JPH036750B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic commutator type electric motor, and particularly to one that efficiently utilizes electric power supplied from a power source.

Conventionally, in an electronic commutator type motor, a transistor or the like is used to perform pressure reduction control from a DC power source with a constant output voltage, and supply a driving voltage corresponding to the speed of the motor, for example. FIG. 1 shows an example of the configuration of a conventional electronic commutator type motor. In Fig. 1, 1 is a DC power supply, 2 is an energization controller, 3, 4, and 5 are drive transistors, 6, 7, and 8 are three-phase coils, and 9 is a field magnet attached to the rotor. .

The energization controller 2 switches the driving transistor to be energized according to the rotation of the magnet 9, and also applies a voltage to the coils 6, 7, and 7 according to the rotation speed.
Supply to 8. Therefore, the voltage of the DC power supply 1 is dividedly applied to the drive transistors 3, 4, 5 and the coils 6, 7, 8. As a result, the power supplied by the DC power supply 1 is the sum of the effective power consumption in the coil and the collector loss of the drive transistor.

In a normal electric motor, the collector loss of the drive transistor is quite large, and the ratio of effective power consumption to power supplied by the power supply (power efficiency) is small.
It was around 10% to 30%. In particular, electric motors with a wide variable speed range, such as multi-speed switching, and electric motors with a wide variable drive force, such as winding motors, tend to have significantly lower efficiency when operating at low speeds and low driving forces. Ta.

In addition, in the configuration shown in FIG. 1, the coil 6,
Since current flows only in one direction through the coils 7 and 8, the coil utilization rate is low and the motor efficiency is even lower.

Taking these points into consideration, the present invention provides a power-efficient electronic commutator that uses switching-type voltage conversion means that can supply current to the coil in both directions and extract a variable output DC voltage. The purpose of the present invention is to provide a type of electric motor that is particularly suitable for variable speed electric devices, variable driving force electric devices, etc., and has excellent power efficiency during low speed operation and low driving force operation. That's what you're trying to get.

That is, the configuration of the present invention includes a position detection means for detecting the position of a motor movable part, a multi-phase coil, a switching type voltage conversion means for obtaining a variable output DC voltage from a DC power supply, and a voltage conversion means for obtaining a variable output DC voltage from a DC power supply. A first drive transistor group consisting of K drive transistors (K is an integer of 3 or more) connected between one output terminal and each power supply terminal of the coil, and a command to supply current to the coil. a first distribution control means that distributes and controls energization of the first drive transistor group in response to a signal and in response to the output of the position detection means; the other output terminal of the voltage conversion means; and the coil. a second drive transistor group consisting of K drive transistors connected between the respective power supply terminals of the coil; and voltage detection means for obtaining a voltage signal corresponding to an average value of terminal voltages of the respective power supply terminals of the coil. , responsive voltage detecting means for obtaining a responsive voltage in response to the output voltage of the voltage converting means, corresponding to a difference between a voltage signal of the voltage detecting means and a responsive voltage of the responsive voltage detecting means, and
a second distribution control means for distributing and controlling energization of the second drive transistor group in response to the output of the position detection means; and an operation detection control means for controlling the output voltage of the voltage conversion means; The operation detection means includes a reference voltage generation means for obtaining a reference voltage signal, and a comparison means for comparing the operating voltage of the drive transistor in the energized state of the first drive transistor group with the reference voltage signal,
The voltage converting means is configured to reduce the output voltage of the voltage converting means when the operating voltage of the driving transistor in the energized state increases, and to increase the output voltage when the operating voltage decreases. The output voltage is controlled, and the reference voltage generating means is configured to change the reference voltage signal in response to the command signal, and when the current supplied to the coil becomes smaller, the reference voltage signal changes. It is characterized by being made small, thereby achieving the intended purpose.

Further, another configuration of the present invention includes a position detection means for detecting the position of a motor movable part, a multi-phase coil, a switching type voltage conversion means for obtaining a variable output DC voltage from a DC power supply, and a voltage conversion means for obtaining a variable output DC voltage from a DC power source. a first drive transistor group consisting of K (here, K is an integer of 3 or more) drive transistors connected between one output terminal of the means and each power supply terminal of the coil, and a current to the coil; a first distribution control means that distributes and controls energization of the first drive transistor group in response to a command signal instructing supply and in response to the output of the position detection means; and the other of the voltage conversion means. A second drive transistor group consisting of K drive transistors connected between an output terminal and each of the power supply terminals of the coil, and a voltage signal corresponding to an average value of the terminal voltage of each of the power supply terminals of the coil. responsive voltage detecting means for obtaining a responsive voltage in response to the output voltage of the voltage converting means; corresponding to a difference between a voltage signal of the voltage detecting means and a responsive voltage of the responsive voltage detecting means, and a second distribution control means for distributing and controlling energization of the second drive transistor group in response to the output of the position detection means; and an operation detection control means for controlling the output voltage of the voltage conversion means; The operation detection control means includes a reference voltage generation means for obtaining a reference voltage signal, and a comparison means for comparing the operating voltage of the drive transistor in the energized state of the second drive transistor group with the reference voltage signal. , the voltage converting means is configured to reduce the output voltage of the voltage converting means when the operating voltage of the driving transistor in the energized state increases, and to increase the output voltage when the operating voltage decreases, according to the output of the comparing means. The reference voltage generating means is configured to change the reference voltage signal in response to the command signal, and when the current supplied to the coil becomes smaller, the reference voltage signal changes. This is characterized by the fact that it is made smaller, thereby achieving the intended purpose.

The present invention will be explained below based on illustrated embodiments. FIG. 2 is a circuit diagram showing one embodiment of the present invention. In Fig. 2, 1 is a DC power supply;
3, 4, 5 are first drive transistors; 6, 7,
8 is a three-phase coil, 9 is a field magnet attached to the rotor, and part 1 is surrounded by a broken line.
1 is a Hall element 4 that senses the magnetic flux of the magnet 9
A position detector 1, 42, 43, 44, 45, 46 detects the rotational position of the magnet 9 (motor movable part); a first distribution controller that distributes and controls energization of 4 and 5, 13, 14,
15 is connected in series to the current path formed by the coils 6, 7, 8 and the first drive transistor group 3, 4, 5 (each input terminal is connected to the power supply side, and each output terminal is connected to the first drive transistor group a second drive transistor (16) connected to each output terminal of 3, 4, 5;
17 is a second distribution controller that distributes and controls the energization of the second drive transistors 13, 14, and 15 in response to the output of the position detector 11; A switching type voltage converter 18 is inserted in series with the DC power supply 1 to obtain a variable output DC voltage V _M , and a switching voltage converter 18 detects the operating voltage when the first drive transistors 3, 4, and 5 are energized; This is an operation detection controller that controls the output voltage of the voltage converter 17 based on a signal. Also, 2
1 and 22 are DC voltage sources, 23 is a command signal, 24 is a current converter that outputs a current i ₁ corresponding to the command signal 23, and 19 is a current i ₂ , i that responds to the output current i ₁ of the current converter 24. It is a similar current generator that generates ₃ .

Next, its operation will be explained. Command signal 2
3 is input to the current converter 24, compared with the voltage value of the voltage source 22, and converted into a current i ₁ according to the difference between the two. The command signal 23 is obtained by known speed detection means and speed voltage conversion means, and changes its value in accordance with the rotational speed of the magnet 9.

FIG. 3 shows a specific example of the configuration of the current converter 24. The command signal 23 and the voltage source 22 are applied to the bases of the differential transistors 111 and 112, respectively,
The current value of the constant current source 115 is distributed to each collector side according to the voltage difference. The collector current of transistor 111 is inverted by a current mirror of transistors 116 and 117, compared with the collector current of transistor 112, and output (current sinked) through transistor 118.

The output i ₁ of the current converter 24 is the analog current generator 19
is input. Similar current generator 19 includes transistors 25, 26, 27, 28 and resistors 29, 30, 3.
It is composed of a current mirror circuit consisting of 1,
Currents i ₂ and i ₃ that are similar (proportional or approximately proportional) to the output i ₁ of the current converter 24 are output. The current i ₂ is converted into a voltage signal V 1 by the diode 54 and resistor 55 of the first distribution controller 12, and the current i ₃ is converted to the voltage signal V ₁ by the operation detection controller 1.
It is converted into a voltage signal V ₂ by a resistor 61 and diodes 62 and 63 of 8. These voltages V ₁ and V ₂ change in response to the command signal 23 (change in conjunction with each other).

First, the normal rotation drive operation will be explained.
Here, consider _VM to be constant. The first distribution controller 12 is inserted in series in the current path to the coils 6, 7, and 8 (current path for the first drive transistors 3, 4, and 5), and is used for current detection to detect the supplied current. resistor 47, voltage drop of resistor 47 and command signal 2
A first current controller 48 receives a voltage signal V ₁ responsive to V 3 and obtains an output current responsive to both.
and a first transistor consisting of transistors 50, 51, and 52.
selector 53.

FIG. 4 shows a specific example of the configuration of the first current controller 48. A voltage signal V ₁ is input to the base side of the transistor 121, a voltage drop signal of the resistor 47 is input to the emitter side, and a corctor current responding to the difference between the two is obtained. The current is inverted and output,
The signal is supplied to the first selector 53.

Transistors 50, 51 of the first selector 53,
The emitters 52 are commonly connected, and the output voltages of the Hall elements 41, 42, and 43 of the position detector 11 are applied to the base side, respectively. Hall element 4
1, 42, 43 sense the magnetic flux of magnet 9,
An analog voltage signal is generated according to the rotational position. The common emitter current of the transistors 50, 51, and 52 is divided into collector currents according to the difference in their base voltages, and the collector current of the transistor with the lowest base voltage is the largest, and the collector current of the other transistors is zero. Become. The collector currents of the transistors 50, 51, 52 become the base currents of the first drive transistors 3, 4, 5, are amplified and supplied to the coils 6, 7, 8.

The current supplied to the coils 6 , 7 , 8 (the current flowing through the drive transistors 3 , 4 , 5 ) is detected as a voltage drop across the resistor 47 and is input to the first current controller 48 . As a result, the first current controller 48, the first selector 53, the first drive transistor 3,
4, 5 and the resistor 47 constitute a first feedback loop (current feedback loop), and the coils 6, 7,
The current supplied to the first drive transistors 3, 4, and 5 is reliably set to a current value corresponding to the voltage signal V ₁ (therefore, the command signal 23 ₎ .
The influence of variations becomes significantly smaller. Further, as the magnet 9 rotates, the Hall elements 41, 42,
the first drive transistor 3, so that the output voltage of 43 changes and supplies current to the corresponding coil
4 and 5 are controlled and switched.

Note that the capacitor 49 is provided for phase compensation (prevention of oscillation) of the feedback loop described above. Further, a series circuit of capacitors 94, 96, 98 and resistors 95, 97, 99 connected in parallel to the coils 6, 7, 8 reduces the spike voltage caused by switching of the energizing path.

The second distribution controller 16 includes a detection/comparator 71 that detects the average value of the voltage at the terminals of the coils 6, 7, and 8 (here, the voltage at the neutral point of the star-shaped connection), a transistor 77, It is constituted by a second selector 80 consisting of 78 and 79. Detector/comparator 7
1 is a second voltage input terminal that inputs the voltage at the neutral point of the coils 6, 7, and 8 (the average value of the voltage seen from the side power supply terminal to the terminals of the coils 6, 7, and 8) through the resistor 72.
The current controller 76 and the reference voltage generator 75 obtain a divided voltage Vr of the output voltage V _M of the voltage converter 17 using resistors 73 and 74. The reference voltage Vr by the reference voltage generator 75 is also controlled by the second current controller 76.
The second current controller 76 outputs (current sinks) a current corresponding to the difference between the detected voltage (voltage at the neutral point) and the detected voltage (voltage at the neutral point).

FIG. 5 shows a specific example of the configuration of the second current controller 76. When a detection voltage is applied to the base side of the transistor 131 and a reference voltage Vr is applied to the base side of the transistor 132, the current of the constant current source 35 changes depending on the difference between the two.
It is distributed to 32 collector sides. transistor 1
The collector current of 31 and 132 is the transistor 13
The current mirror 6,137 inverts the current and compares it with the collector current of the transistor 132, and a current corresponding to the difference is output (current sucked) through the transistor 140 and supplied to the second selector 80. The output current of the second current controller 76 increases as the detected voltage (neutral point voltage) decreases.

Transistors 77, 78 of the second selector 80,
The emitters 79 are commonly connected, the outputs of the Hall elements 44, 45, and 46 of the position detector 11 are applied to each base terminal, and the common emitter current is distributed to the collector side according to the base voltage. The collector currents of the transistors 77, 78, and 79 become the base currents of the second drive transistors 13, 14, and 15, and switch and control the energization of the coils 6, 7, and 8.

Therefore, the detection/comparator 71 and the second selector 8
0, second drive transistor 13, 14, 15,
A second feedback loop is configured by the coils 6, 7, and 8, and operates so that the detected voltage (neutral point voltage) becomes a predetermined voltage (corresponding to the reference voltage Vr).
A current equal to the current flowing through the drive transistors 3, 4, and 5 (corresponding to the command signal 23) also flows through the second drive transistors 13, 14, and 15, and the coils 6,
A bidirectional current (a current whose direction changes as the magnet 9 rotates) is stably supplied to the magnets 7 and 8.

To explain this, when the current flowing through the first drive transistor becomes transiently larger than the current flowing through the second drive transistor, the voltage at the terminals of the coil (based on the side power supply voltage) becomes smaller overall. Correspondingly, the detection voltage of the detection/comparator 71 becomes smaller. This decrease in the detected voltage increases the output current of the second current controller 76, which increases the base current and thus the collector current of the second drive transistor via the second selector 80. As a result, a current equal to the current flowing through the first drive transistor (collector current) is output from the second drive transistor. Further, the detection voltage of the detection/comparator 71 is equal to the reference voltage Vr of the reference voltage generator 75.
Alternatively, it is stably controlled to approximately the same value. In addition,
A capacitor 81 is provided for phase compensation (to prevent oscillation) of the second feedback loop.

In this way, the first feedback loop and the second feedback loop stably supply the current corresponding to the command signal 23 to the coil corresponding to the output of the position detector 11, and as the magnet 9 rotates, the current is stably supplied to the coil corresponding to the output of the position detector 11. coil 6,
The current paths to 7 and 8 are switched sequentially, and current is supplied in both directions.

Next, a method of controlling the output voltage V _M by the operation detection controller 18 and the voltage converter 17 will be explained.
The output _i3 of the similar current generator 19 is the operation detection controller 1.
8, resistor 61, diode 62, 63
As a result, a reference voltage signal V ₂ of a predetermined voltage value is generated from the common connection terminal (emitter side) of the first drive transistors 3, 4, and 5. Voltage signal V ₂ is a voltage signal
It changes in conjunction with V ₁ (both V ₁ and V ₂ are command signal 2).
3), when the supply current to the coils 6, 7, and 8 (i.e., the conduction current of the first and second drive transistors) is large, the signal V 2 is made large, and when the supply current is small, the signal V ₂ is made large. V ₂ is made smaller. The emitter side of each of the detection transistors 64, 65, and 66 is connected to a reference potential point (signal) as a reference terminal.
_V2 point) in a direct current manner (directly or via a resistor, diode, etc.), and each base side serves as a detection terminal to connect the first drive transistor 3,
It is connected to each output terminal 4 and 5. As a result, the operating voltage of the first drive transistors 3, 4, and 5 in the energized state (the absolute value of the collector-emitter voltage V _CE ) is compared with the reference voltage signal V ₂ , and the operating voltage value is determined. When the emitter-base forward voltage V _D becomes smaller than the signal V ₂ ,
The corresponding detection transistors 64, 65, and 66 become conductive and output current to the collector side.

For example, FIG. 6 shows the current path when drive transistors 13 and 4 are activated. The current path is as follows: output V _M of voltage converter 17 → second drive transistor 13 → coils 6, 7 → first drive transistor 4 → resistor 47 → side power supply. Therefore, the operating voltage of the first drive transistor 4 in the energized state is lower than the voltages of the other drive transistors 3 and 5. The detection transistors 64, 65, 66 compare the operating voltages of the first drive transistors 3, 4, ₅ with the reference voltage signal V2, and in FIG. ₂ by V _D , the detection transistor 65 becomes active and outputs a collector current.

The output currents of the detection transistors 64, 65, and 66 are combined (collector sides are commonly connected) and inverted and amplified by a current mirror consisting of a diode 67, a transistor 69, and resistors 68 and 70.
In other words, an output current corresponding to the operating voltage of the first drive transistor when energized is obtained, and the voltage converter 1
7.

The voltage converter 17 includes a switching transistor 101 that constitutes a semiconductor switching element for power supply control inserted in series in the power supply path from the positive terminal (Vs = 20V) of the DC power supply 1 to the coils 6, 7, and 8. , a switching controller 100 that controls on/off the switching transistor 101, and a flywheel diode 105.
, inductance element 106, and capacitor 1
07. The switching controller 100 can utilize various well-known configurations, such as a triangular wave generator that generates a 50 KHz triangular voltage signal, and a comparator that converts the output of the operation detection controller 18 into a voltage signal and then compares it with the triangular wave signal. , a duty pulse signal corresponding to the output signal of the operation detection controller 18 is obtained, and the switching transistor 101 is controlled on/off. The output voltage V _M of the voltage converter 17 changes in relation to the on time and off time (substantive duty ratio) of the switching transistor 101. When this switching transistor 101 is on, the voltage becomes ViVs, and the DC power supply 1 supplies current to the load side through the inductance element 106. When the switching transistor 101 is turned off, the flywheel diode 105 is turned on, and the energy stored in the inductance element 106 is supplied to the load side. As a result, the output voltage V _M of the voltage converter 17 has a value corresponding to the duty (on time ratio) of the on time of the transistor 101.

The output current of the operation detection controller 18 is the voltage converter 1.
7, when the current value increases, the on-time ratio of the switching transistor 101 is increased to increase the output voltage _VM , and when the current value decreases, the on-time ratio is decreased to decrease the output voltage _VM . Therefore, the operation detection controller 18, the voltage converter 17 and the first drive transistors 3, 4, 5
A third feedback loop is formed by detecting the operating voltage of the first drive transistors 3, 4, and 5 when they are energized, and the operating voltage is the reference voltage signal _V2.
The output voltage _VM of the voltage converter 17 is controlled to a predetermined value (approximately V ₂ −V _D ) corresponding to the voltage. To explain this, when the operating voltage of the first drive transistors 3, 4, and 5 decreases, the output current of the operation detection controller 18 increases, and the on-time of the switching transistor 101 increases due to the operation of the switching controller 100. By increasing the ratio and increasing the output voltage V _M of the voltage converter 17, the first
Increase the operating voltage of the drive transistor. The same applies to the opposite case.

Next, the overall operation of the first, second and third feedback loops will be explained. Now, assuming that the feedback loop is in a balanced state, the voltage drop across the resistor 47 will be a value corresponding to the command signal 23, and the voltage drop across the first drive transistor 3, 4, 5 and the second drive transistor 13, 14, 15 will be a value corresponding to the command signal 23. supplies a current corresponding to the command signal 23 to the coil selected by the position detector 11 (first and second feedback loops),
The operating voltage of the first drive transistors 3, 4, 5 in the energized state is equal to the voltage signal V ₂ (therefore,
This becomes a predetermined small value within the active region corresponding to the command signal 23) (third feedback loop). Further, the average value of the voltages at the terminals of the coils 6, 7, and 8 (voltage at the neutral point) is a predetermined value corresponding to the reference voltage signal Vr of the reference voltage generator 75 (second feedback loop).
Here, the reference voltage generator 75 obtains a reference voltage Vr by dividing the output voltage V _M of the voltage converter 17 by resistors 73 and 74, and here, Vr is divided by V _M /2.
Or it is approximately V _M /2. As a result, the operating voltage of the second drive transistors 13, 14, 15 when energized is the same as that of the first drive transistors 3, 4, 5.
It is equal to or approximately equal to the operating voltage when energized, and is a small value within the active region. This results in
The voltage Vs of the DC power supply 1 is applied to each part of the circuit as shown in FIG.

Let us consider a case where the command signal 23 becomes slightly smaller from such a state.

The decrease in the command signal 23 is the output of the current converter 24.
By increasing i ₁ , the output current of the similar current generator 19
The values of i ₂ and i are increased, and the voltage signals V ₁ and V ₂ are increased.

When the voltage signal V ₁ increases, the base current, and therefore the collector current, of the first drive transistors 3, 4, and 5 in the energized state increases, and the current corresponding to the voltage signal V ₁ is passed through the coil 6,
7 and 8 (first feedback loop).

The current flowing through the first drive transistors 3, 4, 5 transiently flows through the second drive transistors 13, 1.
4 and 15, and the voltage at the terminals of coils 6, 7, and 8 becomes smaller. Along with this, the detection voltage signal of the detection/comparator 71 becomes smaller than the reference voltage signal Vr, increasing its output current, and increasing the output current of the second drive transistor 13,
The base current, and therefore the collector current, of the transistors 14 and 15 in the energized state increase (the second
feedback loop), the current flowing through the second drive transistor becomes equal to the current flowing through the first drive transistor.

Due to the operation of the first and second feedback loops,
Since the current supplied to the coils 6, 7, and 8 increases and the voltage drop thereof becomes larger, the operating voltages of the first drive transistor and the second drive transistor become smaller.

When the first drive transistors 3, 4, and 5 are energized, a decrease in the operating voltage of the transistors and an increase in the voltage signal _V2 are detected by the operation detection controller 18, and the output current is increased, and the voltage converter 1
The on-time ratio of the switching transistor 101 of No. 7 is increased to increase its output voltage V _M (third feedback loop).

The increase in V _M is detected by the second distribution controller 16.
The reference voltage Vr of the comparator 71 is increased, and the average value of the voltages at the terminals of the coils 6, 7, and 8 is increased.

, (actually, the operations of ~ occur almost simultaneously), the output voltage V _M is set such that the operating voltage of the first drive transistor when energized becomes a predetermined value corresponding to the voltage signal V ₂ . Voltage converter 17 is generated and becomes stable (the whole is stable,
equilibrium).

Even when the command signal 23 changes significantly, it similarly settles into a stable state (it can be considered that the above-mentioned minute changes occur continuously).

The electric motor of this embodiment has greatly improved efficiency in the following points.

(1) Since current flows through the coil in both directions, the utilization rate of the coil is high.

(2) The operating voltages of the first drive transistor and the second drive transistor are small values in the active region, and their collector losses are small (due to the operation of the second feedback loop and the third feedback loop).

(3) Since a switching type voltage converter is used, the loss associated with the voltage converter is extremely small.

In addition, the operation of the first feedback loop ensures that the current supplied to the coil corresponds to the command signal, and the operating voltage when the first drive transistor is energized (and the operating voltage when the second drive transistor is energized) This reduces inter-phase variations in operating voltage (operating voltage), making detection easier and more stable.

Furthermore, in this embodiment, the reference terminal side is DC-connected (directly or via a resistor, diode, etc.) to the potential point of the reference voltage signal _V2 , and the detection terminal side is DC-connected to the drive transistors 3, 4, Since detection transistors 64, 65, and 66 consisting of PNP transistors connected to each output terminal of the first drive transistors 3, 4, and 5 are used, the elements required to detect the operating voltage of the first drive transistors 3, 4, and 5 are as follows. , transistor,
Just a diode, a resistor, and a single silicon
It becomes possible to integrate circuits on a chip.

As a result, when the circuit portion of the electric motor shown in FIG. 2 is constructed from a monolithic integrated circuit, the number of external parts is reduced and manufacturing is facilitated. In addition, the detection characteristics have small variations between phases, and the current required for detection can be small. Furthermore, if a PNP transistor with a lateral structure is used as the detection transistor, the base-emitter breakdown voltage and the base-collector breakdown voltage can be increased, improving reliability.

Further, in this embodiment, a reference voltage signal is used for comparison with the operating voltage of the first drive transistors 3, 4, and 5.
V ₂ is changed in response to the command signal 23, and when the supply current to the coils 6, 7, and 8 (that is, the current flowing through the drive transistor) is large, the voltage V ₂ is increased, and when the supply current is small, the voltage V ₂ is increased. is made smaller. As a result, the output voltage of the voltage converter 17 is controlled so that the operating voltage of the drive transistor reliably becomes a small voltage value within the active region, regardless of the magnitude of the current flowing therein. Such characteristics, especially when considering the saturation of the drive transistor,
is important.

This will be explained. Generally, the saturation voltage of a transistor increases in proportion to the conducting current (collector current), and conversely, the active region becomes narrower (see FIG. 8).

Now, consider a case where the voltage signal V ₂ is constant (the voltages across the resistor 61 and diodes 62 and 63 are constant). If the first drive transistor is in a saturated state and operates to increase the current flowing through it, the operating voltage (in this case, the saturation voltage) increases as the current flowing therein increases. Therefore, the difference between the reference voltage signal V ₂ and the operating voltage becomes smaller, the output current of the detection transistor becomes smaller, and the voltage converter 1
7's output voltage V _M is decreased. As a result, even though there is still sufficient margin in the output range of the voltage converter 17, the output current of the operation detection controller 18 is small, so the voltage V _M becomes stable at a small value (third feedback loop malfunction).

On the other hand, if the voltage signal V ₂ is changed in response to the energizing current as in this embodiment, the increase in the voltage signal V ₂ can be larger than the increase in the saturation voltage of the drive transistor as the energizing current increases. To,
The detection transistor is fully forward biased and
The output current of the motion detection controller 18 increases, and the output voltage V _M of the voltage converter 17 also increases to the maximum value of the output range. That is, regardless of the current supplied to the coil, as long as the output of the voltage converter 17 is within the response range, the third feedback loop operates reliably. Furthermore, since the operating voltage of the drive transistor can be set low when the current supplied to the coil is small, the collector loss can be significantly reduced.

Further, the operation detection controller 18 changes its output current in response to the operating voltage when the operating voltage of the second drive transistor becomes less than or equal to a predetermined value (V ₂ −V _D ), so that the operating voltage becomes lower than the predetermined value (V 2 −V D ). V ₂ −V _D ) or higher, the output current becomes constant (zero) and does not change. Figure 9 shows its characteristics. If such a characteristic is adopted, when the operating voltage of the first drive transistor decreases and becomes saturated, a current corresponding to the difference between the operating voltage (saturation voltage) and the reference voltage _V2 will be output, so that The larger the difference, the larger the output current becomes, and the response operation of the third feedback loop becomes more stable and reliable. Further, the response range of the motion detection controller 18 may be narrow, and the configuration can be simplified. Note that when the operating voltage of the first drive transistor is sufficiently larger than V ₂ −V _D , the output current of the operation detection controller 18 is transiently constant (zero), but the output current of the third feedback loop is As a result of the operation, the output voltage V _M of the voltage converter 17 becomes smaller, and the output current of the operation detection controller 18 becomes stable in a region where it responds to the operating voltage.

Furthermore, the reference voltage Vr of the detection/comparator 71 of the second distribution controller 16 is set to the output voltage of the voltage converter 17.
Changes linked to V _M (in the example shown in Fig. 2, VrV _M /
2), the average voltage of the coils 6, 7, and 8 (based on the power supply terminal) changes in conjunction with V _M , and the operating voltage when the second drive transistor is energized is the same as that of the first drive transistor. It becomes equal or almost equal to the operating voltage when the current is applied. As a result, the operating voltage of the second drive transistor becomes a small value within the active region, and its collector loss can also be sufficiently reduced.

FIG. 10 shows a circuit connection diagram representing another embodiment of the present invention. In this example, in the detection/comparator 71 of the second distribution controller 16, resistors 151, 152, and 153 are connected in a star shape from the terminals of the coils 6, 7, and 8, and the voltage at their common connection point is detected. ing. Further, the current from the constant current source 150 is supplied to the resistor 61 and diodes 62, 63 of the operation detection controller 18, so that the reference voltage _V2 is kept constant. Other parts and operations are the same as those in the embodiment shown in FIG. 2, and their explanations will be omitted.

FIG. 11 shows a circuit connection diagram representing still another embodiment of the present invention. In this example, the operation detection controller 18 connects the second drive transistors 13, 14,
The operating voltage at the time of energization of 15 is detected. Along with this, the similar current generator 19 includes a diode 201, a transistor 202, a resistor 203,
A current mirror 204 is added to obtain a current i ₃ that responds (proportional or approximately proportional) to the output current i ₁ of the current converter 24 and supplies it to the motion detection controller 18 . Other configurations and operations are similar to the embodiment shown in FIG.

Next, the configuration and operation of the motion detection controller 18 will be explained. Current i ₃ of similar current generator 19 is resistor 2
05, a reference voltage signal V ₂ of a predetermined voltage value is generated from the common connection terminal of the second drive transistors 13, 14, and 15 by the diodes 206 and 207. The voltage signal V ₂ changes in conjunction with the signal V ₁ (V ₁ , V ₂
(both respond to the command signal 23), when the current flowing through the second drive transistors 13, 14, 15 increases, V ₂ increases, and when the current flowing through the second drive transistors 13, 14, 15 decreases, V ₂ also decreases.

Each base terminal of the detection transistors 208, 209, and 210 is connected to a reference potential point (V ₂
The emitter terminals are connected as detection terminals to the respective output terminals of the second drive transistors 13, 14, 15 via resistors 211, 212, 213, respectively, and the collector terminals are commonly connected and connected to the diodes. 67, transistor 69, resistor 6
Current is supplied to a current mirror consisting of 8 and 70.

FIG. 12 shows the current path when the drive transistors 13 and 4 are activated. At this time, the second
The operating voltage of the drive transistor 13 becomes lower than the voltage of the other drive transistors 14 and 15,
When the value becomes less than a predetermined value (V ₂ −V _D ), the detection transistor 208 becomes conductive and supplies current to the collector side. Therefore, the operation detection controller 18 detects the operating voltage of the second drive transistors 13, 14, and 15 when they are energized, and supplies the voltage converter 17 with an output current (sinking current) according to the detected operating voltage.

The overall operation of the embodiment of FIG. 11 is as follows. Considering the response when the command signal 23 decreases by a minute amount from the equilibrium state, the decrease in the command signal 23 is caused by the output of the current converter 24.
By increasing i ₁ , the output current of the similar current generator 19
Increase i ₂ and i ₃ and increase voltage signals V ₁ and V ₂ .

When the voltage signal V ₁ increases, the base current, and therefore the collector current, of the first drive transistors 3, 4, and 5 in the energized state increases, and the current corresponding to the voltage signal V ₁ is passed through the coil 6,
7 and 8 (first feedback loop).

The current flowing through the first drive transistor transiently becomes larger than the current flowing through the second drive transistor, and the voltages at the terminals of the coils 6, 7, and 8 become smaller. Therefore, the detection voltage of the second distribution controller 16 becomes smaller than the reference voltage signal Vr,
The output current of the detection/comparator 71 is increased, and the base current and therefore the collector current of the second drive transistors 13, 14, and 15 in the energized state increases (second feedback loop), and the second
The current flowing through the first driving transistor becomes equal to the current flowing through the first driving transistor.

Due to the operation of the first and second feedback loops,
Since the current supplied to the coils 6, 7, and 8 increases and the voltage drop increases, the operating voltage of the first drive transistor and the second drive transistor becomes smaller (the voltage at the neutral point becomes equal to Vr). ing).

The decrease in the operating voltage of the second drive transistors 13, 14, 15 and the increase in the voltage signal _V2 when the second drive transistors 13, 14, 15 are energized are detected by the operation detection controller 18, and the output current thereof is increased. The on-time ratio of the switching transistor 101 is increased to increase its output voltage V _M (third feedback loop).

The increase in V _M is detected by the second distribution controller 16.
The reference voltage Vr of the comparator 71 is increased, and the average value of the voltages at the terminals of the coils 6, 7, and 8 is increased.

, (actually, the operations of ~ occur almost simultaneously), the output voltage V _M is set such that the operating voltage of the second drive transistor when energized is a predetermined value corresponding to the voltage signal V ₂ . The converter 17 is generated and becomes stable (the whole becomes stable and in an equilibrium state).

As in the above embodiments, current is supplied to the coil in both directions by the first drive transistor and the second drive transistor, the current supplied to the coil is adjusted to a value according to the command signal, and the operation detection control is performed. If the reference voltage signal of the device is changed according to the finger cooling signal, the following effects can be obtained.

(a) Since the operating voltage of the first drive transistor and the second drive transistor when the current supplied to the coil is small can be significantly reduced, the operating voltage of the first drive transistor and the second drive transistor when the current is supplied to the coil is small. Power losses can be significantly reduced, thus improving power efficiency. In particular, since the supplied current is considerably small during steady speed control, a significant efficiency improvement can be achieved.

(b) Since the operating voltage of the first drive transistor and the second drive transistor can be increased when the current supplied to the coil is large, the first drive transistor and the second drive transistor are stable even when a large current is supplied. Operates in the active region. Therefore, the operating voltage of the drive transistor is stably controlled regardless of the value and fluctuation of the coil current.

It goes without saying that the present invention is not limited to a rotary electric motor that rotates, but can be similarly applied to a so-called linear electric motor in which a movable part of the motor moves relative to each other in a straight line.

Further, the position detecting means is not limited to the magneto-electric transducer such as the Hall element shown in the above-mentioned embodiments, and various known methods such as a method using high frequency coupling can be used. In addition, the drive transistors 3, 4, 5, 13, 14, and 15 are not limited to bipolar transistors, and field effect transistors may be used, and the switching transistor 101 is not limited to bipolar transistors, but may also be field effect transistors. Semiconductor elements such as field effect transistors and thyristors can be used in addition to type transistors and cypolar type transistors.

Furthermore, in the above-mentioned embodiment, the output voltage of the voltage converter was lower than the DC power supply, but the present invention is not limited to such a case. It may be supplied. Further, the configuration of the voltage converter is not limited to the above-described embodiment, and various methods and configurations such as an inverter type, a frequency modulation type chipper type, and a pulse width modulation type chipper type can be adopted. In addition, various modifications are possible based on the gist of the present invention.

As is clear from the above description, the electric motor of the present invention has the advantage of significantly improved power efficiency.
Therefore, if an electronic commutator type motor for use in, for example, audio/visual equipment is configured based on the present invention, it can be made into a power-saving device with extremely low power consumption.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a conventional electric motor, Fig. 2 is a circuit connection diagram representing an embodiment of the present invention, Fig. 3 is a specific configuration example of a current exchanger, and Fig. 4 is a diagram of the first current A diagram showing a specific configuration example of the controller, FIG. 5 is a diagram showing a specific configuration example of the second current controller, FIG. 6 is a diagram for explaining the circuit operation of FIG. 2, and FIG. 7 is a circuit diagram. FIG. 8 is a diagram showing the voltage distribution in each part, FIG. 8 is a diagram showing the operating region of the transistor, FIG. 9 is a diagram showing the detection characteristics of the operation detection controller, and FIG. 10 is a circuit connection showing another embodiment of the present invention. FIG. 11 is also a circuit connection diagram showing still another embodiment of the present invention, and FIG. 12 is a diagram for explaining the operation of the circuit shown in FIG. 11. 1... DC power supply, 3, 4, 5... First drive transistor, 6, 7, 8... Coil, 9... Magnet, 11... Position detector, 12... First distribution controller, 13, 14, 15... second drive transistor, 16... second distribution controller, 17...
Voltage converter, 18... Operation detection controller, 19...
Similar current generator, 23... Command signal, 24... Current converter, 41, 42, 43, 44, 45, 46
... Hall element, 48 ... First current controller, 5
3...first selector, 64, 65, 66, 20
8,209,210...detection transistor, 71
...Detection/comparator, 75...Reference voltage device, 76...
...Second current controller, 80...Second selector, 1
00... Switching controller, 101... Switching transistor.

Claims (1)

[Scope of Claims] 1. A position detection means for detecting the position of a movable part of a motor, a multi-phase coil, a switching type voltage conversion means for obtaining a variable output DC voltage from a DC power supply, and one of the voltage conversion means. K (K is 3) connected between the output terminal of the coil and each power supply terminal of the coil.
a first drive transistor group consisting of drive transistors (an integer greater than or equal to); and a first drive transistor group corresponding to a command signal instructing current supply to the coil and in response to an output of the position detection means. a first distribution control means for distributing and controlling energization of the group; and a second drive transistor consisting of K drive transistors connected between the other output terminal of the voltage conversion means and each of the power supply terminals of the coil. a voltage detecting means for obtaining a voltage signal corresponding to an average value of the terminal voltage of each of the power supply terminals of the coil, a responsive voltage detecting means for obtaining a responsive voltage responsive to the output voltage of the voltage converting means, and a voltage detecting means for obtaining a responsive voltage responsive to the output voltage of the voltage converting means; second distribution control that distributes and controls energization of the second drive transistor group in response to the difference between the voltage signal of the detection means and the response voltage of the response voltage detection means and in response to the output of the position detection means; and an operation detection control means for controlling the output voltage of the voltage conversion means, and the operation detection control means includes a reference voltage generation means for obtaining a reference voltage signal, and an energization state of the first drive transistor group. It is configured to include comparison means for comparing the operating voltage of a certain drive transistor and the reference voltage signal, and when the operating voltage of the drive transistor in the energized state increases, the output voltage of the voltage converting means is reduced, so that the operating voltage increases. The output voltage of the voltage conversion means is controlled according to the output of the comparison means so that the output voltage is increased when the output voltage becomes smaller, and the reference voltage generation means is configured to increase the output voltage of the reference voltage in response to the command signal. An electric motor configured to change a signal so that the reference voltage signal decreases when a current supplied to the coil decreases. 2. A position detection means for detecting the position of a motor movable part, a multi-phase coil, a switching type voltage conversion means for obtaining a variable output DC voltage from a DC power supply, one output terminal of the voltage conversion means and the coil. K (K is 3) connected between each power supply terminal of
a first drive transistor group consisting of drive transistors (an integer greater than or equal to); and a first drive transistor group corresponding to a command signal instructing current supply to the coil and in response to an output of the position detection means. a first distribution control means for distributing and controlling energization of the group; and a second drive transistor consisting of K drive transistors connected between the other output terminal of the voltage conversion means and each of the power supply terminals of the coil. a voltage detecting means for obtaining a voltage signal corresponding to an average value of the terminal voltage of each of the power supply terminals of the coil, a responsive voltage detecting means for obtaining a responsive voltage responsive to the output voltage of the voltage converting means, and a voltage detecting means for obtaining a responsive voltage responsive to the output voltage of the voltage converting means; second distribution control that distributes and controls energization of the second drive transistor group in response to the difference between the voltage signal of the detection means and the response voltage of the response voltage detection means and in response to the output of the position detection means; and an operation detection control means for controlling the output voltage of the voltage conversion means, and the operation detection control means includes a reference voltage generation means for obtaining a reference voltage signal, and an energization state of the second drive transistor group. It is configured to include comparison means for comparing the operating voltage of a certain drive transistor and the reference voltage signal, and when the operating voltage of the drive transistor in the energized state increases, the output voltage of the voltage converting means is reduced, so that the operating voltage increases. The output voltage of the voltage conversion means is controlled according to the output of the comparison means so that the output voltage is increased when the output voltage becomes smaller, and the reference voltage generation means is configured to increase the output voltage of the reference voltage in response to the command signal. An electric motor configured to change a signal so that the reference voltage signal decreases when a current supplied to the coil decreases.