JPS61164485A - Air conditioner - Google Patents

Abstract

PURPOSE:To always hold the target rotating speed of a motor by comparing with a set rotating speed when an AC motor varies due to the variations in a load or a power source voltage, and correcting the phase angle in response to the compared result. CONSTITUTION:The rotation of a fan motor 1 is controlled to coincide with the rotating speed stored in an ROM 16. When a fan motor 1 varies its rotating speed due to a variation in a load, the varied rotating speed is input to an ROM 15 to become incoincident to the content of the ROM 16, the content of an RAM 19 is added or subtracted in the incoincident amount, the counting time of a timer 20 increases or decreases in response to the content of the RAM 19, the conduction timing of a triac 6 varies by the increase or decrease of the counting time to control the phase so that the content of the RAM 15 coincides with that of the ROM 16.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an air conditioner that includes a blower using an AC motor as a drive source and that controls the phase of this motor, and particularly relates to speed control of the blower.

<Prior Art> Generally, air conditioners are equipped with a blower using a motor as a drive source, and these motors are broadly classified into DC motors and AC motors.

Among these, DC motors are extremely superior as motors for use in modern air conditioners that require switching of air flow in multiple stages, as the speed can be easily controlled and the speed is relatively stable. On the other hand, since there is no DC power source for air conditioners for home use, a device to convert AC power to DC is required, which not only makes the blower device itself very expensive, but also makes the air conditioner itself larger. Moreover, there is a problem that the weight increases.

Therefore, it is effective to use an AC motor that can directly use an AC power source as a blower drive motor for an air conditioner, but it is not easy to control the speed and is not suitable as a motor for an air conditioner.

FIG. 4 is a block diagram of a conventional air conditioner using an AC motor. In this figure, 1 is an AC motor as a fan motor, 2 is a power plug for supplying AC power to this motor 1, 3 is a microcomputer for controlling the speed of this AC motor 1, and 4 is this microcomputer. 3 is a DC constant voltage power supply that supplies DC power; 5 is a driver; 6 is a triac that adjusts the continuity of the power supply to the motor 1;
7 is a zero cross detection circuit that detects phase angle 0 of the power supply and outputs a signal.

In the microcomputer 3 mentioned above, the speed of the blower according to the air conditioning mode and the air conditioning state is stored in advance in a multi-stage setting, and the speed set in advance by the microcomputer 3 is stored in advance. A necessary one is selected from among them to control the speed of the motor l.

Now, to explain the operation of the air conditioner shown in FIG. 4, when the mode is set to drive the blower, the microcomputer 3 outputs a drive signal pulse, and this signal causes a gate current to be applied to the triac via the driver 5. The current flows and the triac 6 becomes conductive.

When the triac 6 becomes conductive, power is supplied to the motor 1, the motor 1 begins to rotate, and the blower also begins to rotate as the motor 1 is driven.

The alternating current flowing through the motor 1 is less than the holding current of the triac 6 at a phase angle of 0, and due to this current drop, the triac 6 is turned off, and the instantaneous zero cross detection circuit 7 detects a phase angle of 0. Then, a pulse signal is input to the microcomputer 3.

The microcomputer 3 to which the signal with the phase angle O has been input outputs a pulse to turn on the triac 6 again after a preset delay time (predetermined phase angle) according to the rotational speed of the selected motor 1. , this pulse is introduced into the triac 6 via the driver 5, so that the triac 6
conducts after a delay of a predetermined time (phase), and the power supply voltage that has been cut off for the triac OFF time is supplied to the motor. Thereafter, in the same manner, an AC voltage that is cut off by a delay phase angle that is preset according to the selected rotational speed is applied to the motor.

In the phase angle control performed in this way, the rotation speed of the motor is controlled by adjusting the cut-off time (phase angle), that is, the delay time (phase angle) set in the microcomputer. When the angle is 0, the power supply voltage is supplied by 100X and the maximum speed is reached, and when the delay phase angle is 90, the supply voltage is 0 and the motor stops.

However, in the above air conditioner that performs phase control, the speed of the motor (blower) is controlled only by phase control based on zero-cross detection of the power supply voltage, so fluctuations in the AC power supply voltage and variations in torque at various parts of the blower occur. ,
There has been a problem in that the rotational speed of the blower is affected by variations in the load of the air conditioner and the like, making it impossible to stably blow air.

In this way, when the blower speed fluctuates, for example, when the rotation speed decreases, the cooling/heating capacity decreases due to a decrease in the amount of air blown, and conversely, when the rotation speed increases, the blower generates noise ( This causes the inconvenience of increased wind noise.

In addition, in terms of air blowing speed control, for example, when controlling the air blowing amount in multiple stages within a certain predetermined range, the speed cannot be stabilized with the above-mentioned phase control, so the speed can only be controlled in about four stages, for example, and the speed can be changed to, for example, 1O stage. The present invention has been made in view of the above points, and although an AC motor is used as the drive source for the fan, it is not possible to perform detailed air conditioning. The purpose of the present invention is to provide an air conditioner that can perform stable speed control.

<Example 2 Embodiments of the present invention will be described below with reference to the drawings.

Components that are the same as those in the prior art are designated by the same reference numerals, and descriptions thereof will be omitted.

FIG. 1 is a circuit diagram of an embodiment of the present invention.

In FIG. 1, 8 is a microcomputer that controls the speed of an AC motor 1 as a 77-inch motor, and 9 is a rotational speed detection means for detecting the rotational speed of this motor 1. The detected rotational speed is input to the microcomputer 8.

Next, the relationship between the microcomputer 8 and the detection means 9 will be explained using FIG.

FIG. 2 is a functional block diagram of the above embodiment.

In FIG. 2, 1 is the AC motor, and 9 is the rotational speed detecting means.

This rotational speed detection means 9 is composed of a magnet 11 attached to the rotation shaft 10 of the motor 1 and a magnetic detection means 12 that detects the magnetism of this magnet 11. This magnetic detection means 12 includes, for example, a Hall element. The magnet 11 is provided with a magnetic detection element such as the above, and is arranged to face the magnet 11, and detects the alternating current voltage generated by the rotation of the magnet 11.

Reference numeral 13 denotes an F/V conversion means, which is connected to the magnetic detection means 12.
The AC voltage detected by the converter is converted into a DC voltage proportional to the frequency of this voltage.

14 is an A/D converter, and this A/D converter 14 is connected to the F/V conversion means 13, and this F/V
The voltage output from the conversion means 13 is converted into a digital signal.

A RAM 15 is connected to the A/D converter 14 and stores the digital signal output from the A/D converter 14.

Reference numeral 16 denotes a ROM, and this ROMI 6 stores the number of revolutions of the fan motor in a plurality of stages preset according to the air conditioning state.

17 is a comparator, and this comparator 17 is
The rotation speed signal of the motor l inputted from RAMI 5 is compared with the rotation speed signal selected from among the rotation speeds stored in ROM 16, and the rotation speed from RAMI 6 is the same as the rotation speed from ROMI 7. When the number of rotations from the RAM 16 exceeds the number of rotations, an H signal is output, and conversely, when the number of rotations from the RAM 16 is less than the number of rotations from the ROM 17, an output signal L is output.

Reference numeral 18 denotes an adder/subtracter, which adds 1 bit to the contents of RAMI 9 connected to this adder/subtracter 18 when receiving the signal from the comparator 17 and receives an H signal; When the signal input from comparator 17 is an L signal, the contents of RAMI 9 are subtracted by 1 bit.

Reference numeral 20 denotes a phase angle timer. This timer 20 starts counting upon input of the pulse signal from the zero-cross detection circuit 7, and counts up to a digital value corresponding to the phase angle data set in the RAM 19. When this happens, a conduction signal is output to the triac gate 6.

The other configurations are the same as the conventional one.

Next, regarding the operation of the air conditioner with the above configuration, 70 in FIG.
-Explain with chart.

First, when the fan motor 1 is stopped, the current generated from the magnetic detection means 9 is 0, and an 0 times signal is introduced into the RAM 2S.

Here, depending on the air conditioning mode and indoor temperature status, ROMI
When a specific rotation speed is selected from among the rotation speeds stored in the comparator 17, since the contents of the RAM 15 are smaller than the contents of the ROM, an L signal is output from the comparator 17, and this L signal is sent to the adder/subtractor. Introduced on 18th.

Here, since the content of RAMI 9 is initially set to 0, the content of RAM 19 is subtracted by introducing the L signal, but since the initial content is 0, the content of RAM 19 remains O.

O, which is the content of this RAMI 9, is input to the phase angle timer, and based on this input content, the phase angle timer 2
0 counts the delay time.

At this time, when the zero cross detection signal from the zero cross detection circuit 7 is input to the phase angle timer 20, the phase angle timer 20 counts the delay time based on the contents of the RAM 19, but the contents of the RAM'M19 become O. Therefore, the conduction signal of the triac 6 is output simultaneously with the input of the zero-cross detection signal, and as a result, 100% power with a phase angle of 0 is supplied to the motor 1.

By supplying this electric power, the motor 1 is driven and air is blown.

When the motor 1 is driven in this manner, the magnet 11 attached to the rotating shaft 10 also begins to rotate at the same rotation speed.

When the magnet 11 rotates in this manner, an alternating magnetic field is generated around the magnet 11, and this magnetic field is transmitted to the magnetic detection means 12.
is converted into an AC voltage with the same frequency as the rotation speed.

This AC voltage is input to the F/V converting means 13, where it is converted into a DC voltage proportional to the frequency, and is input to the microcomputer 8. The input voltage passes through the A/D converter 14, is converted into a digital signal, and is input to the RAM 15 as a rotation speed signal.

While the air blowing operation is being performed in this way, the RAM
Until the content of ROMI 15 exceeds the content of ROMI 6, power at the phase angle O is supplied to the motor 1.

Here, when the content of RAMI 5 exceeds the content of ROMI 6, an H signal is output from the comparator 17, and the content of RAM 19 is added by the adder/subtractor 18.
The count time of the phase angle timer 20 becomes longer depending on the contents of M19. As a result, the triac 6 is delayed by the time counted by the timer 20 from the zero cross, and then ONL by the conduction signal output from the timer 20. , power whose phase angle is controlled by this delay time is supplied to the fan motor 1.

Therefore, compared to the case where 100% of the power of the phase angle O is supplied, the power supplied to the motor 1 is reduced, and as a result, the number of revolutions of the motor 1 is also reduced.

Due to this decrease in the rotational speed, the rotational speed signal input to the RAM 15 also decreases, and the contents of the RAM 15 approach the contents of the ROM 16.

In this way, the rotation of the fan motor 1 is controlled to match the rotation speed stored in the ROM 16.

When the rotation speed of the fan motor 1 controlled in this way fluctuates due to changes in load, etc., this fluctuating rotation speed is input to the RAMI 5, which causes a discrepancy with the contents of the ROM 16, and the contents of the RAM 19 are changed by the amount of this discrepancy. is added or subtracted, the count time of the timer 20 increases or decreases according to the contents of RAMI 9, and the conduction timing of the triac 6 changes depending on the increase or decrease of this count time, so that the contents of RAMI 5 match the contents of ROMI 6. Phase control is performed so as to

Similarly, if another rotation speed is selected from the contents stored in ROMI 6, the contents of ROMI 6 and R
The contents of AM15 are compared, and according to the comparison result, the ON timing of the try book 6 is controlled according to the delay time counted by the timer 20, and the power supply to the motor 1 is controlled. For air conditioners,
Since the phase of the power supplied to the monitor 1 is controlled while comparing the actual rotation speed of the fan motor 1 with the preset rotation speed, even if load fluctuations or power supply voltage fluctuations occur, the The rotation speed of the fan motor 1 can be adjusted to the rotation speed determined.

Moreover, since this fan motor 1 is an AC motor,
A household power source can be used as is without the need for a DC power source, making it possible to reduce the cost of air conditioners.

In addition, since the rotation speed of the motor is detected by the magnet 11 and a magnetic detection means such as a Hall element, there are no worn parts and the mechanical strength is extremely high, and accurate detection is possible even when dust or the like is attached. It is possible to perform
Stable rotation speed detection can be performed over a long period of time.

Effects> As described above, the present invention provides an air conditioner equipped with an air blower using an AC motor as a drive source and a control circuit that controls the rotation speed of this air blower by phase control. means for storing the rotation speed of the blower; means for detecting the rotation speed of the blower; means for selectively extracting the rotation speed stored in the storage means according to the air conditioning condition; means for comparing the rotational speed of the blower; means for generating a signal for correcting the phase angle of the power source that controls the rotational speed of the blower according to the comparison result; and means for correcting the phase angle according to the signal; This is an air conditioner characterized by comprising:

Therefore, even if the AC motor of the blower fluctuates due to changes in load or power supply voltage, the rotation of this motor is picked up by the detection means and compared with the set rotation speed, and the rotation speed of the motor is determined according to the result of this comparison. Since the phase angle of the power supply voltage that controls the motor is corrected by the amount of variation, the motor can always be maintained at the target rotation speed.

Therefore, even though an AC motor is used as the drive motor, the speed of the motor can be controlled reliably. Since numerical control was not reliable and had many fluctuations, it was only possible to control the number of steps. However, according to the present invention, it is possible to control the air in about 10 steps, for example. Allows control.

Moreover, in the case of the present invention, since an AC motor is used as the driving force source of the blower, it is possible to reduce the cost of the blower compared to the case where an orthogonal motor is used.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of an embodiment of the present invention, Fig. 2 is a functional block diagram of the same example, Fig. 3 is a flowchart of the same side, and Fig. 4 is a circuit diagram of a conventional air conditioner. l: AC motor, 6: Triack, 7: Zero cross detection circuit, 8: Microcomputer, 9: Rotation speed detection means, 11: Magnet, 12: Magnetic detection means, 16: ROM, 17: Comparator, 18: Adder/subtractor, 20: Timer. Agent Patent attorney Aihiko Fuku (2 others) Figure 1 Figure 4

Claims (1)

[Claims] 1. An air conditioner equipped with a blower using an AC motor as a drive source and a control circuit that controls the rotational speed of the blower by phase control, the air conditioner having a plurality of preset stages. means for storing the number of revolutions; means for detecting the number of revolutions of the blower; means for selectively extracting the number of revolutions stored in the storage means according to air conditioning conditions; means for comparing the rotational speeds; means for generating a signal for correcting the phase angle of a power source that controls the rotational speed of the blower according to the comparison result; and means for correcting the phase angle according to the signal; Air conditioner equipped. 2. The air conditioner according to claim 1, wherein the rotation speed detection means is a magnet attached to the blower and means for detecting the magnetism of the magnet.