JPS62248952A - Ultrasonic humidifying device - Google Patents

Abstract

PURPOSE:To make it possible to correctly control humidity with favorable responsiveness and little humidity ripple by providing a humidity sensor, the resistance value of which changes by the detected indoor humidity, and a current control circuit, which controls the current of an oscillation circuit in response to the output corrected by a temperature sensor of the humidity sensor under the state that the set humidity is given by controlling an operating part. CONSTITUTION:A humidity sensor 33 gets atmospheric humidity detected by a detection terminal 43 because the decrease of a resistance value between terminals 42 and 42 accompaniying the phenomena of water molecule adsorption onto a porous sintered body 10 corresponds to the atmospheric humidity. By controlling the base current of a transistor 10 in an LC oscillation circuit 9 by means of a current control circuit 64 in response to the differential voltage (Ve-Vf) or the difference between the output voltage Ve issued from a humidity detectig circuit 46 in accordance with the detection of humidity by a humidity sensor 33 and the reference voltage Vf corresponding to the set humidity sent from a humidity setting circuit 53 so as to control the oscillation output of an oscillation circuit 9, an automatic changing-over from/to strong humidifying operation to/from weak humidifying operation is realized. When the atmospheric humidity becomes nearly equal to the set humidity, the weak humidifying operation is realized without fail and consequently the adjustment control with little humidity ripple is effected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an ultrasonic humidifier that atomizes liquid in a water tank using ultrasonic waves to humidify a room.

(Prior art) Conventional ultrasonic humidifiers are equipped with a humidity sensor using a nylon film that expands and contracts depending on the humidity, and turns a microswitch on and off using this humidity sensor. When the microswitch is turned on, the humidifier is turned on. Generally, the humidifier is configured to operate at a constant output and stop the humidifier when the humidifier is turned off.

(Problems to be Solved by the Invention) In the above configuration, the humidity sensor is a mechanical humidity sensor that uses the expansion and contraction of a nylon film, so the response is poor, and the microswitch may simply operate the humidifier intermittently. Therefore, there was a problem that the humidity and pull were large, making the user feel uncomfortable.In addition, the humidity of the guide is closely related to the temperature, and the humidity sensor itself is affected by the ambient temperature, so There is a problem that the output of the humidity sensor fluctuates due to temperature changes.
Conventional devices have had the problem of not being able to accurately control humidity because no countermeasures have been taken into consideration for this problem.

This invention was made in view of these points, and provides an ultrasonic humidifier that has good responsiveness, can control humidity with little ripple, and can accurately control humidity even when there are changes in indoor temperature. This is what we are trying to provide.

[Structure of the Invention] (Means for Solving the Problems) This invention atomizes the liquid in the water tank using ultrasonic waves by driving an ultrasonic generation vibrator placed at the bottom of the water tank using an oscillation circuit. In an ultrasonic humidifier that humidifies a room, there is a temperature sensor that detects the indoor humidity and whose resistance value changes depending on the detected humidity, and a temperature sensor that corrects the change in output due to the change in resistance value due to temperature changes of the humidity sensor. The current control system is equipped with a temperature sensor whose resistance value changes depending on the detected temperature, a humidity setting operation section that can variably set the humidity, and a current control circuit that controls the current of the oscillation circuit by adjusting the operation section. The circuit operates to control the current of the oscillation circuit in accordance with the output corrected by the temperature sensor of the humidity sensor in a state where a set humidity is given by adjustment of the operating section.

(Function) In the present invention having such a configuration, the humidity detected by the humidity sensor is corrected according to the temperature state detected by the temperature sensor. Then, the current of the oscillation circuit is controlled based on the relationship between the set humidity set on the operating section and its corrected output, thereby performing automatic N-node adjustment of the atomization amount.

(Embodiment of the Invention) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, a fan motor 1 is provided to discharge mist generated in accordance with the driving of an ultrasonic vibrator 2 to the outside of the ultrasonic humidifier. A power switch 4 is connected therebetween. A primary coil 5 of a step-down transformer 5 is connected in parallel with the fan motor 1, and the secondary 1111 coil 5b of this step-down transformer 5 is constructed by connecting four diodes 6 in a bridge manner as shown in the figure. Lines L and L! through the full-wave rectifier circuit 7. It is connected to the. Therefore, line L! A DC voltage with a high potential on the line Ll side appears between the lines L1 and 511, and a smoothing capacitor 8 is connected between the lines L1 and 511. LC oscillation circuit 1 with a well-known configuration for driving the ultrasonic transducer 2! &9 is provided so as to be supplied with power from between line Ll and line L, and the connection relationship of this LC oscillation circuit 9 will be explained below. That is, the oscillating NPN transistor 10
, its collector is connected to the line Ll via the choke coil 11, its emitter is connected to the line L, and its base is connected to the line L! A capacitor 12 and a variable resistor 1 for setting the oscillation output are connected between the
3 are connected in parallel.

Further, a capacitor 14 is connected between the collector and emitter of the transistor 10, and a capacitor 15 and the ultrasonic vibrator 2 are connected in series between the collector and the base of the transistor 10. The ultrasonic vibrator 2 is disposed at the bottom of a water tank (not shown) of the ultrasonic humidifier, and when excited by the LC oscillation circuit 9, generates ultrasonic waves to atomize the water in the water tank. It is composed of

On the other hand, a constant voltage circuit 18 consisting of a series circuit of a resistor 16 and a Zener diode 17 of the polarity shown is connected between the lines L3 and L3, which are connected to both terminals of the Zener diode 17. , a constant DC voltage is output between the two. A square wave generation circuit 19 is connected between lines L3 and L2, and this square wave generation circuit 19 will be explained below. That is, line L3
and 53, a resistor 20.21 and a diode 22 with the polarity shown are connected in series.
A circuit for dividing the output voltage of 8 is constructed. The glass input terminal (+) Fi of the operational amplifier 23 is connected to the line L via the time constant capacitor 24 and the diode 22, and is also connected to the line L3 via the resistor 25, and furthermore, the plus input terminal ( +) is connected to line L2 via resistor 26 and diode 22. In addition, the output terminal and negative input terminal of the operational amplifier 23 (
- ), and a resistor 28 is connected between the output terminal of the operational amplifier 23 and the positive input terminal (10). And the operational amplifier 23 mentioned above. Capacitor 24. The resistors 25, 26, 27 and 28 form a square wave oscillator 29 of well-known construction, and from this square wave oscillator 29 a square wave voltage V& of the waveform shown in FIG.
is output. Furthermore, in the square wave generation circuit 19,
The square wave voltage V is applied to the negative input terminal (-) of the operational amplifier fso, which acts as an inverting circuit, and the positive input terminal (+) of the operational amplifier 30.
A constant DC voltage is input from the common connection point of the resistors 20 and 21. Therefore, the operational amplifier 30 outputs an inverted square wave voltage vb as shown in FIG. Output terminals 31 and 32 of path 19
(Output terminal and negative input terminal of operational amplifier 7″30)
A square wave AC voltage will be output from.

The electrical resistance type humidity sensor 33.32 is connected between the output terminals 31.32 in FIG. 1 so that the square wave AC voltage is applied thereto.
A resistor 34, 35 and a thermistor 36 which is a temperature sensor are connected in series, a resistor 37 is connected in parallel with the series circuit of the humidity sensor 33 and a resistor 34, and a resistor 38 is connected in parallel with the thermistor 36. ing. The humidity sensor 33 is arranged to sense the atmospheric humidity around the ultrasonic humidifier, and an example of its specific configuration is shown in FIG. That is, the humidity sensor 33 has a ceramic porous sintered body 40 disposed in a case 39 having a ventilation mesh 39m on the circumferential side, and leads drawn out from both opposing sides of the porous sintered body 400. Connect wire 41.41 to terminal 4
2.42, the resistance value decrease between the terminals 42 and 42 due to the water molecule adsorption phenomenon of the porous sintered body 40 corresponds to the atmospheric humidity.

Therefore, the atmospheric humidity can be detected based on the voltage change characteristics of the detection terminal 43 (common connection point of the resistors 34 and 35) in FIG. Moreover, the third circuit of this humidity sensor 33 is
As shown in the figure, the resistance component R changes depending on the atmospheric humidity.
This corresponds to a parallel connection of o and a unique capacitor component co. The thermistor 36 connected in series to the humidity sensor 33 is for correcting the output voltage characteristics of the humidity sensor 33 (i.e., the output voltage characteristics from the detection terminal 43) according to the ambient temperature. The resistor 34
．． 37 is provided for linearizing the output voltage characteristics of the humidity sensor 33, and a resistor 38 is provided for matching the characteristics of the thermistor 36.

Note that 44 is a noise prevention capacitor connected between the detection terminal 43 and the line L8. 45 is an operational amplifier for output conversion, which is connected to the resistor 34゜35.37.38.
The humidity detection circuit 43 is configured together with the thermistor 36 and the positive input terminal (+) is connected to the output terminal, and the negative input terminal (-) Fi detection terminal 43
The output terminal 9 is connected to an intermediate terminal 48 via a resistor 47.

This intermediate terminal 48 is connected to a diode 49 with the polarity shown.
The output terminal 511d is connected to the output terminal 32 via a diode 50 having the illustrated polarity, and the output terminal 511d is connected to the line L via a smoothing capacitor 52.

It is connected to the.

Now, 53 is the humidity setting circuit, which is line I'!
+L1 resistor 54. It is constructed by connecting a series circuit of a variable resistor 55 and a resistor 56, and outputs a reference voltage vf corresponding to a desired set humidity RHa (see FIG. 5) to a sliding terminal 55a of the variable resistor 55, which is an operating section. It has become. 57 is an operational amplifier constituting the voltage difference detection circuit 58, the positive input terminal (+) of which is connected to the output terminal 51 via a resistor 59 and to the line L via a resistor 60. The negative input terminal ←) is connected to the sliding terminal 56a of the variable resistor 55 through a resistor 6, and is also connected to the output terminal through a resistor 62, and the output terminal is connected through a resistor 63. Connected to line L2.

On the other hand, 64 is a current control circuit, which will be described below. That is, 65 and 66 are lines L! .

A bias resistor is connected in series between L and L, and their common connection point is connected to the sliding terminal 13m of the variable resistor 13 via a diode 67 of the polarity shown. 68
and 69 are NPN type transistors, each emitter is connected to the line L, and the transistor 68
The collector of transistor 69 is connected to the common connection point of resistors 65 and 66 via resistor 70, and the collector of transistor 69 is directly connected to the common connection point of resistors 65 and 66. 71
and 72 are operational amplifiers serving as voltage comparison circuits, each of which has a negative input terminal (-) connected to the output terminal of the operational amplifier 57, and a resistor between each positive input terminal (+) and the output terminal. 73 and 74 are connected, respectively, to respective paces of the transistors 68 and 69 via respective output terminals #'i resistors 75 and 26. 77ii reference voltage generation circuit, this is line LllsL.

The common connection point of the resistors 78 and 79 is connected to the positive input terminal (+) of the operational amplifier 7, and the resistors 79 and 80 are connected in series between them.
The common connection point is the positive input terminal (10) of the operational amplifier 72.
It is connected to the.

Next, the operation of this embodiment will be explained.

When the power switch 4 is turned on, the fan motor 1 is energized and driven by the AC power supply 3, and a DC voltage is output between the lines L1+IJ1, and a constant DC voltage is output between the lines L3+LR. Therefore, a pace current flows through the transistor 10 through the diode 61 and the variable resistor 13 due to the voltage divided by the resistors 65 and 66, and the LC oscillation circuit 9 starts to perform an oscillation operation, and accordingly, the ultrasonic vibration The child 2 is driven and humidification operation is performed. In this case, when a pace current flows through the transistor 1o according to the divided voltage of the resistors 65 and 66, the 1ltLc oscillation circuit 9 starts to oscillate at the maximum output, and therefore the amount of humidification by the ultrasonic transducer 2 increases. When the temperature is high, strong humidification operation will be performed. On the other hand, line L3. The square wave generation circuit 19 is driven by outputting a DC constant voltage across L1, and its output terminal 31.3
2, a square wave AC voltage is output based on the square wave voltages v1 and vb, and this square wave AC voltage is applied to the series circuit of the humidity sensor 33, resistors 34, 35, and thermistor 36. Then, as shown in FIG. 4(e), the detection terminal 43/C outputs a detection voltage vc whose level changes according to the electrical resistance value of the humidity sensor 33 (i.e., atmospheric humidity). Given to opean f4s. The detected voltage vl at this time is a voltage that has been temperature-corrected by the thermistor 36. In this case, when the square wave voltage v1 is output to the output terminal 32, the diode 4
9 is cut off, the detection voltage v0 is output to the intermediate terminal 48 only during the output period of this square wave voltage V, and therefore the intermediate terminal 48 has the voltage V0 as shown in FIG. 4(d).
An intermediate output voltage Vd is generated as shown in FIG. , a DC output voltage V, is output, and this output voltage V, is expressed as RH on the horizontal axis.
As shown in FIG. 5 (%), the humidity exhibits a linear characteristic that decreases as the humidity increases.

Then, this output voltage V6 and the reference voltage Vf, for example, Vfl, from the humidity setting circuit 53 are given to the operational amplifier 57, so the operational amplifier 57Fi outputs the difference voltage (v6-vfl) between its output voltage v6 and the reference voltage Vf1. This will be applied to the negative input terminals of the operational amplifiers 71 and 72. In the reference voltage generation circuit 77, the reference voltage vg is output to the common connection point of the resistors 78 and 29, and the resistors 79 and 8
The reference voltage vh is output to the common connection point of 71 and Hifu 2 are the differential voltages (
v, -vfl) and reference voltages vg and vh. In this case, when the humidity of the humidified atmosphere such as indoors is low, the electrical resistance value of the humidity sensor 33 is high, so the output voltage V0 is large, the differential voltage (v6-vfl) is also large, and (ve
-Vt1)':;A~, vh, so that the output signals of Rio (amplifier 7) and 72 are at low level. As a result, the atmospheric humidity gradually increases due to the strong humidification operation as described above, and the output voltage v0 increases accordingly.
is gradually decreasing, but now the differential voltage (v
If e-vfl) becomes smaller than the reference voltage vg, then (
In FIG. 5, the humidity is RH1.

output voltage vf2), the output signal of the operational amplifier 7 becomes high level, and the transistor 68 is turned on.
As a result, the resistor 70 is connected to the resistor 66 in parallel. Therefore, the divided voltage generated at the common connection point of the resistors 65, 66 and 70 becomes smaller, the pace current of the transistor 10 decreases accordingly, the oscillation output of the LC oscillation circuit 90 becomes smaller, and the ultrasonic transducer 2 The amount of humidification decreases, and it becomes possible to switch to weak humidification operation. After that, the atmospheric humidity further increases and the differential voltage (v, -vfl)
When becomes approximately zero, that is, when the atmospheric humidity becomes approximately the set humidity RH2 and the output voltage V6 is approximately equal to the reference voltage v11,
When the output signal of the operational shift 2 becomes high level and the transistor 69 is turned on, the resistor 66 is short-circuited and no pace current flows through the transistor 10, and the LC oscillation circuit 9 stops its oscillation operation. This stops the humidification operation. Thereafter, when the atmospheric humidity becomes lower than the set humidity RH2, the above-described operation is repeated.

According to this embodiment, the following effects can be obtained. That is, since the atmospheric humidity is detected as a change in electrical resistance by the electrical resistance type humidity sensor 33, the response is better than that of a conventional mechanical humidity sensor using a nylon film.

Also, since the humidity detected by the humidity i sensor 33 is corrected by the ambient temperature detected by the thermistor 36, the operating temperature is 7°5.
The output voltage v0 given to 7 becomes a humidity detection voltage according to the ambient temperature state. This voltage v6 is then compared with the reference voltage f by the operational amplifier 57, and the difference voltage is output, and the drive control of the ultrasonic transducer 2 is performed thereby, allowing accurate humidity control according to the ambient temperature state. can.

Furthermore, a difference voltage (VaVO) between the output voltage v0 from the humidity detection circuit 46 based on humidity detection by the humidity sensor 33 and the reference voltage vf corresponding to the set humidity from the humidity setting circuit 53 is detected by the difference voltage detection circuit 58, This differential voltage (Va
5LC by the current control circuit 64 depending on the magnitude of Vr).
By controlling the pace current of the transistor IO of the oscillation circuit 9, the oscillation output of the oscillation circuit 9 is controlled in two stages, thereby automatically switching between the two stages of strong humidification operation and weak humidification operation. When the atmospheric humidity approaches the set humidity, weak humidification operation is always performed, and adjustment control with less humidity ripple can be performed. Moreover, as mentioned above, when the atmospheric humidity gets close to the set humidity, the strong humidification operation switches to the weak humidification operation, so the user knows that the atmospheric humidity is low because the strong humidification operation is in progress, and the weak humidification is performed. It is extremely convenient to use because it is possible to know that the atmospheric humidity has increased to near the set humidity by switching to operation.

In the above embodiment, the control circuit 64 is used to switch between two stages of strong humidification operation and weak humidification operation, but if more circuits each consisting of a combination of a transistor 68, a resistor 70, and an operational amplifier 71 are arranged in parallel, three or more stages can be achieved. It can be switched to multiple stages.

[Effects of the Invention] As described above, according to this invention, responsiveness is good;
Furthermore, it is possible to provide an ultrasonic humidifier that can control humidity with little ripple and can also accurately control humidity even when there is a change in indoor temperature.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is an overall electrical diagram, FIG. 2 is a schematic vertical sectional view of a humidity sensor, and FIG.
The figure is an equivalent circuit diagram of the same humidity/counterfeit sensor, Figures 4(a) to (,
) is an output voltage waveform diagram of each part for explaining the operation, and FIG. 5 is a humidity-output voltage characteristic diagram for explaining the operation. 1...Fan motor, 2...Ultrasonic vibrator, 9...
・LC oscillation circuit, 19... Square wave generation circuit, 33...
・Humidity sensor, 36... Thermistor (temperature sensor),
46... Humidity detection circuit, 53... Humidity setting circuit, 5
5... Variable resistor, 58... Voltage difference detection circuit, 64...
...Current control circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 4 Ve Figure 5

Claims (1)

[Claims] In an ultrasonic humidifier that humidifies a room by atomizing the liquid in the tank using ultrasonic waves by driving an ultrasonic generation vibrator placed at the bottom of the water tank with an oscillation circuit, the humidity in the room is detected. A humidity sensor whose resistance value changes depending on the
a temperature sensor that detects temperature and whose resistance value changes depending on the detected temperature to correct a change in output due to a change in resistance value due to temperature change of the humidity sensor; and a humidity setting operation unit that can variably set the humidity; and a current control circuit that controls the current of the oscillation circuit by adjusting the operating section, and the current control circuit outputs an output corrected by the temperature sensor of the humidity sensor in a state where a set humidity is given by adjusting the operating section. An ultrasonic humidifier that operates to control the current of an oscillation circuit according to the current.