JP3770039B2 - Motor rotation position detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for detecting the rotational position of a motor, and more particularly to a technique for avoiding the influence of noise in the detection.
[0002]
[Prior art]
FIG. 2 is a circuit diagram showing a conventional technique for detecting the position of the motor. For example, the motor 14 is a three-phase motor for a fan of an air conditioner, and is rotationally driven while its rotational position is fed back.
[0003]
Specifically, the drive current from the inverter 13 is given to the motor 14 via the connector 18 and the wiring group 51. The position detection circuit 15 detects the rotational position of the motor 14 that rotates in response to the drive current. The output of the position detection circuit 15 is given to position signal output circuits 16u, 16v, and 16w provided corresponding to the U phase, V phase, and W phase that form three phases, respectively.
[0004]
The microcomputer 11 is connected to a first power source 21 that supplies a relatively low voltage, for example, 5 V, and operates using this as an operating power source. The microcomputer 11 receives the position signals obtained from the position signal output circuits 16u, 16v, 16w, and controls the driver 12 based on the position signals. The driver 12 supplies a drive signal group 61 generated based on this control to the inverter 13, and the inverter 13 performs switching based on the drive signal group 61. In order to drive the inverter 13 in which high voltage switching is performed, the driver 12 is connected to a second power supply 40 that supplies a relatively high voltage, for example, 15 V, and operates as an operating power supply.
[0005]
Connectors 17u, 17v, 17w are provided corresponding to the position signal output circuits 16u, 16v, 16w, respectively, and have terminals E, F, G, respectively. The terminals E of the connectors 17u, 17v, and 17w input predetermined voltages to the position signal output circuits 16u, 16v, and 16w, respectively, and the terminal F functions to output position signals generated by the position signal output circuits 16u, 16v, and 16w, respectively. Have In addition, a ground potential is input to any terminal G.
[0006]
The terminals E, F, and G are connected to the connector 25 by wiring collected as a harness 50. Any terminal E of the connectors 17u, 17v, and 17w is connected to the terminal E of the connector 25. Any terminal G of the connectors 17u, 17v, 17w is connected to the terminal G of the connector 25, and is grounded through this. Terminals F of connectors 17u, 17v, and 17w are connected to terminals F1, F2, and F3 of connector 25, respectively.
[0007]
Terminals F1, F2, and F3 of the connector 25 are connected to the filter 22 and the pull-up circuit 23. The filter 22 is a low-pass filter, and terminals F1, F2, and F3 are connected to the input terminals 11u, 11v, and 11w of the microcomputer 11 through the filter 22, respectively. The pull-up circuit 23 includes resistors 231, 232, and 233, and the terminals F1, F2, and F3 are pulled up to the first power source 21 by these resistors, respectively. As a result, the position signal is adjusted to a value suitable for the input of the microcomputer 11 operating with the first power supply 21.
[0008]
Then the microcomputer 11, the driver 12, an inverter 13, a first power source 21, a second power supply 40, the filter 22, the pull-up circuit 23, both connectors 18 and 25, the control board is P plate commonly called in the air conditioner 100, and connected to the connectors 17u, 17v, 17w and the motor 14 by a harness 50 and a wiring group 51, respectively.
[0009]
[Problems to be solved by the invention]
In the configuration as described above, the microcomputer 11 is operated by the first power supply 21 and the terminals F1, F2, and F3 of the connector 25 are also pulled up by the first power supply 21, so that the terminal E of the connector 25 1 Power supply 21 was connected.
[0010]
However, since the harness 50 connects the control board 100 and the connectors 17u, 17v, and 17w, noise on the harness 50 propagates to the control board 100. This noise further propagates to the microcomputer 11 via the terminal E of the connector 25 and the first power supply 21.
[0011]
Normally, although the capacitor 24 is connected between the first power source 21 and the ground in the vicinity of the connector 25 so as to share noise, noise propagation to the microcomputer 11 cannot be eliminated at all. If noise propagates to the first power source 21, this may cause the microcomputer 11 to malfunction.
[0012]
The present invention has been made in view of the above circumstances, and provides a technique for preventing propagation of noise to a microcomputer even when noise is placed on a harness connecting the position signal output circuit and the microcomputer. The purpose is that.
[0013]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a rotational position detecting device for a motor, wherein the first power source (21) is an operating power source and the control means (11) for controlling the rotation of the motor (14), A position signal output means (16u, 16v, 16w) for outputting a position signal indicating the rotational position of the motor (14) to the control means; and an operating power source for the position signal output means (16u, 16v, 16w), A second power source (40) different from the first power source (21) is provided.
[0014]
And said control means (11), said first power supply (21), wherein a control board that the second power supply (40) is provided (100), the position signal output means (16u, 16v, 16w) and the control board ( 100), and the second power source (40) is connected to the position signal output means (16u, 16v, 16w) by the wiring group (50). Is input from the position signal output means (16u, 16v, 16w) to the control means (11) by the wiring group (50).
[0015]
According to a second aspect of the present invention, there is provided a motor rotational position detecting device according to the second aspect, wherein an inverter (13) for supplying a drive current to the motor (14) and the control means (11). The control board (100) is further provided with a driver (12) that generates a drive signal (61) for driving the inverter (13) under the control of the above, and uses the second power supply (40) as an operation power supply.
[0016]
Preferably, according to a third aspect of the invention, a rotating position detecting apparatus for a motor according to claim 2, wherein said second power supply (40) supplies a voltage greater than the first power supply (21), The position signal output means (16u, 16v, 16w) is an open collector type, and the control means (11) has an input end (11u, 11v, 11w) for inputting the position signal, and the input end (11u , 11v, 11w) is further provided with a voltage adjustment circuit (31) having resistors (311, 312, 313) for pulling down.
[0017]
According to a fourth aspect of the present invention, there is provided the rotational position detecting device for a motor according to the third aspect , wherein the voltage adjusting circuit (31) connects the input terminal (11u, 11v, 11w) to the second power source. It further has resistors (314, 315, 316) that pull up to (40).
[0018]
According to a fifth aspect of the present invention, there is provided the motor rotational position detecting device according to the fourth aspect , wherein the rotational position detecting device is connected to the input end (11u, 11v, 11w) and the input end (11u, 11v, 11w). ) Is further provided with a voltage limiting circuit (30).
[0019]
[Action]
In the motor rotational position detection device according to the first aspect of the present invention, the operation power supply of the position signal output means and the operation power supply of the control means are provided separately from each other.
[0020]
The exchange of the second power source and the position signal is performed via the wiring group for connecting with said control board and the position signal output means.
[0021]
In the motor rotational position detecting device according to the second aspect of the present invention, the second power source as the operating power source of the driver is shared with the operating power source of the position signal output means.
[0022]
In the motor rotational position detection device according to the third aspect of the present invention, the position signal output means that operates based on the second power source is of an open collector type, so that the voltage is suitable for the control means that operates on the first power source. A position signal having a larger voltage is output.
[0023]
According to a fourth aspect of the present invention, the voltage adjustment circuit divides and supplies the voltage supplied from the second power source to the input terminal of the control means.
[0024]
In the motor rotational position detecting device according to the fifth aspect of the present invention, the voltage at the input end of the control means is limited to a predetermined voltage.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a circuit diagram illustrating a motor drive control circuit according to an embodiment of the present invention.
[0026]
Similarly to the conventional technology, the motor 14 is connected by the connector 18 and the wiring group 51 mounted on the control board 100, and the connectors 17u, 17v and 17w are connected by the connector 25 and the harness 50 mounted on the control board 100, respectively. ing.
[0027]
Here, the wiring group 51 is composed of three wirings according to the number of phases of the motor 14. That is, the three-phase output of the position detection circuit 15 that detects the rotational position of the motor 14 is given to the position signal output circuits 16u, 16v, and 16w.
[0028]
The harness 50 includes five wirings, three of which are wirings connected to the terminals F of the connectors 17u, 17v, and 17w, and have a function of giving a position signal to the terminals F1, F2, and F3 of the connector 25. is doing. The other two wires are a wire connecting the terminals E of the connectors 17u, 17v, 17w in common and a wire connecting the terminals F of the connectors 17u, 17v, 17w in common, to the position signal output circuits 16u, 16v, 16w. It has a function of supplying operating power.
[0029]
The position signal output circuits 16u, 16v, and 16w all have the same configuration, that is, an npn transistor Q and resistors R1 and R2 connected to the collectors thereof. The base of each transistor Q receives a corresponding output of the position detection circuit 15. The emitters of the transistors Q of the position signal output circuits 16u, 16v, and 16w are connected to terminals G of the connectors 17u, 17v, and 17w, respectively. The resistors R1 of the position signal output circuits 16u, 16v, and 16w are connected to terminals E of the connectors 17u, 17v, and 17w, respectively. The collectors of the transistors Q of the position signal output circuits 16u, 16v, and 16w are connected to the terminals F of the connectors 17u, 17v, and 17w through the resistors R2, respectively, so that a so-called open collector type circuit is configured. In each of the connectors 17u, 17v, and 17w, a capacitor C is provided between the terminals E and G for noise removal.
[0030]
In the control board 100, the microcomputer 11 is connected to the first power supply 21 as an operating power supply, and is connected to the second power supply 40 to control the driver 12 using this as the operating power supply. The driver 12 gives a drive signal group 61 to the inverter 13 under the control of the microcomputer 11 to cause the inverter 13 to switch. The output current of the inverter 13 is given to the motor 14 via the connector 18 and the wiring group 51.
[0031]
The control of the driver 12 by the microcomputer 11 is performed based on position signals given to the terminals F1, F2, and F3 of the connector 25. Terminals F1, F2, and F3 of the connector 25 are connected to terminals F of the connectors 17u, 17v, and 17w, respectively, and the position signals given to these are sent to the microcomputer 11 via the voltage divider circuit 31, the Zener diode group 30, and the filter 22. Given to. Further, a capacitor 24 of, for example, 0.1 μF is provided between the terminals E and G of the connector 25 for noise removal.
[0032]
The filter 22 constitutes a low-pass filter for each phase. That is, resistors 224, 225, and 226 are connected between the terminals F1, F2, and F3 and the input terminals 11u, 11v, and 11w, respectively, and the input terminals 11u, 11v, and 11w are connected through the capacitors 221, 222, and 223, respectively. Is grounded. The resistance values of the resistors 224, 225, and 226 are set to 1 kΩ, for example, and the capacitance values of the capacitors 221, 222, and 223 are set to 0.1 μF, for example.
[0033]
Unlike the conventional case, the second power supply 40 is connected to the terminal E of the connector 25. Therefore, a voltage supplied from the second power source 40, for example, a voltage of 13.5 to 16.5 V is applied to the position signal output circuits 16u, 16v, and 16w. Normally, the position signal output circuits 16u, 16v, and 16w are designed to be operable even when a voltage of about 18V is applied. Therefore, even if the second power supply 40 is connected to the connector 25 as described above, the position signal is output. The output circuits 16u, 16v, and 16w operate normally.
[0034]
Since the control board 100 is provided with the second power supply 40 for supplying a relatively high voltage to the driver 12, there is no mounting difficulty in connecting the second power supply 40 to the terminal E of the connector 25. Absent. Moreover, since the second power supply 40 is provided separately from the first power supply 21 supplied to the microcomputer 11, even if noise is placed on the harness 50 and propagates to the second power supply 40, the first power supply 21 is supplied to the first power supply 21. Noise propagation is suppressed to a greater extent than in the conventional case.
[0035]
Thus, even if the wiring for supplying power to the position signal output circuits 16u, 16v, and 16w and the wiring for supplying the position signal to the microcomputer 11 are combined in the same harness 50, the operation power supply to be supplied to each of them. Are different from each other, noise on the harness does not adversely affect the microcomputer 11 having a particularly low operating voltage.
[0036]
However, since a relatively high voltage is supplied from the second power supply 40 to the position signal output circuits 16u, 16v, and 16w, a relatively low voltage, for example, 4.5 to 5.5 V is supplied from the first power supply 21 to operate. In order to use the input signal of the microcomputer 11, it is not always preferable to employ the conventional pull-up circuit 23 as it is. This is because when the transistor Q is turned off, the terminal F is pulled up via the resistors R1 and R2, so that the potential of the input signal of the microcomputer 11 may become too high.
[0037]
Therefore, in this embodiment, a voltage dividing circuit 31 for adjusting the voltage of the position signal is employed instead of the pull-up circuit 23. The voltage dividing circuit 31 divides resistance between the second power supply 40 and the ground, and adjusts the voltage applied to the input terminals 11u, 11v, and 11w to a value suitable for the input of the microcomputer 11. Specifically, the resistors 311, 312, 313 are provided between the terminals F 1, F 2, F 3 and the ground, respectively, and the resistors 314, 315, 316 are respectively connected between the terminals F 1, F 2, F 3 and the second power supply 40. Is provided.
[0038]
For example, in the position signal output circuits 16u, 16v, and 16w, the resistance values of the resistors R1 and R2 are set to about 7 to 13 kΩ and 1 kΩ, respectively. Corresponding to this, for example, the resistance values of the resistors 311, 312, and 313 are all set to 5.1 kΩ, and the resistance values of the resistors 314, 315, and 316 are all set to 30 kΩ. Thus, even if the transistor Q is turned off, the resistors 314, 315, and 316 perform a pull-down function, so that the potentials of the terminals F1, F2, and F3 are suppressed to about 5V. When the transistor Q is turned on, the potentials of the terminals F1, F2, and F3 are suppressed to about 1V or less. Therefore, according to the transistor Q that is turned on / off by the output of the position detection circuit 15, an appropriate voltage is applied to the microcomputer 11 according to the binary logic at the input terminals 11u, 11v, and 11w. The resistors 311, 312, and 313 having a pull-up function are not necessarily required, and the voltage dividing circuit 31 may be a pull-down circuit including only the resistors 314, 315, and 316. However, in general, providing these facilitates the design according to the first power supply 21, the second power supply 40, the resistors R1 and R2, and the on-resistance and on-voltage of the transistor Q.
[0039]
Note that, for example, a Zener diode group 30 shown in FIG. 1 is preferably provided between the voltage dividing circuit 31 and the filter 22 as a circuit that limits the voltage applied to the input terminals 11u, 11v, and 11w. This is because an excessive voltage is not applied to the input terminals 11u, 11v, and 11w even if the values of the resistors R1 and R2 and the resistors 311 to 316 vary somewhat. Specifically, the cathodes of the Zener diodes 301, 302, and 303 are connected to the terminals F1, F2, and F3, respectively, and the anodes of the Zener diodes 301, 302, and 303 are all grounded. The Zener voltages of the Zener diodes 301, 302, and 303 are set to 4.7 V, for example.
[0040]
Of course, depending on the values of the resistors R1 and R2, the pull-up circuit 23 may be adopted instead of the voltage dividing circuit 31, and the voltage dividing circuit 31 and the pull-up circuit 23 divide the supply voltage of the second power source 21, Or you may pull up to this.
[0041]
【The invention's effect】
According to the motor rotational position detecting device of the present invention, a wiring is provided between the control means and the position signal output means, and the position signal output means and the control means even if noise is superimposed on the wiring. Since a separate operating power supply is provided, malfunction of the control means can be prevented.
[0042]
And be superimposed noise on the wiring group, it is possible to obtain the effect of the rotational position detecting device of a motor according to claim 1, wherein.
[0043]
According to the second aspect of the present invention, since the control board is provided with the second power source for supplying the voltage to the driver, the wiring to the position signal output means is connected to the second power source. There is no difficulty in mounting to connect two power sources.
[0044]
According to the third aspect of the present invention, the voltage adjustment circuit adjusts the voltage of the position signal to a voltage suitable for the control means.
[0045]
According to the rotational position detecting device of a motor according to a fourth aspect of the present invention, by providing both the pull-up resistor and the pull-down resistor to the voltage regulator circuit, it is possible to facilitate the design.
[0046]
According to the rotational position detection device for a motor according to claim 5 of the present invention, an excessive voltage is not applied to the input terminal of the control means even if there are variations in the specifications of the rotational position detection device.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing an embodiment of the present invention.
FIG. 2 is a circuit diagram showing a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Microcomputer 11u, 11v, 11w Input terminal 12 Driver 13 Inverter 14 Motor 16u, 16v, 16w Position signal output circuit 21 1st power supply 31 Voltage adjustment circuit 40 2nd power supply 50 Harness 61 Drive signal group 100 Control board 311 312 313, 314, 315, 316 Resistance

Claims (5)

Control means (11) for controlling the rotation of the motor (14) using the first power supply (21) as an operating power supply;
Position signal output means (16u, 16v, 16w) for outputting a position signal indicating the rotational position of the motor (14) to the control means;
A second power source (40) different from the first power source (21), which is an operating power source for the position signal output means (16u, 16v, 16w) ;
A control board (100) provided with the control means (11), the first power source (21), and the second power source (40);
A wiring group (50) for connecting the position signal output means (16u, 16v, 16w) and the control board (100) ;
The second power source (40) is connected to the position signal output means (16u, 16v, 16w) by the wiring group (50),
The position signal is the position signal output means by the wire group (50) (16u, 16v, 16w) are entered from to said control means (11), the rotational position detecting device of the motor. An inverter (13) for supplying a drive current to the motor (14);
A drive signal (61) for driving the inverter (13) under the control of the control means (11) is generated, and a driver (12) using the second power source (40) as an operating power source is connected to the control board ( further comprising at 100), the rotational position detecting device of a motor according to claim 1, wherein. The second power source (40) supplies a larger voltage than the first power source (21),
The position signal output means (16u, 16v, 16w) is an open collector type,
The control means (11) has input terminals (11u, 11v, 11w) for inputting the position signal,
Voltage adjustment circuit (31) having resistors (311, 312, 313) for pulling down the input terminals (11u, 11v, 11w)
The motor rotational position detection device according to claim 2 , further comprising: The motor according to claim 3 , wherein the voltage adjustment circuit (31) further includes a resistor (314, 315, 316) for pulling up the input terminal (11u, 11v, 11w) to the second power source (40). Rotation position detection device. A voltage limiting circuit (30) connected to the input terminals (11u, 11v, 11w) and configured to limit the voltage at the input terminals (11u, 11v, 11w).
The motor rotational position detection device according to claim 4 , further comprising:

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