JPS5893489A - Brushless dc motor - Google Patents

Abstract

PURPOSE:To reduce the number of parts and manufacturing steps of a brushless DC motor by controlling the operation of the second drive transistor group at the energizing state time so that the operating voltage of the first drive transistor group at the energizing state time becomes the prescribed value. CONSTITUTION:In the first distribution controller 102, the first drive transistor groups 26-28 are controlled in energization by a voltage/current converter 105 which responds to the outputs of Hall elements 15-17 and inputs a command signal correspondence voltage fed via a voltage/current converter 62 an a current mirror circuit 110 from a command signal 60 and the current detection voltage from a resistor 21, and a differential circuit 104. In the second distribution controller 103, the second drive transistor groups 46-48 are controlled in energization via a differential circuit 108 by the output of a detection comparator 106 which responds to the output of Hall elements 18-20 and compares the operation voltage at the energizing state time of the second drive transistor groups 46-48 with the reference voltage signal obtained from a current mirror circuit 110, and the reduction of the operating voltage is compensated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a multi-phase coil to
This relates to a brushless DC motor in which the power supply to the motor is electronically switched using transistors or the like.

The F-less DC mode I has a small clip μ, no noise caused by brushes, and has a long life, so it is applied to various audio equipment. Special Public Showa 1s-ssis
The publication describes that in such a brushless DC motor, current is passed in both directions to the star-connected three-phase coil ν (
It is disclosed that the coil can be used in a full-wave drive mode to improve the coil utilization efficiency. According to this, a first transistor group supplies a constant current to a multiphase carp μ, and a second transistor group controls the potential at a common connection point of the multiphase carp μ to a predetermined value. are doing.

However, in such a configuration, in addition to the terminal that supplies current to the coil A/, the common connection terminal (required simply to detect voltage) must also be drawn out from the motor side and connected to the circuit element. As a result, manufacturing of wires with a large number of wires was popular.

Taking these points into consideration, the present invention provides a brushless DC motor that achieves stable and reliable full-wave drive by wiring only terminals that supply current to multi-phase coils (no wiring for common connection terminals required). , is provided.

The structure of the brushless DC motor according to the present invention is as follows.

and a position detection means for detecting the position of the motor movable part.

A plurality of phase coils μ; i) a first drive transistor group that supplies current to the coil A/; and in response to the output of the position detection means, distribution control of energization of the first fD'lAm) fungistor group; a first distribution control means for controlling the carp;
and a second drive transistor group inserted in series in the current path formed by the first drive transistor group, and a second drive transistor group that controls energization of the second drive transistor group in response to the output of the position detection means. distribution control means; the second distribution control means includes a reference voltage generation means for obtaining a reference voltage signal; The operating state of the second drive transistor group is controlled according to the output of the comparing means O, and the reference voltage generating means is configured to include a comparing means for comparing the current supplied to the coil ν. The reference voltage value is changed in conjunction with the current, and is characterized in that it increases when the current is large and decreases when the current is small.

Furthermore, the configuration of the brushless DC motor according to the present invention includes a reference voltage generating means for generating a constant reference voltage signal, and one end connected to a potential point of the reference voltage generating means in a DC manner,
a plurality of detection transistors, one end of which is connected to each output terminal of the second drive transistor group in a direct current manner; The operating voltage is compared with the reference voltage signal, and the operating state of the second drive transistor group is controlled in accordance with the combined value of the output currents of the respective detection transistors.

An embodiment of the present invention will be described below based on the drawings. 1st
The figure is an electrical circuit wiring diagram showing one embodiment of the present invention.

In FIG. 1, jll> is a field magnet attached to the rotor, and <121O! 1114 is a star-connected three-phase carp μ group, @@- is the first drive transistor group,
tmh power decoy is the second drive transistor group, white is carp lol Q! This is a resistor for detecting the combined supply current to 9304. In addition, the part (101) surrounded by the broken line is a magnet) (Ho element +1@as0 that senses the magnetic flux of the river)
75 (position detector constructed by Islm-, (
102) is Ho, A151c 1,011 as (171), the corresponding first drive transistor group ＠
A first distribution controller that distributes electricity to - (10m)
is a second distribution controller that distributes and controls the energization of the corresponding drive transistor group 11i2 (b) in response to the output of the Iv element llsllSI. Furthermore, (11
0) is the force V tomifu circuit, - and (105) are the voltages? It is a current converter.

Next, its operation will be explained. When 22V is applied as the power supply voltage Vcc, the command voltage signal (9 voltages obtained by detecting the rotational speed of low I and converting it using a well-known method) is compared with the voltage value of the DC power supply 1 by the voltage/current converter. , a current corresponding to the difference between the two flows out.

An example of the configuration of voltage/current converter #- is shown in FIG.

Signal - and power supply @- are differential functions, ri (152) and (
153), and the current value of the constant current source -150) is distributed to each collector side according to the voltage difference. Its collector current is the transistor (157) and 1
58) transistors (1, 6o) and transistors (161) (16
2).

The output of the voltage/current conversion 1SI12 is supplied to the current mirror circuit (11G), where it is converted into a voltage signal by a diode and a resistor, and the fungistor () responds to the command signal and draws the required current. The output of the French star is supplied to a second distribution controller (103) and is converted into a voltage signal by means of a diode 5it and a resistor.

The voltage drop between the voltage signal and the resistance is determined by the voltage/current converter (
105), and a current corresponding to the difference between the two is output, and is supplied as a common emitter current of the transistor @(Incorporated)- constituting the first differential circuit (014).

Figure 3 shows an example of the configuration of the voltage/current converter (105).
A voltage signal) is applied to the pace side of the transistor (171), and a voltage drop signal of the resistor is applied to the emitter side, and a collector current according to the difference between the two flows, and from the transistors (171) and (174) The current is reversed by the force V and is supplied to the first differential circuit (104).

The output voltage of the H μ element am am Oη is applied to each base terminal of the transistor 翰(corporate) − of the differential □ circuit (104), and the common emitter current is applied to each collector side according to the difference in the pace voltage. The collector current of the transistor with the lowest pace voltage is the largest, and the collector currents of the other transistors are almost zero. Further, as the magnet (Ill) rotates, the most active transistor is switched in sequence.

Each collector current of the transistor - becomes each pace current of the first drive transistor group @@-, and the current is amplified and supplied to the corresponding coil pva20:104. The supply current to the carp A/62 Is H is detected as a voltage drop across the resistor @η, and the voltage-to-current converter (105)
is input to the inverting input terminal of

As a result, the voltage/current converter (105), the first differential circuit (164) and the first drive transistor group
- and resistor - to the first feedback V-pu (current feedback y
−p) is constructed, and carp A/ +12 (IB (14
The current supplied to the controller is ensured to have a current value that corresponds to the voltage signal (therefore, the command voltage signal -IQ). The conclusion. As a result, the influence of the transistor group - 7 (Wotsuki) will be extremely small.

In addition, the output voltage of the Hall element (a) changes with the rotation of the field magnet (01), and the first drive transistor group (a) is energized so that a current is supplied to the corresponding coil (y). A capacitor (goods) that controls and switches
is provided for phase compensation of the feedback μm amplifier mentioned above.

Next, the operations of the first distribution controller (103) and the second drive F-star group M-complement will be explained. The second distribution controller (103) controls the second drive transistor group -@? l
It is composed of a detection/comparator (106) that compares the operating voltage of the transistor in the negative energized state with a reference voltage value, and a second differential circuit (10g).

The output of the current mirror circuit (lty) is the detector/comparator (
106) K is input, and a reference voltage signal of a predetermined voltage value is generated from the common connection terminal (emitter side) of the second drive transistor group - Ω by the resistor and diode Q.

For the detection transistor MCl31e14, a PNP type (Fungis) is used, and each emitter side is connected to the second terminal as an input terminal.
are connected in a DC manner to each output terminal of the first group of drive transistors @a-η- via a resistor -m-, and each pace side is used as a reference terminal, and the reference potential point (signal 00 point) is connected in a DC manner (
Commonly connected (directly or through a resistor). As a result, the operating voltage Vcm (absolute value) of the transistor in the energized state of the second drive transistor group -m- (collector
The emitter voltage) and the reference voltage signal (b) are compared,
When the operating voltage value becomes smaller than the forward voltage vw& between the emitter and the pace than the signal line, the corresponding detection transistor becomes conductive and outputs a current to the collector side.

Figure 4 shows the current path when the drive transistor is active. (Incorporated) → Resistor D → e side power supply P1 The operating voltage Vcx (absolute value) of the second drive transistor in the energized state becomes smaller than the voltage VC of the other drive transistors I.Detection transistor IL
14i is the voltage Vc of the second driving tone V star group←η-
m and a reference voltage signal), and outputs a collector current according to the difference. In Figure 4, the operating voltage of the second drive transistor is higher than the voltage signal
When the forward voltage between the emitters becomes smaller, the detection transistor a(H becomes active and outputs a collector current.The output currents of each detection transistor c12-(Incorporated) are combined (
The collector side is connected in common), flows into the pace side of the transistor (c), and generates a voltage according to the combined current. on the other hand,
A predetermined DC voltage is applied to the pace of the transistor (F4) through a resistor (to) and a diode ffl, and the current value of the constant current source - is distributed to the collector side in response to the base voltage difference of the transistor tl'4 (740). , is supplied as a common emitter current of the second differential circuit (108).

Differential circuit (1Gg) transistor (each base of IMM)
, 'l□ The output voltage of the Hall element aa is applied to the terminals, and the common emitter current is distributed to the collector side according to the pace voltage. Each collector current of the transistor becomes each pace current of the second drive transistor, and the current supply to the carp μ0210:4tJ4r is switched and controlled.

Therefore, the comparator (106) during detection, the second differential circuit (
108), the 20th dynamic transistor V star group (41←71- constitutes a second feedback μm group, and the operating voltage Vcx of the transistor in the energized state of the second driving transformer 9x group 14η- To further explain this, the decrease in the operating voltage of the second drive transistor is detected and compared by a detection and comparator (106). This reduces the sink current (collector current of transistor t14), reduces the pace current of the second drive transistor, and therefore the collector current, and as a result, increases the operating voltage of the second drive transistor.

If such feedback μm1 is applied, the operation of the 20th differential circuit (10g) and the second drive transistor group ←η- will be stabilized, and the hydraulic power t that responds to the output of the position detection 19 (101) will be stabilized. Switching of transistors is performed reliably and smoothly.

In addition, since the value of the reference voltage signal @ can be set sufficiently small compared to Vcc, even if the voltage drop at A4 is quite large, the first drive transistor in the energized state is in the active region. <<, the first feedback μm and the second feedback μm described above operate stably. That is, the maximum value of the voltage supplied to the carp 1vazos (141) can be sufficiently large.

Furthermore, in this embodiment, the pace side is DC-connected (directly or via a resistor) to the potential point of the reference voltage signal (B), and the emitter side is DC-connected to the second drive transistor group.
〇This is because a PNP type detection transistor connected to each output terminal of η- is used.

The elements required to detect the operating voltage of the second drive Y transistor group @4-1 are transistors @e131 (foundation),
diodes, resistors 9!4NN-(2), etc., and can be integrated into a circuit on a single silicon Φ chip (it is well known that transistors, diodes, and resistors can be integrated). As a result, when the motor drive circuit part in Fig. 1 is constructed using a chip integrated circuit,
The number of external parts is small, making manufacturing extremely easy. In addition, its detection characteristics have no variation in correlation, and the current required for detection is small.Furthermore, if a PNP type transistor with a WOTEF μ structure is used as the detection transistor I, the pace-emitter withstand voltage and the emitter-collector voltage can be reduced. This increases the withstand voltage between coils and eliminates the risk of damage caused by spike voltages in the coil.

Further, in this embodiment, the second drive transistor t#@@
The reference voltage signal (to be compared with the operating voltage of -η-) is changed in conjunction with the command voltage signal -, and the coil A/+121 (
When the supply current to 13I (that is, the current flowing between the first drive transistor and the second drive transistor) is large, the signal is made large, and when the supply current is small, the signal is made small. As a result, the second drive transistor group 14E9t4? The operating voltage Vc of the transistor in the energized state of 1 (c) reliably remains at a small voltage value in the active region even if the energized current changes significantly.
The current flowing through the drive transistor group is controlled.

Such a behavior becomes important especially when considering the saturation characteristics of the second drive transistor. This will be explained with reference to FIG. The saturation voltage of the transistor increases in proportion to the current flowing through it, and conversely, the active region becomes narrower.If we assume that the voltage signal (current) is constant, then the current flowing through the second drive transistor increases. As you go, you will come to a traffic light (
The difference between (b) and the saturation voltage decreases as the current increases, and in severe cases, the relationship in magnitude is reversed. In such a state, the feedback loop described above acts in the opposite direction, and the maximum value of the supplied current is limited. That is, an increase in the energization current of the second drive transistor increases the operating voltage (in this case, the saturation voltage) and reduces the difference between the reference voltage signal) and the operating voltage, and as a result, the energization of the second drive transistor increases. On the other hand, if the voltage signal (b) is changed in response to the energizing current as in this embodiment, the above-mentioned □ malfunction will not occur, so reliable operation can be obtained. I can do it.

- Note that the capacitor (6) is provided for phase compensation of the above-mentioned second feedback y-de. Also, carp ua3・
Capacitor 1- and resistor -W connected to the terminal of 1-kenne
The s- series circuit reduces the spike voltage associated with switching one current path.

In the above-mentioned embodiment, an example was shown in which three-phase coils μ were connected in a star shape, but the present invention is not limited to such a case, but generally,
A motor having a multi-phase coil μ can be constructed. Furthermore, it goes without saying that the drive transistor is not limited to a Paipov type transistor, but may also be a field effect type transistor.
Other than that, various modifications can be made without changing the gist of the present invention.

Furthermore, in the embodiment described above, the first drive transistor group @
The reference voltage signal 轡 which is compared with the operating voltage in @(c) was made to open in response to the command voltage signal -, but it is also possible to supply it from a constant voltage source and always maintain a predetermined reference voltage signal. good.

As described above, according to the present invention, the operating voltage of the transistor in the conduction state of the second drive transistor group is detected, and the operating voltage of the transistor in the conduction state of the second drive transistor group is detected so that the voltage becomes a predetermined value. Since the energizing current ' is controlled, the number of connection terminals to the motor coil can be reduced, and the number of parts and manufacturing man-hours can be reduced. It was. Drive circuit and carp
For example, when the circuit shown in FIG. 1 is constructed from a one-chip integrated circuit, the number of output bins is also reduced.

Therefore, if a pushless DC motor for audio equipment or video equipment is constructed based on the present invention, equipment with good performance can be obtained at low cost.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit wiring diagram showing an embodiment of the present invention;
3 and 3 are circuit diagrams each showing an example of the configuration of a voltage/current converter, FIG. 4 is a diagram for explaining the operation of the circuit in FIG. 1, and FIG. 5 is a diagram showing the operating area of a transistor. be. (Ill ----1f Gnet, H(II (141
-”!I A/, fiH 翰-first drive transistor group,
-(2) (Foundation)-Detection Tooneji XJ, 141←η Decoy...
second drive transistor group, bell--voltage/current converter, (101) "-position detector, (102)...first distribution controller s (1oz)-second distribution controller, (
104)...First differential circuit, (10ri'-voltage ψ
Current converter, (106) - Detector/comparator, (10g) -
...Second differential circuit, (110)-current miff-circuit agent Yoshihiro Morimoto

Claims (1)

[Claims] t Position detection means for detecting the position of a movable part of the motor, a multi-phase coil μ, a first drive transistor group for supplying current to the coil μ, and an output of the position detection means. a first distribution control means for distributing and controlling the energization of the first drive 177121 group in accordance with the above, and a second drive transistor group inserted in series in a current path formed by the coil μ and the first drive transistor group; 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, the second distribution control means comprising:
The structure includes a reference voltage generating means for obtaining a reference voltage signal, and a comparing means for comparing the operating voltage of the transistor in the energized state of the second drive transistor group with the reference voltage value, and the output of the comparing means is The operating state of the second driving transistor group is controlled accordingly, and the reference voltage generating means is arranged to change its reference voltage value in conjunction with the current supplied to the coil, so that the large current A plano-less DC motor that is large when the current is applied and becomes small when the current is small. 2 position detection means for detecting the position of the motor movable part; a plurality of phase coils; a first drive transistor group for supplying current to the coil μ; a first distribution control means for distributing and controlling the energization of the drive transistor group; a second transistor that distributes and controls energization of the second drive transistor group in response to the output;
distribution control means, and the second distribution control means includes reference voltage generation means for generating a predetermined reference voltage signal;
a plurality of detection transistors, one end of which is connected to the potential point of the reference voltage generating means in a DC manner, and one end of which is connected to each output terminal of the second drive transistor group in a DC manner; The detection transistor causes the second
No, KakuD)? The brushless DC motor is configured to compare the operating voltage of the transistors in the energized state of the detection transistor group with the reference voltage signal, and control the operating state of the second drive transistor group according to a composite value of the output currents of the respective detection transistors.