LED lighting device

Abstract

To solve such a problem that, in a conventional technique in which an identification resistor having a resistance value different for each type of lamp fitting is connected in parallel with an LED in the lamp fitting, and the type of connected lamp fitting is determined by gradually increasing the voltage applied to the lamp fitting, reading a current value flowing through the identification resistor in a state where the applied voltage is equal to or less than the forward voltage (Vf), that is, in a state where the LED does not emit light, and specifying the resistance value of the identification resistor, the type of identification resistors had to be increased as the type of lamp fitting increased.SOLUTION: An LED lighting device performs first determination that specifies a group of lamp fittings based on a resistance value of an identification resistor when the voltage applied to the lamp fitting is equal to or less than the forward drop voltage (Vf) of the lamp fitting, and performs second determination that specifies the type of lamp fitting based on a power value supplied to the lamp fitting in a state where the voltage applied to the lamp fitting exceeds the forward drop voltage (Vf).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an LED lighting device in which, when multiple different types of lighting fixtures are connected to a single common power supply, the type of lighting fixture is automatically determined on the power supply side, and current control is performed on the lighting fixture according to the type of lighting fixture, causing the lighting fixture to emit light. [Background technology]

[0002] As an LED lighting device equipped with a power supply device having the above-mentioned automatic discrimination function, one has been proposed in which a discrimination resistor with a different resistance value for each type is built into the lighting fixture (see, for example, Patent Document 1).

[0003] In this device, an identification resistor with a different resistance value for each type of lighting fixture is connected in parallel to the LED inside the lighting fixture, and the voltage applied to the lighting fixture is gradually increased.When the applied voltage is below the forward voltage (Vf), i.e., when the LED is not emitting light, the current value flowing through the identification resistor is read and the type of connected lighting fixture is determined by identifying the resistance value of the identification resistor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-133229 A (Claim 1, Figure 2) Summary of the Invention [Problem to be solved by the invention]

[0005] As the number of types of lighting fixtures connected to a power supply unit increases, it becomes necessary to increase the number of types of resistance values ​​of the discrimination resistor. However, if the resistance range of the discrimination resistor is set narrowly, the resistance values ​​become close to each other, causing a problem in that the error in the resistance value of the discrimination resistor cannot be ignored.

[0006] On the other hand, if the range of the resistance value of the discrimination resistor is widened, if the resistance value of the discrimination resistor is too small, the current flowing through the discrimination resistor will increase, increasing the power consumed by the discrimination resistor and increasing power consumption. Also, if the resistance value of the discrimination resistor is too large, the voltage applied to the discrimination resistor when passing the current required for discrimination through the discrimination resistor may exceed the above Vf, resulting in the LED lighting up before the type of device can be identified.

[0007] In view of the above problems, an object of the present invention is to provide an LED lighting device that can identify the type of lighting fixture without setting many different resistance values ​​for the identification resistor. [Means for solving the problem]

[0008] In order to solve the above problems, the LED lighting device of the present invention is an LED lighting device comprising: a plurality of types of detachable lighting fixtures each incorporating an LED and a discrimination resistor connected in parallel to the LED; and a power supply unit which, when one of the plurality of types of lighting fixtures is detachably connected, determines the type of the connected lighting fixture and supplies a preset power to the identified lighting fixture to light up the LED in the lighting fixture; the plurality of types of lighting fixtures are divided into groups whose number is less than the number of types, and each group incorporates a discrimination resistor with a different resistance value, and the power supply unit determines the type of the connected lighting fixture and supplies a preset power to the identified lighting fixture to light up the LED in the lighting fixture; The invention is characterized in that a first determination is made to identify the group of the lamp from the resistance value of the identification resistor when the voltage applied to the lamp is equal to or less than the forward drop voltage (Vf) of the lamp, and a second determination is made to identify the type of lamp from the power value supplied to the lamp when the voltage applied to the lamp exceeds the forward drop voltage (Vf) of the lamp, and the first determination is made to identify the group of the lamp from the resistance value of the identification resistor, and constant current control is performed so that a current according to the type of connected lamp flows to the LED by passing a current through the identification resistor and reading the resistance value of the identification resistor before the LED emits light.

[0009] The lighting fixtures are divided into several groups with similar forward voltages (Vf), and a first determination is made to identify this group when the applied voltage is below Vf, as in the conventional method. Next, once the group of connected lighting fixtures has been identified, a second determination is made to identify the type of lighting fixture when the voltage applied to the lighting fixture exceeds Vf and the LED begins to emit light.

[0010] By performing these two-stage determinations, the first determination and the second determination, many types of lighting fixtures can be identified using identification resistors with a small number of resistance values. [Effects of the Invention]

[0011] As is clear from the above description, in the present invention, even if the number of types of lamps to be identified increases, it is not necessary to increase the number of types of resistance values ​​of the identification resistor. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 shows a configuration of an embodiment of the present invention. [Figure 2] Diagram showing the status of the LED inside the lamp [Figure 3] A diagram explaining the method for identifying the type of lighting fixture based on the relationship between voltage and current DETAILED DESCRIPTION OF THE INVENTION

[0013] Referring to FIG. 1, reference numeral 1 denotes a power supply device, and in this embodiment, this power supply device 1 is provided with eight connectors 11. Any one of a plurality of types of lighting fixtures 2 is detachably connected to each connector 11. An LED and an identification resistor, which will be described later, are connected in parallel within this lighting fixture 2. Each connector 11 is also provided with a power supply unit 12. This power supply unit 12 supplies power to the lighting fixture 2 connected to the connector 11 in response to a control signal from a control device 3. The power supply unit 12 performs constant current control and is provided with a voltage dividing resistor 13 for detecting the voltage applied to the lighting fixture 2 and a resistor 14 for detecting the value of the current flowing through the lighting fixture 2. The voltage applied to and the value of the current flowing through the lighting fixture 2 are input to the control device 3, which controls the power supply unit 12 based on these voltage and current values.

[0014] Referring to Figure 2, this figure shows the configuration of 12 types of lighting fixtures as an example of the types of lighting fixtures. To make the following explanation easier to understand, it is assumed that all the LEDs 4 used in each lighting fixture are the same, and therefore the Vf of each individual LED 4 is the same. Furthermore, it is assumed that the four types of resistors R1, R2, R3, and R4, which are given symbols as identification resistors, have the same resistance value.

[0015] The one on the top left has one system 41 with one LED4 built in, which is represented as 1-1, and the one on the top right has three systems (41, 42, 43) with one LED4 connected in parallel, which is represented as 3-1.The number of LEDs 4 connected in series increases successively, and the one on the bottom right has three systems with four LEDs 4 connected in series connected in parallel, which is represented as 3-4.

[0016] Referring also to Figure 3, the three types (1-1, 2-1, and 3-1) shown in the upper part of Figure 2 have the same Vf. Therefore, as shown in the upper part of Figure 3, a voltage V lower than Vf is applied to luminaire 2 so that the current Ig is lower than the current If at Vf. The resistance value of discrimination resistor R1 can be determined from Vg and Ig. This resistance value determines whether luminaire 2 is one of the types shown in the upper part of Figure 2 (first determination). Next, the current value is increased to Ic, which is higher than If. The voltage value at that state is Vc1 if luminaire 1-1, Vc2 if luminaire 2-1, and Vc3 if luminaire 3-1. This makes it possible to determine whether the connected luminaire is 1-1, 2-1, or 3-1 (second determination). Thereafter, current control is performed according to the determined type.

[0017] The same discrimination is performed for the other lighting fixtures, but the group shown in the bottom row of Figure 3 is the same as the group shown in the bottom row of Figure 2, where four LEDs are connected in series in groups of one to three. This group has four times the Vf of the group with one LED each as described above. Therefore, this group uses a discrimination resistor R4 with four times the resistance of the discrimination resistor R1 in the group shown in the top row of Figure 3.

[0018] Therefore, if a current Ig slightly lower than If is passed through the LED, it will not emit light, but the voltage Vg in that state will be higher than that shown in the upper part of Figure 3. The group is identified by finding the resistance value of R4 from this Vg value (first determination). After the group has been identified by this first determination, the specific type is identified in the same way as shown in the upper part of Figure 3 above (second determination).

[0019] In this way, the 12 types of lighting fixtures 2 can be identified by the four types of discrimination resistors (R1 to R4).

[0020] The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention. [Explanation of symbols]

[0021] 1 Power supply 2 lamps 3. Control device 11 Connector 12 Power supply section 13 Voltage dividing resistor 14 Resistance R1,R2,R3,R4 Discrimination resistance

Claims

[Claim 1] and a power supply unit which, when one of the plurality of types of lighting fixtures is detachably connected, identifies the type of the connected lighting fixture and supplies a preset power to the identified lighting fixture to cause the LED in the lighting fixture to light up. The LED lighting device is characterized in that: the plurality of types of lighting fixtures are divided into groups whose number is less than the number of types; each group has a built-in discrimination resistor with a different resistance value; a first determination is made to identify the group of the lighting fixture from the resistance value of the discrimination resistor when the voltage applied to the lighting fixture is equal to or less than the forward voltage drop (Vf) of the lighting fixture; a second determination is made to identify the type of lighting fixture from the power value supplied to the lighting fixture when the voltage applied to the lighting fixture exceeds the forward voltage drop (Vf); the first determination is made to identify the group of the lighting fixture from the resistance value of the discrimination resistor; and constant current control is performed so that a current corresponding to the type of connected lighting fixture flows through the LED by passing a current through the discrimination resistor and reading the resistance value of the discrimination resistor before the LED lights up.

Images