2 is a specific circuit diagram of FIG. 1. The motor 4 has two phase armature windings 2 and 3 forming a stator.
and a rotor 1 in the form of a permanent magnet. The rotor 1 is disk-shaped and rotates with a rotation axis at the center. In this example, the circumference of the rotation axis is divided into two regions of 180 degrees each, and each region is They are respectively a north pole magnetized portion (N) and a south pole magnetized portion (S).

The armature winding 2 is connected to the power line +V via the emitter-collector path of the transistor 5, while the armature winding 3 is connected to the power line +V via the emitter-collector path of the transistor 6. ing. The transistor 5 forms a switching drive section 55 for the armature winding 2, and when the transistor 6 is in an on state, current is supplied to the armature winding 2 from the power supply line +V. Further, the transistor 6 forms a switching drive section 55 for the armature winding 3, and the transistor 6
When in the on state, current is supplied to the armature winding 3 from the power supply line +V.

In the transistor 5, a base current is supplied to the base of the transistor 5 via the resistor 7 from the induced voltage detection circuit 18 due to the induced voltage obtained in the armature winding 3. Furthermore, the transistor 6 supplies a base current to the base of the transistor 6 via the resistor 8 from the induced voltage detection circuit 28 due to the induced voltage obtained in the armature winding 2 .

In this way, the induced voltages obtained in the armature windings 2 and 3 supply current to each of them, thereby imparting rotational torque to the rotor and causing it to rotate.

However, at startup, armature windings 2 and 3 have
Since no induced voltage is generated, no signal can be given to the switching drive unit. Therefore, the CR charging/discharging detection circuit 54, which will be described below, obtains a signal at the time of starting, and operates the switching drive section 55, thereby controlling the armature winding 2.
and 3, thereby applying rotational torque to the rotor and starting it.Next, the current supply operation is automatically started by the induced voltage obtained in the armature winding due to rotation, and this induced voltage The waveform synthesizing section performs a switching operation such that the current supply operation is performed and the rotation is performed.

Next, the operation of the CR charge/discharge detection circuit 54 will be explained using FIGS. 2 and 3.

In FIG. 2, capacitor 39 is charged through resistor 38, and when transistor 50 is on, capacitor 39
discharge. The on/off control of the transistor 50 is controlled using the voltage waveform (C) of charging and discharging the capacitor 39 shown in FIG. 3 and the reference voltages AV and BV divided by the resistors 40, 41 and 42. capacitor 39
The signal from the comparison circuit 43 that compares and detects the charging/discharging voltage (C) of the capacitor 39 with the reference voltage AV and the charging/discharging voltage (C) of the capacitor 39
) and the reference voltage BY are constructed by connecting one of the input terminals of each of the Nant gate circuits 45 and 46 to the respective output of the opposite Nant gate circuit 45 and 46. It is supplied to each input of the latch circuit 53, and its output is passed through the OR gate circuit 48 to the resistor 49.
is supplied to the base of the transistor 50 via D.
- It is supplied to the rectangular wave voltage generator 47 connected to the DI large input Ω output of the FF circuit.

From the moment the power is turned on, charging of the capacitor 39 and the resistor 38 starts, and the charging voltage C of the capacitor increases as shown in FIG. 3 (When it reaches the reference voltage BV, the comparison circuit 44 turns off, Nant gate circuits 45 and 46
The output of the latch circuit 53 is turned on, and passes through the OR gate circuit 48, four resistors, and the transistor 50.
, the transistor 50 is turned on and the capacitor 39 is discharged. When the charging/discharging voltage C of the capacitor reaches the reference voltage AV, the comparator circuit 43 is turned off, and the latch circuit 53 is turned on by the Nant gate circuits 45 and 46. The output is turned off, and by turning off the transistor 50 via the OR gate circuit 48 and the resistor 49, charging of the capacitor 39 and the resistor 38 is started again.

However, as one of the inputs of the lunar agate circuit 48, the signal K of the induced voltage synthesis circuit 37 is input, but this is a signal assuming that no induced voltage is generated, and the signal is turned off. The signal from the latch circuit 53 becomes the signal from the OR gate circuit 48. Therefore, the signal of the latch circuit 53 is off when the capacitor 39 is being charged, and is on when the capacitor 39 is being discharged. This signal is simultaneously input to the CK terminal of the rectangular wave voltage generator 47 using the D-FF circuit. Therefore, when the signal of the latch circuit 53 rises, that is, when the capacitor 39 discharges, the outputs Q and Ω are inverted, and rectangular wave voltages E and F having opposite polarities are sent out. The above rectangular wave voltage E is supplied to the base of the transistor 16 via the resistor 17, and the diodes 14 and 15 are connected to the 0N10FF
do. On the other hand, the rectangular wave voltage F is supplied to the base of the transistor 26 via the resistor 27, and the diodes 24 and 25 are turned ON10FF.

It is divided by diode 14, 15, resistor 12, and resistor 11, and is input to the e terminal of induced voltage detection circuit 18, and to the input terminal of e, it is divided by diode 13, resistor 1o, resistor 9, and electric machine 143. The voltage is input to the induced voltage detection circuit 18 and supplied to the base of the transistor 5 via the resistor 7.

On the other hand, it is divided by the diode 24, 25, the resistor 22, and the resistor 21, and is input to the e terminal of the induced voltage detection circuit 28, and the input terminal of e has the diode 23, the resistor 20, the resistor 19, and the armature winding is input to the induced voltage detection circuit 28 and supplied to the base of the transistor 6 via the resistor 8. With this configuration, the transistors are switched and driven by signals from the waveform synthesis sections 51 and 52 based on the input configuration of the induced voltage detection circuit.

Now, the signal of the rectangular wave voltage E of the rectangular wave voltage generator 47 is supplied to the base of the transistor 16 via the resistor 17, and if the rectangular wave voltage E is off, the signal of the rectangular wave voltage E of the
is in the off state, and the e terminal of the induced voltage detection circuit 18 is higher by one diode, so the output G is off,
Transistor 5 via resistor 7 is also turned off, and no current is supplied to armature winding 2. Conversely, if the signal of the rectangular wave voltage E is on, the transistor 16 is on, shorting out the diodes 14 and 15, so the e terminal of the induced voltage detection circuit 18 is higher by the amount of the diode 13. Output G turns on, turns on transistor 5 via resistor 7, and supplies current to armature winding 2.

On the other hand, the rectangular wave voltage F has the opposite polarity to the rectangular wave voltage E, and similarly to the above, the rectangular wave voltage F turns on/off the transistor 26 and shorts the diodes 24 and 25, thereby causing the induced voltage detection circuit 28 By determining the input of the armature winding 3, it turns on/off the transistor 6
supplies current to.

Therefore, the induced voltage detection circuits 18 and 28 detect the induced voltage at the same time, and at startup, current is caused to alternately flow through the armature windings 2 and 3 by the signals of the rectangular wave voltages E and F to the rotor. Apply rotational torque to rotate. At this time, when the transistors 5 and 6 are alternately turned on and off, an induced voltage is generated in the armature winding only when the transistors are in the off state.

If this induced voltage becomes higher than the voltage of one diode, the induced voltage detection circuits 18 and 28 will output signals G and H due to the induced voltage generated in the armature winding, regardless of the rectangular wave voltages E and F. Turn on transistors 5 and 6/
Turn it off and supply current to the armature winding to rotate it.

FIG. 4 shows waveforms of various parts during startup according to the present invention. When the charging/discharging voltage C of the capacitor 39 starts discharging, the induced voltage detection circuit outputs G and H are inverted, and the current supply to the electric machine 1,000 windings n2 and 3 is switched.

Repeat this operation several times and at the same time armature windings 2 and 3
The induced voltages I and 7E generated in the rectangular wave voltages E and F
The induced voltage detection circuit 1 via the waveform synthesis units 51 and 52
8 and 28, armature windings 2 and 3
If an induced voltage is generated at let When the rotation is controlled by the induced voltage, this induced voltage is detected and the output from the induced voltage synthesis circuit 37 is used to control the charging and discharging operation of the CR.

The induced voltage I generated in the armature winding 2 is connected to the emitter of the transistor 32 via a resistor 30, while the induced voltage J generated in the armature winding 3 is connected to the emitter of the transistor 3 via a resistor 29. be done. This transistor 3
The bases of 1 and 32 are both connected to the power supply V, and
The collectors are connected together and connected to the resistor 33 and the resistor 34
Grounded to ND. The voltage is divided by the resistors 33 and 34 and connected to the input terminal (■) of the induced voltage synthesis circuit 37, while the ○ terminal is inputted from the power supply +V by being divided by the resistors 35 and 36. As a result, if the induced voltage generated in the armature windings 2 and 3 exceeds the voltage between the base and emitter of the transistor, the output of the induced voltage synthesis circuit 37 becomes ON, is input to the OR gate circuit 48, and is input to the resistor 49. is supplied to the base of transistor 50 through
The rectangular wave voltages E and F are constant voltages with opposite polarities.

Furthermore, if the rotor is forcibly locked and stopped during rotation, no induced voltage will be generated, so the induced voltage detection circuit outputs G and H will start to operate due to the rectangular wave voltages E and F, and the induced voltage will no longer be generated. The voltage composite output turns off and starts charging and discharging CR again, and with this charging and discharging voltage C, square wave voltages E and F alternately turn on and off, supplying current to each armature winding. to apply rotational torque.

In this way, the motor 4 can be started quickly and then driven stably, and even if the motor 4 locks during rotation and stops rotating, it can be restarted.

Effects of the Invention As is clear from the above description (According to the DC brushless motor according to the present invention, at the time of startup, the current supply control to the armature windings of each phase is controlled by the rectangular wave voltage from the CR charging/discharging voltage detection circuit. Then, if an induced voltage is generated in the armature winding of each phase, the current supply to the armature winding is automatically controlled using the induced voltage generated in the armature winding. By performing this and rotating, it is possible to properly rotate and drive the rotor without providing a means for detecting the position of the rotor's magnetic pole.For this reason, it is possible to eliminate the need for space for a means for detecting the position of the rotor's magnetic pole in the DC brushless motor. This makes it possible to reduce the constraints on the configuration and characteristics of the DC brushless motor, and to eliminate the delicate work that requires high precision required for installing the rotor magnetic pole position detection means. You can.Also,
Due to inconveniences such as unstable driving operation due to the fact that the detection operation of the rotor magnetic pole position detecting means is affected by environmental conditions such as temperature and humidity when using the rotor magnetic pole position detecting means. To be released.

Furthermore, when the rotor is locked and no induced voltage is generated, charging and discharging of the CR starts again, and current supply control is performed alternately to the armature windings of each phase to restart the rotor and maintain a proper rotational state. can be moved to.

[Brief explanation of the drawing]

FIG. 1 shows a DC brushless according to an embodiment of the present invention. 1... Rotor, 2, 3... Armature winding, 4... DC brushless two-phase motor, 18.2
8... Induced voltage detection circuit, 37... Induced voltage synthesis circuit, 47... Rectangular wave voltage generation circuit, 51.52... Waveform synthesis circuit, 53...
... Latch circuit, 54 ... CR charge/discharge detection circuit, 55 ... Switching drive section. Name of agent: Patent attorney Toshio Nakao and one other person Figure 3

Claims (1)

[Claims] first and second switching drives that intermittently supply current to each of the armature windings of the first and second phases;
The first voltage generator alternately sends out rectangular wave voltages according to the signal from the potential detection circuit of the R charge/discharge detection circuit, and has opposite polarity to each other.
and a rectangular wave voltage generator that sends out a second rectangular wave voltage;
First and second waveform synthesis sections that synthesize this rectangular wave voltage and the induced voltage obtained from each of the armature windings, and a rectangular wave generated by the first and second rectangular wave voltage generation sections at the time of startup. is supplied to the first and second switching drive units to operate the first and second switching drive units, and if an induced voltage is generated in each armature winding of the first and second phases, first and second induced voltage detection circuits that operate the first and second switching drive units based on signals from the first and second waveform synthesis units; A DC brushless motor comprising an induced voltage synthesis circuit that controls the CR charging/discharging detection circuit using a signal obtained by synthesizing induced voltages.