JP2013101064A - Control device for water supply unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a water supply unit for driving an electromagnetic valve by a lead switch without using any microcomputer or relay.SOLUTION: A control device of a water supply unit for storing water for humidification includes: an electromagnetic valve 4 for water supply which operates with a voltage Vfor opening and closing a water supply pipe to a water supply pan; and a lead switch 91 included in a float switch 6 which operates in accordance with a water level in the water supply pan, of which withstand voltage is V, for directly putting the electromagnetic valve 4 for water supply in an ON or OFF state at a self-contact in accordance with the water level. Then, a varister 92 connected in parallel with the lead switch 91 is configured such that a breakdown voltage Vhas a relation: V<V<V.

Description

  The present invention relates to a water supply unit that supplies water to, for example, a humidifier attached to an air conditioner, and more particularly to a control device for managing the amount of water stored in the container.

  A humidifier may be attached to the air conditioner. Such a humidifier requires a water supply unit that can stably supply clean water (see, for example, Patent Document 1). The water supply unit has a container for storing water drawn from the water supply, and manages the amount of water stored in the container by a control device including a float switch and a solenoid valve.

  A reed switch is optimal in terms of performance and price as a detection unit of the float switch. The contact output of the reed switch is taken in, for example, a microcomputer of the air conditioner, and a solenoid valve driving relay is driven based on the output of the microcomputer. The relay contacts constitute an excitation circuit for the solenoid valve, and the solenoid valve is driven.

JP 2008-224167 A (FIG. 1)

  However, the humidifier may be attached as an option of the air conditioner. In this case, it is more convenient to directly drive the solenoid valve without being controlled by the microcomputer of the air conditioner body. . Also, in order to install the optional humidifier easily and at low cost, we want to omit the relay. However, the contact of a reed switch normally used for a float switch does not have a withstand voltage performance sufficient for opening and closing a circuit including a large inductance such as a solenoid valve.

  In view of this problem, an object of the present invention is to provide a control device for a water supply unit that can drive an electromagnetic valve with a reed switch without using a microcomputer or a relay.

(1) The present invention is a control apparatus of a water supply unit for storing water for humidification, operated by the voltage V _1, and the water supply electromagnetic valve for opening and closing the water supply pipe into the container of the water supply unit, the container included in the float switch to operate in accordance with the water level, the withstand voltage is V _3, depending on the water level in the container, directly the water supply solenoid valve with its own contacts, leads to the state of on or off a switch, connected in parallel with the reed switch, the breakdown voltage _{V 2,} and a, a varistor having a relationship of _{V 1 <V 2 <V 3} .

The control device of the water supply unit configured as described above, when the bounce occurs during or OFF operation of the ON operation of the reed switch, the inductance of the solenoid valve, a high voltage exceeding the breakdown voltage of the varistor (varistor voltage) V ₂ When generated, the varistor becomes a low resistance and suppresses the voltage applied across the reed switch. Therefore, across the reed switch, the voltage exceeding the withstand voltage V ₃ is not applied. Thus, by protecting the reed switch with the varistors connected in parallel, the electromagnetic valve can be directly driven by the reed switch.

(2) In the control device for a water supply unit of (1), the reed switch may be attached to the same substrate as the varistor.
In this case, it is possible to easily attach the reed switch and the varistor together on a single substrate.

(3) In the control device for a water supply unit of (2), it is preferable that the reed switch is attached to one surface of the substrate and the varistor is attached to the other surface of the substrate.
In this case, the substrate can be made very compact.

  (4) In the control device for a water supply unit according to any one of (1) to (3), the float switch has a stem and a flange on the fixed side, and a slider that slides on the stem on the movable side, and the slider. The reed switch may be attached to a case extending from the flange.

  If the reed switch is attached to the stem, the reed switch may be damaged if excessive force is applied from the slider to the stem. Thus, the reed switch is extended from the flange instead of the stem. By attaching to the case, the reed switch can be prevented from being damaged.

  According to the control apparatus for a water supply unit of the present invention, the solenoid valve can be directly driven by the reed switch without using a microcomputer or a relay.

It is a figure which shows the structure of the water supply unit containing the control apparatus which concerns on one Embodiment of this invention. It is a figure which shows the state which the water level rose to the predetermined position from the state of FIG. It is a circuit diagram of the control apparatus of a water supply unit. It is a figure which shows an example of how to attach a reed switch and a varistor.

  FIG. 1 is a diagram illustrating a configuration of a water supply unit 1 including a control device according to an embodiment of the present invention. The humidifier 100 includes the water supply unit 1, a humidification unit 21, and a drain electromagnetic valve 30. Such a humidifier 100 is mounted on an air conditioner (not shown) as an optional device, for example. In the figure, the main body portion of the water supply unit 1 includes a water supply pan 2 as a container for storing water for humidification, water supply pipes 3 a and 3 b for supplying water to the water supply pan 2, and a water supply electromagnetic valve 4. ing. Tap water is supplied to the water supply pipe 3a from a water pipe (not shown).

  A support member 5 having a vertical portion 5 v and a horizontal portion 5 h is fixed to the water supply pan 2. A float switch 6 is attached to the horizontal portion 5 h of the support member 5. The float switch 6 includes a fixed portion 7 fixed to the support member 5, a movable portion 8 that moves up and down according to the water level, and a sensor portion 9 having a sensor function. The fixing portion 7 includes a stem 7s and a flange 7f that are integrally formed with each other, and a pin 7p that is horizontally attached to the lower end of the stem 7s.

  The movable portion 8 has a slider 8s that can slide up and down in contact with the stem 7s, a magnet 8m (single-sided magnetization with a rectangular parallelepiped) attached to the slider 8s, and a float 8f attached to the lower end of the slider 8s. A notch 8s1 is formed in the slider 8s, and the movable portion 8 can be moved up and down while being guided by the pin 7p by passing the pin 7p horizontally through the notch 8s1.

  The sensor unit 9 includes a resin case 90 and a reed switch 91 and a varistor 92 housed in the case 90. The case 90 is formed integrally with the flange 7f, or formed separately and fixed to the flange 7f, so that the case 90 extends from the flange 7f. The reed switch 91 responds to the magnetism of the magnet 8m and is turned on or off according to the position of the magnet 8m, that is, the water level. For example, at the position of the illustrated magnet 8m, the reed switch 91 is on. The varistor 92 is connected to the reed switch 91 in parallel.

  A water discharge pipe 20a and a return pipe 20b are connected to the water supply pan 2. And the circulation route of the water which passes along the humidification unit 21 from the outlet pipe 20a, and returns to the water supply pan 2 by the return pipe 20b is formed. The humidification unit 21 includes a humidification unit 211 and a pump 212. By operating the pump 212, the water in the water supply pan 2 circulates through the humidifying unit 211. The humidifying unit 211 discharges water into the air as water vapor. Accordingly, the water in the water supply pan 2 gradually decreases. FIG. 1 is a diagram at a timing when water supply from the water supply to the water supply pan 2 starts during normal operation.

  The drain pipe 20a communicates with the drain pipe 20c, and a drain solenoid valve 30 is connected to the drain pipe 20c. The electromagnetic valve 30 for drainage is normally closed, but all the water in the water supply pan 2 can be discharged by opening it. For example, the cleanliness of the water can be maintained by periodically draining the water from the water supply pan 2 and replacing it with new water.

  Now, when the float 8f and the slider 8s are lowered as the water level decreases and the state shown in FIG. 1 is reached, the reed switch 91 is turned on from off. When the reed switch 91 is turned on, the water supply electromagnetic valve 4 is opened, and tap water is supplied to the water supply pan 2. As a result, the water level rises.

FIG. 2 is a diagram showing a state in which the water level has risen to a predetermined position from the state of FIG. In this state, the reed switch 91 is off. When the reed switch 91 is turned off, the water supply electromagnetic valve 4 is closed and the supply of tap water to the water supply pan 2 is stopped.
The reed switch 91 has hysteresis. Even if the water level drops slightly from the state shown in FIG. 2, the reed switch 91 does not turn on immediately, continues off, and turns on in the state shown in FIG. Conversely, even if the water level rises slightly from the state of FIG. 1, it does not immediately turn off, continues on, and turns off in the state of FIG. 2. Thus, the water level goes back and forth between the state shown in FIG. 1 and the state shown in FIG. 2, and the amount of stored water is always maintained at least at the water level shown in FIG.

FIG. 3 is a circuit diagram of the control device of the water supply unit. In the figure, this circuit is configured by connecting the water supply electromagnetic valve 4 shown in FIGS. 1 and 2, a reed switch 91 as an element of the float switch 6, and a connector 10 as shown in the figure. . The connector 10 is connected to the main body side of the air conditioner, for example, and receives power supply of AC200V, for example, when the humidifier 100 is operated. The reed switch 91 directly turns the water supply solenoid valve 4 on (excited) or off (de-energized) at its own contact. When the operating voltage (rated) of the water supply solenoid valve 4 is V ₁ (200 V in this case), the breakdown voltage (varistor voltage) of the varistor 92 is V ₂ , and the withstand voltage between the contacts of the reed switch 91 is V ₃ , The values are designed so that V ₁ <V ₂ <V ₃ .

  In FIG. 3, when the reed switch 91 is turned on, the water supply electromagnetic valve 4 is excited, and tap water is supplied to the water supply pan 2. In a transitional state when the reed switch 91 is turned on from off, the bounce of the contact causes the switch to be stably turned on after being repeatedly turned on and off several times in a very short time. When such an on-operation bounce occurs or an off-operation occurs, a high voltage is generated by the inductance of the water supply electromagnetic valve 4 and is applied to both ends of the reed switch 91.

At this time, the same high voltage is also applied to both ends of the varistor 92. When a high voltage exceeding the breakdown voltage (varistor voltage) V ₂ of the varistor 92 is generated, the varistor 92 becomes low resistance and suppresses the voltage applied to both ends of the reed switch 91. Therefore, across the reed switch 91, even in the voltage V ₂ is instantaneously applied voltage exceeding the withstand voltage V ₃ is not applied. Thus, by protecting the reed switch 91 with the varistor 92 connected in parallel, the water supply electromagnetic valve 4 can be directly driven (on / off) by the reed switch 91. That is, according to the control device, the water supply electromagnetic valve 4 can be directly driven by the reed switch 91 without using a microcomputer or a relay.

  In addition, when the contact of the reed switch 91 is momentarily opened by the bounce at the time of the on operation, the varistor 92 having a low resistance takes over the inrush current to the water supply electromagnetic valve 4 instead of the reed switch 91. Thus, the inrush current is suppressed.

  FIG. 4 is a diagram illustrating an example of how to attach the reed switch 91 and the varistor 92. In the figure, lead wires 91 a and 91 b of a reed switch 91 are attached to one surface of a substrate (insulating substrate) 11. The lead wires 92a and 92b of the varistor 92 are attached to the other surface. For example, if the varistor 92 is slightly exposed to the through hole of the substrate 11 through the end portions of the lead wires 91a and 91b, it can be soldered together with the end portions of the lead wires 92a and 92b. Also, the lead wires 12 and 13 led out to the outside can be soldered to the same place.

  In this case, the reed switch 91 and the varistor 92 can be easily attached to the single substrate 11 in a compact manner. In addition, since both sides are used, the substrate 11 can be configured very compactly. Also, soldering is integrated, and simple and reliable circuit connection can be realized. According to such a configuration, the varistor 92 can be apparently incorporated as one member of the float switch 6, so that it is easier to manufacture than providing the varistor separately from the float switch 6. Further, it is also preferable in that it can be physically isolated from the water supply electromagnetic valve 4 that generates an impact during operation.

  Further, since the case 90 that accommodates the reed switch 91 is attached so as to extend from the flange 7f, breakage of the reed switch can be prevented. If the reed switch 91 is mounted inside the stem 7s, the reed switch 91 may be damaged when an excessive force is applied from the slider 8s to the stem 7s.

As the varistor 92, a zinc oxide varistor is suitable, but a varistor in which two Zener diodes are connected to face each other in opposite directions can also be used.
Moreover, although the control apparatus of the water supply unit of the said embodiment was demonstrated as what is optionally attached to an air conditioner, it can be mounted also in a dedicated humidifier or a ventilation system.

1: Water supply unit 2: Water supply pan (container)
3a, 3b: Water supply pipe 4: Water supply solenoid valve 6: Float switch 7f: Flange 7s: Stem 8f: Float 8s: Slider 11: Board 90: Case 91: Reed switch 92: Varistor

Claims (4)

A control device for a water supply unit (1) for storing water for humidification,
Operated by the voltage _{V 1,} the water supply pipe into the container (2) of the water supply unit (1) and (3a, 3b) water supply electromagnetic valve for opening and closing the (4),
Wherein contained within the container float switch (6) which operates in accordance with the water level in the (2), the withstand voltage is V _3, depending on the water level in the container (2), the water supply solenoid valve (4) A reed switch (91) that directly turns on or off at its own contact;
Which is connected in parallel with a reed switch (91), the breakdown voltage _{V 2 is,} V _{1 <control} of the water supply unit, characterized in that it comprises a varistor (92) in a relationship of V 2 _{<V 3.}   The water supply unit control device according to claim 1, wherein the reed switch (91) is attached to the same substrate (11) as the varistor (92).   The control device for a water supply unit according to claim 2, wherein the reed switch (91) is attached to one surface of the substrate (11), and the varistor (92) is attached to the other surface of the substrate (11). . The float switch (6) has a stem (7s) and a flange (7f) on the fixed side, and is provided integrally with the slider (8s) and the slider (8s) in sliding contact with the stem (7s) on the movable side. Having a float (8f),
The said reed switch (91) is a control apparatus of the water supply unit of any one of Claims 1-3 attached to the case (90) extended from the said flange (7f).

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