JPH08237992A - Motor drive circuit and air-conditioner with motor drive circuit - Google Patents

Abstract

PURPOSE: To drive a motor while decreasing the number of output ports by an arrangement wherein three or more signals are delivered from one output port of an output circuit and converted into a plurality of different signals through a conversion circuit. CONSTITUTION: A signal is delivered from a port U or a bar U in a microcomputer to point P. A comparator 46 functions to produce a waveform at an output port U'. When such waveform is transmitted to the point P, a comparator 47 functions to produce a waveform at an output port bar U'. Similarly, two different signal waveforms are outputted from conversion circuits 40V, 40W. Conventionally, six output ports are required for driving a motor but the number of output ports of microcomputer can be halved in the inventive drive circuit and the output port can be saved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a motor drive circuit for driving a motor used in an air conditioner or the like, for example, a fan fan motor or a compressor motor. Regarding the air conditioner.

[0002]

2. Description of the Related Art A circuit for driving a motor such as a brushless motor (for example, a compressor motor, not shown) is shown in FIG. In the figure, 25 is a control device (microcomputer), 19, 20, 21, 22, 23, 24 are switching transistors, 1 is a compressor, and a compressor motor is driven by turning on / off the switching transistors 19 to 24. Has become. In the drive circuit configured as above, six output ports of the microcomputer are used to drive one motor. Blower fan 5,
The signal for driving 6 is shown by one dotted line for convenience.

[0003]

In the motor drive circuit described above, six output ports of the microcomputer are required to drive one motor, and therefore, there are many motors to be driven and many control targets. In some cases, there was a shortage of output ports. When the output port is insufficient,
The circuit will have to be replaced by a microcomputer equipped with more output ports. When replaced in this way, there is a disadvantage that the price of the drive circuit becomes high.

The present invention provides a motor drive circuit capable of driving a motor with a small number of output ports, and an air conditioner equipped with this drive circuit.

[0005]

In order to solve the above problems, the first invention is a motor drive circuit comprising an output circuit having a plurality of output ports, and a motor connected to the circuit, The output circuit is provided with a conversion circuit configured to output three or more different signals from one output port and converting the output signals into a plurality of different outputs.

A second aspect of the present invention is a motor drive circuit comprising a macro computer having a plurality of output ports and a motor connected to the microcomputer,
The output port of the microcomputer is configured to output a high signal, a low signal and an open signal,
It is provided with a conversion circuit for converting into a plurality of different outputs according to these outputs.

A third aspect of the present invention is an air conditioner including a microcomputer having a plurality of output ports and a motor drive circuit composed of a fan motor connected to the microcomputer. , A high signal, a low signal, and an open signal are output, and a conversion circuit for converting into a plurality of different outputs according to these outputs is provided.

[0008]

In the motor drive circuit according to the first aspect of the invention, three or more signals are output from one output port of the output circuit, and the conversion circuit converts the signals into a plurality of different signals. Multiple different signals can be obtained for one output port, saving output ports.

In the motor drive circuit according to the second invention,
3 signals from one output port of the microcomputer
One or more signals are output, and the conversion circuit converts the signals into a plurality of different signals, so that it is possible to obtain a plurality of different signals for one output port and save the output port. You can

In the air conditioner according to the third aspect of the invention, like the second aspect of the invention, since the conversion circuit converts into a plurality of different signals according to these signals, a plurality of different signals for one output port. The signal can be obtained and the output port can be saved.

[0011]

Embodiments of the present invention will be described with reference to the drawings.
Reference numeral 100 is an air conditioner equipped with the motor drive circuit according to the present invention. Reference numeral 1 denotes a compressor (which includes a compressor motor (not shown)), and a condenser 2, a decompressor 3, and an evaporator 4 are sequentially connected in an annular shape by a refrigerant pipe to form a refrigeration cycle. In addition, 5 is a ventilation fan of a condenser, 6 is a ventilation fan of an evaporator. Reference numeral 7 denotes a printed circuit board in the control device, and diodes 9 to 1 for rectifying voltage (power source section) from an AC power source 8 having a rating of 100 [V] on the printed circuit board.
2 and the capacitor 15, the noise filter 16, the indicator lamp 17 and the resistor 18, and the six N's forming the inverter circuit.
PN type transistors 19 to 24, a control device (output circuit) 25, etc. are mounted. The control unit 25 is composed of, for example, a microcomputer and supplies switching signals based on the PWM method to the transistors 19 to 24 of the inverter circuit.
At the same time, the operation of the blower fans 5 and 6 is also controlled. Further, reference numeral 26 is a power switch for cutting off or connecting the AC power supply. The control unit 25 operates by turning on this switch.

A solar cell 39 outputs a direct current output via the converter 27. The converter 27 always outputs the output voltage of the solar cell 37, which changes according to the amount of solar radiation, to the direct current 28
The voltage is boosted so as to maintain 0 [V].

The output of the solar cell is weak, and the direct current is 280
When the voltage cannot be raised to [V], the changeover switch 28 is automatically changed over to the AC power source side.

The changeover switch 28 connects either the direct current from the AC power source 8 side or the output from the solar cell 26 side to the inverter circuit. As the changeover switch 28, one that can be manually operated is used. The state shown in FIG. 1 is a state in which the changeover switch is connected to the solar cell side. Note that the signal line 200 does not show the correct number of signal lines and the conversion circuit.

Reference numerals 40U, 40V and 40W denote conversion circuits, which are the same and are constructed as shown in FIG. 41 and 42 are 10K ohm resistance and 4 respectively
3,44,45 are 10K ohm, 20K ohm, 1 respectively
0K ohm resistance, 46 and 47 are comparators, 48 and 4, respectively
Reference numerals 9 are low-pass filters, respectively, for removing a carrier component. U'and U bar 'are output ports, respectively. u is an output port of the control unit 25, and a high signal, a low signal, and an open signal are output from this output port. This open signal is set and output by software inside the microcomputer, and the output port is in an open state. Therefore, the point P (the same potential as the output port u) has the potential of VCC when a high signal is output from this port, and VCC is the resistances 41 and 42 when an open signal is output from the port. And becomes a VCC potential of ½ and becomes a ground potential (0 V) when a low signal is output from the port.

When U is a high signal, it outputs a high signal, and when U is a high signal, it outputs a low signal.
Is set by the software (program) of the microcomputer so that an open signal is output when both U and U are low signals.

In the air conditioner thus constructed, the drive circuit portion of the motor operates as follows. A signal as shown in FIG. 3 is output from the internal ports U and U bar of the microcomputer. At the point P where U and U bar are combined, the waveform becomes like the third signal line from the top of the figure (the same as the output waveform of the output port u, and the same waveform from the output ports v and w). Is output, but the phase of each of the waveforms is shifted by 120 degrees). Then, when such a waveform is transmitted to the point P, the comparator 46 functions to output the second waveform from the bottom in FIG. 3 to the output port U ′.
When the waveform as described above is transmitted to the point P, the output of the output port U bar ′ is the bottom waveform of FIG. 3 due to the operation of the comparator 47. Similarly, the conversion circuits 40V, 40
W also outputs two different signal waveforms.

Therefore, in the conventional case (FIG. 5), the motor could not be driven without using the six output ports, but when the drive circuit according to the present invention is used, the output port of the microcomputer is half. Since only three of these are required, the output port of the microcomputer can be saved, many motors can be driven, and the number of controlled objects can be increased.

There is the present invention as a method for outputting three or more signals with one microcomputer port, but this is only a signal for driving a motor, for example, U and U bar, which are simultaneously turned on at the same time timing. It was limited to the case where no signal was output. The waveform of FIG. 4 shows the waveform when the ON signal is output at the same timing as U and V even for the drive signal of the motor. In the present invention, it is impossible for the microcomputer to output two or more signals at the same timing due to the circuit configuration. Therefore, special work is required in terms of software. The output signal synthesizes the output signal with a signal (carrier) that is several times to several tens of times the required signal,
After that, the low-pass filter removes the carrier component so that it appears as if two different types of signals were output at the same timing.

[0020]

According to the first and second aspects of the invention, a plurality of different signals can be obtained for one output port, the output port can be saved, and many motors can be driven. It is possible to expand the control target.

According to the third invention, like the first and second inventions, the output port can be saved, many air conditioning motors can be driven, and many air conditioning equipments can be controlled. it can.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of an air conditioner including a motor drive circuit according to the present invention.

FIG. 2 is an electric circuit diagram showing a main part of a drive circuit of the motor.

FIG. 3 is a signal waveform diagram showing signals of respective portions of the drive circuit of the motor.

FIG. 4 is a signal waveform diagram showing different signals of respective portions of the drive circuit of the motor.

FIG. 5 is an electric circuit diagram of an air conditioner including a conventional motor drive circuit.

[Explanation of symbols]

 25 microcomputer (output circuit) 40U conversion circuit 40V conversion circuit 40W conversion circuit 100 air conditioner u output port v output port w output port

Claims (3)

[Claims] 1. An output circuit having a plurality of output ports,
In a motor drive circuit including a motor connected to this circuit, one output port of the output circuit is configured to output three or more different signals, and a plurality of different signals are output according to these outputs. A motor drive circuit comprising a conversion circuit for converting the output. 2. A motor drive circuit comprising a microcomputer having a plurality of output ports and a motor connected to the microcomputer, wherein a high signal, a low signal and an open signal are output from the output port of the microcomputer. A motor drive circuit comprising a conversion circuit configured to output, and converting into a plurality of different outputs according to these outputs. 3. An air conditioner comprising a microcomputer having a plurality of output ports and a motor drive circuit configured by a fan motor connected to the microcomputer, wherein a high signal is output from the output port of the microcomputer. An air conditioner provided with a drive circuit for a motor, which is configured to output a low signal and an open signal, and which is provided with a conversion circuit for converting the output into a plurality of different outputs.