JP6384258B2 - LED module and LED lighting device - Google Patents

Description

  The present invention relates to an LED module and an LED lighting device.

  Patent Document 1 discloses an LED lighting device including an automatic blinking circuit. The LED lighting device includes an LED assembly connected to the output side of the rectifier circuit, an LED drive unit that controls energization to the LED assembly, and an LED drive unit that is energized based on detected LED illuminance and input voltage. Input control means for limiting the current value to be output. Further, the LED illumination device is provided with a protection circuit including a protection element and a protection switching element configured to stop the lighting of the LED assembly by detecting a temperature abnormality inside the LED illumination device. As the protective element, a PTC thermistor or the like whose electric resistance increases at a high temperature is used. If the resistance value of the protection element rises when the temperature in the LED lighting device rises abnormally, the protection switching element is switched from OFF to ON, thereby turning off the lighting of the LED unit by the LED driving means. Composed.

JP 2012-139971 A

  However, according to the configuration of Patent Document 1, the LED circuit that constitutes the LED unit, the lighting circuit that constitutes the LED driving means, and the protection circuit for protecting them are integrally formed. Therefore, when the above protection circuit is applied to a configuration in which the LED module and the lighting device (power supply device) are separately provided, a large number of complicated wirings are required between the LED module and the lighting device. It is not an effective implementation. Furthermore, the above protection circuit cannot be applied to an LED module that is connected to an existing lighting device later.

  Therefore, the present invention provides an LED module and an LED lighting device that are configured independently of a lighting device, and a configuration that enables abnormal protection of the LED module or the lighting device without requiring separate wiring with the lighting device. The issue is to provide.

  An LED module having first and second terminals according to the first aspect of the present invention is connected between an LED having an anode end connected to the first terminal and between the cathode end of the LED and the second terminal. Switch element, a temperature detection circuit for detecting the temperature of the LED module, and a switch element that conducts when the detected temperature detected by the temperature detection circuit is less than the threshold, and when the detected temperature exceeds the threshold And a control circuit configured to open the circuit.

  The LED module includes a switch element connected in series to the LED, a temperature detection circuit that detects the temperature of the LED module, and a switch element that conducts when the detected temperature is lower than a predetermined value, and the detected temperature is equal to or higher than the predetermined value. A control circuit configured to open the switch element is provided. Accordingly, in the LED module configured independently from the lighting device, it is possible to protect the LED module or the lighting device connected to the LED module without requiring separate wiring between the lighting device and the lighting device.

  An LED lighting device including an LED module having a first terminal and a switch module having a second terminal according to the second aspect of the present invention is included in the LED module, and an anode end is connected to the first terminal. An LED, a switch element included in the switch module and connected between the cathode end of the LED and the second terminal, and a temperature detection element, configured to detect the temperature of the LED module, and at least temperature detection When the element is included in the LED module and the remaining part is included in the switch module, and the detected temperature detected by the temperature detection circuit is lower than the threshold, the switch element is made conductive, and the detected temperature is equal to or higher than the threshold. Is configured so that the switch element is opened, all or a part is included in the switch module, and the remaining part is And a control circuit included in the ED module.

  According to the LED module, an LED module including an LED and a temperature detection element and a switch module including a switch element connected to the LED are provided. A control circuit configured to turn on the switch element when the temperature detected by the temperature detection element is lower than the predetermined value and to open the switch element when the detected temperature is equal to or higher than the predetermined value is provided with the LED module and the switch. It is distributed and mounted on modules as appropriate. As a result, in an LED lighting device including an LED module configured independently of the lighting device, it is possible to protect the LED module or the lighting device connected to the LED module without requiring separate wiring between the lighting device and the LED lighting device. It becomes. In addition, the above-described effects can be obtained with a simple additional configuration even for an existing LED module in which only LEDs are mounted.

  In the LED module of the first form or the LED lighting device of the second form, the control circuit includes a thyristor, and the anode terminal of the thyristor is connected to the control terminal of the switch element and connected to the first terminal via a resistor. It is preferable that the thyristor be connected by a circuit in which the cathode terminal of the thyristor is connected to the second terminal and the voltage to the second terminal rises when the detected temperature becomes equal to or higher than the threshold. According to this configuration, when the detected temperature rises abnormally, a holding current flows through the thyristor and the conduction state is maintained. Therefore, the non-conduction state of the switch element, that is, the protection state by turning off the LED is maintained, and the progress of the abnormality or the failure can be surely prevented.

  In addition, the control circuit includes a transistor, the collector terminal of the transistor is connected to the control terminal of the switch element and is connected to the first terminal via a resistor, and the emitter terminal of the transistor is connected to the second terminal, It may be configured such that the transistor is turned on by a circuit in which the voltage to the second terminal rises when the temperature becomes equal to or higher than a threshold value. According to this configuration, when the abnormality is eliminated after the occurrence of the abnormality, the conduction of the switch element, that is, the lighting of the LED can be restored.

  The control circuit includes first and second transistors, the collector terminal of the first transistor is connected to the control terminal of the switch element, and is connected to the first terminal via the first resistor. The emitter terminal of the first transistor is connected to the second terminal via the second resistor, the base terminal of the first transistor is connected to the collector terminal of the second transistor, and the first terminal via the third resistor. And the emitter terminal of the second transistor is connected to the emitter terminal of the first transistor, and the second transistor is turned on by a circuit in which the voltage to the second terminal decreases when the detected temperature becomes equal to or higher than the threshold value. You may comprise as follows. According to this configuration, the return characteristics from the LED turn-off operation to the turn-on return operation can be set as appropriate.

It is a block diagram which shows the LED module by the 1st Embodiment of this invention. It is a figure which shows the circuit structure of the LED module in 1st Embodiment. It is a block diagram which shows the LED lighting apparatus by the 2nd Embodiment of this invention. It is a figure which shows the circuit structural example of the LED lighting apparatus in 2nd Embodiment. It is a figure which shows the circuit structural example of the LED lighting apparatus in 2nd Embodiment. It is a figure which shows the alternative circuit structural example of the LED lighting apparatus in 2nd Embodiment. It is a figure which shows the circuit structure of the LED module by the modification of this invention. It is a figure which shows the circuit structure of the LED module by the modification of this invention. It is a figure which shows the circuit structure of the LED module by the modification of this invention.

<First Embodiment>
FIG. 1 shows a block diagram of an LED module 1 according to the first embodiment of the present invention. The LED module 1 is placed separately from the lighting device (power supply device or ballast) 5. The LED module 1 has a high potential side terminal T1 and a low potential side terminal T2. The terminals T1 and T2 are respectively connected to the high potential output terminal T3 and the low potential output terminal T4 of the lighting device 5 via wirings W1 and W2. Connected. The lighting device 5 may be an AC / DC converter that receives an AC power supply such as a commercial power supply and outputs a desired DC current (LED current), or a DC power supply such as a battery that inputs a desired DC current. It may be a DC / DC converter that outputs (LED current). That is, a direct current from the lighting device 5 is supplied to the LED module 1.

  The LED module 1 includes an LED 10, a switch element 20, a temperature detection circuit 30, and a control circuit 40 between terminals T1 and T2. These circuit elements are mounted on the same substrate, for example. The classification of which circuit element each circuit belongs to is for convenience of explanation and does not restrict the present invention.

  FIG. 2 shows a circuit configuration of the LED module 1. Hereinafter, a circuit wiring having substantially the same potential as the terminal T1 is referred to as a line L1, and a circuit wiring having approximately the same potential as the terminal T2 is referred to as a line L2. The terminals T1 and T2 mean nodes where the wirings W1 and W2 are connected to the LED module 1, and may be configured by connectors, sockets, or the like, or may be nodes arranged on the substrate. .

  The LED 10 includes an LED array in which a plurality of LED elements 11 are connected in series, and an anode end of the LED 10 is connected to a terminal T1, that is, a line L1. In addition, said LED array may be one in which a plurality of LED elements 11 are connected in series and parallel.

  The switch element 20 is connected in series to the LED 10 and is composed of an NPN-type MOSFET in this embodiment. Specifically, the drain terminal (input terminal) of the switch element 20 is connected to the cathode end of the LED 10, the source terminal (output terminal) is connected to the terminal T2, that is, the line L2, and the gate terminal (control terminal) will be described later. Connected to the control circuit 40. The switch element 20 may be an IGBT or the like. In this case, the input terminal is a collector terminal and the output terminal is an emitter terminal. Hereinafter, the switch element 20 is also referred to as an FET 20 as necessary. Further, in this specification, for semiconductor switch elements such as FETs, transistors, thyristors, and diacs, “conducting” and “on” are substantially synonymous, and “non-conducting”, “off”, and “opening” are assumed. Are also substantially synonymous.

  The temperature detection circuit 30 includes a series circuit of a resistor 31 and a PTC (positive characteristic) thermistor 32 that is a temperature detection element. The resistor 31 is connected to the line L1, the PTC thermistor 32 is connected to the line L2, and the voltage between the lines L1 and L2 is divided by the resistor 31 and the PTC thermistor 32. When the ambient temperature (main body temperature) rises, the resistance value and both-ends voltage of the PTC thermistor 32 rise, and thereby the temperature rise of the LED module 1 is detected. The temperature of the LED module 1 may be the temperature of the circuit board or the ambient temperature in the vicinity of the LED 10. In addition, when the LED module 1 is included in the housing, the temperature of the LED module 1 may be any temperature inside or outside the housing.

  The control circuit 40 includes a thyristor 41, resistors 42, 45 and 47, a diac 43, a Zener diode 44, and a capacitor 46. The anode terminal of the thyristor 41 is connected to the gate terminal of the FET 20, and is connected to the line L1 through the resistor 42, and the cathode terminal is connected to the line L2. The control terminal of the thyristor 41 is connected to one end of the diac 43, and the other end of the diac 43 is connected to the connection point of the resistor 31 and the PTC thermistor 32. When the voltage of the PTC thermistor 32 rises with respect to the line L2 and the diac 43 is turned on, the thyristor 41 becomes conductive. A Zener diode 44 and a resistor 45 are connected in parallel to the gate-source of the FET 20 to optimize the gate-source voltage when the thyristor 41 is non-conductive. The capacitor 46 and the resistor 47 optimize the input voltage and current from the output part of the temperature detection circuit 30 to the control terminal of the thyristor 41 and the operating conditions of the diac 43. Instead of the diac 43, other switch elements such as a Zener diode can be used.

  Below, operation | movement of the LED module 1 is demonstrated. As a general rule, the control circuit 40 causes the switch element 20 to conduct when the detected temperature detected by the temperature detection circuit 30 is less than the abnormal threshold value (during normal lighting), and when the detected temperature becomes equal to or higher than the abnormal threshold value (abnormal). At the time of occurrence), the switch element 20 is opened. That is, the LED module 1 turns on the LED 10 when it is normally lit, and shuts off the LED 10 by cutting off the current path to the LED 10 when it is abnormal.

The following is mainly assumed as a cause that the detected temperature becomes equal to or higher than the abnormal threshold in the LED module 1 (in particular, the LED 10).
First, when an abnormality occurs in the output current control (for example, constant current control) of the lighting device 5 and an output current exceeding the rated current of the LED 10 is input to the LED 10, an abnormal temperature rise occurs in the LED module 1. Can occur.
Second, when the LED module 1 is set to be turned on only at night, but the LED 10 is turned on during the day due to a failure of the automatic flasher separately connected to the lighting device 5, the LED An abnormal temperature rise can occur in the module 1.
Third, when the terminal T1 or T2 (or wiring W1 or W2) of the LED module 1 is not correctly connected to the output terminal of the lighting device 5 (for example, when connected to the input terminal of the lighting device 5), A current or voltage exceeding the rating of the LED 10 is input to the LED 10, and an abnormal temperature increase may occur in the LED module 1.
Fourth, when the LED module 1 is connected to a lighting device (HID ballast, copper iron ballast, LED power supply device with an excessive rated current, rated voltage, or rated power, etc.) that is not compatible with the LED module 1, Current, voltage, or power exceeding the rating may be input to the LED 10, and an abnormal temperature increase may occur in the LED module 1.
In the state where the first to fourth abnormalities occur, the LED module 1 or the lighting device 5 or both may fail.

  At the time of normal lighting, that is, when the detected temperature is lower than the abnormal threshold, the resistance value of the PTC thermistor 32 and the voltage between both ends thereof are relatively low. In this case, the voltage applied to the diac 43 is equal to or lower than the breakdown voltage of the diac 43, and the diac 43 is maintained in the off state. As a result, no current flows through the control terminal of the thyristor 41, and the thyristor 41 is maintained in a non-conductive state. Therefore, the voltage between both ends of the resistor 45 among the voltages obtained by dividing the voltage between the lines L1 and L2 by the resistors 42 and 45 (the clamp voltage when clamped by the Zener diode 44, the same applies hereinafter) is the gate − Applied between source terminals. As a result, the FET 20 is maintained in a conductive state.

  On the other hand, when the detected temperature becomes equal to or higher than the abnormal threshold value at the time of abnormality, the resistance value of the PTC thermistor 32 and the voltage at both ends thereof (that is, the voltage with respect to the line L2) increase. Then, the voltage applied to the diac 43 exceeds the breakdown voltage of the diac 43, and the diac 43 is turned on. As a result, a current flows through the control terminal of the thyristor 41, and the thyristor 41 becomes conductive. Therefore, the gate-source voltage of the FET 20 becomes substantially zero, and the FET 20 is turned off. Then, the current flowing from the resistor 42 via the thyristor 41 to the line L2 becomes the holding current of the thyristor 41, and the conduction state of the thyristor 41 and the non-conduction state of the FET 20 are maintained. This non-conduction state of the FET 20 is continued until the power supply from the lighting device 5 to the LED module 1 is stopped and restarted. According to this configuration, the conduction state of the thyristor 41 is latched at the time of abnormality, and the non-conduction state of the switch element 20, that is, the protection state by turning off the LED 10, is maintained, and the development of abnormality or failure can be reliably prevented.

  As described above, according to the present embodiment, the switch element 20 connected in series to the LED 10, the temperature detection circuit 30 that detects the temperature of the LED module 1, and the switch element 20 when the detected temperature is less than a predetermined value. The LED module 1 is provided with a control circuit 40 configured to be electrically connected and to open the switch element 20 when the detected temperature is equal to or higher than a predetermined value. Thereby, in the LED module 1 configured independently from the lighting device 5, a configuration is provided in which the LED module 1 or the lighting device 5 can be protected from abnormality without requiring a separate wiring with the lighting device 5. .

<Second Embodiment>
In the first embodiment, the LED module, the switch element 20, the temperature detection circuit 30, and the control circuit 40 are included in the LED module. However, in the present embodiment, the above components are dispersed in the LED module and the switch module. The structure arrange | positioned is shown. FIG. 3 is a block diagram of the LED lighting device 4 including the LED module 2 and the switch module 3 according to the present embodiment. In the present embodiment, the same reference numerals are given to substantially the same components as those in the first embodiment, and detailed description thereof will be omitted.

  The LED module 2 has a terminal T1 on the high potential side, and the terminal T1 is connected to the high potential output terminal T3 of the lighting device 5 via the wiring W1. The switch module 3 has a terminal T2 on the low potential side, and the terminal T2 is connected to the low potential output terminal T4 of the lighting device 5 via the wiring W2. In this way, the LED lighting device 4 is provided separately from the lighting device 5. In this embodiment, the LED module 2 and the switch module 3 are mutually connected by each wiring mentioned later. Alternatively, the LED module 2 and the switch module 3 may be connected by a connector or the like and integrally formed.

  The LED module 2 includes an LED 10 and a portion including at least a PTC thermistor 32 of the temperature detection circuit 30 (hereinafter referred to as “temperature detection circuit 30 ′”). The LED 10 and the temperature detection circuit 30 ′ are mounted on the substrate B 1 of the LED module 2. The switch module 3 includes the switch element 20, the part (if any) of the temperature detection circuit 30 other than the temperature detection circuit 30 ', and all or part of the control circuit 40 (hereinafter referred to as "control circuit 40'"). Including. The switch element 20 and the control circuit 40 ′ are mounted on the substrate B2 of the switch module 3. In addition, when there exists the remaining part which is not contained in control circuit 40 'among the control circuits 40, the part is mounted in board | substrate B1. In other words, the main part of the temperature detection circuit 30 is included in the LED module 2 as the temperature detection circuit 30 ′, and the main part of the control circuit 40 is included in the switch module 3 as the control circuit 40 ′. The PTC thermistor 32 may be fixed by being soldered to the substrate B1, or may be fixed without being soldered.

  4A and 4B show examples of the circuit configuration of the LED lighting device 4. FIG. As shown in FIG. 4A or 4B, the LED 10 and the PTC thermistor 32 (temperature detection circuit 30 ′) are mounted on the substrate B1, and the switch element 20, the resistor 31, and the control circuit 40 are mounted on the substrate B2. . In the board B1, the PTC thermistor 32 is not electrically connected to any circuit, but the component main body is mounted or disposed on the board B1. Then, the temperature of the LED module 2 detected by the PTC thermistor 32 included in the LED module 2 and the resistor 31 included in the switch module 3 is input to the control circuit 40.

  In the example shown in FIG. 4A, the LED module 2 is connected to the switch module 3 by wirings W3 to W6. The cathode end of the LED 10 is connected to the drain terminal of the FET 20 via the terminal T31-wiring W3-terminal T32, and the line L1 is connected to the resistors 31 and 42 via the terminal T41-wiring W4-terminal T42. The high potential side terminal of the PTC thermistor 32 is connected to the connection point of the diac 43 and the resistor 31 via the terminal T51-wiring W5-terminal T52, and the low potential side terminal of the PTC thermistor 32 is terminal T61-wiring W6-terminal. Connected to line L2 via T62.

  In the example shown in FIG. 4B, the LED module 2 is connected to the switch module 3 by wirings W3 to W6, but the configuration of the wiring W4 is different from the example of FIG. 4A. In the example of FIG. 4B, the wiring W4 is directly connected between the terminal T1 and the terminal T42, for example, outside the LED module 2 (that is, without passing through the inside). In this case, the terminal T41 is unnecessary.

  By such component distribution, the LED module 2 including the LED 10 and the PTC thermistor 32 and the switch module 3 including the switch element 20, the resistor 31, and the control circuit 40 are connected with relatively few wires and terminals. Moreover, the LED module 2 thru | or the LED illumination apparatus 4 can be comprised only by adding a simple structure also to the existing LED module in which LED10 was only mounted. In particular, when the PTC thermistor 32 is not soldered to the substrate B1 and the wiring W4 is directly connected to the terminal T1 (FIG. 4B), the wiring pattern on the substrate of the existing LED module on which only the LED 10 is mounted. Is preferable in terms of substrate cost management.

  As an alternative example, as shown in FIG. 5, the LED 10, the temperature detection circuit 30 and the resistor 42 are mounted on the LED module 2 (board B <b> 1), and the switch element 20 and the control are mounted on the switch module 3 (board B <b> 2). A portion (control circuit 40 ′) other than the resistor 42 of the circuit 40 may be mounted.

  In this case, the LED module 2 is connected to the switch module 3 by the wirings W3 and W6 to W8. 4A and 4B, the cathode end of the LED 10 is connected to the drain terminal of the FET 20 via the terminal T31-wiring W3-terminal T32, and the low-potential side terminal of the PTC thermistor 32 is connected to the terminal T61-wiring W6. -It is connected to the line L2 via the terminal T62. Then, as shown in FIG. 5, the resistor 42 is connected to the circuit wiring on the anode side of the thyristor 41 via the terminal T71-wiring W7-terminal T72, and the high potential side terminal of the PTC thermistor 32 is connected to the terminal T81-wiring W8. -It is connected to the diac 43 via the terminal T82.

  In this distribution, between the LED module 2 (substrate B1) and the switch module 3 (substrate B2), the only wiring to which the potential of the high potential line L1 can be applied is the wiring W3 (when the switch element 20 is non-conductive). ), A low voltage circuit is formed as a whole on the substrate B2. Thereby, the insulation design in the switch module 3 becomes relatively easy.

  Each of the above terminals T31 to T82 means a node to which the associated wiring is connected to each module, and may be constituted by a connector, a socket, or the like, or an insertion hole provided in each module. Alternatively, a node provided on each substrate may be used.

  Regarding the operation of the LED lighting device 4, the circuit configuration of the LED lighting device 4 is the same as the circuit configuration of the LED module 1 (FIG. 2) of the first embodiment. Therefore, the operation of the LED lighting device 4 is also described in the first embodiment. The operation is the same as that of the module 1.

  As described above, the LED lighting device 4 according to the present embodiment includes the LED module 2 including at least the temperature detection element 31 of the LED 10 and the temperature detection circuit 30, and the switch module 3 including the switch element 20 connected to the LED 10. Prepare. A control circuit 40 configured to cause the switch element 20 to conduct when the detected temperature is lower than the predetermined value and to open the switch element 20 when the detected temperature is equal to or higher than the predetermined value is provided between the LED module 2 and the switch. The module 3 is appropriately distributed and mounted. Thereby, in the LED lighting device 4 including the LED module 2 configured independently from the lighting device 5, it is possible to protect the LED module 2 or the lighting device 5 from abnormality without requiring a separate wiring with the lighting device 5. Configuration is provided. In addition, the above-described effects can be obtained with a simple additional configuration even for an existing LED module in which only LEDs are mounted.

<Modification>
Although preferred embodiments of the present invention have been described above, the present invention can be modified into various modes as shown below, for example. Modifications 1 and 2 below relate to the control circuit 40, and Modifications 3 and 4 relate to the temperature detection circuit 30. These modified examples 1 or 2 and modified examples 3 or 4 can be combined with each other unless otherwise specified.

(1) Modification 1 (Modification of the control circuit 40)
In each of the above embodiments, the thyristor 41 is used as a control switch element in the control circuit 40. However, a transistor may be used instead of the thyristor 41. Thereby, when the detected temperature becomes equal to or higher than the abnormal threshold and then returns to less than the abnormal threshold, the LED 10 can be turned on again. FIG. 6 shows an LED module 1 having a control circuit 40 according to this modification. In this modification, substantially the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, the control circuit 40 includes a transistor 48, the collector terminal of the transistor 48 is connected to the gate terminal of the FET 20, the emitter terminal is connected to the line L <b> 2, and the base terminal is connected to the diac 43. Note that a gate resistor may be added as appropriate to the transistor 48, or the transistor 48 may be a transistor with a built-in resistor.

  During normal lighting, that is, when the detected temperature is less than the abnormal threshold value, the resistance value of the PTC thermistor 32 and the voltage between both ends thereof are relatively low, and the diac 43 is maintained in the off state. Therefore, no current flows through the base terminal of the transistor 48, and the transistor 48 is kept off. As a result, the voltage across the resistor 45 among the voltages obtained by dividing the voltage between the lines L1 and L2 by the resistors 42 and 45 is applied between the gate and the source of the FET 20, and the FET 20 is maintained in a conductive state.

  On the other hand, when the abnormality occurs and the detected temperature becomes equal to or higher than the abnormality threshold value, the resistance value of the PTC thermistor 32 and the voltage at both ends thereof (voltage with respect to the line L2) are increased, and the diac 43 is turned on. Accordingly, current flows through the base terminal of the transistor 48, and the transistor 48 is turned on. As a result, the gate-source voltage of the FET 20 becomes substantially zero, and the FET 20 is turned off. Thereafter, when the detected temperature returns below the abnormal threshold value and the resistance value of the PTC thermistor 32 and the voltage at both ends thereof decrease, the above-described operating state during normal lighting is obtained again.

  Thus, according to the configuration of the present modification, when the abnormality is eliminated after the abnormality occurs, the conduction state of the switch element 20, that is, the lighting of the LED 10 can be restored. In addition, although this modification was demonstrated as a modification of the LED module 1 of 1st Embodiment, the structure of this modification is applicable also to the LED lighting apparatus 4 of 2nd Embodiment. In this case, it is only necessary to replace the thyristor 41 with the transistor 48 in the circuit arrangement shown in FIG.

(2) Modification 2 (Modification of the control circuit 40)
In each of the above embodiments, the thyristor 41 is used as a control switch element in the control circuit 40. However, a Schmitt trigger circuit using a transistor may be used instead of the thyristor 41. Thereby, hysteresis can be given to the lighting return operation of the LED 10 with respect to the temperature change detected by the temperature detection circuit 30. FIG. 7 shows an LED module 1 having a control circuit 40 according to this modification. In this modification, substantially the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 7, the temperature detection circuit 30 includes a series circuit of a PTC thermistor 33 and a resistor 34. The PTC thermistor 33 is connected to the line L1, and the resistor 34 is connected to the line L2. When the ambient temperature rises, the resistance value and both-end voltage of the PTC thermistor 33 increase, and the both-end voltage of the resistor 34 decreases, thereby detecting the temperature rise of the LED module 1.

  The control circuit 40 includes transistors 49 and 50 and resistors 51 and 52 instead of the thyristor 41. The collector terminal of the transistor 49 is connected to the gate terminal of the FET 20 and to the line L1 through the resistor 42. The emitter terminal of the transistor 49 is connected to the line L2 via the resistor 51. The base terminal of the transistor 49 is connected to the collector terminal of the transistor 50 and to the line L1 through the resistor 52. The emitter terminal of the transistor 50 is connected to the emitter terminal of the transistor 49, and the base terminal is connected to the diac 43.

  During normal lighting, that is, when the detected temperature is less than the abnormal threshold, the resistance value and the voltage at both ends of the PTC thermistor 33 are relatively low, so the voltage generated at the resistor 34 is relatively high, and the diac 43 is in the on state. Maintained. Accordingly, a current flows through the base terminal of the transistor 50, and the transistor 50 is maintained in the on state. Thus, no current flows through the base terminal of the transistor 49, and the transistor 49 is maintained in an off state. Therefore, the voltage across the resistor 45 among the voltages obtained by dividing the voltage between the lines L1 and L2 by the resistor 42 and the resistor 45 is applied between the gate and source terminals of the FET 20. As a result, the FET 20 is maintained in a conductive state.

  On the other hand, when the abnormality occurs and the detected temperature becomes equal to or higher than the abnormality threshold, the resistance value of the PTC thermistor 33 and the voltage at both ends increase, so the voltage generated in the resistor 34 (voltage with respect to the line L2) decreases and the diac 43 turns off. It becomes a state. Therefore, no current flows through the base terminal of the transistor 50, and the transistor 50 is turned off. Accordingly, current flows through the base terminal of the transistor 49, and the transistor 49 is turned on. Therefore, the voltage across the resistors 45 and 51 among the voltages obtained by dividing the voltage between the lines L1 and L2 by the parallel circuit of the resistor 42 and the resistors 45 and 51 is applied between the gate and source terminals of the FET 20. In addition, each resistance value shall be set so that the both-ends voltage of resistance 45 and 51 at this time may become lower than the ON threshold value of FET20. Thereby, the FET 20 is turned off.

  Here, the transistor 49 is changed from the on state to the off state (the FET 20 is turned off from the conductive state) rather than the output of the diac 43 required for the transistor 49 to shift from the off state to the on state (FET 20 is turned on from the conductive state). The output of the diac 43 necessary for shifting is larger. Therefore, after the detected temperature exceeds the abnormal threshold and the LED 10 is turned off, the lighting of the LED 10 is restored after the detected temperature has decreased by a predetermined amount or more. This predetermined amount (hysteresis amount) is determined by appropriately setting the values of the resistors 42, 51 and 52.

  Thus, according to the configuration of the present modification, the interval from the turn-off operation of the LED 10 to the turn-on return operation can be set to a desired length. In addition, although this modification was demonstrated as a modification of the LED module 1 of 1st Embodiment, the structure of this modification is applicable also to the LED lighting apparatus 4 of 2nd Embodiment. In this case, the circuit (LED 10 and PTC thermistor 33) above the broken line A in FIG. 7 is included in the LED module 2 (substrate B1), and the circuit below the broken line A (switch element 20, resistor 34 and control circuit 40). Is included in the switch module 3 (substrate B2). As shown in FIG. 7, since there are only three circuit lines separated by the broken line A, the LED module 2 and the switch module 3 can be connected with fewer lines.

(3) Modification 3 (Deformation of temperature detection element)
In each of the above embodiments, the PTC thermistor is used as the temperature detection element of the temperature detection circuit 30. However, an NTC (negative characteristic) thermistor whose resistance value decreases as the ambient temperature (main body temperature) increases may be used. In this case, for example, as shown in FIG. 8, the NTC thermistor 35 is connected to the line L1, the resistor 36 is connected between the NTC thermistor 35 and the line L2, and the connection point of the NTC thermistor 35 and the resistor 36 is connected to the diac 43. Connected. The circuit operation of this modification is substantially the same as the circuit operation described in the first embodiment.

  In addition, although this modification was demonstrated as a modification of the LED module 1 of 1st Embodiment, the structure of this modification is applicable also to the LED lighting apparatus 4 of 2nd Embodiment. In this case, as shown in FIG. 8, the circuit (LED 10 and NTC thermistor 35) above the broken line B is included in the LED module 2 (substrate B1), and the circuit below the broken line B (switch element 20, resistor 36 and A control circuit 40) is included in the switch module 3 (substrate B2). Alternatively, as shown in FIG. 8, a circuit (LED 10, NTC thermistor 35 and resistor 42) above the broken line C is included in the LED module 2 (substrate B1), and a circuit below the broken line C (switch element 20, resistor). 36 and the remaining part of the control circuit 40) may be included in the switch module 3 (substrate B2). In either case, as shown in FIG. 8, since there are only three circuit wirings divided by the broken line B or C, the LED module 2 and the switch module 3 can be connected with fewer wirings.

(4) Modification 4 (Deformation of temperature detection element)
In each of the above embodiments, a return type element (PTC thermistor) is used as the temperature detection element of the temperature detection circuit 30. On the other hand, for the purpose of protecting only the lighting device 5, that is, assuming that the LED module 1 or 2 in which an abnormality has been detected once is not reused, a non-recoverable type such as a temperature fuse may be used as the temperature detection element. . When using a thermal fuse, the operating temperature of the thermal fuse is set to the abnormal threshold. In each embodiment, when a temperature fuse is used instead of the PTC thermistor 32, when the temperature of the LED module 1 or 2 reaches the above operating temperature, the temperature fuse is blown, and as a result, the thyristor 41 is turned on, and the switch element 20 is turned on. Turned off. Thereafter, regardless of the power supply state from the lighting device 5 to the LED module 1 or 2, the switch element 20 is in a non-conductive state, and the LED 10 is continuously turned off. Since this modification is premised on a non-recoverable protection operation, a configuration using a thyristor 41 (each embodiment) as a control switch element in the control circuit 40 or a transistor 48 (modification 1) It is desirable to adopt a configuration using

1, 2 LED module 3 Switch module 4 LED lighting device 10 LED
20 switch element 30 temperature detection circuit 31, 34, 36 resistance 32, 33 PTC thermistor (temperature detection element)
35 NTC thermistor (temperature detection element)
40 control circuit 41 thyristor 42, 45, 47, 51, 52 resistor 43 diac 48, 49, 50 transistor T1, T2 terminals

Claims (8)

A first terminal and a second terminal that are separately provided from a lighting device including an AC / DC converter or a DC / DC converter that outputs a direct current, and to which the direct current is supplied from the lighting device through only two wires. An LED module comprising:
An LED having an anode connected to the first terminal;
A switching element connected between the cathode end of the LED and the second terminal;
A temperature detection circuit for detecting the temperature of the LED module;
A control circuit configured to conduct the switch element when the detected temperature detected by the temperature detection circuit is less than a threshold value, and to open the switch element when the detected temperature is equal to or higher than the threshold value; Bei example, the LED, the switching element, the temperature detection circuit and the control circuit are mounted on the same substrate, L ED module. The LED module according to claim 1, wherein the control circuit includes a thyristor,
The anode terminal of the thyristor is connected to the control terminal of the switch element and connected to the first terminal via a resistor, the cathode terminal of the thyristor is connected to the second terminal, and the detected temperature is An LED module configured such that the thyristor is turned on by a circuit in which a voltage to the second terminal rises when a threshold value is exceeded. The LED module according to claim 1, wherein the control circuit includes a transistor,
The collector terminal of the transistor is connected to the control terminal of the switch element and connected to the first terminal via a resistor, the emitter terminal of the transistor is connected to the second terminal, and the detected temperature is An LED module configured such that the transistor is turned on by a circuit in which a voltage with respect to the second terminal increases when a threshold value is exceeded. 2. The LED module according to claim 1, wherein the control circuit includes first and second transistors,
The collector terminal of the first transistor is connected to the control terminal of the switch element and connected to the first terminal via a first resistor, and the emitter terminal of the first transistor has a second resistor. The base terminal of the first transistor is connected to the collector terminal of the second transistor and is connected to the first terminal via a third resistor, The emitter terminal of the second transistor is connected to the emitter terminal of the first transistor, and the second transistor is turned on by a circuit in which the voltage with respect to the second terminal decreases when the detected temperature is equal to or higher than the threshold value. LED module configured in Is separately installed from the lighting apparatus including an AC / DC converter or DC / DC converter outputs a DC current, Bei give a switch module having an LED module and a second terminal having a first terminal, two from the lighting device An LED illuminating device in which the direct current is supplied to the first and second terminals only through the wiring of
The LED module includes a first substrate; the switch module includes a second substrate;
Is mounted on the first substrate, an LED anode end is connected before Symbol first terminal,
Is mounted on the second substrate, a switching element connected between the cathode terminal of the previous SL LED said second terminal,
Has a temperature detecting element, wherein being configured to detect the temperature of the LED module is mounted on at least the temperature sensing element is the first substrate, the temperature of the portion of Balance is mounted on the second substrate A degree detection circuit;
The switch element is made conductive when the detected temperature detected by the temperature detection circuit is lower than a threshold value, and is opened when the detected temperature is equal to or higher than the threshold value. There wherein is mounted on the second substrate, LED lighting device and a control circuit portion of Balance is mounted on the first substrate. The LED lighting device according to claim 5, wherein the control circuit includes a thyristor,
The anode terminal of the thyristor is connected to the control terminal of the switch element and connected to the first terminal via a resistor, the cathode terminal of the thyristor is connected to the second terminal, and the detected temperature is An LED lighting device configured such that the thyristor is turned on by a circuit in which a voltage to the second terminal rises when a threshold value or more is reached. 6. The LED lighting device according to claim 5, wherein the control circuit includes a transistor,
The collector terminal of the transistor is connected to the control terminal of the switch element and connected to the first terminal via a resistor, the emitter terminal of the transistor is connected to the second terminal, and the detected temperature is An LED lighting device configured such that the transistor is turned on by a circuit in which a voltage with respect to the second terminal increases when a threshold value is exceeded. The LED lighting device according to claim 5, wherein the control circuit includes first and second transistors,
The collector terminal of the first transistor is connected to the control terminal of the switch element and connected to the first terminal via a first resistor, and the emitter terminal of the first transistor has a second resistor. The base terminal of the first transistor is connected to the collector terminal of the second transistor and is connected to the first terminal via a third resistor, The emitter terminal of the second transistor is connected to the emitter terminal of the first transistor, and the second transistor is turned on by a circuit in which the voltage with respect to the second terminal decreases when the detected temperature is equal to or higher than the threshold value. LED lighting device constructed in

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