WO2018221084A1

WO2018221084A1 - Circuit and method for ultraviolet led disconnection detection, water sampling dispenser, and pure water production device

Info

Publication number: WO2018221084A1
Application number: PCT/JP2018/016627
Authority: WO
Inventors: 隆文星野; 尾崎　大介; 岡部　修一; 杏助松村; 正崇飛彈
Original assignee: オルガノ株式会社
Priority date: 2017-05-31
Filing date: 2018-04-24
Publication date: 2018-12-06
Also published as: JP2018205026A; TW201908746A

Abstract

A disconnection detection circuit that detects disconnection of an ultraviolet LED and has: a constant current power source that connects to an anode and cathode in the ultraviolet LED and supplies DC power to the ultraviolet LED; and a relay having an input unit connected in parallel between the anode and the cathode. The relay is operated by increase in voltage between the anode and the cathode, caused by disconnection of the ultraviolet LED, and the disconnection is detected.

Description

UV LED disconnection detection circuit and method, water sampling dispenser, and pure water manufacturing apparatus

The present invention relates to a disconnection detection circuit and method for detecting disconnection of an ultraviolet light emitting diode (LED: Light Emitting Diode), a water sampling dispenser having such a disconnection detection circuit, and a pure water production apparatus.

In fields such as bioscience, it is necessary to reduce the number of viable bacteria in pure water because the results of experiments and analysis are affected when the number of viable bacteria in pure water is large. Therefore, conventionally, water is sterilized by irradiating water with ultraviolet rays. As an ultraviolet light source for sterilization, a mercury lamp has been widely used for a long time, but recently, an ultraviolet LED with a short wavelength and a high output has become available, so an ultraviolet LED should be used instead of a mercury lamp. It has become to. For example, Patent Document 1 incorporates an ultraviolet sterilizer that irradiates water to be treated with ultraviolet rays generated by ultraviolet LEDs in a pure water production apparatus that treats the treated water to produce pure water. It is disclosed. Further, as an apparatus for sterilizing water used in a laboratory or the like, Patent Document 2 discloses an apparatus in which an ultraviolet light source composed of an ultraviolet LED is provided at the end of a tube and water is sterilized by passing through the tube. Patent Document 3 discloses a configuration in which an ultraviolet light source including an ultraviolet LED is provided on a lid portion of a container to sterilize water to be treated in the container. Ultraviolet LEDs are smaller than mercury lamps and are less likely to deteriorate even when light emission and quenching are repeated. Therefore, application to fields where it is difficult to apply mercury lamps is also expected.

JP 2016-123930 A Special table 2016-523594 gazette Special table 2016-525906 gazette

UV LED is an electronic component that may break. For example, when an ultraviolet LED is used as an ultraviolet light source for sterilizing pure water, if the ultraviolet LED is disconnected, pure water that has not been sterilized is supplied, which is serious in the results of experiments conducted using the pure water. May have a negative effect. Similarly, when the ultraviolet LED is used for purposes other than sterilization, the disconnection of the ultraviolet LED may have a significant influence. Thus, when using an ultraviolet LED, it is considered to provide a circuit for detecting disconnection in the ultraviolet LED. However, commercially available disconnection detectors are expensive, and there is a demand for cost reduction of the configuration for detecting disconnection.

An object of the present invention is to provide a disconnection detection circuit and method that can detect disconnection of an ultraviolet LED with a simple configuration and at low cost, and a water collection dispenser having such a disconnection detection circuit.

The disconnection detection circuit of the present invention is a disconnection detection circuit that detects disconnection of an ultraviolet LED, and is connected to an anode and a cathode of the ultraviolet LED and supplies a DC power to the ultraviolet LED, an anode and a cathode And a relay having an input unit connected in parallel between them, and the disconnection is detected by operating the relay by a rise in voltage between the anode and the cathode when the ultraviolet LED is disconnected.

The method of the present invention is a method for detecting disconnection of an ultraviolet LED, wherein a constant current power source is connected to the anode and cathode of the ultraviolet LED to drive the ultraviolet LED at a constant current, and the anode and cathode when the ultraviolet LED is disconnected. As the voltage rises, the relay having the input connected in parallel between the anode and the cathode is operated to detect disconnection.

The water sampling dispenser of the present invention is a water sampling dispenser used for pure water sampling, and connects an electromagnetic valve connected to a pure water source, a nozzle for discharging pure water, and an outlet and a nozzle of the electromagnetic valve. A flow path, an ultraviolet LED arranged to irradiate ultraviolet light to pure water flowing through the flow path, a constant current power source connected to the anode and cathode of the ultraviolet LED and supplying DC power to the ultraviolet LED, an anode A relay having an input connected in parallel between the cathode and the cathode, and controlling the opening and closing of the solenoid valve, operating a constant current power source when the solenoid valve is opened, detecting that the relay has been activated, and detecting the ultraviolet LED And a control unit that generates an alarm when the disconnection is detected.

The pure water production apparatus of the present invention is a pure water production apparatus having at least a storage tank for storing pure water, and is an ultraviolet LED that is attached to the storage tank and arranged to irradiate the pure water in the storage tank with ultraviolet light. And a constant current power source for supplying DC power to the ultraviolet LED by connecting to the anode and cathode of the ultraviolet LED, a relay having an input connected in parallel between the anode and the cathode, and controlling the opening and closing of the solenoid valve And a controller that operates a constant current power source when the solenoid valve is opened, detects that the relay is activated, detects disconnection of the ultraviolet LED, and generates an alarm when the disconnection is detected.

According to the present invention, the disconnection of the ultraviolet LED can be detected with a simple configuration and at a low cost.

It is a circuit diagram which shows the structure of the disconnection detection circuit of one Embodiment. It is a flow sheet which shows an example of composition of a pure water manufacturing device and a water sampling dispenser. It is a front view which shows the internal structure of a water sampling dispenser. It is a circuit diagram which shows the disconnection detection circuit integrated in the water sampling dispenser.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a disconnection detection circuit according to an embodiment of the present invention. When driving an ultraviolet LED, it is generally necessary to prevent a forward current exceeding the rated value from flowing. Therefore, a mechanism for limiting the current flowing through the ultraviolet LED is required. The disconnection detection circuit according to the present embodiment detects disconnection of the ultraviolet LED 11, and supplies a DC power while limiting the current to the ultraviolet LED 11 to drive the ultraviolet LED 11 at a constant current, and a relay 13. It is equipped with. The positive output (+) of the constant current power supply 12 is connected to the anode A of the ultraviolet LED 11, and the negative output (−) is connected to the cathode K. The input unit 14 of the relay 13 is connected in parallel between the anode A and the cathode K of the ultraviolet LED 11. In the illustrated example, the relay 13 is a mechanical relay, and the input unit 14 is configured as an operating coil of the relay 13, that is, a solenoid. The output unit 15 of the relay 13 has three contacts 16 to 18. The contact 16 is a common contact COM, the contact 17 is a normally closed contact NC, and a contact that is electrically connected to the contact 16 only when there is no predetermined input in the input unit 14, that is, when the operating coil is not activated. It is. The contact 18 is a normally-open contact NO, and is a contact that is electrically connected to the contact 16 only when there is a predetermined input in the input unit 14, that is, when the operating coil is activated. Here, the relay 13 is a mechanical relay, but the relay 13 may be, for example, a solid state relay or a semiconductor relay.

When the ultraviolet LED 11 is driven at a constant current, the voltage between the anode A and the cathode K, that is, the forward voltage, is determined by the forward current voltage characteristics of the ultraviolet LED 11, but is approximately 2 to 4V. On the other hand, the constant current power supply 12 is supplied with a certain high voltage so that a predetermined current can be stably output. Therefore, the open-circuit voltage of the constant current power supply 12, that is, the output voltage when there is no load is, for example, about 10 to 20V. Here, it is assumed that the operating voltage of the relay 13 is higher than the forward voltage of the ultraviolet LED 11 and lower than the open state voltage of the constant current power supply 12. If the ultraviolet LED 11 is operating normally, the voltage applied to the input part 14 of the relay 13 is the forward voltage of the ultraviolet LED 11, so the relay 13 does not operate, while if the ultraviolet LED 11 is disconnected, the input Since the voltage applied to the unit 14 becomes the open state voltage of the constant current power source 12, the relay 13 is activated. In this disconnection detection circuit, for example, the power supply voltage VDD is applied to the contact 18 which is the normally open contact NO of the relay 13, the ground potential GND is applied to the contact 17 which is the normally closed contact NC, and then the contact which is the common contact COM. By determining whether the potential of 16 is the power supply voltage VDD or the ground potential GND, the disconnection of the ultraviolet LED 11 can be detected.

When the disconnection in the ultraviolet LED 11 occurs and the potential of the contact 16 of the relay 13 becomes, for example, the power supply voltage VDD, an alarm signal can be issued based on the signal from the contact 16. Furthermore, the operation | movement of the apparatus related to ultraviolet-ray LED11 which a disconnection produced can also be stopped as needed.

Next, an apparatus to which an ultraviolet LED is provided and to which a disconnection detection circuit based on the present invention is applied will be described. Here, a water sampling dispenser that is connected to a pure water production apparatus or the like and discharges pure water according to demand will be described as an example of equipment provided with ultraviolet LEDs. Of course, the device to which the disconnection detection circuit according to the present invention is applied is not limited to the water sampling dispenser.

When using pure water in research institutions, etc., pure water is often produced using a relatively small pure water production apparatus. In order to collect pure water at a use point, for example, in a beaker, a flask, a test tube or the like, a water collection dispenser connected to a pure water production apparatus is widely used. The water sampling dispenser includes a nozzle that discharges pure water, and an open / close valve that is provided in a path of pure water to the nozzle and supplies pure water to the nozzle and shuts off the supply. The water sampling dispenser is usually provided at a use point away from the main body of the pure water production apparatus, and is connected to a pure water outlet of the pure water production apparatus main body by piping. When the user operates the on-off valve, pure water is discharged from the nozzle, and thus the user can collect pure water in an amount according to the necessity. As the on-off valve, for example, an electromagnetic valve can be used. When using a solenoid valve, the solenoid valve is controlled by a push button switch that can be operated by a finger or a foot switch that can be operated by a foot, and pure water is discharged from the nozzle. Furthermore, by combining the flow sensor and the solenoid valve, the specified amount of pure water can be removed by opening the solenoid valve until the flow rate measured by the flow sensor reaches the specified value when there is a single switch operation. It is also possible to collect water.

FIG. 2 shows a pure water production apparatus and a water dispenser. The pure water production apparatus can be broadly divided into a primary pure water production apparatus 30 that supplies tap water and generates primary pure water, and a primary pure water produced by the primary pure water production apparatus 30 via a pipe 45. It consists of a subsystem 50 that is supplied and produces pure water with higher purity, that is, a secondary pure water system. The subsystem 50 includes a circulation purification system. In the primary pure water production apparatus 30, supply water such as tap water is introduced into an activated carbon cartridge (CC) 32 through a valve 31. The outlet water of the activated carbon cartridge 32 is sent to a reverse osmosis device (RO) 35 having a reverse osmosis membrane via a pressure switch (PS) 33 and a pump 34. A pipe 43 having an orifice 36 is connected to the concentration side of the reverse osmosis device 35, and waste water from the concentration side is discharged through the pipe 43. The orifice 36 is provided to keep the pressure on the concentration side of the reverse osmosis device 35 constant. The water that has passed through the reverse osmosis membrane of the reverse osmosis device 35 is then sequentially passed to non-regenerative ion exchange devices (CP: also called cartridge polishers) 39 and 41 arranged in two stages in series. The

non-regenerative ion exchangers

39 and 41 are each filled with a strongly acidic cation exchange resin and a strongly basic anion exchange resin in a mixed bed. In the pipe between the reverse osmosis device 35 and the first non-regenerative ion exchange device 39, a conductivity meter (CI) for measuring the conductivity and temperature of water sent to the non-regenerative ion exchange device 39, respectively. 37 and a thermometer (TI) 38 are connected. A conductivity meter 40 is also provided in the piping between the first and second non-regenerative

ion exchange devices

39 and 41. A check valve 42 is provided at the outlet of the non-regenerative ion exchange device 41. The outlet of the check valve 42 is an outlet of the primary pure water production apparatus 30 and is connected with a pipe 45.

The subsystem 50 includes a storage tank 51 to which primary pure water is supplied from a pipe 45 through a valve 52. The storage tank 51 includes an ultraviolet irradiation device 53 for sterilizing the pure water in the storage tank 51 by irradiating ultraviolet light, a level sensor (LS) 54 for detecting the level of pure water in the storage tank 51, and a vent filter 55. And are provided. The storage tank 51 communicates with the atmosphere via the vent filter 55, and the pressure in the storage tank 51 is maintained at atmospheric pressure. As the ultraviolet irradiation device 53, for example, a device using an ultraviolet LED, a device using an ultraviolet lamp, or the like can be used.

A pump 56 for feeding pure water in the storage tank 51 is provided at the outlet of the storage tank 51, and an ultraviolet oxidation device (UV) 57, a non-regenerative type provided in two stages in series, is provided at the outlet of the pump 56.

Ion exchange devices

58 and 59 and an ultrafiltration device (UF) 60 are provided in this order. A pipe 101 branched from the outlet pipe of the pump 56 is provided, and an outlet port 71 is provided at the tip of the pipe 101. The ultrafiltration device 60 is provided with a pipe 106 for draining water on the primary side of the ultrafiltration membrane, and the pipe 106 is provided with a valve 107. A pipe 102 connected to an outlet port 72 is connected to the outlet of the ultrafiltration device 60, and a resistance meter (RI) for measuring the electrical resistivity and temperature of pure water flowing therethrough is connected to the pipe 102, respectively. 63 and a thermometer 64 are connected. A pipe 103 for returning pure water to the storage tank 51 side is also provided at the outlet of the ultrafiltration device 60, and a constant flow valve 61 is attached to the tip of the pipe 103. Connected to the pipe 103 is a TOC meter (TOCI) 62 for measuring the total organic carbon (TOC) concentration of pure water flowing therethrough. A pipe 104 returning to the storage tank 51 and a pipe 105 connected to the outlet port 73 are connected to the outlet of the constant flow valve 61. A back pressure valve 65 is provided in the pipe 105. A sampling valve 66 used for sampling pure water is attached to the pipe 104.

In the subsystem 50, a circulation purification system is formed that returns from the storage tank 51 to the storage tank 51 through the pump 56, the ultraviolet oxidation device 57, the non-regenerative

ion exchange devices

58 and 59, the ultrafiltration device 60, and the constant flow valve 61. The primary pure water is further purified while circulating through this circulation purification system, thereby obtaining pure water to be supplied to the use point. The ultraviolet oxidizer 57 is for decomposing all organic carbon in pure water and has a sterilizing action. The operation of the circulation purification system may be stopped at night or on holidays, and during the stop period. In order to suppress the growth of viable bacteria in the storage tank 51, it is preferable to provide the ultraviolet irradiation apparatus 53 in the storage tank 51 separately from the ultraviolet oxidation apparatus 57. Since it is necessary to be able to dissociate water, a low-pressure mercury lamp is generally used as the ultraviolet light source in the ultraviolet oxidation device 57. Further, in the subsystem 50, a valve 68 is connected to the pipe 45 in order to discharge the primary pure water from the pipe 45 as waste water as it is. A valve 69 for draining the inside of the storage tank 51 is also provided at the outlet of the storage tank 51. A check valve 67 is provided between the drain side of the valve 69 and the inlet side of the storage tank 51. Further, a main controller 70 is provided to control the overall operation of the pure water production apparatus. The main controller 70 may be connected to a sensor that detects water leakage in the pure water production apparatus.

The outlet ports 71 to 73 provided in the subsystem 50 are ports that are connection positions of the water sampling dispenser 80. The water sampling dispenser 80 is connected to any one of the outlet ports 71 to 73 by, for example, a flexible pipe 75. Here, three outlet ports 71 to 73 are provided, but the connection points of the outlet ports to the circulation purification system are not limited to those shown in FIG. However, it is preferable to connect the water sampling dispenser 80 to the outlet port 72 from the viewpoint of water quality and pressure. The number of outlet ports connected to the circulation purification system is not limited to 3, but can be increased or decreased. For example, a plurality of outlet ports connected to the outlet of the ultrafiltration device 60 may be provided, and one water sampling dispenser 80 may be connected to each of the outlet ports.

Next, the water sampling dispenser 80 will be described. The circulation purification system of the subsystem 50 is provided with an ultraviolet irradiation device 53 and an ultraviolet oxidation device 57, and sterilization is performed on the pure water circulating in the circulation purification system, but a pipe branched from the circulation purification system For example, since pure water in the

pipes

75, 101, 102, 105 and the water collection dispenser 80 does not circulate, there is a possibility that viable bacteria will propagate at these positions. Therefore, the water collection dispenser 80 described here is provided with an ultraviolet sterilization mechanism using an ultraviolet LED in itself, and can always supply pure water with a reduced number of viable bacteria contained therein.

The water dispensing dispenser 80 is roughly composed of a head portion 80a and a main body portion 80b, and the head portion 80a and the main body portion 80b are connected by a flexible pipe 84. As a usage form of the water sampling dispenser 80, for example, it is used for pouring pure water one after another to a large number of test tubes arranged in line on a laboratory table. Therefore, a control mechanism and the like necessary for functioning as the water sampling dispenser 80 are provided in the main body 80b, and a portion that actually becomes a pure water spout can be gripped by the user and moved to a desired position. It is provided in the head portion 80a.

The head part 80a discharges pure water sent from the main body part 80b through the pipe 84, and is provided at the end of the flow path 85 connected to the pipe 84 and pure water. And an ultraviolet irradiation unit 87 that irradiates the pure water flowing through the flow path 85 with ultraviolet rays. The ultraviolet irradiation unit 87 functions as an ultraviolet sterilization mechanism, and an ultraviolet LED is used as the ultraviolet source in the ultraviolet irradiation unit 87. Furthermore, the head unit 80a includes a switch 88 that is operated by the user in order to discharge pure water according to the user's demand.

In the main body 80b, a pipe 81 having one end connected to the pipe 75 from the subunit 50, a flow sensor (FI) 82 provided in the pipe 81, an electromagnetic valve 83 attached to the other end of the pipe 81, A control unit 90 for controlling the operation of the water dispensing dispenser 80 and an operation panel 89 connected to the control unit 90 are provided. The electromagnetic valve 83 is opened by a drive signal from the control unit 90. The operation panel 89 receives, for example, settings of the water sampling amount and water sampling mode from the user and performs necessary display for the user. Examples of the water sampling mode include a quantitative mode and an arbitrary amount mode. The control unit 90 performs overall control of the water sampling dispenser 80. For example, the control unit 90 receives a water sampling request input from the user via the switch 88 of the head unit 80a, and the water sampling mode is the quantitative mode. In this case, the solenoid valve 83 is opened until the accumulated value of the flow rate detected by the flow rate sensor 82 reaches the set value, so that the amount of pure water indicated by the set value is supplied to the head unit 80a. Control. When the water sampling mode is an arbitrary amount mode, the control unit 90 performs control to open the electromagnetic valve 83 only during a period in which the switch 88 is operated. In addition, the control unit 90 performs control so that the ultraviolet LED in the ultraviolet irradiation unit 87 is driven only when the electromagnetic valve 83 is open regardless of the water sampling mode. Further, the control unit 90 may be connected to the control circuit 70 of the pure water production apparatus by a wiring (not shown) and display information such as water quality obtained from the control circuit 70 on the operation panel 89.

FIG. 3 shows the external appearance of the head portion 80a of the water sampling dispenser 80 and the internal structure. The head portion 80a is provided with a handle 118 or a handle, and a button 119 is provided at a position where a user who holds the handle 118 can easily operate with the finger. The button 119 is mechanically connected to a switch 88 (not shown in FIG. 3), and the switch 88 is operated when the button 119 is pressed. The flow path 85 includes a joint 111 serving as a connection portion with the pipe 84, a housing 112 connected to the joint 111 and including a through flow path 114 therein, and a joint 115 having one end connected to an outlet of the through flow path 114 of the housing 112. And a backflow prevention mechanism 117, and the other end of the joint 115 is connected to the inlet of the backflow prevention mechanism 117 via the joint 116. The outlet of the backflow prevention mechanism 117 opens to the outer surface of the head portion 80a, and the nozzle 86 is attached thereto by, for example, screwing.

The ultraviolet irradiation unit 87 includes an ultraviolet LED 11, a substrate 94 with the ultraviolet LED 11 attached to the first surface, and a radiator (heat sink) attached to the second surface opposite to the first surface of the substrate 94. ) 95. The radiator 95 is for radiating heat generated when the ultraviolet LED 11 is driven. The through-flow channel 114 of the housing 112 is provided with a bent portion, and a hollow portion 113 is formed from the bent portion toward one side surface of the housing 112, and the hollow portion 113 is viewed from the through-flow channel 114 side. A quartz glass plate 96 serving as an ultraviolet light introducing window is provided in the inner part. The quartz glass plate 96 is provided so as to face the first surface of the substrate 94, and the ultraviolet light emitted from the ultraviolet LED 11 enters the through flow path 114 through the quartz glass plate 96 and the hollow portion 113. Become. With this configuration, the head unit 80a irradiates the pure water flowing through the flow path 85 with ultraviolet rays, and performs ultraviolet sterilization treatment on the pure water. By using a material that reflects ultraviolet light such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF) as a material constituting the housing 112, it becomes possible to efficiently irradiate the pure water with ultraviolet light. . In particular, in the present embodiment, ultraviolet rays are incident on the position of the bent portion in the through flow path 114 as shown in the drawing, so that the material constituting the inner wall of the joint 111 or the pipe 84 is made of PTFE, PVDF, or the like. In the figure, as indicated by an arrow labeled UV, ultraviolet rays can be made incident into the pipe 84, and ultraviolet rays can be irradiated onto pure water more efficiently.

Mercury lamps conventionally used as ultraviolet light sources are large in size and are not suitable for frequent on / off operation, so only when there is a demand for pure water to be incorporated in the water sampling dispenser, especially its head part It was difficult to light up. In the water sampling dispenser 80 shown here, by using the ultraviolet LED 11, it becomes possible to perform the ultraviolet sterilization treatment of pure water at a position immediately before the position at which the pure water is discharged in the water sampling dispenser 80. It becomes possible to perform the sterilization process with respect to the pure water to be surely performed.

FIG. 4 shows a circuit configuration of the water sampling dispenser 80. In the water collection dispenser which discharges the pure water sterilized by the ultraviolet LED, there is a risk of discharging pure water containing viable bacteria when the ultraviolet LED is disconnected. Therefore, in the water dispensing dispenser 80 shown in FIG. 4, a constant current power source 12 for driving the ultraviolet LED 11 provided in the head portion 80a and a relay 13 for detecting disconnection of the ultraviolet LED 11 are provided. A disconnection detection circuit similar to that shown in FIG. Although not shown in FIG. 2, the constant current power source 12 and the relay 13 are provided in the main body 80b. The output of the constant current power supply 12 is turned on / off by a signal from the control unit 90. The control unit 90 is connected to the operation panel 89 and the button 88 of the head unit 80 a, and the flow rate detection value is input from the flow rate sensor 82. In accordance with these inputs, the control unit 90 starts the operation of the constant current power supply 12 when the electromagnetic valve 83 is opened, and stops the constant current power supply 12 when the electromagnetic valve 83 is closed. The current power source 12 is controlled. The ultraviolet LED 11 and the button 88 provided in the head portion 80a and the main body portion 80b are electrically connected by, for example, wiring (not shown) provided along the pipe 84.

In the disconnection detection circuit, the contact 17 as the normally closed contact NC of the relay 13 is connected to the ground potential, and the power supply voltage is applied to the contact 18 as the normally open contact NO. The contact 16 that is the common contact COM is connected to the control unit 90. Since the input of the relay 13 does not exist when the constant current power supply 12 is stopped, the potential of the contact 16 is the ground potential (that is, L level). Even when the constant current power supply 12 is operating and the ultraviolet LED 11 is operating normally, the relay 13 does not operate as described above, so the potential of the contact 16 is the ground potential. On the other hand, when the constant current power supply 12 is operating but the ultraviolet LED 11 is disconnected, the relay 13 is activated and the potential of the contact 16 becomes the power supply voltage or a value close thereto, that is, H level. Therefore, the control unit 90 can detect the disconnection of the ultraviolet LED 11 by detecting that the voltage of the signal sent from the contact 16 of the relay 13 becomes H level as a failure detection.

The control unit 90 can display an alarm indicating the disconnection on the operation panel 89 when the disconnection of the ultraviolet LED 11 is detected, for example. Or after displaying an alarm, you may perform control which stops water supply, without sending a drive signal with respect to the solenoid valve 83 so that the water sampling by the water sampling dispenser 80 cannot be performed. When a plurality of water sampling dispensers 80 are connected to the subsystem 50, there is little influence even if the water sampling dispenser in which the ultraviolet LED 11 is disconnected is stopped.

Although the case where the disconnection detection of the ultraviolet LED 11 provided in the water sampling dispenser 80 is detected has been described above, the disconnection detection circuit according to the present invention performs sterilization by irradiating the pure water in the storage tank 51 with ultraviolet rays, for example. Therefore, it can also be used for detection of disconnection of the ultraviolet LED used in the ultraviolet irradiation device 53. When detecting the disconnection of the ultraviolet LED used in the ultraviolet irradiation device 53, the output of the disconnection detection circuit is supplied to the main controller 70, for example. When the main controller 70 detects the disconnection of the ultraviolet LED in the ultraviolet irradiation device 53, the main controller 70 displays an alarm indicating the disconnection on a display device (not shown) or on the operation panel 89 of the water sampling dispenser 80. be able to.

The pure water production apparatus described above includes a subsystem 50 having a storage tank 51, a pump 56, an ultraviolet oxidation device 57, non-regenerative

ion exchange devices

58 and 59, an ultrafiltration device 60 and a constant flow valve 61. However, using ultraviolet LEDs to sterilize the pure water stored in the storage tank and detecting the disconnection of the ultraviolet LEDs by the disconnection detection circuit according to the present invention is applied only to a pure water production apparatus having a subsystem. It is not something. An ultraviolet irradiation device having an ultraviolet LED is provided for a pure water production apparatus that does not have a subsystem but has a storage tank for storing pure water, and for sterilizing the pure water in the storage tank, and is disconnected based on the present invention. A detection circuit can be provided.

11 UV LED
DESCRIPTION OF SYMBOLS 12 Constant current power supply 13 Relay 14 Input part 15 Output part 50 Subsystem 51 Storage tank 53 Ultraviolet irradiation device 70 Main controller 90 Control part

Claims

A disconnection detection circuit for detecting disconnection of an ultraviolet LED,
A constant current power source connected to the anode and cathode of the ultraviolet LED to supply DC power to the ultraviolet LED;
A relay having an input connected in parallel between the anode and the cathode;
Have
A disconnection detection circuit that detects the disconnection by operating the relay according to an increase in voltage between the anode and the cathode when the ultraviolet LED is disconnected.
The disconnection detection circuit according to claim 1, wherein the relay is a mechanical relay, and the input unit is an operating coil of the relay.
The disconnection detection circuit according to claim 1, further comprising a control unit that controls a solenoid valve that intermittently supplies pure water and that generates an alarm when the disconnection is detected.
A method for detecting disconnection of an ultraviolet LED,
A constant current power source is connected to the anode and cathode of the ultraviolet LED to drive the ultraviolet LED at a constant current,
The disconnection is detected by operating a relay having an input unit connected in parallel between the anode and the cathode by a rise in voltage between the anode and the cathode when the ultraviolet LED is disconnected. Method.
A water sampling dispenser used for pure water sampling,
A solenoid valve connected to a source of pure water;
A nozzle for discharging pure water;
A flow path connecting the outlet of the solenoid valve and the nozzle;
An ultraviolet LED arranged to irradiate the pure water flowing through the flow path with ultraviolet rays;
A constant current power source connected to the anode and cathode of the ultraviolet LED to supply DC power to the ultraviolet LED;
A relay having an input connected in parallel between the anode and the cathode;
When controlling the opening and closing of the solenoid valve and operating the constant current power source when the solenoid valve is opened, detecting that the relay is activated, detecting disconnection of the ultraviolet LED, and detecting the disconnection A control unit for generating an alarm;
A water dispensing dispenser having.
The water dispensing dispenser according to claim 5, wherein the control unit performs control to maintain the solenoid valve closed when the disconnection is detected.
A pure water production apparatus comprising at least a storage tank for storing pure water,
An ultraviolet LED attached to the storage tank and arranged to irradiate ultraviolet light to the pure water in the storage tank;
A constant current power source connected to the anode and cathode of the ultraviolet LED to supply DC power to the ultraviolet LED;
A relay having an input connected in parallel between the anode and the cathode;
When controlling the opening and closing of the solenoid valve and operating the constant current power source when the solenoid valve is opened, detecting that the relay is activated, detecting disconnection of the ultraviolet LED, and detecting the disconnection A control unit for generating an alarm;
A pure water production apparatus having: