JPS644438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a DC motor that performs mechanical operations by supplying power, and in particular provides a DC motor that efficiently utilizes power supplied from a power source. .

Conventionally, when controlling the speed of a DC motor, for example, a transistor or the like is used to reduce and control the voltage from a DC power source with a constant output voltage, and supply a drive voltage corresponding to the speed of the motor.

FIG. 1 shows an example of the configuration of a conventional DC motor. In the figure, 1 is a DC power supply, 2 is a transistor for power supply control, 3 is a motorized part, and transistor 2
A control signal depending on the speed, for example, is applied to the base terminal 4 of the motor. In this way, when power is supplied by changing the voltage between the collector and emitter of the transistor, the power supplied by the DC power supply is the sum of the effective power consumption in the motorized part and the collector loss of the transistor. In a normal DC motor, the collector loss of the transistor is quite large, and the ratio of the effective power consumption to the power supplied by the power supply (power efficiency) is small, about 10% to 30%. In particular, DC motors with a wide speed variable range, such as multi-speed switching, and DC motors with a wide variable drive force range, such as winding motors, have a significantly lower efficiency during low speed and low driving force operation. was.

Taking these points into consideration, the present invention uses a switching type voltage converter that can take out a variable output DC voltage, and the voltage converter is designed to maintain the operating voltage of a control semiconductor such as a transistor at a predetermined value. By controlling the output of the motor, a DC motor with good power efficiency is provided. In particular, the present invention is suitable for variable speed electric devices, variable driving force electric devices, etc., and is an electric motor with excellent power efficiency during low speed operation and low driving force operation. The present invention will be explained below based on illustrated embodiments.

FIG. 2 is a basic block diagram of the present invention. In the figure, 5 is a DC power supply, 6 is a switching type voltage converter, and 7 is a control semiconductor such as a transistor or FET that constitutes a power supply control means.
Reference numeral 8 denotes an operation detector for detecting the operating state of the control semiconductor 7, which constitutes a control means. Reference numeral 9 represents an energization switch, 10 represents an electric part, 11 represents an operation detection signal, and 12 represents a control signal.

The switching type voltage converter 6 includes, for example, a switching semiconductor, an inductance element,
It is composed of flywheel diodes, capacitors, etc., and by turning on and off switching semiconductors, other DC voltages are generated from the DC power supply 5, which is the power supply source, and the output voltage varies depending on the on time and off time ( can vary widely depending on the on-time duty). The output voltage of the voltage converter 6 is supplied to the motorized section 10 through the control semiconductor 7 and the energization switch 9.

A control signal 12 is applied to the control semiconductor 7, and its operating voltage or operating current is changed according to the control signal 12, and the voltage or current according to the control signal 12 is supplied to the energization switch 9 and the motorized part 10. . The operating voltage of the control semiconductor 7 is detected by the operation detector 8, and the operation detection signal 11 is applied to the voltage converter 6 to control its switching state so that the operating voltage of the control semiconductor 7 becomes a predetermined value. There is.
That is, the operation detector 8 detects changes in the operating voltage of the control semiconductor 7 due to changes in the control signal 12, controls the switching state of the voltage converter 6 according to the operation detection signal 11, and performs voltage conversion. By changing the output voltage of the device 6, the operating voltage of the control semiconductor 7 is set to a predetermined value. As a result, the operating voltage of the control semiconductor 7 is maintained at a predetermined low voltage regardless of the voltage or current supplied to the motorized section 10.

The motorized section 10 includes a fixed magnetized field section such as a permanent magnet, and a plurality of drive windings disposed at positions interlinked with the field magnetic flux generated by the field section. One of the magnetic part and the drive winding is movable relative to the other (rotatably or linearly movable). The energization switch 9 is composed of, for example, a commutator (brush) or a semiconductor switch, and switches the energization path to the drive winding in accordance with the relative position of the field part of the motorized part 10 and the drive winding.
A special driving force is generated in the electric part 10 in the same direction.

In this way, if the output voltage of the voltage converter 6 is changed so that the operating voltage of the control semiconductor 7 is set to a predetermined low voltage value, the control semiconductor 7 will change regardless of the voltage or current supplied to the motorized part 10. Operating voltage can be reduced. As a result, the loss in the control semiconductor 7 can be reduced.

FIG. 3 shows a circuit configuration of a specific embodiment of the present invention based on the basic configuration shown in FIG. 2 above. This will be explained below, and the same reference numerals are given to the same parts as those explained in FIG. 2.

The output voltage V _c of the voltage converter 6 changes in accordance with the on time and off time (duty of the on time) of the switching transistor 20 . When the transistor 20 connected in series to the 20V DC power supply 5 is on, V _i V _s is established, and the DC power supply 5 supplies current to the inductance element 24, the capacitor 25, and the load side. When the transistor 20 is off, the flywheel diode 23 is on, supplying the energy stored in the inductance element 24 to the capacitor 25 and the load side. As a result, the output voltage V _c of the voltage converter 6 is
The value corresponds to the duty of the on time of the transistor 20.

The output voltage V _c of the voltage converter 6 is changed to the output voltage V e according to the control signal 12 by a control transistor 7 a, which is a control semiconductor 7 connected in series to the power supply path to the energization switch 9 _. Energization switch 9
and supplied to the electric part 10. The operating voltage (V _c −V _e ) of the control transistor 7a is detected by the differential transistors 33 and 34 forming the operation detector 8. Constant voltage element 27 and resistor 28,2
9,30 to a _{predetermined} potential (usually 0.5~
3V) is applied to the base of transistor 33.

On the other hand, the supply voltage is applied to the base of transistor 34.
V _e is applied through resistor 35, and both
3 and 34 for comparison. When the operating voltage is lower than a predetermined value, the transistor 33 is turned on;
The transistor 34 is turned off, and the terminal voltage of the resistor 37, that is, the operation detection signal 11 becomes the ground potential. At this time, the switching controller 26 controls the transistor 22 and the switching transistor 2.
Increase the on-time duty of 0. As a result, the output voltage V _c of the voltage converter 6 is increased, and the operating voltage of the control transistor 7a is brought closer to a predetermined value.

Conversely, when the operating voltage is high, the transistor 33 is turned off and the transistor 34 is turned on, current is supplied to the resistor 37, and the operation detection signal 11 becomes high. The switching controller 26 turns off the transistor 22 and the switching transistor 20, or reduces the duty of the on time, thereby reducing the output voltage V _c of the voltage converter 6 and bringing the operating voltage of the control transistor 7a closer to a predetermined value. In addition,
In the figure, 13 is a field part using a permanent magnet, 31 is a protection diode for preventing reverse voltage breakdown of the transistor 33, and 32 is a power current generated from the DC power supply 5.

The energization switch 9 connects the drive windings X,
Depending on the relative positions of Y, Z and the field section 13, the driving windings to be energized are switched to always generate driving force in the same direction. The energization switch 9 may be a mechanical commutator (brush) or an electronic commutator that combines a non-contact position detection means and a transistor (semiconductor).

FIG. 4 shows a circuit configuration of another embodiment of the present invention. Note that in FIG. 4, the same reference numerals are given to those having the same functions as those explained in FIG. 3, and redundant explanations will be omitted. In the embodiment shown in FIG. 4, the current supplied to the motorized section 10 is set to a value corresponding to a command signal 41. In the embodiment shown in FIG.

To explain this, the current supplied to the motorized section 10 is detected by a current detector 14 made up of a resistor 38 connected in series to the power supply path. The current detection signal 40 and command signal 41 of the current detector 14 are input to the current controller 39, and the current I _e according to the difference between the two is inputted to the current controller 39.
flows into the current controller 39. The current I _e becomes the base current of the control transistor 7a, and controls the degree of conductivity (conducting current) of the control transistor 7a, that is, the current supplied to the conduction switching device 9. Therefore, a loop is formed as follows: supply current→current detector 14→current controller 39→control transistor 7a→supply current, and the supply current to motorized section 10 has a value according to command signal 41.

In this way, the supply current is detected and the command signal 41
If the value is set in accordance with , it is possible to reduce variations in the driving force generated in the electric part 10 .

As shown in the embodiments described above, when a switching type voltage converter is used to maintain the operating voltage of the control transistor at a predetermined value, the following effects can be obtained.

(1) Power loss in the control transistor and voltage converter is small, and the power usage efficiency of the entire DC motor is extremely high. Therefore, it is particularly suitable for variable output motors such as variable speed and variable drive power.

(2) Switching noise associated with voltage conversion does not occur in the motorized part.

(3) The rated power of the control transistor can be small;
The size is also smaller.

(4) Less heat dissipation in the control transistor and voltage converter.

Furthermore, as shown in the embodiment shown in FIG. Change in relative position of moving parts (rotation)
Since it is not affected by fluctuations in the combined resistance value due to
The variation (unevenness) in the generated driving force is also reduced, resulting in a high-performance DC motor.

In the above embodiment, the operating voltage of the control semiconductor is directly detected, and the output voltage of the voltage converter is changed in accordance with the detection signal, thereby achieving stable and reliable operating voltage detection. However, the present invention is not limited to such a case, and it goes without saying that the operating voltage of the control semiconductor may be indirectly detected using other methods, such as using a control signal.
Generally, the power reduction effect of the present invention can be obtained if the operating voltage of the control semiconductor is set to a predetermined value or within a predetermined range by an operating voltage detector and a voltage converter switching controller.

Moreover, the present invention is not limited to rotational motion, and can also be implemented in the case of a so-called linear type DC motor in which the field portion and the drive winding move linearly relative to each other. Further, the number of phases is not limited to three, but it is also possible to use a structure with a larger number of phases.

Furthermore, in the above embodiment, the output voltage of the voltage converter is lower than the DC power supply, but the present invention is not limited to such a case, and the present invention is not limited to such a case. It may also be supplied to

As is clear from the above description, the DC motor of the present invention can significantly improve power efficiency. Therefore, if an electronic commutator type DC motor for audio equipment is constructed based on the present invention, it can have extremely low power consumption and high performance.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the configuration of a conventional DC motor, FIG. 2 is a basic block diagram of the present invention, and FIGS. 3 and 4 are drive circuit diagrams of specific embodiments of the present invention. 5... DC power supply, 6... Voltage converter, 7... Control semiconductor, 7a... Control transistor, 8... Operation detector, 9... Energization switch, 10... Motorized part,
11...Operation detection signal, 12...Control signal, 13
... Field section, 14 ... Current detector, 26 ... Switching controller, 38 ... Resistor, 39 ... Current controller, 40 ... Current detection signal, 41 ... Command signal, X, Y, Z ...Drive winding.

Claims (1)

[Claims] 1. It has a plurality of drive windings disposed at positions interlinking with the field magnetic flux generated by the field part fixedly magnetized by the magnetic poles of a permanent magnet, and the drive windings are energized. An electric part that performs mechanical operation;
It is composed of a switching transistor, an inductance element, a flywheel diode, and a capacitor, and the on-time of the switching transistor is variable according to the duty from a DC power supply of a predetermined voltage by the on/off operation of the switching transistor. Voltage conversion means for producing an output DC voltage; power supply control means including a control semiconductor provided in a current path from the voltage conversion means to the drive winding; and current detection for detecting the current supplied to the drive winding. means, current control means for controlling the energizing current of the control semiconductor so that the output signal of the current detection means has a value according to the command signal, and operating voltage detection means for detecting the operating voltage of the control semiconductor. , comprising switching control means for controlling the duty of the on-time of the switching transistor according to the output of the operating voltage detection means,
The current detecting means and the current controlling means control the current flowing through the control semiconductor to a large extent in accordance with the command signal, and at the same time, the voltage converting means and the operating voltage detecting means control the operating voltage of the control semiconductor to a predetermined value. A direct current motor configured to control a value.