JPH0988878A - Device and method for adjusting air volume of blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set the variable width of adjustment of the air volume to an approximately same degree irrespective of the frequency of the AC voltage to be supplied to a motor by detecting the phase angle from the output signal of a constant setting part based on the zero-cross pulse, and controlling a semi- conductor AC switch by the detected signal to control the number of revolution of the motor. SOLUTION: An air volume adjusting device 1 to adjust the air volume by controlling the number of revolution of a fan motor of a blower is provided with a zero-cross pulse generating part 2, a constant setting part 3, an adjustment part 4, a phase angle detecting part 5, a waveform shaping part 6, a TRIAC driving part 7, and a TRIAC 8. The constant setting part 3 switches resistors 18, 19 by a switch 21, and when the constant is switched to the prescribed value which is preset to the constant setting part 3, the output signal from the constant setting part 3 based on the zero-cross pulse is inputted in the phase angle detecting part 5. The phase angle is detected from the inputted signal, and a semiconductor AC switch is controlled based on the phase angle to control the number of revolution of a motor 56.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower air flow rate adjusting device and an air flow rate adjusting method for adjusting the air flow rate by controlling the number of revolutions of a fan motor of a blower used for combustion equipment and the like.

[0002]

2. Description of the Related Art Conventionally, when the air volume of a blower is adjusted, it is carried out by controlling the rotation speed of an AC fan motor. This adjustment method is generally shown in FIGS. 7 and 8. The adjusting device is adopted. That is,
The air volume adjusting device shown in FIG. 7 has a phase circuit d consisting of a resistor a-variable resistor b-capacitor c, a diac (two-pole AC switch) e, a triac f, etc., and the resistance value of the variable resistor b. By adjusting the diac e
The phase of the gate pulse output from the triac f to the triac f is changed to change the conduction angle of the triac f, and
The voltage supplied from the motor to the motor h is variable.

Further, the air flow rate adjusting device shown in FIG. 8 has a resistance a.
-Phase circuit d consisting of variable resistor b-capacitor c,
Zener diode i, thyristor j, diode k
And the diac e and the triac f etc., the gate pulse from the diac e is phase-shifted and the conduction angle of the triac is changed by adjusting the resistance value of the variable resistor b as in FIG. 7. It is the one.
The air volume characteristics of these air volume adjusting devices generally have the characteristics shown in FIG. In FIG. 9, the horizontal axis represents the phase delay time, the vertical axis represents the air volume, the solid line represents the case where the frequency of the AC power supply g is 60 Hz, and the dotted line represents the case where it is 50 Hz.

[0004]

However, in these air flow rate adjusting devices, it is difficult to set the variable adjustment range of the air flow rate to approximately the same level regardless of the frequency of the AC power supply supplied to the motor. There was a problem. That is, since the constant of the phase circuit d is only adjusted by the variable resistor b and the constants such as the resistance value of the resistor a and the electrostatic capacitance of the capacitor c can be set to only one, for example, the AC power supply g When the frequency is set to 60 Hz and a constant is set, the variable range of the air volume becomes small and the air volume does not fall below a predetermined value when used at 50 Hz.
If the constant is set with emphasis on Hz, the motor may stop when used at 60 Hz.

This is because, as shown in the air flow rate characteristic of FIG. 9, the air flow rate of the motor h varies greatly depending on the frequency of the AC power supply g even with the same phase delay time. For example, the phase delay time α1 to α2 (α1 ~ Α2 is 60Hz, 50Hz
The same), the air volume adjustment width W3 of 60 Hz is 50
It differs from the air volume adjustment width W4 of 10 to 10 times, and the air volume variable adjustment width cannot be set to substantially the same level regardless of the frequency of the AC power supply. Therefore, for example, AC power supply g
In the region where the frequency is 60 Hz, the air volume adjusting device set for 60 Hz must be used, and in the region of 50 Hz, the air volume adjusting device set for 50 Hz must be used.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a blower capable of setting the variable adjustment range of the air volume to substantially the same level regardless of the frequency of the AC voltage supplied to the motor. An object is to provide an air volume adjusting device and an air volume adjusting method.

[0007]

In order to achieve the above object, an air flow rate adjusting device for a blower according to claim 1 detects a zero cross of an AC voltage and generates a zero cross pulse, and a zero cross pulse generator. It is controlled by a constant setting part that sets a constant according to the frequency, a phase angle detection part that detects the phase angle from the output signal of the constant setting part based on the zero-cross pulse of the zero-cross pulse generator, and an output signal of the phase angle detection part. Equipped with a semiconductor AC switch,
It is characterized in that the amount of air is adjusted by controlling the rotation of the motor connected to the semiconductor AC switch based on the constant set by the constant setting unit.

According to this air flow rate adjusting device, switching to the predetermined constant preset in the constant setting section in response to the commercial AC voltage frequencies of 60 Hz and 50 Hz,
The output signal from the constant setting unit based on the zero-cross pulse is input to the phase angle detection unit. The phase angle detection unit detects the phase angle from this signal, and based on this phase angle, controls the ON / OFF of a semiconductor AC switch such as a triac, and controls the rotation speed of the motor connected to the semiconductor AC switch. To be done. Since the constant of the constant setting unit can be set according to the frequency of the AC voltage, the variable adjustment range of the air volume can be set to be approximately the same whether the frequency is 60 Hz or 50 Hz. It can be used, for example, stopping of the motor at 60 Hz is prevented.

According to a second aspect of the present invention, there is provided an air volume adjusting device for a blower, which detects a zero cross of an AC voltage and generates a zero cross pulse, a frequency detecting section which detects a frequency of the AC voltage, and a frequency detecting. Constant setting section that sets a constant based on the detection result of the section, the phase angle detection section that detects the phase angle from the output signal of the constant setting section based on the zero-cross pulse of the zero-cross pulse generation section, and the output signal of the phase angle detection section And controlling the rotation of a motor connected to the semiconductor AC switch based on the constant set by the constant setting unit to adjust the air volume.

According to this air volume adjusting device, the frequency of the AC voltage supplied to the motor is automatically detected by the frequency detecting section, and the constant is automatically set by the constant setting section based on the detected frequency. It The phase angle is detected by the phase angle detection unit from the output signal based on the constant set by the constant setting unit, and the rotation speed of the motor is controlled in the same manner as described above.

Further, in the air flow rate adjusting device according to the third aspect, the constant setting section sets the first impedance element for setting the initial delay amount and the second and third impedance values having impedance values corresponding to the frequency of the AC voltage. An impedance element and a second
And a switching means for switching the third impedance element according to the frequency, and an adjustable variable impedance element. According to this air volume adjusting device, the initial delay amount is set by the first impedance element, and the constant corresponding to the frequency of the AC voltage is set by the variable impedance element and the second or third impedance element switched by the switching means. The variable impedance element is set and the constant is variably adjusted.

Further, in the air volume adjusting device according to a fourth aspect of the present invention, the initial delay amount of the constant setting section is switched in accordance with the frequency of the AC voltage. It can be switched according to the frequency, and the amount of airflow can be changed in detail and in a wider range.

According to a fifth aspect of the present invention, there is provided an air volume adjusting method for controlling the phase of an AC voltage to vary the rotational speed of a motor of the blower to adjust the air volume. According to the above, a plurality of preset constants are selectively selected, and the phase of the AC voltage is controlled based on these constants to change the rotation speed of the motor. According to this air volume adjusting method, by manually or automatically switching to one of a plurality of constants corresponding to the frequency of the AC voltage, the variable volume of the air volume is approximately the same regardless of the frequency of the AC voltage. Is set to.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 3 show a first embodiment of an air volume adjusting device for a blower according to the present invention, FIG. 1 is a circuit diagram thereof, FIG. 2 is a timing chart for explaining the operation, and FIG. 3 is an example of air volume characteristics. It is a graph which shows. In FIG. 1, the air volume adjusting device 1 has a zero-cross pulse generating unit 2, a constant setting unit 3, an adjusting unit 4, a phase angle detecting unit 5, a waveform shaping unit 6, a triac driving unit 7, a triac 8 and the like.

The zero-cross pulse generator 2 has resistors 10 and 11 and a comparator 12 connected in series, and one end of the resistor 10 is connected to an output terminal of a rectifying bridge 14 connected between AC voltage terminals 13a and 13b. Has been done. One end of the resistor 11 is grounded, and the connection point between the resistor 11 and the resistor 10 is
It is connected to one input terminal of the comparator 12. Also,
The other input terminal of the comparator 12 is connected to the resistor 15, and the output terminal of the comparator 12 is connected to the constant setting unit 3 via the resistor 16.
It is connected to the.

The constant setting section 3 includes three resistors 17, 18,
19 and one capacitor 20 and a changeover switch 21 as a changeover means, one end of the resistor 17 is connected to the power supply line V of the DC voltage V1 (for example, approximately DC7V),
The other end of the resistor 17 is connected to the common terminal of the changeover switch 21. The resistor 17 sets an initial delay amount T described later. The change-over switch 21 has two terminals connected to one ends of resistors 18 and 19, respectively, and the other ends of the resistors 18 and 19 are grounded via a capacitor 20 and are also connected to the resistor 16.

The resistors 17, 18 of the constant setting section 3
The phase circuit A for 60 Hz is formed by the capacitor 20, and the resistor 17, the resistor 19, and the capacitor 20 form a phase circuit.
A phase circuit B for 0 Hz is configured. That is, resistance 1
8 is set to a resistance value for 60 Hz, and resistor 19 is set to a resistance value for 50 Hz. A variable resistor 24 that constitutes the adjusting unit 4 is connected between the common terminal of the changeover switch 21 of the constant setting unit 3 and the connection points of the resistors 18 and 19 and the capacitor 20, and the variable resistor 24 is, for example, It is attached to the case (not shown) of the blower and is arranged so that its resistance value can be adjusted.

The phase angle detector 5 has a comparator 25 and three resistors 15, 26, 27, etc. One input terminal of the comparator 25 is connected to the power supply line V via the resistor 26. , And is connected to the other input terminal of the comparator 12 of the zero-cross pulse generator 2 via the resistor 27. The resistor 15 is connected between the resistor 27 and the ground. Comparator 2
5, the power supply terminal is connected to the power supply line V and is grounded via the capacitor 28, and the output terminal is connected to the power supply line V via the resistor 29 and the waveform shaping is performed via the capacitor 30. It is connected to the section 6.

The waveform shaping section 6 has an IC 32 composed of a monostable multivibrator which generates a pulse signal for a fixed time, and the trigger input terminal of this IC 32 is connected to the capacitor 30 and a power source via a resistor 34. Connected to the line V, the two level determination input terminals are connected to the power supply line V via the resistor 35, and the capacitor 36.
Is grounded through. Further, in the IC 32, a resistor 37 is connected between the power supply terminal and the output terminal, a capacitor 38 is connected between the power supply terminal and the ground, and a phase compensation terminal is grounded through the capacitor 33.
The triac drive unit 7 is connected to the output terminal of the IC 32.

The triac driver 7 includes a transistor 4
The output terminal of the IC 32 is connected to the base of the transistor 40, and the emitter of the transistor 40 is grounded. Further, a diode 41 a on the input side of the phototriac 41 is connected between the collector of the transistor 40 and the power supply line V via a resistor 42. Output side diode 41 of phototriac 41
Resistors 43 and 44 are connected to both ends of b, respectively, and these are connected between both terminals of a triac 8 as a semiconductor AC switch. Resistor 44 of diode 41b
The terminal on the side is connected to the gate terminal of the triac 8,
A snubber circuit composed of a series circuit of a resistor 46 and a capacitor 47 is connected between both terminals of the triac 8.

On the output side of the rectifying bridge 14, a Zener diode 51 and a diode 52 for generating a DC voltage V1 and a smoothing electric field capacitor 50 are connected via a resistor 22. Further, in FIG. 1, each circuit other than the adjusting unit 4 is formed on one printed circuit board (not shown), and terminals 13a to 13c, 53a, 53b, 54a to 54c are provided on this printed circuit board. , AC terminals 55 are connected to the terminals 13a and 13b, AC motors 56 are connected to the terminals 53a and 53b, and terminals of the variable resistor 24 of the adjusting unit 4 are connected to the terminals 54a to 54c. There is. The motor 55 is connected to the terminal 13c when the phase control is not performed.

Next, the operation of the air volume adjusting device 1 will be described with reference to FIG.
The timing chart will be described. First, the frequency of the AC power supply 55 used by the blower is 60 Hz or 50
After confirming whether the frequency is Hz, the changeover switch 21 of the constant setting unit 3 is switched to the resistance 18 side for 60 Hz and to the resistance 19 side for 50 Hz according to the frequency. In addition,
In the following description, the frequency of the AC power supply 55 is 60H for convenience.
It will be described as z.

When a sine wave AC voltage is supplied from the AC power supply 55 with the changeover switch 21 switched to the 60 Hz side (resistor 18 side), this voltage is supplied to the rectifying bridge 1.
4 is full-wave rectified by the voltage Va shown in FIG.
Is output from the output terminal. This voltage Va is divided by the resistors 10 and 11 to become the voltage Vb shown in FIG. 2B, which is input to one input terminal of the comparator 12.

The voltage Va is the Zener diode 51.
And the diode 52 generate a DC voltage V1 (approximately DC 7 V), and this DC voltage V1 is divided by the resistors 15, 27 and the like to generate a DC voltage V2 (approximately 0.2 V) shown in FIG. 2B.
5 V) and is input to the other input terminal of the comparator 12. The comparator 12 compares the voltage Vb with the voltage V2, and outputs the zero-cross pulse P1 having a predetermined width shown in FIG. 2C at the time when the voltage Vb <the voltage V2, that is, every half cycle of the AC voltage. .

When this zero-cross pulse P1 is output, the capacitor 20 is discharged (reset), so that the voltage Vd having the waveform shown in FIG.
And is input to the other input terminal of the comparator 25. The rising shape of the voltage Vd changes depending on the constant composed of the resistor 18 and the variable resistor 24 of the phase circuit A. On the other hand, one input terminal of the comparator 25 is
The DC voltage V3 shown in FIG. 2D obtained by dividing the voltage V1 by the resistors 26 and 27 is input, and this voltage V3 and the voltage Vd are compared by the comparator 25.

When the voltage Vd is higher than the voltage V3 (Vd> V3), the comparator 25 outputs the pulse P2 shown in FIG. 2 (e) which becomes the "Low" level. This pulse P2
Is shaped into a pulse P3 shown in FIG. 2 (f) by the resistor 34 and the capacitor 30 of the waveform shaping unit 6, and this pulse P3 is input to the trigger input terminal of the IC32. I
When the pulse P3 is input, the C32 shapes the waveform by comparing it with a predetermined level and outputs the pulse P4 shown in FIG. 2 (g) from its output terminal.

When this pulse P4 is input to the base of the transistor 40 of the triac drive unit 7, the transistor 40 is turned on, a current flows through the input side diode 41a of the phototriac 41, and the output side triac 41b. Turns on. TRIAC 41b
When is turned on, a signal is output from the one terminal to the gate of the triac 8, and the triac 8 is turned on.
As a result, the two terminals of the triac 8 become conductive, and the motor 56 connected to the terminals 53a and 53b is connected to the motor 56 from the terminals 13a and 13b via the triac 8 as shown in FIG.
The voltage V + shown in (h) (voltage corresponding to the half cycle on the plus side of the AC voltage) is supplied.

When the AC voltage of the negative half cycle is supplied from the AC power supply 55, each part operates in the same manner as the positive half cycle, and the triac 8 is turned on.
The voltage V− shown in FIG. 2H is supplied to the motor 56.
By alternately supplying the voltage V + and the voltage V- to the motor 56, an AC voltage is supplied to the motor 56, and the AC motor 56 rotates at a rotation speed corresponding to the magnitude of the AC voltage. become.

The magnitude of the AC voltage supplied to the motor 56 is determined by the range S of the voltage V + and the voltage V- shown in FIG. 2 (h). That is, the range S is determined by adjusting the resistance value of the variable resistor 24 of the constant setting unit 3 to change the slope of the rising portion of the voltage Vd shown in FIG. In the case of 60 Hz, it is represented by the following equation (1), and in the case of 50 Hz, it is represented by the equation (2).

[0030]

[Equation 1]

[0031]

[Equation 2]

Incidentally, a in FIG. 2 (h) represents an initial delay amount, and this initial delay amount T is determined by the resistor 17 of the phase circuits A and B. In this embodiment, 60 Hz and 50 Hz are also set. Also, T = Rs × C (where Rs is resistance 1
7 is the resistance value of C, and C is the capacitance of the capacitor 20).

When the air volume control device 1 according to the first embodiment was mounted on an actual blower, the air volume characteristics shown in FIG. 3 were obtained. In FIG. 3, the horizontal axis represents the phase delay time, the vertical axis represents the air flow rate, and the solid line indicates 60 Hz and the dotted line indicates 50 H.
The case of z is shown. From this characteristic, the air flow rate variable width W1 in the case of 60 Hz with the phase delay time α1 to α2 (corresponding to α1 to α2 in FIG. 9) and the phase delay time 5 of α1 to α3.
There is no big difference of more than ten times or more as shown in the conventional example with the air volume variable width W2 in the case of 0 Hz, and they are almost the same, and the air volume variable width is approximately the same regardless of the frequency of the AC power source. Became clear.

That is, by rotating the variable resistor 24 from the outside to change its resistance value, the value of the range S is changed as shown in the above equations (1) and (2), which causes the motor 56. The voltage supplied to
The rotation speed will change, but by setting the values of the resistors 18 and 19 appropriately and switching them according to the frequency, the rotation speed of the motor 56 regardless of whether the frequency is 60 Hz or 50 Hz. The variable range (variable adjustment range of air volume) is set to substantially the same level.

As described above, according to the above-described embodiment, the constant setting unit 3 is provided with the resistor 18 for 60 Hz and the resistor 19 for 50 Hz in advance, and the resistors 18 and 19 are changed over to the changeover switch 2.
Since each resistor is switched by 1,
By setting the resistance values of Nos. 8 and 19 to predetermined values, the variable adjustment widths W1 and W2 of the air volume by the motor 56 are set to 60 Hz.
It is possible to set approximately the same in the case of 50 Hz and in the case of 50 Hz. As a result, it is possible to prevent problems such as the air volume not falling below a predetermined value in the case of 50 Hz, and the motor 56 stopping in the case of 60 Hz.
Therefore, it is suitable for use as a blower for equipment such as grain dryers, combustion equipment for heating machines, and the like in which stopping of the fan motor at the minimum air volume is a problem.

Further, since one blower can be used in both the 60 Hz region and the 50 Hz region, the versatility is increased, and it is not necessary to set the blowers for 60 Hz and 50 Hz respectively, which complicates parts management and product management. Can be eliminated, and the cost of the product can be reduced. Further, since the air flow rate adjusting device 1 can be formed on one printed circuit board and can be electronically operated, reliability is improved and maintenance and the like can be easily performed.

FIG. 4 is a circuit diagram showing a modification of the first embodiment, which is characterized in that the initial delay amount a of the constant setting unit 3 is switchable. That is, the common terminal of the changeover switch 21 is directly connected to the power supply line V,
The resistors 18, 60 and the resistors 19, 61 connected in series between the two terminals of the changeover switch 21 and the capacitor 20.
Are connected respectively. Two diodes 62 and 63 connected in opposite directions are connected in series between the connection points of the resistors 18 and 60 and the connection points of the resistors 19 and 61. The variable resistor 24 is connected between the connection points of the diodes 62 and 63 and the connection points of the resistors 18 and 19.

According to the constant setting section 3, the initial delay amount (T = Rs ×) when the frequency is 60 Hz by the resistor 60.
The resistance value of the resistor 60 is set to C: Rs, and the initial delay amount (T = Rs × C: R) in the case of 50 Hz is set by the resistor 61.
For s, the resistance value of the resistor 61) is set. Further, the range S is expressed by the following formula (3) when the frequency of the alternating voltage is 60 Hz and by the following formula (4) when the frequency is 50 Hz.
In this modified example, since the initial delay amount T can be set according to the frequency, it is possible to obtain a function effect that a wider and finer variable adjustment width can be set.

[0039]

(Equation 3)

[0040]

[Equation 4]

FIG. 5 is a circuit diagram showing a second embodiment of the air flow rate adjusting device according to the present invention. The feature of this embodiment resides in that the frequency of the AC power supply is automatically detected and the constant is automatically set based on the detected frequency. The second embodiment will be described below. The air volume adjusting device 101 according to the second embodiment includes a frequency detecting unit 102, a constant setting unit 103, a waveform shaping unit 104, and the like. Since the zero-cross pulse generator 2, the adjuster 4, the phase shift angle detector 5, the triac driver 7, the triac 8 and the like are the same as those in the first embodiment, the same reference numerals are given and their description is omitted.

The frequency detecting section 102 has two 1-shot multi-purpose ICs 107 and 108, and one trigger input terminal of the IC 107 is connected to the output terminal of the comparator 12 of the zero-cross pulse generating section 2. . The trigger input terminal is connected to the power supply line V via the resistor 110 and is also grounded via the capacitor 111. .
The other trigger input terminal and the power supply terminal of the IC 107 are connected to the power supply line V, and the capacitor 10
It is grounded via 9, and a capacitor 112 is connected between the one-shot constant terminals, and one one-shot constant terminal is connected to the power supply line V via a resistor 113 and a variable resistor 114. One of the trigger input terminals of the IC 108 is connected to the output terminal of the IC 107.

In the IC 108, the other trigger input terminal and the power supply terminal are connected to the power supply line V, the capacitor 115 is connected between the one-shot constant terminals, and one of the one-shot constant terminals is connected through the resistor 116. It is connected to the power supply line V. The output terminal of this IC108
It is connected to the constant setting unit 103. These two IC1
The pulse widths of 07 and 108 are, for example, 9.1 for the IC 107.
It is set to msec, and the IC 108 is set to 100 msec. In addition, check terminals 117 and 118 are connected between the output terminal of the IC 107 and the ground and between both ends of the resistor 113 and the variable resistor 114 connected in series.

The constant setting section 103 has four transistors 120 to 123 and phase circuits A and B, and the output terminal of the IC 108 is connected to the base of the transistor 120. In the transistor 120, the emitter is grounded, the collector is connected to the base of the transistor 121, and the transistor 120 is connected to the base of the transistor 122 via the diode 125 connected in the reverse direction. The base of the transistor 122 is connected to the power supply line V via the resistor 130.
, The emitter is grounded, and the collector is connected to the base of the transistor 123.

The emitters of the transistors 121 and 123 are connected to the power supply line V, and the collectors are connected to the resistors 126 and 127 forming the phase circuits A and B, respectively. The resistance 126 is set to a resistance value for 60 Hz, and the resistance 127 is set to a resistance value for 50 Hz. The connection point of the resistors 126 and 127 is the resistor 128.
, And the other end of the resistor 128 is grounded via a capacitor 129.

The collector of the transistor 131 is connected to the connection point of the resistor 128 and the capacitor 129,
The transistor 131 is connected to the output terminal of the comparator 12 via the diode 132 whose base is connected in the reverse direction, and is also connected to the power supply line V via the resistor 133. Also, the resistance 1 of the constant setting unit 103
Between the connection point of 26, 127 and the power supply line V, the adjustment unit 4
Is connected to the variable resistor 24, and the phase angle detector 5 is connected to the connection point of the resistor 128 and the capacitor 129.

The phase angle detector 5 is constructed in the same manner as in the first embodiment, the constant setting unit 103 is connected to the other input terminal of the comparator 25, and the output terminal of the comparator 25 has a waveform shaping function. The unit 104 is connected. This waveform shaping section 10
4 has a transistor 135, and this transistor 1
The output terminal of the comparator 25 is connected to the base of 35, and the emitter is connected to the power supply line V.

Further, resistors 136 and 137 connected in series are connected to the collector of the transistor 135, and the connection point of the resistors 136 and 137 is connected to the base of the transistor 40 of the triac driver 7 via the capacitor 138. It is connected. The emitter of the transistor 40 is grounded, and the collector is connected to the phototriac 41 via the resistor 42 as in the first embodiment. A backflow prevention diode 140 is connected between the rectifying bridge 14 and the resistor 22, and the resistor 44 connected to the phototriac 41 is connected to the capacitor 14.
1 are connected in parallel.

The air volume adjusting device 101 operates as follows. That is, the zero-cross pulse generator 1 generates a single zero-cross pulse P1 (see FIG. 2) by the voltage of a half cycle of the AC voltage that is full-wave rectified by the rectifying bridge 14, and this pulse P1 is generated by the frequency detector 102. IC1
07 trigger input terminal. The IC 107 is composed of a retrigger type 1-shot multi IC with a pulse width of 9.1 msec and an AC voltage frequency of 5
In the case of 0 Hz (pulse width is 10 msec), a pulse is generated and output, and the frequency is 60 Hz (pulse width is 8.3).
msec), no pulse is generated and its output is "H
maintain the “high” level state.

The IC 108 outputs "High" level when a pulse is input from the IC 107,
When no pulse is input from 107, the output is “Lo
w level. The output of this IC 108 is "High.
AC power supply 5 depending on "h" level or "Low" level
5 frequencies (see FIG. 1) are detected.

The frequency is detected by the frequency detector 102,
For example, when the frequency is 60 Hz, the output signal of the IC 108 becomes the “Low” level, the transistor 120 of the constant setting unit 103 is turned off, and the transistor 122 is turned on. When the transistor 122 is turned on, the transistor 123 is also turned on, and the phase circuit A including the resistor 126, the resistor 128, and the capacitor 129 is connected. On the other hand, when the frequency is 50 Hz, the output signal of IC 108 is "H
Then, the transistor 120 is turned on and the transistor 122 is turned off. Transistor 1
When 20 is turned on, the transistor 121 is also turned on, and the phase circuit B including the resistor 127, the resistor 128, and the capacitor 129 is connected.

That is, based on the detection result of the frequency detection unit 102, the transistor 121 and the transistor 123
One of the two is turned on, and the phase circuits A and B are automatically connected. When the predetermined phase circuits A and B are connected by the constant setting unit 103, a signal corresponding to the constant is generated based on the zero-cross pulse P1 output from the comparator 12 of the zero-cross pulse generating unit 2, and the phase angle detecting unit 5 Is input to the other input terminal of the comparator 25 of
By this signal, each circuit after the comparator 25 operates in the same manner as in the first embodiment, and causes the motor 56 to operate as shown in FIG.
The AC voltage as shown in FIG.
Rotates at a predetermined rotation speed. In the second embodiment, the voltage waveforms and pulses of the respective parts are substantially the same as those in the first embodiment, so the description thereof will be omitted.

As described above, according to the air flow rate adjusting device 101 of the second embodiment, the frequency of the AC voltage is automatically detected by the frequency detecting section 102, and the transistor 123 of the constant setting section 103 or the constant setting section 103 is detected by this detection signal. Since the transistor 121 is automatically turned on / off and one of the phase circuits A and B is connected, it is not necessary to change the changeover switch 21 one by one as in the first embodiment, and it is not necessary to care about the frequency. Since it is eliminated, the handling becomes easy, and the versatility is further improved. In addition, it is possible to further promote the computerization of the air volume control device 101, and to obtain the effect that the reliability can be further improved.

FIG. 6 shows a modification of the second embodiment described above, which is characterized in that the initial delay amount a of the constant setting unit 103 can be switched as in the case of FIG. That is, the emitters of the transistors 123 and 121 are resistors 15
Two diodes 1 connected in series in the opposite directions to each other are connected between the emitters of both the transistors 123 and 121 and are connected to the power supply line V via 0 and 151, respectively.
52 and 153 are connected. Also, the transistor 1
The collectors of 23 and 121 are connected to the capacitor 129 via resistors 126 and 127, respectively, and the diode 15
The variable resistor 24 is connected between the connection point of 2,153 and the connection point of the resistors 126,127.

According to the constant setting unit 103, the initial delay amount (T = Rs × C: Rs is the resistance value of the resistor 150, C is the electrostatic capacitance of the capacitor 129) in the case of 60 Hz by the resistor 150, as in FIG. The capacitance is set and the initial delay amount (T = Rs × C: Rs) in the case of 50 Hz is set by the resistor 151.
Is set to the resistance value of the resistor 151. According to this modification, it is possible to obtain the effect that the range S of the air volume adjusting device 101 according to the second embodiment can be varied in a more detailed and wide range.

The circuit configuration of each part in each of the above embodiments is an example, and each embodiment may be appropriately combined,
Alternatively, another appropriate circuit configuration can be adopted.
Further, in each of the above embodiments, the triac is used as the semiconductor AC switch, but the present invention is not limited to this, and other suitable semiconductor AC switches may be used, which deviates from the gist of the present invention. In the range that does not
It goes without saying that various changes can be made.

[0057]

As described above in detail, according to the air flow rate adjusting device and the air flow rate adjusting method of the blower of the present invention, a constant corresponding to the frequency of the AC power source can be set in advance. Even in the case, it is possible to obtain an effect that it is possible to obtain a variable adjustment range of the same air volume.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of an air volume adjusting device for a blower according to the present invention.

FIG. 2 is a timing chart for explaining the operation thereof.

FIG. 3 is a graph showing an example of the air volume characteristic.

FIG. 4 is a circuit diagram of a main part showing the modified example thereof.

FIG. 5 is a circuit diagram showing a second embodiment of an air volume adjusting device for a blower according to the present invention.

FIG. 6 is a circuit diagram of a main part showing the modification example.

FIG. 7 is a circuit diagram showing a conventional air volume adjusting device.

FIG. 8 is a circuit diagram showing another conventional air volume adjusting device.

FIG. 9 is a graph showing air volume characteristics in a conventional air volume adjusting device.

[Explanation of symbols]

 1 ・ ・ ・ ・ ・ ・ ・ ・ Air flow adjustment device 2 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Zero cross pulse generator 3 ・ ・ ・ ・ ・ ・ ・ ・ Constant setting unit 4 ・ ・ ・ ・・ ・ ・ ・ Adjuster 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Phase angle detector 6 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Waveformer 7 ・ ・ ・ ・ ・ ・ ・ ・ Triac driver 8・ ・ ・ ・ ・ ・ ・ ・ TRIAC 12 ・ ・ ・ ・ ・ ・ Comparators 17, 18, 19 ・ ・ ・ Resistor 20 ・ ・ ・ ・ ・ ・ Capacitor 24 ・ ・ ・ ・ ・・ ・ ・ Variable resistor 25 ・ ・ ・ ・ ・ ・ ・ ・ ・ Comparator 41 ・ ・ ・ ・ ・ ・ ・ ・ ・ Phototriac 55 ・ ・ ・ ・ ・ ・ ・ ・ ・ AC power supply 56 ・ ・ ・ ・ ・ ・・ ・ Motor 101 ・ ・ ・ ・ ・ ・ Air flow adjustment device 102 ・ ・ ・ ・ ・ ・ Frequency detection unit 103 ・ ・ ・ ・ ・ ・ Constant setting unit 104 ・ ・ ・ ・ ・ ・ ・ ・ Waveform shaping Department 120, 121, 122, 123 ... Transistors 126, 127, 128 ..... Resistors 129 ..... Capacitors A, B ..... Phase circuits P1 ...・ ・ ・ ・ ・ ・ ・ ・ ・ Zero cross pulse T ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Initial delay amount

Claims (5)

[Claims] 1. A zero-cross pulse generator that detects a zero-cross pulse of an AC voltage and generates a zero-cross pulse, and a constant setting unit that sets a constant according to the frequency of the AC voltage.
A phase angle detecting section for detecting a phase angle from an output signal of the constant setting section based on a zero cross pulse of the zero cross pulse generating section; and a semiconductor AC switch controlled by the output signal of the phase angle detecting section, An air flow rate adjusting device for a blower, which controls the rotation of a motor connected to the semiconductor AC switch based on a constant set by a constant setting section to adjust the air flow. 2. A zero-cross pulse generator that detects a zero-cross pulse of an AC voltage, generates a zero-cross pulse, a frequency detector that detects the frequency of the AC voltage, and a constant is set based on the detection result of the frequency detector. A constant setting section, a phase angle detecting section for detecting a phase angle from an output signal of the constant setting section based on a zero cross pulse of the zero cross pulse generating section, and a semiconductor AC switch controlled by the output signal of the phase angle detecting section. And controlling the rotation of a motor connected to the semiconductor AC switch based on the constant set by the constant setting unit to adjust the air flow. 3. The constant setting unit sets a first impedance element for setting an initial delay amount, second and third impedance elements having impedance values corresponding to the frequency of the AC voltage, and the second and third impedance elements. 3. An air volume adjusting device for a blower according to claim 1, further comprising a switching means for switching the impedance element of No. 3 according to the frequency and an adjustable variable impedance element. 4. The air volume adjusting device for a blower according to claim 3, wherein the initial delay amount of the constant setting unit is switched according to the frequency of the AC voltage. 5. By controlling the phase of the alternating voltage,
In the air volume adjusting method for adjusting the air volume by varying the rotation speed of the blower motor, according to the frequency of the AC voltage,
Select one of the preset constants,
An air flow rate adjusting method for a blower, characterized in that the phase of an AC voltage is controlled based on the constant to vary the rotation speed of the motor.