JP6339470B2 - LED lighting device and LED lighting device - Google Patents

Description

  The present invention relates to an LED lighting device and an LED lighting device capable of detecting a short circuit or disconnection failure with a simple protection circuit and avoiding damage to a normal LED module.

  In recent years, many illuminating devices have been proposed in which the light emitting unit is replaced with an LED (Light Emitting Diode). An LED lighting device in which a large number of LED elements are integrated to increase the amount of light has been proposed, but the forward voltage of the LED elements fluctuates due to variations in individual differences and the ambient temperature, and there is a problem that uniform light emission cannot be obtained. Are known. Moreover, when a failure occurs in a part of the LED element and a current exceeding the maximum allowable current flows through another normal LED element, a problem that the normal LED element is damaged is known.

  In Patent Document 1, the current flowing through the LED element (light-emitting diode) is limited to a maximum allowable current or less, and LED lighting that can be dimmed over a range from all light to extinction according to a dimming signal from the outside. As a device, a current comparison circuit that compares the current detected by the current detection circuit and the maximum allowable current, and a dimming signal is input from the outside, and a predetermined DC voltage and voltage detection circuit corresponding to the dimming signal are detected. The voltage comparison circuit that compares the voltage and the current comparison circuit that outputs a predetermined DC voltage corresponding to the dimming signal from the DC lighting circuit according to the comparison result output from the voltage comparison circuit LED point having control means for controlling the DC lighting circuit so as to reduce a predetermined DC voltage according to the dimming signal when the current flowing through the light emitting diode is equal to or greater than the maximum allowable current in the comparison result Apparatus is disclosed.

JP 2008-310963 A

  As a method for realizing an LED lighting device with a large amount of light, connecting a plurality of LED modules composed of N LED elements in parallel is performed. If power is supplied all at once in this way, the state of the load will change greatly when some of the LED elements are short-circuited or broken, and the current value will show an abnormal value, possibly leading to the failure of all LED modules. There was a structural problem.

Although it is conceivable to provide the same number of power supplies as the number of modules and control the current value in units of modules, there is a problem of high costs. It is also a problem to be solved to provide an LED lighting device and an LED lighting device that can protect each LED module with a simple circuit configuration.
In addition, an underwater fish lamp with a light emitting part underwater is also required to be able to recognize on the water that an abnormality has occurred in the LED module with a simple circuit configuration.

  Then, an object of this invention is to provide the LED lighting device and LED lighting device with which the said subject was eliminated.

The LED lighting device of the present invention has one or a plurality of unit series modules formed by connecting a plurality of LED elements in series, a plurality of LED modules connected in parallel to each other, and a direct current connected to the LED modules. A variable constant voltage power supply unit for supplying a voltage; a plurality of level conversion circuits which are connected to the LED modules in a one-to-one relationship and convert a DC voltage supplied from the variable constant voltage power supply unit into a control target voltage; and the variable In a LED lighting device having a dimming control circuit that controls a DC voltage output supplied from a constant voltage power supply unit to light up with a desired light amount, only a maximum value of a current flowing through the plurality of LED modules is detected. A maximum value detection circuit for input to the dimming control circuit, wherein the dimming control circuit has a maximum value of a current flowing through the plurality of LED modules substantially equal to a reference voltage. And controlling so as to.
In the LED lighting device, further, a minimum value detection circuit that detects only a minimum value of a current flowing through the plurality of LED modules, and a minimum value of a current input from the minimum value detection circuit is set to a threshold value based on a disconnection determination reference value. A disconnection detection circuit that determines that a disconnection failure has occurred when the value falls below the limit may be provided.
In the LED lighting device, the dimming control circuit may collectively control currents flowing through the plurality of LED modules.
In the LED lighting device, the dimming control circuit may control the light amount of the LED module by a PWM signal.

In the LED lighting device, the rated power consumption may be 200 W to 3000 W.
The LED lighting device may be an underwater fish collection lamp, and may further include a lighting monitor device that displays the lighting status of the LED module in multiple stages.

  The LED lighting device according to the present invention includes a variable constant voltage power supply unit that supplies a DC voltage to a plurality of LED modules connected in parallel to each other, a one-to-one connection with the LED module, and the variable constant voltage power supply unit A plurality of level conversion circuits for converting a supplied DC voltage into a voltage to be controlled, and a dimming control circuit for controlling a DC voltage output supplied from the variable constant voltage power supply unit and lighting it with a desired light amount. In the LED lighting device provided, the LED module has one or a plurality of unit series modules formed by connecting a plurality of LED elements in series, and detects only the maximum value of the current flowing through the plurality of LED modules. A maximum value detection circuit for input to the dimming control circuit, wherein the dimming control circuit has a maximum value of a current flowing through the plurality of LED modules substantially equal to a reference voltage. And controlling so as to.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to detect a short circuit or a disconnection failure with a simple protection circuit, and to provide the LED lighting device and LED lighting device which can avoid damage to a normal LED module.
In addition, in an LED lighting device that is an underwater fish collecting light, it is possible to recognize an abnormality of the LED module on the water.

1 is a schematic circuit configuration diagram of an LED illumination device according to Embodiment 1. FIG. It is a circuit block diagram of a level conversion circuit. It is a block diagram of the circuit for detecting an overcurrent and a disconnection. It is a general | schematic circuit block diagram of the maximum value detection circuit. It is a general | schematic circuit block diagram of the minimum value detection circuit. It is a general | schematic circuit block diagram of the LED lighting apparatus which concerns on Example 2 of an embodiment.

An LED lighting apparatus according to a preferred embodiment of the present invention will be described.
<< Embodiment 1 >>
[Constitution]
FIG. 1 is a schematic circuit configuration diagram of an LED lighting apparatus according to Embodiment 1. The LED lighting device according to the present embodiment has a circuit configuration including N sets of LED modules 3 formed by connecting two unit series modules each including a plurality of LED elements 31 connected in series. In the present embodiment, the unit series module is composed of 36 LED elements, but the number of elements is not limited to the illustrated number. For example, the unit series module is composed of 10 to 50 LED elements. Is possible. The LED element 31 may be constituted by a package type or may be constituted by a bare chip mounted with COB (chip on board).
N sets of LED modules 3 _{1 to} 3 _N are connected in parallel, and N sets of level conversion circuits 4 ₁ to 4 _N are connected one-on-one. Here, N is a positive natural number. For example, the number of LED modules is 2 to 30, preferably 2 to 10.

Since the light output of the LED elements 31 changes in accordance with the flowing current, all the LED elements 31 have the same specifications. However, since the forward voltage fluctuates due to variations in individual differences and the ambient temperature, variations in proper forward current occur even with the same specification. If the current flowing through the LED element 31 exceeds the maximum rating, there arises a problem that the LED element 31 is damaged or its life is shortened. Therefore, in this embodiment, level conversion for monitoring the current flowing through the LED modules 3 _{1 to} 3 _N Circuits 4 ₁ to 4 _N are provided.

As shown in FIG. 2, the level conversion circuit 4 includes a resistor 41, a current sensing amplifier 42, a transistor 43, and resistors 44 and 45.
The resistor 41 is a detection resistor on the high side (high potential side) for constant current control.
The current sensing amplifier 42 is configured to supply a voltage to the base of the transistor 43 in order to generate a constant current proportional to the voltage of the resistor 41.
The transistor 43 constitutes a constant current circuit that operates in conjunction with the current sensing amplifier 42 in order to allow a constant current proportional to the current flowing through the resistor 41 to flow. The transistor 43 may be replaced with a MOSFET.
The resistor 44 is a resistor for converting a value proportional to the current flowing through the LED element 31 into a voltage and also converting it into a low side (low potential) potential.
The resistor 45 is a resistor for sensing current, and is configured with a low value (for example, 1Ω) from the viewpoint of reducing power loss.

The level conversion circuit 4 converts the voltage to be controlled by flowing a constant current through the resistor 44, and performs dimming control (0 to 100% dimming control) of the LED element 31. For example, when the dimming control of 0 to 100% is performed by varying the current flowing through the LED element 31 by the variable constant voltage power supply 9 in the range of 0 to 0.7 A, the resistor 41 is set to 1 kΩ on the level conversion circuit 4 side. A constant current of 0 to 0.7 mA is configured, and this constant current is passed through the resistor 44 to convert it into a control target voltage. In this case, by setting the resistance 44 to a high resistance value (for example, 1 k to 10 kΩ) as much as possible, a control operation up to a very small current region is possible.
For example, when the resistance 44 is 10 kΩ, 0 to 0.7 mA flows through the resistance 41, and thus a voltage of 0 to 7 V is generated at both ends of the resistance 44. Since this voltage contains a lot of noise, it is input to the current detection amplifier 53 through a low-pass filter composed of a resistor 51 and a capacitor 52. The output of the current detection amplifier 53 is the maximum value detection circuit 13 and the minimum value. Connected to the detection circuit 15. The low-pass filter circuit 5 includes this low-pass filter and a current detection amplifier 53.

The level conversion circuit 4 according to a preferred embodiment includes a low-pass filter circuit 5 connected to each LED module 3 on a one-to-one basis. As will be described later, since the influence of noise is large when the dimming level is set to several percent or less, the low-pass filter circuit 5 cuts a noise component present at a high frequency.
The low-pass filter circuit 5 includes a detection resistor 51 and a capacitor 52. The detection resistor 51 is composed of, for example, a 10 kΩ resistor.
The capacitor 52 is configured by a 0.1 μF capacitor, for example.
The output amplifier 53 is configured for impedance conversion, and inputs the amplified output signal to the maximum value detection circuit 13.

  The DC / DC converter 6 is a flyback converter, and inputs a pulse signal to the gate of a power device (for example, a MOSFET) by the PWM modulator 8 to supply an appropriate DC voltage to each LED module. For example, assuming that the number of unit series modules of each LED module is 36 and the forward voltage of the LED element 31 is 3.5 V, the supply voltage required for 100% lighting is 126 V, and the LED is turned off. However, since the forward voltage of the LED element is 2.5 V or less, the supply voltage is about 90 V, and the output voltage is varied according to the dimming setting range. The DC / DC converter 6 and the AC / DC converter 7 constitute a variable constant voltage power supply 9. The constant current power supply cannot be used because there is a problem that the current value of each of the other LED modules increases when the LED module fails.

  The PWM modulator 8 adjusts the total amount of emitted light between 0% and 100% by performing pulse width modulation that modulates by changing the duty ratio of the pulse wave. The LED lighting device of Embodiment 1 is an underwater fish collection lamp, and the frequency of the PWM signal is, for example, 100 kHz. This underwater fishing light is used for the purpose of collecting a wide range of fish with a light amount of 100% at first, collecting the fish by gradually reducing the light amount, and finally adjusting the light to 0%.

The dimming setting circuit 11 inputs a voltage signal (for example, 0 to 7 V) as a dimming signal to the dimming control amplifier 12 as a reference voltage. On the other hand, a voltage signal corresponding to the maximum load current of each of the LED modules 3 _{1 to} 3 _N is input to the dimming control amplifier 12 and controlled so as to be substantially the same as the reference voltage. By performing such control with the dimming control amplifier 12, when an overcurrent occurs in any of the LED modules 1 to N, the output of the entire LED module is suppressed and the LED element 31 is damaged. Acts to prevent. A dimming control circuit 10 shown in FIG. 3 includes a dimming setting circuit 11 and a dimming control amplifier 12, and is connected to a variable constant voltage power source 9. In this embodiment, the current value control for each LED module is not performed, and the power supply voltage is collectively controlled. This is because, in order to perform current value control for each LED module, the same number of power supplies as the number of modules are required, resulting in high costs.

Maximum value detection circuit 13 is a circuit for detecting a maximum value of the current flowing to the LED module ₃ 1 to 3 _N, N-number of maximum value detection amplifier connected one-to-one with the LED module ₃ 1 to 3 _N It has. The maximum value detection circuit 13 detects only the maximum value of the current flowing through the N LED modules, and the dimming control amplifier 12 based on the dimming signal from the dimming setting circuit 11 with respect to this maximum current. Control is performed by. As a result, the current of each LED module becomes equal to or less than the current value based on the dimming setting, and it becomes possible to drive all the LEDs under appropriate conditions even when there is a load fluctuation due to short circuit or disconnection of the LED element. .

  As shown in FIG. 4, the maximum value detection circuit 13 includes N maximum value detection amplifiers and N diodes connected in the forward direction to the output of the maximum value detection amplifier. The output is connected to the ground of the maximum value detection amplifier through a detection resistor at one point. Of the N maximum value detection amplifiers, only the current of the maximum value detection amplifier with the highest output voltage flows to the detection resistor, and the other maximum value detection amplifiers have a higher voltage on the cathode side of the diode than the input voltage. A reverse bias state occurs and no current flows. Therefore, the maximum value current signal can be detected by operating only the maximum value detection amplifier to which the maximum voltage is input.

The overcurrent detection circuit 14 determines that there is an overcurrent when the maximum value (OUT-MAX) is equal to or greater than a reference value (for example, + 30% of the target current value). Since the maximum value of the current flowing through each LED module is compared and controlled based on a reference value based on the dimming setting, it is determined that an overcurrent has occurred when a current value greater than the reference value is detected. Then, the abnormality display lamp blinks because there is an abnormality in the lighting device. For example, when the current value of each LED module 3 _{1 to} 3 _N at 100% lighting is 0.7 A and the input voltage to the overcurrent detection circuit 14 is 7 V, the overcurrent determination reference value is set to 10 V. In this case, 100% lighting is not detected as an overcurrent. On the other hand, when the maximum value of the current of each LED module exceeds 1.0 A, it is detected as an overcurrent. When there is an overcurrent, the maximum value detection circuit 13 and the dimming control amplifier 12 reduce the outputs of the LED modules 3 _{1 to} 3 _{N as} a whole.

N minimum value detecting circuit 15, of the LED module ₃ 1 to 3 _N, is used to detect the LED module that is no longer current flows by disconnection, which is connected in one-to-one with the LED module ₃ 1 to 3 _N The minimum value detection amplifier is provided. The minimum value detection circuit 15 detects only the minimum value of the current flowing through the N LED modules and outputs the detected value to the disconnection detection circuit 16. In the present embodiment, it is determined that a disconnection failure has occurred when the value falls below 70% with respect to the disconnection determination reference value. However, if it is 1% or less of the dimming range, the disconnection failure is not determined. . Further, in this embodiment, the disconnection failure of the lighting device is detected in a form including disconnection due to damage to the LED element 31 and disconnection on the cable side supplying power.

  As shown in FIG. 5, the minimum value detection circuit 15 includes N minimum value detection amplifiers and diodes connected in the reverse direction to the outputs of the N minimum value detection amplifiers. The output is connected to the ground of the minimum value detection amplifier through a detection resistor at one point. Of the N minimum value detection amplifiers, only the current of the minimum value detection amplifier with the lowest output voltage flows to the detection resistor, and the other minimum value detection amplifiers have a lower voltage on the cathode side of the diode than the input voltage. A reverse bias state occurs and no current flows. Therefore, the minimum value current signal can be detected by operating only the minimum value detection amplifier to which the minimum value voltage is input.

The disconnection detection circuit 16 determines that there is a disconnection when the minimum value (OUT-MIN) is equal to or less than the reference value (for example, −50% of the lower limit current value). When the disconnection detection circuit 16 determines that there is a disconnection, the abnormality display lamp of the remote control unit 80 blinks. At the time of disconnection, the load decreases and the current increases. However, the maximum value detection circuit 13 and the dimming control amplifier 12 reduce the outputs of the LED modules 3 _{1 to} 3 _{N as} a whole.

<Circuit protection function>
When one LED module 3 _i breaks down, the current of other normal LED modules (3 _{1 to} 3 _i-1 and 3 _{i + 1 to} 3 _N ) generally increases by that amount, and is higher than the set current. It is considered that a large amount of current flows. In the present embodiment example, even when the load condition changes, the maximum value of the current flowing through each of the LED modules 3 _{1 to} 3 _N is always adjusted to the dimming setting value, and there is no disconnection of the LED modules (3 ₁ to 3 avoid excessive current flows in the LED element 31 at 3 _i-1 and _{3 i} + 1 _{~3 N)} to an output rise suppressing control can be protected.

In Embodiment 1, as shown in FIG. 3, the determination of overcurrent and disconnection is performed by measuring the maximum value and the minimum value of the current.
As a circuit configuration for detecting the overcurrent flowing through the LED modules 3 _{1 to} 3 _N , a configuration in which the overcurrent detection circuit 14 is provided for each group can be considered, but it is necessary to provide the same number of detection circuits as the LED modules, As the circuit becomes complicated, the problem of cost increase arises. Therefore, in the first embodiment, the current flowing through each LED module is collectively monitored, and only the maximum value is detected, thereby greatly reducing the number of circuits for detecting overcurrent and solving the problem of cost increase. ing.
Similarly, regarding the disconnection of the LED modules 3 _{1 to} 3 _N , the current flowing through each LED module is collectively monitored, and only the minimum value is detected, thereby greatly reducing the number of circuits and solving the problem of cost increase. Yes.

<< Embodiment 2 >>
As shown in FIG. 6, the LED lighting device according to the second embodiment includes a circuit unit 60, a light emitting unit 70, and a remote control unit 80 as main components. The light emitting unit 70 and the remote control unit 80 constitute an LED lighting device.

The circuit unit 60 includes a substrate 63 on which the DC / DC converter 61 and the power supply control unit 62 are mounted, a blinking cycle setting switch 64, an AC / DC converter 65, and a current detection circuit 66 as main components. Is housed in a waterproof box.
The DC / DC converter 61 reduces the 144 V DC voltage supplied from a plurality of power supply devices (for example, four 240 W / 36 V power supply devices) to 126 V and supplies it to the light emitting unit 70 when the dimming setting is 100%. To do.

The power supply control unit 62 includes a PWM modulation device, a dimming control device, a disconnection determination device, an abnormality detection device, a lighting monitor device, and a pulse lighting device.
The PWM modulation device is realized by a PWM modulation circuit similar to that of the first embodiment. The LED lighting device of Embodiment 2 is also an underwater fish collecting lamp, and adjusts the total amount of light emitted by the underwater lamp between 0 and 100%. In addition, if the LED lighting apparatus of Embodiment 2 provides the support member which can attach the light emission part 70 in the air, it can also be used as an air fish collection lamp with the same circuit structure.

  The dimming control device is realized by the dimming setting circuit 11, the dimming control amplifier 12, the maximum value detection circuit 13, and the overcurrent detection circuit 14, and all the elements have the same configuration as in the first embodiment. Only the maximum value of the current value flowing through the six LED modules 71 is detected by the six maximum value detection circuits 13, and the overcurrent detection circuit 14 indicates that the maximum value is equal to or greater than the reference value (for example, + 10% of the target current value). When it becomes, it is determined that there is an overcurrent. When it is determined that there is an overcurrent, the current amount is controlled to avoid damage to the LED element 31 when an overcurrent occurs, and a warning informing the occurrence of an overcurrent is output from the remote control unit 80.

  The disconnection determination device is the same as that of the first embodiment (see FIG. 3), and is realized by the disconnection detection circuit 14 and the minimum value detection circuit 15. Only the minimum value of the current value flowing through the six LED modules 71 is detected by the six minimum value detection circuits 15, and the disconnection detection circuit 16 determines that the minimum value is less than the reference value (for example, −30% of the target current value). When it becomes, it determines with disconnection. If it is determined that there is a disconnection, the remote controller 80 outputs a warning notifying the disconnection.

  The abnormality detection device detects overcurrent, disconnection, and LED substrate temperature abnormality. When an overcurrent and a disconnection are detected, the failure lamp blinks. Further, when the LED substrate temperature rises abnormally, the thermal guard 72 operates and the failure lamp is turned on.

The lighting monitor device is for confirming the lighting status where the lighting status cannot be grasped from the ship with an underwater fish lamp used under water. In the present embodiment, the lighting display is performed in five stages of 5% or less, 20%, 40%, 60%, and 80 to 100%. In particular, when the brightness is 5% or less, the brightness of the indicator lamp is linked with the dimming control, and the brightness until the lamp is turned off can be monitored.
The pulse lighting device includes a blinking cycle setting switch 64, and can select a pulse lighting cycle from a plurality of preset pulse patterns.

  The AC / DC converter 65 includes a control power supply device for driving the power supply control unit 62 and a lighting power supply device for lighting the underwater fish collection lamp. The lighting power supply device and the control power supply device may be combined, or may be separate. In the present embodiment example, a lighting power supply device with an output of 144 V is configured by connecting three power supply devices with the same specification (rated power 240 W, DC voltage 48 V) in series, but the number of power supply devices is not limited to this, For example, 144 V output may be obtained by connecting four 36 V power supply devices in series.

The light emitting unit 70 includes six LED modules 71 including 72 LED elements, and the LED modules 71 are connected in parallel. Each LED module 71 is configured by connecting in parallel two unit series modules in which 36 LED elements are connected in series. The LED elements have a maximum current value rating of 0.7 A and a forward voltage of 3.5 V (I _f = 0.35 A), and all have the same specifications. The total luminous flux of the light emitting unit 70 is 39,000 lm, the rated power consumption is about 600 W, and the water depth is 300 m. The rated power consumption is not limited to the example, and it is technically possible to configure a power consumption in the range of 200 W to 3000 W, for example.

  The thermal guard 72 performs intermittent control for shutting down the power supply when the substrate temperature becomes high and restarting the power supply after a predetermined time has elapsed. When the thermal guard 72 is activated, the remote controller 80 outputs a warning notifying the activation of the thermal guard 72. The cable 73 has a length of 25 to 300 m, for example, and electrically connects the circuit unit 60 and the light emitting unit 70 disposed in the ship.

The remote control unit 80 is electrically connected to the circuit unit 60 and can control the circuit unit 60 and the light emitting unit 70. As described above, the remote control unit 80 outputs warnings of overcurrent, disconnection, and thermal guard operation to the dimming monitor 82, so that fishermen can know the abnormality of the circuit unit 60 and the light emitting unit 70 in the ship. It is. More specifically, a warning is displayed on the error display LED 81. In addition to this, a warning may be output by sound from a speaker. Since it is assumed that the light emitting unit 70 is located in the sea where it cannot be visually recognized, it is significant that the abnormality of the light emitting unit 70 can be known on board. Even when the light emitting unit 70 is arranged in the air, the operator of the remote control unit 80 in a place where the abnormality of the light emitting unit 70 cannot be immediately recognized can recognize the abnormality of the light emitting unit 70. (This effect is not limited to a fish lamp, but is also observed in a projector, for example).
The dimming setting volume 83 is a knob-type variable resistor, and can adjust the total amount of emitted light between 0% and 100%.

  As mentioned above, although preferable embodiment of this invention was described, the technical scope of this invention is not limited to description of the said embodiment. Various modifications / improvements can be added to the above-described embodiments, and forms to which such modifications or improvements are added are also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 3 LED module 4 Level conversion circuit 5 Low-pass filter circuit 6 DC / DC converter 7 AC / DC converter 8 PWM modulator 9 Variable constant voltage power supply 10 Dimming control circuit 11 Dimming setting circuit 12 Dimming control amplifier 13 Maximum value detection circuit 14 Overcurrent detection circuit 15 Minimum value detection circuit 16 Disconnection detection circuit 31 LED elements 41, 44, 45 Resistor 42 Current sensing amplifier 43 Transistor 51 Resistor 52 Capacitor 53 Current detection amplifier 60 Circuit unit 61 DC / DC converter 62 Power supply control unit 63 Substrate 64 Flashing cycle setting switch 65 AC / DC converter 66 Current detection circuit 70 Light emitting unit 71 LED module 72 Thermal guard 73 Cable 80 Remote control unit 81 Error display LED
82 Dimming monitor 83 Dimming setting volume

Claims (8)

A plurality of LED modules having one or a plurality of unit series modules formed by connecting a plurality of LED elements in series, and connected in parallel to each other;
A variable constant voltage power supply for supplying a DC voltage to the LED module;
A plurality of level conversion circuits which are connected to the LED modules on a one-to-one basis and convert a DC voltage supplied from the variable constant voltage power supply unit into a control target voltage;
In a LED lighting device comprising a dimming control circuit that controls a DC voltage output supplied from the variable constant voltage power supply unit and lights it with a desired light amount,
A maximum value detection circuit for detecting only the maximum value of the current flowing through the plurality of LED modules and inputting the detected value to the dimming control circuit;
The LED lighting device, wherein the dimming control circuit controls a maximum value of a current flowing through the plurality of LED modules to be substantially the same as a reference voltage.   Further, a minimum value detection circuit that detects only the minimum value of the current flowing through the plurality of LED modules, and a minimum value of the current input from the minimum value detection circuit that falls below a threshold value from the disconnection determination reference value The LED lighting device according to claim 1, further comprising a disconnection detection circuit that determines that a disconnection failure has occurred.   The LED lighting device according to claim 1, wherein the dimming control circuit collectively controls currents flowing through the plurality of LED modules.   4. The LED lighting device according to claim 1, wherein the dimming control circuit controls the light amount of the LED module by a PWM signal.   The LED illumination device according to any one of claims 1 to 4, wherein the rated power consumption is 200W to 3000W.   6. The LED lighting device according to claim 1, wherein the LED lighting device is an underwater fish collection lamp.   The LED lighting device according to claim 6, further comprising a lighting monitor device that displays the lighting status of the LED module in multiple stages. A variable constant voltage power supply for supplying a DC voltage to a plurality of LED modules connected in parallel to each other;
A plurality of level conversion circuits which are connected to the LED modules on a one-to-one basis and convert a DC voltage supplied from the variable constant voltage power supply unit into a control target voltage;
In a LED lighting device comprising: a dimming control circuit that controls a DC voltage output supplied from the variable constant voltage power supply unit and lights it with a desired amount of light;
The LED module has one or a plurality of unit series modules formed by connecting a plurality of LED elements in series,
A maximum value detection circuit for detecting only the maximum value of the current flowing through the plurality of LED modules and inputting the detected value to the dimming control circuit;
The LED lighting device, wherein the dimming control circuit controls a maximum value of a current flowing through the plurality of LED modules to be substantially the same as a reference voltage.