JPS5927197B2 - brushless electric motor - Google Patents

Description

Detailed Description of the Invention The present invention uses a brushless type (or electronic commutator) that detects the rotational position of the rotor using a Hall element and supplies current to the stator windings to rotate the rotor. (type) electric motor.

Conventionally, many brushless motors have been proposed and put into practical use, which use Hall elements to detect the rotational position of the rotor and use the output to conduct semiconductor switching means such as transistors to energize the stator windings. has been done.

The Hall element in such conventional brushless motors is usually placed within the range of the magnetic field of the main permanent magnet of the rotor (of course, apart from the main permanent magnet, there is a permanent magnet for position detection that rotates with the rotor). Although there is no problem in providing a Hall element and arranging a Hall element in the vicinity thereof, it is clear that this complicates the structure and is disadvantageous in terms of cost.

)6, and generally the Hall element is supplied with DC voltage, and the output voltage obtained from the output terminal is used to operate the semiconductor switching means to supply current to the stator winding. In this case, the current conduction angle of one stator winding is approximately 1800 (electrical angle). For example, in a motor with a two-pole rotor and four-phase windings (one coil per phase, there are four coils), two Hall elements are
The two windings are energized by one Hall element. However, when the rotor is rotated uniformly, the waveform of the voltage generated at the output terminal of the Hall element is sinusoidal. If this is done, the waveform of the current flowing to each winding through the 6 related transistors will also become almost sinusoidal. 1. The driving torque is almost constant. However, if it is necessary to use a large current, it is necessary to provide an intermediate amplification stage between the switching transistor and the Hall element. In this case, the waveform of the current flowing through each of the six windings is no longer like a sine wave but more like a trapezoidal wave. Or, it becomes like a rectangular wave.6Moreover, since the conduction angle of each winding is 1800, it is practically always 2.
Since two stator windings are energized, the generated torque pulsates, and at the same time, the amount of reactive current that does not generate mechanical force increases, reducing the efficiency of the motor. Based on the above, some ideas for making the conduction angle smaller than 1800 have been proposed, for example, in Japanese Patent Publication No. 48-36603 or in Japanese Utility Model Publication No. 48-36603.
This is proposed in Japanese Patent No. 40889. Figure 1 is. A typical electrical circuit diagram of such a conventional example is shown.
This will be explained below. Here, a DC motor with a two-pole rotor and four stator windings is shown, and two Hall elements are used to detect the rotational position of the rotor. are shifted by 90 degrees and are placed at desired positions under the action of the magnetic field of the rotor.

In FIG. 1, the output terminal voltages of Hall elements 1 and 2 are respectively applied to first differential transistor groups 1a, 1b and 2a.
, 2b, and as the rotor rotates, the output of one Hall element 1 turns on and off the differential transistors 1a and 1b alternately, and the output of the other Hall element 2 The differential transistors 2a, 2
b is turned on and off alternately. Furthermore, the four collector outputs of the differential transistors 1a, 1b and 2a, 2b are connected to a second transistor whose four emitters are commonly connected.
By connecting the bases of the differential transistor groups 3, 4, 5, and 6 to the bases of the differential transistor groups 3, 4, 5, and 6, only one of the second differential transistor groups 3, 4, 5, and 6 is always connected. It is designed to conduct electricity. As a result, the switching transistor groups 7, 8, 9, 10 operated by the second differential transistor group 3-6 and driving the stator windings 11, 12, 13, 14, respectively, are also always in operation. Only one of them will be conductive. Figure 2 is the same as above.
The output voltage waveform of the Hall element in the figure is shown.
a, V1b are the differential output voltages of Hall element 1, and V2
a and V2b are differential output voltages of the Hall element 2.

Figure 3 shows the stator windings 11, 12, 1 in Figure 1 above.
3 and 14 show the waveforms of the current flowing, and 111 and 1 in Figure 6
12, 113, and 114 correspond to the respective stator windings mentioned above.

What can be said about the conventional example shown in FIG. 1 is that at least the output voltage of the Hall element must be substantially sinusoidal as shown in FIG.

(Of course, a triangular waveform is also possible.) If this is a trapezoidal waveform or a rectangular waveform, the base voltages of the second differential transistor group 3 to 6 also become a trapezoidal waveform or a rectangular waveform. 6 As a result, the functions of the second differential transistor group 3 to 6 do not function sufficiently, and the purpose of always having only one transistor conductive cannot be achieved. Considering that the Hall element is generally placed within the magnetic field of the main permanent magnet of the rotor, this fact means that the magnetization waveform itself is constrained. This means that the degree of freedom of the magnetization waveform is lost.

One way to make the current conduction angle of the stator winding narrower than 180 degrees (electrical angle) without being affected by the magnetization waveform of the main permanent magnet is to use a TTL circuit, for example, to change the output of the Hall element into a waveform. After shaping and converting it into a rectangular pulse wave, the desired pulse is synthesized using a logic circuit. This may lead to a method of switching the switching transistors in sequence, but if this is done, the current between each winding will switch too sharply, and in some cases the windings may vibrate. Therefore, when used in audio equipment, there is a risk of deterioration of the SN ratio.

In the present invention, the current conduction angle of each of the six stator windings is 1800 (electrical angle).
The above-mentioned problem is solved by making the magnet smaller than that, not being affected by the magnetization waveform of the main permanent magnet of the rotor, and by making the current in each stator winding switch smoothly. be.

Hereinafter, six embodiments of the present invention will be explained based on illustrated embodiments. FIG. 4 shows a main part configuration diagram of a mechanical section of an embodiment of the present invention, which includes 64 pairs of two-pole rotors and stator windings 62 including two Hall elements.

In the figure, a rotor 6101 magnetized to two poles 100 is a stator core, 102, 103, 104, 105 are four stator windings 6106, 107 are holes constituting a rotational position detection means of the rotor 100. It is element. Note that these two Hall elements 106 and 107 are provided because the rotor 100 has two poles. They are arranged offset by 901. FIG. 5 shows an electric circuit section of a motor considered as an improvement on the conventional example,
In particular, it is a wiring diagram of a circuit section suitable for driving the electric motor shown in FIG. 4.

In the figure, 110 and 111 are Hall elements corresponding to the two Hall elements 106 and 107 shown in FIG. is supplied. Hall output voltage terminal 11 of the two Hall elements 110 and 111
0a, 110b and 111a, 111b are each connected to a differential amplifier. In this example, as the simplest example of the above-mentioned differential amplifier, a differential transistor constituted by two transistors having six emitters in common is adopted. First, the Hall output voltage terminal 11 of the Hall element 110
0a, 110b are first differential transistors 112a, 1
12b, respectively. The emitters of the first differential transistors 112a, 112b are commonly connected 6, and the common emitters are connected to a current source 113 (current is I.). This current source 113 ultimately becomes a current command source for the stator winding. Further, well-known current mirror circuits 114a, 114b are connected to the collectors of the differential transistors 112a, 112b, and the collector currents 1A, IA of the first differential transistors 112a, 112b are connected to the current mirror circuit 11.
4a, 114b so that the current flows to the common emitters of the second two sets of differential transistors 115a, 115b and 116a, 116b. Note that the Hall output voltage terminals 111a, 1 of another Hall element 111
11b is a second pair of differential transistors 115a, 11
5b and 116a, 116b, in which case the 6-hole output voltage terminal 111a is connected to the differential transistor 115a and another differential transistor 116.
Connected to the base of a 6 or 6 hole output voltage terminal 11
1b is connected to the bases of the differential transistor 115b and another differential transistor 116b, respectively. Next, the collector outputs of the two sets of second differential transistors (four in total) are connected to the bases of stator winding drive switching transistors 120a, 120b, 120c, and 120d, respectively. Winding wire 121a,
121b, 121c, and 121d are the switching transistors 120a, 120b, 120c, and 12, respectively.
It is connected between the collector of 0d and the DC power supply +E1.

The stator windings 121a to 121d correspond to the four sets of stator windings shown in FIG. 4. Next, the operation of this electric circuit section will be explained. FIG. 6 shows the Hall output voltage of the Hall element as the rotor rotates, and FIG. 110b).

FIG. 6b shows two outputs B, B of the Hall element 111 (B, B are Hall output voltage terminals 111a, 1, respectively).
11b), and as shown in Figure 6, there is a phase difference of 90 voltage between the two (with respect to A and B, and A and B). As is clear from this figure, the Hall output voltage does not necessarily have to be like a sine wave; it may be like a trapezoidal wave as shown in the figure6 or even like a rectangular wave. . Next, the output of the first differential transistor operating in response to the Hall output voltage of the Hall element 110 (collector output current 1A to A) is as shown in FIG.

This waveform roughly corresponds to the output voltage of the Hall element, but since the differential transistor itself has a gain, the rise and fall of the current are somewhat steep, but the switching can still be said to be smooth. Now, the current mirror circuit 114a
, 114b, the current 1A, IX is passed through the second two sets of differential transistors 115a, 115b and 116a,
116b, where they are further distributed according to the Hall output voltage of the Hall element 111, as shown in FIG. That is, the respective collector currents 1AB and IA of a pair of transistors 115a and 115b of the second differential transistors that operate in response to the Hall output voltage of the Hall element 111
B is as shown in FIG. 8, and another transistor 1
The respective collector currents 1AB and AB of the pair consisting of 16a and 116b are as shown in FIG. Since the above current smoothly switches in steps of 90 A, 6 if this current operates the four switching transistors for driving the stator winding 5, the current flowing through each of the four sets of stator windings will be At a conduction angle narrower than 180° (90° in this case). Moreover, it enables smooth sequential switching. Further, as described above, the Hall output voltage of the Hall element does not necessarily have to be sinusoidal, and therefore does not constrain the magnetization waveform of the main permanent magnet of the rotor.

FIG. 9 is a block diagram of an electric circuit according to an embodiment of the present invention, which is a circuit suitable for driving the electric motor shown in FIG. 4, and is a further improvement of the circuit shown in FIG. 5. .

That is, the embodiment of FIG. 9 includes a first differential amplifier;
There is no such thing as a current mirror circuit between the second differential amplifier, and the output of the first differential amplifier directly serves as the current command for the second differential amplifier. Therefore, the circuit configuration is simpler. has been made into However, in this case, the input bias voltage value of the first differential amplifier and the input bias voltage value of the second differential amplifier must be different. Especially the 9th
As in the embodiment of the invention illustrated in the figure, two differential amplifiers are used.
In the simplest case, which consists of two PNP transistors with their emitters connected in common, the input bias voltage value (base bias voltage value) of the first differential amplifier is equal to the input bias voltage value of the second differential amplifier. (base bias voltage value). The value must be at least equal to the emitter-base junction voltage of the semiconductor (usually 0.6 to 0.8 volts for silicon semiconductors), otherwise the semiconductor will be cut off and will not operate. Therefore, 62 Hall elements 210
It is necessary to provide an offset in advance to the DC average output potential of and 211. This will be explained below with reference to the drawings.

210 and 211 are two Hall elements, which correspond to the Hall elements 106 and 107 shown in FIG.
As shown in the figure, DC current is supplied from a DC power supply +E2.

Further, the circuit configuration is such that an offset occurs in advance in the DC average output potential of both. For example, as shown in the figure, the first input control terminal 210 of one Hall element 210
c is directly connected to one terminal of the DC power supply +E2, and the second input control terminal 210d is connected to the first input control terminal 210d, which is an impedance element.
The other terminal of the DC power supply +E2 (
Furthermore, the first input control terminal 211c of the other Hall element 211 is connected to one terminal of the DC power supply +E2 via the second resistor 209b, and the second input control terminal 211d is directly connected to the ground. By doing so, Hall element 2
10 is configured to hold a higher DC average output potential than 211. Hall output voltage terminals 210a, 210b and 211a, 211b of the two Hall elements
are each connected to a differential width amplifier. Figure 9 shows two Ps with a common emitter, which is the simplest differential amplifier.
It is composed of NP type transistors. First, the Hall output voltage terminals 210a and 210b of the Hall element 210 are connected to the first
are connected to the bases of differential transistors 212a and 212b, respectively. First differential transistor 212a
, 212b are supplied with a constant current 1 from a current source 213. is supplied. This current source 213 ultimately becomes a current command source for the stator winding. Furthermore, the current outputs 1
two sets of second differential transistors 216a,
216b and the common emitters of 215a and 215b, respectively.

In addition. Hall output voltage terminal 211a of Hall element 211
, 211b are two sets of differential transistors 215a, respectively.
, 216a and 215b, 216b. Next, the collector outputs of the two sets of second differential transistors (four in total) are connected to switching transistors 220a and 220b for driving stator windings.
, 220c, 220d, and each stator winding 221a, 221b, 221c, 221d is connected to the base of the switching transistor 220a, 220d, respectively.
b, 220c, and 220d and the DC power supply +E1. It goes without saying that each stator winding described above corresponds to the four sets of stator windings shown in FIG. Next, the operation of this embodiment will be explained.

Two outputs A of the Hall element 210 as the rotor rotates.
, (However, A and A are respectively Hall output voltage terminals 21
0a, 210b) is also the 6th differential output voltage.
The two outputs B and YES of the Hall element 211 (B and 100 respectively indicate the differential output voltages of the Hall output voltage terminals 211a and 211b) are as shown in FIG. 6b. It will be as shown. Next, the respective collector output currents of 1 A of the first differential transistors 212a and 212b are as shown in FIG.

Now, next, two sets of second differential transistors 215a and 215b to which the Hall output voltage of the Hall element 211 is input.
, and 216a, 216b further divide the current 1A, and the result is as shown in FIG.

Therefore, if the four output currents of these two sets of second differential transistors operate the four switching transistors for driving the stator windings, the current flowing through each of the four sets of stator windings is 1800. This enables smooth sequential switching with a narrower energization angle (900 in this case). Therefore, this embodiment has the advantage that although the circuit configuration is much simpler than that shown in FIG. 5, the same function can be obtained. In addition. In this embodiment, the simplest example of a differential amplifier is constructed of two PNP transistors whose emitters are commonly connected. However, the present invention is not limited to such a configuration, and the functions of a differential amplifier If it is an electronic circuit containing a semiconductor that performs
Similarly, the simplest example is two NPN transistors whose emitters are commonly connected.

However, in this case, as mentioned above, the base bias voltage value of the first differential transistor needs to be lower than the base bias voltage value of the second differential transistor. Needless to say. FIG. 10 shows the electric circuit configuration of another embodiment of the present invention. 6 This is also the fourth embodiment.
This circuit is suitable for driving the electric motor shown in the figure.

This embodiment is almost the same as the embodiment shown in FIG. 9, except that the input control terminal paths of the two Hall elements 210 and 211 are connected in series, and power is supplied from the DC voltage +E2. Ru. With this configuration, an offset will naturally occur in the DC average output potential between the two Hall elements, which is not only convenient in the case of this embodiment, but also allows the amount of current applied to the Hall elements to be as shown in Figure 9. It has the advantage that it requires only half the amount of the embodiment shown, and in ordinary applications, these circuits are often driven by a single power supply, so it also has the advantage that power can be saved after all. Note that this embodiment employs a circuit using differential transistors, each of which uses two NPN type transistors whose emitters are commonly connected, as the differential amplifier.

In addition, in this embodiment, the same reference numerals are given to those functionally equivalent to the embodiment shown in FIG. 6. In addition, in the case of the above embodiment of the present invention, the current flowing through the two Hall elements is the same, and there is no means for inserting a resistor or the like in series with the Hall elements to adjust them individually, so there is no variation in the sensitivity of the Hall elements. However, as is common not only to this example but also to the entire invention, even if Hall elements with significantly different sensitivities are used,6 ultimately The only difference is the smoothness of the rise and fall of the current waveform flowing through the stator winding, and there is a great advantage that there is no deviation in the conduction angle or its phase.

This will now be explained based on the embodiment shown in FIG. 10 by analogy with the drawings. First, FIG. 11 shows Hall element output voltages with significantly different sensitivities. Let us assume that FIG. 11a is a voltage with high sensitivity and FIG. 11b is a voltage with low sensitivity. If the first differential transistor is operated by a highly sensitive Hall element, its collector output currents A and IX will have a steep current waveform with six rises and six falls, as shown in FIG.
On the other hand, if the second differential transistor is operated by a Hall element with low sensitivity, its collector output current is 1A.
B, IAB, IAB, and IAB have different smoothness of rise and fall as shown in Fig. 13. Current angle 6
It can be said that the phase does not change.

Therefore, if the switching transistor is driven with this current, a current approximately similar to the waveform shown in FIG. 13 will be applied to each stator winding. As described above, according to the present invention, even if Hall elements with different sensitivities are driven with the same current. Normal operation of the motor can be expected even if the Hall output voltages are significantly different.

As described above, FIGS. 9 and 10 show an electric circuit for driving the brushless motor of the present invention, particularly an electric motor using 64 pairs of two-pole rotor stator windings and two Hall elements, as illustrated in FIG. 4. Although we have given an example of this configuration, this electric motor is not limited to only such a configuration. If it has two Hall elements and four sets of stator windings (of course, each set may have many partial windings), then the number of rotor magnetic poles is a multiple of two. Needless to say, everything is configurable.

Now, next, FIG. 14 shows another embodiment of the mechanical part of the brushless motor of the present invention, in which a two-pole rotor and three sets of stator windings 63 are shown.
It consists of two Hall elements.

In the figure, 300 is a two-pole rotor, 301 is a stator core, 30
2, 303, 304 are three sets of stator windings, 306, 30
Reference numerals 7 and 308 denote Hall elements, and these three Hall elements are arranged with a 120° shift. In addition, in the case of this embodiment, the Hall elements 306 to 308 are connected to the stator 3.
It is located at a location offset by 306 from the center of the salient pole of 01.

FIG. 15 is a circuit configuration diagram of another brushless motor that can be considered as an improvement on the conventional motor, and is particularly an example configured to drive the motor shown in FIG. 14.

In the figure, 310, 311, 312 are Hall elements, and the three Hall elements 306, 307, 308 shown in FIG.
As shown in Figure 6, DC current is supplied from DC power supply +E2. Hall output voltage terminals 310a, 310b, and 311a of these three Hall elements,
311b, 312a, and 312b are each connected to a differential amplifier. In the drawing, a differential transistor circuit composed of two transistors whose emitters are connected in common, which is an example of the simplest circuit, is used as a differential amplifier. First, the Hall output voltage terminals 310a and 310b of the Hall element 310 are connected to the first differential transistor 315a.
, 315b, respectively. The emitters of the first differential transistors are commonly connected, and this common emitter is further connected to a current source 313 (current is assumed to be 1). This current source 313 ultimately becomes a current command source for the stator winding. Further, six well-known current mirror circuits 314a, 314b are connected to the collectors of the differential transistors 315a, 315b.
The collector currents 1A, IA of the first differential transistors 315a, 315b are the current mirror circuits 314a, 3
14b, the second two sets of differential transistors 316
a, 316b and 317a, 317b, respectively. Note that the Hall voltage output terminals 311a and 311b of the six other Hall elements 311 are connected to one set of 316a and 316b of the second differential transistor.
6 and Hall elements 312 respectively connected to the bases of
Hall voltage output terminals 312a and 312b are connected to the bases of another pair of second differential transistors 317a and 317b, respectively. Next, two of the collector outputs (total of four) of the two sets of second differential transistors are connected and a total of three outputs are obtained.

In this configuration example, as shown in FIG.
6b and the collector output of the transistor 317a,
This and transistor 316a and transistor 317b
In addition to the collector output of
AB, IAB+AC, AC) are taken out 6 and connected to the stator winding driving switching transistor 320a,
320b and 320c, respectively.

Note that the stator windings 321a, 321b, 321c are connected to the switching transistors 320a, 320b, respectively.
, 320c and the DC power supply +E1. Also. The stator windings 321a, 321b, 3
21c is the three sets of stator windings 302, 303,
Corresponds to 304. Next, the operation of this electric circuit section will be explained.

Figure 16 shows the Hall output voltages of the Hall elements 310 to 312 obtained as the rotor rotates, and Figure 16a
are the two outputs A, A of the Hall element 310 (however, A,
A indicates the differential output voltage of the Hall output voltage terminals 310a and 310b, respectively).

FIG. 16b shows two outputs B and B of the Hall element 311 (B and B are the Hall output voltage terminals 311a and 311a, respectively).
311b). Figure 16c
are the two outputs C, C of the Hall element 312 (however, C,
C represents the differential output voltage of the Hall output voltage terminals 312a and 312b, respectively). The above three output voltages each have a phase difference of 120.

Furthermore, as is clear from this figure, the Hall output voltage does not have to be like a sine wave; it may be like a trapezoidal wave as shown in the figure, or it may be like a rectangular wave. . The first differential transistor operates in response to the Hall output voltage of the Hall element 310, and its outputs IA and IX are sent to the common emitters of the two sets of second differential transistors through current mirror circuits 314a and 314b, respectively. Given. Since the two sets of second differential transistors operate with the Hall output voltages of the Hall elements 311 and 312, the collector output current of the second differential transistors becomes as shown in FIG. 17.

In this case, the collector output current of transistor 316a is represented by IAB, and
The combined output current obtained by adding the collector outputs of transistor 16b and transistor 317a is now expressed as IA100+Xc, and the collector output current of transistor 317b is
It comes to be expressed in thousands. The above-mentioned current smoothly switches in steps of 1.2 million, so if this current operates the three stator winding drive switching transistors, the current flowing through the three sets of stator windings will be 180 million. This enables smooth sequential switching with a narrower conduction angle (in this case, 120 currents). Furthermore, as mentioned above, the Hall output voltage of the Hall element does not necessarily have to be sinusoidal, so the magnetization waveform of the main permanent magnet of the rotor is not constrained by the above implementation. Same as in the example.

FIG. 18 is a circuit configuration diagram of still another embodiment of the brushless motor of the present invention, which is a circuit suitable for driving the motor shown in FIG. 14, and which has the configuration illustrated in FIG. 15. This is a further improvement.

That is, the improvement is that there is no such thing as a current mirror circuit between the first differential amplifier and the second differential amplifier,
The output of the first differential amplifier directly serves as the current command for the second differential amplifier, which simplifies the circuit. As a result, the input bias voltage value of the first differential amplifier and the input bias voltage value of the second differential amplifier must be different. In particular, when the differential amplifier is configured with two NPN transistors as in the embodiment of the present invention shown in FIG. 18, the input bias voltage value (base bias voltage value) of the first differential amplifier needs to be slightly lower than the input bias voltage value (base bias voltage value) of the second differential amplifier. Its value is as described above. In this embodiment, all the input control terminal paths of the three Hall elements are connected in series and powered from the DC power supply +E2, so an offset naturally occurs in the DC average output potential between each Hall element, and at least the first The DC average output potential of the Hall element 310 that operates the differential transistor is lower than the others.

The power method for feeding power to the Hall element is not limited to the one shown in the embodiment, but is also the power method shown in the example of FIG. It goes without saying that the offset may be generated by adopting a method such as However, the first
The implementation method shown in FIG. 8 is advantageous in that the overall amount of current applied to the Hall element is small. Components in this embodiment that are functionally equivalent to those shown in FIG. 15 are given the same reference numerals. Above, in Figure 18,
A brushless electric motor of the present invention illustrated in the figure, particularly a two-pole rotor,
Although we have given an example of an electric circuit section that drives a motor having three sets of stator windings and three Hall elements, this motor has
It is not limited to such a structure, but as long as it has three Hall elements and three sets of stator windings (of course, partial windings may be applied to each), the number of rotor magnetic poles It goes without saying that any number can be constructed as long as it is a multiple of 2.

The electric motor described above has three or four sets of stator windings, but this can be further expanded.
For example, the present invention is applicable to the case of two sets of windings, and is also applicable to motors with polyphase windings such as 5 sets, 6 sets, 7 sets, etc. It is possible.

In particular, in the case of multi-phase windings, the number of Hall elements to detect the rotor position is required accordingly, but at least one differential amplifier operated by each Hall element is provided. By providing a circuit function that uses the output of one differential amplifier as a current command for another differential amplifier, it is possible to obtain exactly the same effect as described in the above embodiments. It is. As described above, in the brushless motor of the present invention, the current conduction angle of each winding is smaller than 180 degrees (electrical angle), and it is not affected by the magnetization waveform of the main permanent magnet of the rotor. This realizes smooth switching of the current, and also has the effect that even if there are variations in the sensitivity of the Hall elements, it does not adversely affect the rotation of the motor. Although it performs the same function as the configuration examples (not publicly known) shown in FIGS. 5 and 15, which are considered as an improvement on the conventional example, it also requires a circuit such as a current mirror circuit that is required in those configuration examples. It has a number of excellent features, such as being advantageous for cost reduction and integration into integrated circuits, and in some cases reducing current consumption by connecting multiple Hall elements in series and supplying power. It is.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of an example of a conventional brushless motor, and Figure 2 is a circuit diagram of an example of a conventional brushless motor.
The figure is a Hall output voltage waveform diagram in the conventional example shown in Figure 1, Figure 3 is a waveform diagram of stator winding current in the conventional example shown in Figure 1, and Figure 4 is an example of the mechanical part of the brushless motor of the present invention. FIG. 5 is an example of the circuit configuration of a brushless motor considered as an improvement over the conventional example. FIGS. 6A, b, 7, and 8 are signal waveforms of each part in FIG. 5. 9 and 10 are circuit configuration diagrams of each embodiment of the present invention, and FIG.
Figures A and 12 and 13 are signal waveform diagrams of various parts when Hall elements with different sensitivities are used in the embodiment of Figure 10, and Figure 14 is a diagram of the mechanical part of the brushless motor of the present invention. FIG. 15 is a diagram showing another circuit configuration example of a brushless motor considered as an improvement over the conventional example; FIGS. 16A, b, c; and FIGS. 17A, b, c is a signal waveform diagram of each part in FIG. 15, and FIG. 18 is a circuit configuration diagram of still another embodiment of the present invention. 100,300...Rotor, 101,301・
...Stator core, 102, 103, 104, 10
5, 302, 303, 304, 221a, 221b, 2
21c, 221d, 321a, 321b, 321c...
...Stator winding, 106, 107, 210, 211
,306,307,308,310,311,312・
...Hall element, 209a, 209b...
・Resistance, 212a, 212b, 215a, 215b, 2
16a, 216b, 220a, 220b, 220c, 2
20d, 315a, 315b, 316a, 316b, 3
21a, 321b, 321c...transistor, 213,313...current source.

Claims (1)

[Claims] 1. A plurality of Hall elements are used to detect the rotational position of the rotor, and the output signals of the Hall elements are used to sequentially conduct semiconductor switching means to energize the stator winding. The plurality of Hall elements are connected to a DC power source so that the DC average potentials of their Hall output voltages are different, and the Hall output voltages of the plurality of Hall elements are connected to a base input. One or two differential amplifiers are provided for each Hall element, and the collector differential output current of two predetermined differential amplifiers among the differential amplifiers is converted to the remaining difference. The semiconductor switching means is made conductive using the remaining collector differential output current of the differential amplifier, and the stator windings are energized. A brushless electric motor characterized in that the current conduction angle of the winding is smaller than 180 degrees in electrical angle. 2. Two Hall elements are used to detect the rotational position of the rotor, and one Hall element is connected to a first differential amplifier that operates with the Hall output voltage as a base input,
Second and third differential amplifiers that operate with the Hall output voltage as their base input are connected to the other Hall element, and the two collector differential output currents of the first differential amplifier are respectively connected to the second and a third differential amplifier, and the collector differential output currents of the second and third differential amplifiers are used to conduct the semiconductor switching means and energize the stator winding. A brushless electric motor according to claim 1, characterized in that: 3 Three Hall elements are used to detect the rotational position of the rotor, and the input control terminal paths of these Hall elements are connected in series and connected between the DC power supply terminals, and the Hall output voltage of the Hall element is used as the base. A differential amplifier that operates as an input is provided with one differential amplifier for each Hall element, and operates with the Hall output voltage of the Hall element having the highest or lowest DC average potential of the Hall output voltage as the base input. The two collector differential output currents of the amplifier are configured to be the emitter currents of the other two remaining differential amplifiers, and the two collector differential outputs of each of the remaining two differential amplifiers are Claim 1, characterized in that the current is combined into three outputs, which are used to conduct the semiconductor switching means and energize three sets of stator windings. The brushless electric motor described in Section 1.