JP2010030414A - Constant current light emitting device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constant current light emitting device for a vehicle decreasing operating temperature. <P>SOLUTION: A current restricting means 2 includes: a first switch Q1 to establish electrical continuity/discontinuity between a light emitting means 1 and a power source 4; a first bias section which is electrically connected to the first switch and activates the first switch to establish electrical continuity between the power source and the light emitting means when a driving voltage V1 is supplied to the power source, and generates current flowing from the power source to the light emitting means and the first switch, so that the light emitting means is electrically connected to the power source so as to be activated; a second switch Q2 electrically connected to the first switch; and a second bias section which is electrically connected to the second switch and activates the second switch when the current flowing through the first switch exceeds a predetermined threshold value, and causes electrical continuity action of the second switch to be exerted on the first switch thereby to perform switching to discontinue the electrical continuity between the light emitting means and the power source, thereby turning off the current flowing through the light emitting means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light emitting element, and more particularly, to a constant current light emitting device for a vehicle.

  Conventionally, for example, in vehicle lighting, a battery is used as a power source. However, since the battery voltage cannot be maintained at a constant level, in order to use the battery power source as vehicle lighting, the voltage must be rectified to stabilize the voltage. .

  As shown in FIG. 3, the conventional constant voltage light emitting device for a vehicle is electrically connected to a power source 61 of the vehicle, and includes a rectifier 62 electrically connected to the power source 61 and a surge suppressor 63. And a light emitting unit 64 and a voltage adjusting unit 65 connected between the light emitting unit 64 and the rectifier 62. The light emitting unit 64 includes a plurality of light emitting elements D, D,... And a plurality of current limiting resistance elements R1, R1,. The light emitting elements D, D,... Are formed by arranging a series of light emitting element pairs D, D in parallel.

  The voltage adjustment unit 65 includes a constant voltage integrated circuit IC, two resistance elements R2 and R2, and a capacitance element C, and functions to stabilize the drive voltage from the power supply 61 before supplying power to the light emitting unit 64. .

  In the light emitting device, since the power supply 61 is unstable, when the driving voltage varies, the voltage adjusting unit 65 can adjust the driving voltage value to an appropriate value and supply a stable current to the light emitting unit 64. Since the voltage adjusting unit 65 must be continuously adjusted according to the fluctuation of the drive voltage, there is a problem that the operating temperature becomes high, and the operation stability and the service life of the voltage adjusting unit 65 are reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle constant current light emitting device capable of realizing a reduction in operating temperature.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a constant current light emitting device for a vehicle to which a driving voltage (V1) is inputted from a power source (4), the light emitting means (1) and a current limiting device. The light emitting means (1) includes at least one light emitting module (11) including a light emitting element (D), and the current limiting means (2) includes the light emitting means (1). ) And the power source (4) are electrically connected to and disconnected from the first switch (Q1) and the first switch (Q1), and are connected to the power source (4). When the drive voltage (V1) is supplied, the first switch (Q1) is operated so that the power supply (4) and the light emitting means (1) are electrically connected, and the light emission from the power supply (4). A current flowing through the means (1) and the first switch (Q1), A first bias unit that causes the light emitting means (1) to be electrically connected to the power source (4) so as to operate the light means (1), and an electric current to the first switch (Q1). Connected to the second switch (Q2), the first switch (Q1) and the second switch (Q2), and flows to the first switch (Q1). When the current exceeds a predetermined threshold value, the second switch (Q2) is activated, and the second switch (Q2) is acted on to act on the first switch (Q1). It is switched to cut off the continuity between the light emitting means (1) and the power source (4), and has a second bias section for cutting off the current flowing through the light emitting means (1). There is provided a constant current light emitting device for a vehicle.

  According to a second invention, in the first invention, the first switch (Q1) includes a first control terminal (G) electrically connected to the first bias unit, and the light emitting means. The first input terminal (D) electrically connected to (1) and the first output terminal (S) electrically connected to the second bias unit, the second input terminal (D) The switch (Q2) includes a second control terminal (B) electrically connected to the first output terminal (S) and the first bias unit, the first control terminal (G), and the first control terminal (G). A second input terminal (C) electrically connected to the first bias part; and a second output terminal (E) electrically connected to the second bias part. There is provided a constant current light emitting device for a vehicle.

  According to a third invention, in the second invention, the first switch (Q1) includes a gate as the first control terminal (G) and a drain as the first input terminal (D). There is provided a constant current light emitting device characterized by being a metal oxide semiconductor field effect transistor MOS having a source as the first output terminal (S).

  According to a fourth invention, in the second invention, the second switch (Q2) includes a base as the second control terminal (B) and a collector as the second input terminal (C). A constant current light-emitting device for a vehicle is provided, which is a bipolar junction transistor having an emitter as the second output terminal (E).

  According to a fifth aspect, in the second aspect, one end of the second bias unit is electrically connected to the first output end (S) and the second control end (B). The other end of the first resistor element (R10) is electrically connected to the second output end (E), and the first bias portion is electrically connected to the power source (4). The voltage divider has a voltage divider electrically connected to the second output terminal (E), and the voltage divider has a second resistor element (20) and a third resistor element ( 30), and the first control terminal (G) and the second input terminal (C) are connected in series with the second resistance element (R20) and the third resistance element (R30). The constant current light-emitting device for a vehicle is provided.

  According to the sixth invention, in the fifth invention, the brightness enhancing means (3) is further provided, and the brightness enhancing means (3) is electrically coupled to the current limiting means (2). The resistance element (R6), the third switch (Q3) electrically connected to the coupling resistance element (R6), and the third switch (Q3) so that the braking voltage (V2) is input. The coupling resistor element (R6) has one end electrically connected to the first output end (S) and the second control end (B). And the other end is electrically connected to the third switch (Q3), and the third switch (Q3) is electrically connected to the third bias unit. ), A third input terminal (D) electrically connected to the coupling resistance element (R6), and the second output terminal A third output end (S) electrically connected to the end (E), and the third bias unit turns on the third switch (Q3) when supplied with the braking voltage. The coupling resistor element (R6) is connected in parallel to the first resistor element (R10), and the light emitting means (1) and the second switch (Q2) are turned on before the second switch (Q2) is turned on. There is provided a vehicle constant current light emitting device characterized in that the threshold value can be changed so as to increase the amount of current flowing through the first switch (Q1).

  According to a seventh aspect, in the first aspect, the light emitting module (11) further includes a current limiting resistance element (R) for electrically connecting the light emitting element (D) to the power source (4). There is provided a constant current light-emitting device for a vehicle.

  According to the vehicle light emitting device of the present invention, when the current flowing through the first light emitting element and the second light emitting element of the light emitting module in the light emitting means does not exceed the current threshold, the first switch is turned on, The second switch is turned off. On the other hand, when the current flowing through the first light emitting element and the second light emitting element exceeds the current threshold, the second switch is turned on, the first switch is turned off, and the current flowing through the light emitting means is disconnected. Can do. By switching the first and second switches, the current flowing through the light emitting means can be stabilized even when the driving voltage of the power source is unstable and fluctuates. Therefore, according to the switching design of the present invention, overheating due to continuous operation can be prevented. Therefore, the temperature of each operating element can be kept low, and there is an effect of having high stability and a long service life.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram functionally showing an embodiment of a vehicle constant current light emitting device according to the present invention, and FIG. 2 is a circuit diagram of FIG. The vehicle constant current light emitting device of this embodiment includes a light emitting means 1, a current limiting means 2, and a brightness enhancing means 3, and is applied so as to be electrically connected to a power source 4 and a braking device 5 of the vehicle. Is done. The power supply 4 can be operated to output the driving voltage V1, and the braking device 5 can be operated to output the braking voltage V2.

  The light emitting means 1 is used for, for example, a vehicular lamp for lighting, and is applied so as to be electrically connected to a power source 4 and a braking device 5. A plurality of light emitting modules 11, 11,. And three first to third protective elements 12, 12, 12 are provided. Here, electrically connecting the light emitting means 1 to the power source 4 means operating the light emitting means 1 so that the light emitting module 11 of the light emitting means 1 emits light by the driving voltage V1 supplied from the power source 4. Further, electrically connecting the light emitting means 1 to the braking device 5 means that the luminance enhancing means 3 is actuated by the braking voltage V2 from the braking device 5 to increase the luminance of the issuing module 11 of the light emitting means 1. .

  Each of the light emitting modules 11 includes a first light emitting element D1, a second light emitting element D2, and a pair of current limiting resistance elements R and R. In addition, although the number of light emitting elements is two in this example, it cannot be overemphasized that it does not restrict | limit in particular. The current limiting resistance elements R of the respective light emitting modules 11 are connected in parallel, and are connected in series between the first light emitting element D1 and the first and second protection elements 12 and 12. The current limiting resistance element R is a resistance for limiting the current flowing through the light emitting elements D1 and D2.

  As the first to third protection elements 12, 12, and 12, commercially available diodes such as 1N4007 can be used. The first protection element 12 has an anode connected to the power source 4 and a cathode connected to the light emitting module 11. The second protection element 12 has an anode connected to the braking device 5 and a cathode connected to the light emitting module 11. The third protection element 12 has an anode connected to the braking device 5 and a cathode connected to the brightness enhancement means 3. The first and second protection elements 12, 12 can prevent damage caused by unauthorized connection of the power supply 4 to the circuit of the present invention.

  The first protection element 12 is turned on when the drive voltage V1 of the power supply 4 is a positive voltage. The second protection element 12 is turned on when the braking voltage V2 of the braking device 5 is positive and the braking voltage V2 is greater than the drive voltage V1. The third protection element 12 is turned on when the braking voltage V2 of the braking device 5 is positive.

  The current limiting unit 2 includes a first switch Q1, a second switch Q2, a first bias unit, a second bias unit, and a first capacitive element C1. In this example, a pair of first resistance elements R10 and R10 are used as the second bias unit. As the first bias unit, the second and third resistance elements R20 and R30 are used as voltage dividers.

  In this example, the first switch Q1 is an n-channel depletion-type metal-oxide-semiconductor field effect transistor (MOSFET). In fact, other elements may be used as long as they can perform the same function, and are not particularly limited. The first switch Q1 has a first control terminal G electrically connected to the first bias unit as a gate and a cathode of the second light emitting element D2 in the light emitting module 11 of the light emitting means 1 as a drain. The first input terminal D is electrically connected, and the first output terminal S is electrically connected to the first resistance element R10 of the second bias unit as a source. The first switch Q1 is configured such that a larger voltage is received by the drive voltage V1 between the first input terminal D and the first output terminal S.

  For example, an npn bipolar junction transistor (BJT) is used as the second switch Q2. The second switch Q2 includes a second control terminal B electrically connected to the first output terminal S and the first resistance element R10 in the second bias unit, the first control terminal G, and the first control terminal G2. The second input terminal C is electrically connected to the bias portion, and the second output terminal E is connected to the ground GND (hereinafter referred to as ground).

  The second control terminal B is a base of a bipolar junction transistor, the second input terminal C is a collector, and the second output terminal E is an emitter. In fact, as another example of the present invention, a MOSFET may be used as the second switch Q2. However, since the conduction voltage of npnBJT is lower than that of the MOSFET, the resistance of the first resistance element R10 may be reduced. Since the power loss of the first resistance element R10 can be reduced, npnBJT is preferably used as the second switch.

  The first resistance elements R10 and R10 of the second bias unit are connected in parallel, and one end of each is electrically connected to the first output end S and the second control end B, and the other end is The second output terminal E that is grounded is electrically connected. One end of the second resistance element R20 as a voltage divider in the first bias unit is electrically connected to the power source 4 and the braking device 5 via the first protection element 12 and the second protection element 12. .

  The other end of the second resistor element R20 is electrically connected in series to one end of the third resistor element R30. The first control terminal G and the second input terminal C are electrically connected to a connection point between the second and third resistance elements R20 and R30.

  The other end of the third resistor element R30 is electrically connected to the grounded second output terminal E. The first capacitor element C1 is connected in parallel with the third resistor element R30 in order to filter noise.

  The brightness enhancement means 3 is connected to the cathode of the third protection element 12, and is electrically connected to the braking device 5 and the current limiting device 2 via the third protection element 12, and is divided into the third bias section. It has fourth and fifth resistance elements R4, R5 as a voltage device, a second capacitance element C2, a plurality of coupling resistance elements R6, and a third switch Q3.

  One end of the fourth resistance element R4 is connected to the cathode of the third protection element 12, is electrically connected to the braking device 5 via the third protection element 12, and the other end is the fifth resistance element R5. The second capacitive element C2 and the control terminal G of the third switch Q3 are electrically connected. The fifth resistor element R5 has one end electrically connected to the other end of the fourth resistor element R4, one end of the second capacitor element C2, and the third control terminal G of the third switch Q3. The end is grounded. The second capacitive element C2 operates as a filter that cuts noise of the braking voltage V2 from the braking device 5, is connected in parallel to the fifth resistance element R5, and has one end connected to the fifth resistance element R5. One end is connected to the other end of the fourth resistance element R4, and the other end is grounded.

  The plurality of coupling resistance elements R6 are connected in parallel, and one end of the coupling resistance element R6 connected in parallel is electrically connected to one end of the first output terminal S, the second control terminal B, and the resistance element R10, The other end is electrically connected to the input terminal D of the third switch Q3.

  In this example, the third switch Q3 is an n-channel depletion type MOSFET, and a connection point between the other end of the fourth resistor element R4 and one end of the fifth resistor element R5 and the second capacitor element C2. Is electrically connected to the third control terminal G, electrically connected to the other end of the coupling resistor element R6, and to the grounded second output terminal E. The third output terminal S is provided. The third control terminal G is used as a gate in the MOSFET, the third input terminal D is used as a drain, and the third output terminal S is used as a source.

  A surge suppressor 15 is provided between the power supply 4 and the ground GND. Further, a surge suppressor 16 is provided between the braking device 5 and the ground GND. The surge suppressor 15 suppresses a surge current to the light emitting means 1 and the current limiting means 2 due to the drive voltage V <b> 1 from the power supply 4. The surge suppressor 16 suppresses a surge current to the light emitting means 1, the current limiting means 2, and the brightness enhancing means 3 due to the braking voltage V <b> 2 from the braking device 5.

  Next, the operation of the vehicle light emitting device of the present invention will be described.

  The power supply 4 supplies a drive voltage V1 to a first bias unit as a voltage divider having a resistance element R20 and a capacitance element C1. Due to the positive drive voltage V1 from the power supply 4, the first protection element 12 is turned on, a current flows through the resistance elements 20 and R30 of the first bias unit, and the first control terminal G1 of the first switch Q1. Exceeds the conduction voltage of the first switch Q1, and the first control terminal G of the first switch Q1 is made conductive.

  When the first switch Q1 is turned on, the current generated between the light emitting means 1 and the power source 4 is changed from the power source 4 to the current limiting resistor element R, the first and second light emitting elements D1, D2, the first switch Q1, It flows to the ground GND through the first resistance element R10 having the second bias. Thereby, the first and second light emitting elements D1 and D2 of the light emitting module 11 of the light emitting means 1 can be operated.

  When the drive voltage V1 varies and the amount of current passing through the first switch Q1 exceeds a predetermined threshold value, the voltage across the first resistance element (R10) increases, for example, 0 .7 [Volt] is reached, and a voltage exceeding a required conduction voltage is applied between the second control terminal B and the second output terminal E, and the second switch Q2 is turned on. When the second switch Q2 is turned on, the amount of current flowing through the first control terminal G is reduced, and the voltage at the first control terminal G becomes lower than the conduction voltage of the first switch Q1, so that the first switch Q1 is turned off, and the electric circuit between the light emitting means 1 and the power source 4 is cut off. Thereby, the electric current which flows into the light emission means 1 is interrupted | blocked, and the 1st and 2nd light emitting elements D1 and D2 of the light emitting module 11 of the light emission means 1 do not operate | move.

  When the current flowing through the light emitting means 1 is interrupted, the current flowing through the resistance element R10 disappears, the voltage at the second control terminal B becomes lower than the required conduction voltage, and the second switch Q2 is turned off. As a result, a voltage exceeding the conduction voltage of the first switch Q1 is applied again to the first control terminal G, and the first switch Q1 is conducted. When the first switch Q1 is turned on, an electric circuit from the power source 4 to the light emitting means 1 is completed, and the first and second light emitting elements D1 and D2 of the light emitting module 11 of the light emitting means 1 are activated again to emit light. Therefore, the current flowing through the light emitting module 11 of the light emitting means 1 can be stabilized by switching between the first switch Q1 and the second switch Q2.

  In this example, the braking device 5 is activated by the operation of the brake, and the braking voltage V <b> 2 is supplied from the braking device 5. When the positive braking voltage V2 is supplied from the braking device 5, the third protection element 12 is turned on, and the braking voltage V2 is output from the braking device 5 to the third bias unit via the third protection element 12. . When the braking voltage V2 is input to the fourth and fifth resistance elements R4 and R5 as the voltage divider of the third bias unit, the third voltage between the third control terminal G and the third output terminal S is the third. A voltage exceeding the conduction voltage of the switch Q3 is applied to make the third switch Q3 conductive.

  When the third switch Q3 is turned on, the coupling resistance element R6 is connected in parallel to the first resistance element R10, so that a lower equivalent resistance value is generated by the combined resistance. Therefore, before the third switch Q3 is turned on. In contrast, when the same current value flows through the first output terminal S, the voltage between the second control terminal B and the second output terminal E becomes lower, and the second switch Q2 becomes conductive. Has to increase the amount of current flowing through the first output terminal S.

  Therefore, the current flowing through the first switch Q1 when the second switch Q2 is conductive must increase compared to before the third switch Q3 is conductive. Further, when the third switch Q3 is turned on, the resistance value between the first output terminal S and the second output terminal E becomes lower, so that the current flowing through the light emitting means 1 and the first switch Q1 increases. The light emission of the first and second light emitting elements D1 and D2 becomes brighter.

  In other words, when the coupling resistance element R6 is connected in parallel to the first resistance element R10, a large current is allowed to flow through the light emitting means 1 and the first switch Q1 in order to make the second switch Q2 conductive. The threshold value of the value of the current flowing through the first switch Q1 can be changed. Since this large current can flow through the first and second light emitting elements D1 and D2, the luminance of lighting can be increased. Therefore, when the brake is applied, the luminance enhancement means 3 makes the light emission of the first and second light emitting elements D1 and D2 brighter, and the warning display becomes good.

  The voltage of the cathode of the second protection element 12 becomes a voltage equal to a larger voltage among the driving voltage V1 from the power source 4 and the braking voltage V2 of the braking device 5, and between the light emitting means 1 and the ground GND, Since a high voltage of the braking voltage V2 from the braking device 5 and the driving voltage V1 from the power source 4 is applied, the current flowing through the light emitting means 1 can be controlled by controlling the braking voltage V2 of the braking device 5. The luminance display of the light emitting means 1 can be controlled with high accuracy.

  As described above, when the current flowing through the first light emitting element D1 and the second light emitting element D2 of the light emitting module 11 in the light emitting means 1 does not exceed the current threshold value, the first switch (Q1) is turned on, and 2 switch (Q2) is turned off. On the other hand, when the current flowing through the first light emitting element D1 and the second light emitting element D2 exceeds the current threshold value, the second switch (Q2) is turned on, the first switch Q1 is turned off, and the light emitting means 1 can be cut off.

  By switching the first and second switches Q1 and Q2, the current flowing through the light emitting means 1 can be stabilized even if the driving voltage V1 of the power supply 4 is unstable and fluctuates. When the brake is applied, the braking voltage V2 is supplied from the braking device 5 through the third protective element 12 to the brightness enhancing means 3, and the third switch Q3 is turned on, whereby the brightness of the light emitting means 1 during the brake operation is turned on. Can be strengthened.

  Therefore, according to the switching design according to the present invention, it is possible to prevent overheating due to continuous operation and to increase the brightness of the light emitting means 1 during the brake operation.

  The embodiments described above are merely intended to clarify the technical contents of the present invention, and the present invention is not limited to such specific examples and is not construed in a narrow sense. It can be implemented with various modifications within the scope described in the spirit and claims.

  As described above, the vehicle light-emitting device of the present invention is useful in that the temperature of the operating element can be kept low, and it has high stability and a long service life.

1 is a block diagram functionally showing an example of a vehicle constant current light emitting device according to the present invention. FIG. 2 is a circuit diagram of FIG. 1. It is a schematic circuit diagram of the conventional voltage stable light-emitting device for vehicles.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emission means 11 Light emission module 12 Protection element 2 Current limiting means 3 Luminance enhancement means 4 Power supply 5 Braking device B 2nd control end (base)
C Second input terminal (collector)
C1, C2 Capacitance element D First and third input terminals (drains)
D1, D2 Light emitting element E Second output terminal (emitter)
G First and third control terminals (gates)
Q1, Q2, Q3 Switch R Current limiting resistance element R10, R20, R30, R4, R5 Resistance element R6 Coupling resistance element S First and third output terminals (sources)

Claims (7)

A vehicle constant current light emitting device to which a drive voltage (V1) is input from a power source (4),
A light emitting means (1) and a current limiting means (2);
The light emitting means (1) has at least one light emitting module (11) composed of a light emitting element (D),
The current limiting means (2)
A first switch (Q1) that electrically connects / disconnects between the light emitting means (1) and the power source (4);
When electrically connected to the first switch (Q1) and supplied with a driving voltage (V1) to the power source (4), the power source (4) and the light emitting means (1) are electrically connected. The first switch (Q1) is actuated so as to cause a current to flow from the power source (4) to the light emitting means (1) and the first switch (Q1), and the light emitting means (1) A first biasing part that causes the light emitting means (1) to be electrically connected to the power source (4),
A second switch (Q2) electrically connected to the first switch (Q1);
When electrically connected to the first switch (Q1) and the second switch (Q2) and the current flowing through the first switch (Q1) exceeds a predetermined threshold, The second switch (Q2) is actuated and acts on the first switch (Q1) by the conduction action of the second switch (Q2), so that the light emitting means (1) and the power source (4) are connected. The vehicle constant current light-emitting device is provided with a second bias section that is switched to cut off the electrical current and cuts off the current flowing through the light-emitting means (1). The first switch (Q1) includes a first control terminal (G) electrically connected to the first bias unit and the first switch electrically connected to the light emitting means (1). An input end (D) and a first output end (S) electrically connected to the second bias unit;
The second switch (Q2) includes a second control terminal (B) electrically connected to the first output terminal (S) and the second bias unit, and the first control terminal ( G) and a second input terminal (C) electrically connected to the first bias part, and a second output terminal (E) electrically connected to the second bias part. The vehicle constant current light-emitting device according to claim 1.   The first switch (Q1) includes a gate as the first control terminal (G), a drain as the first input terminal (D), and a source as the first output terminal (S). 3. The constant current light emitting device according to claim 2, wherein the constant current light emitting device is a metal oxide semiconductor field effect transistor MOS.   The second switch (Q2) includes a base as the second control terminal (B), a collector as the second input terminal (C), and an emitter as the second output terminal (E). The constant current light-emitting device for a vehicle according to claim 2, wherein the constant current light-emitting device is a bipolar junction transistor. One end of the second bias unit is electrically connected to the first output end (S) and the second control end (B), and the other end is connected to the second output end (E). A first resistance element (R10) electrically connected;
The first bias unit includes a voltage divider electrically connected to the second output terminal (E) so as to be electrically connected to the power source (4).
The voltage divider includes a second resistance element (R20) and a third resistance element (R30) connected in series,
The first control terminal (G) and the second input terminal (C) are electrically connected to a connection point of the second resistance element (R20) and the third resistance element (R30) connected in series. The constant current light-emitting device for vehicles according to claim 2 connected to. Furthermore, it has brightness enhancement means (3),
The brightness enhancement means (3)
A coupling resistance element (R6) electrically connected to the current limiting means (2);
A third switch (Q3) electrically connected to the coupling resistance element (R6);
A third bias unit electrically connected to the third switch (Q3) so that a braking voltage (V2) is input;
One end of the coupling resistance element (R6) is electrically connected to the first output end (S) and the second control end (B), and the other end is electrically connected to the third switch (Q3). Connected,
The third switch (Q3)
A third control terminal (G) electrically connected to the third bias unit;
A third input terminal (D) electrically connected to the coupling resistance element (R6);
A third output end (S) electrically connected to the second output end (E),
When the braking voltage is supplied, the third bias unit drives the third switch (Q3) to conduct, and the coupling resistance element (R6) is connected to the first resistance element (R10). And the threshold so that the amount of current flowing through the light emitting means (1) and the first switch (Q1) can be increased before the second switch (Q2) is turned on. The constant current light-emitting device for a vehicle according to claim 5, wherein the value can be changed.   The vehicle light-emitting component (11) according to claim 1, wherein the light-emitting module (11) further includes a current limiting resistor element (R) for electrically connecting the light-emitting element (D) to the power source (4). Current light emitting device.

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