KR20130133449A - Tell-tale circuit of led lamp in vehicle - Google Patents

Abstract

The present invention relates to a tell-tale circuit of a vehicle LED lamp and, more specifically, to the tell-tale circuit of the vehicle LED lamp which prevents a phenomenon in which the vehicle LED lamp is temporarily turned on and off for failure detection in the process which turns off the vehicle LED lamp by force when an LED of the vehicle LED lamp breaks down. The tell-tale circuit of the vehicle LED lamp according to the present invention comprises; a capacitor; a constant voltage part which produces reference voltage by receiving a vehicle power source; a constant current part which produces reference current using the voltage produced in the constant voltage part; a lamp part including multiple light emitting device parts which parallelly connect a light emitting device part made of the transistor for maintaining the constant current applied from the constant current part, and multiple light emitting devices which are connected in series; a light emitting device power source part which supplies a power source to the multiple light emitting device parts of the lamp part by receiving the vehicle power source; and an error sensing part which outputs an error output value for the failure of one or more among the multiple light emitting devices by comparing the voltage of the multiple light emitting device parts with the reference voltage. [Reference numerals] (200) Tell-tale circuit of a vehicle LED lamp;(210) Constant voltage part;(220) Constant current part;(230) Lamp part;(250) Error sensing part;(270) Control part;(AA) Vehicle pwoer source;(BB) Light emitting device power source part;(CC) Tell-tale power source part

Description

Tell-Tale Circuit of LED Lamps in Vehicles

The present invention relates to a tell-tail circuit of a vehicle LED lamp. More particularly, the present invention relates to a tell-tail circuit of a vehicle LED lamp that prevents a phenomenon of turning on and off for a fault detection during a process of forcibly turning off all LED failures in a vehicle LED lamp.

In general, the vehicle is equipped with lighting devices such as headlights, taillights, fog lights, stop lights or turn signals to prevent driving and accidents. By displaying it, a collision or a collision with a vehicle in the front and rear or right and left directions is prevented in advance and safety is prevented.

In recent years, as the vehicle's equalizer is equipped with various functions, it requires a larger driving voltage than in the related art. On the other hand, the output of the voltage supply device is limited, and in order to operate the added function normally, when a component such as a conventional light bulb, which consumes relatively high power, is used, there is a problem such that normal operation is difficult or life is shortened during operation. . In addition, there is a limit to increasing the capacity of the voltage supply device for the normal operation of the added functions, there is a trend to replace the parts used as the equalizer with a relatively low power consumption as possible.

Reflecting this trend, light emitting devices (LEDs) that are relatively low in power consumption and can be operated with a low driving voltage have recently been used in equalizers. To drive the LEDs while maximizing the advantages of the LEDs, an LED drive module (LDM) is required to supply constant current to the LEDs.

The role of LDM is to supply constant current to the LED to keep the brightness of the LED constant even when the vehicle battery voltage fluctuates, to protect the LED that is weak against surge and noise, and to serve as a controller to implement various designs and light distribution performance. Sometimes.

And when using the LED as an equalizing device, Tell-Tale (Tell-Tale) detects this even when one LED is off (Off) and notifies the passenger or driver.

1 is a circuit diagram illustrating a tel-tail circuit of a conventional vehicle LED lamp.

Referring to FIG. 1, the Tell-tail circuit 100 of the conventional vehicle LED lamp includes a plurality of light emitting device units including a plurality of light emitting devices connected in series with a constant current unit 110 generating a constant current by receiving a vehicle power source, An equalizer 120 that emits light by receiving a current applied from the constant current part in parallel with a plurality of light emitting device parts, a constant voltage part 130 generating a reference voltage by receiving the vehicle power, and the plurality of light emitting devices An error detection unit 140 for comparing a negative voltage and the reference voltage, respectively, and outputting an error output value for the failure of the plurality of light emitting devices; And a controller 150 electrically connected to the failure detection unit to control an enable signal applied to the enable end of the constant current unit by receiving the error output value. Regarding the contents, refer to published patent [2011-0220006])

However, this method detects a string in which the LED is turned off after the power is supplied to the LED and turns it off. When this method is expressed sequentially, after the LED power is turned on, the LED 1 string is turned off and then all the LEDs are turned off. In other words, once the LED is turned on and off, it can be seen as a malfunction when viewed from the outside. In particular, in case of Turn Signal Lamp, the power is repeatedly turned on / off at a certain cycle, so when the LED breaks down, it is repeatedly turned on and off at the initial power-on, and the consumer perceives it as a malfunction. Can be.

The present invention has been made to solve the above problems, having a separate power supply unit, using a time LEDay characteristic due to the use of a high capacity capacitor (Capacitor) for a short time to detect the failure of the vehicle LED lamp failure It is an object of the present invention to provide a tell-tail circuit of a vehicle LED lamp which prevents the on and off phenomenon.

The Tel-tail circuit of the vehicle LED lamp to achieve the above object includes a capacitor, the constant voltage unit for generating a reference voltage by receiving a vehicle power; A constant current unit generating a constant current using the voltage generated by the constant voltage unit; An equalizing unit including a plurality of light emitting device units connected in parallel with a light emitting device unit including a transistor for maintaining the constant current applied from the constant current unit and a plurality of light emitting devices connected in series; A light emitting device power supply unit receiving the vehicle power to supply power to a plurality of light emitting devices of the light emitting unit; And an error detection unit configured to compare voltages of the plurality of light emitting elements and the reference voltage, respectively, and output an error output value for at least one of the plurality of light emitting elements.

Preferably, the tell-tail circuit of the vehicle LED lamp further includes a control unit electrically connected to the failure detecting unit to control an enable signal applied to the enable end of the constant current unit by receiving the error output value. Characterized in that.

Preferably, the tel-tail circuit of the vehicle LED lamp further includes a teltail power supply unit configured to receive the vehicle power and generate power supplied to the error detection unit, wherein the error detection unit supplies power from the teltail power supply unit. It is characterized in that the operation is supplied.

Preferably, the error detecting unit determines that the equalizer is normally driven when the voltages of the plurality of light emitting device parts are greater than the reference voltage, and outputs a high level error output value. When at least one of the voltages is smaller than the reference voltage, the equalizer determines that the driving is abnormal, and outputs a low level error output value.

Preferably, the error detection unit includes a comparison unit for comparing the voltages of the plurality of light emitting element units and the reference voltages, respectively, and outputting a result value; And an end gate unit for checking whether all of the result values output from the plurality of comparison units are high level.

Preferably, when the high level error output value is applied, the control unit applies a high level enable signal to the constant current unit to enable the constant current unit, and when a low level error output value is applied, the low level enable It is characterized by disabling the constant current unit by applying a signal to the constant current unit.

Preferably, the control unit stops or drives the operation of the constant current unit by controlling an enable signal applied to the enable terminal of the constant current unit based on the error output value.

The present invention prevents the phenomenon of turning on and off for a while to detect the failure in the process of forcibly turning off all the LED lamps in the event of a failure of some of the vehicle LED lamps.

This prevents the user from mistaken the LED lamp for malfunction.

1 is a circuit diagram illustrating a tel-tail circuit of a conventional vehicle LED lamp.
2 is a circuit diagram illustrating a tell-tail circuit of a vehicle LED lamp according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description and the accompanying drawings, substantially the same components are denoted by the same reference numerals, respectively, and redundant description will be omitted. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

Unlike the prior art, the tel-tail circuit of the vehicle LED lamp according to the present invention requires the power of the constant voltage unit to be turned on to turn on the vehicle LED lamp, and supplies power to the teltail power unit before the constant voltage unit is turned on. It is determined whether the LED lamp is out of order, and if it is determined to be out of order, the LED lamp is turned off. After that, the power of the constant voltage unit is turned on, and when the power is normally supplied to all the LED lamps, the LED is turned on. That is, by using the tell-tail circuit of the vehicle LED lamp according to the present invention, when one of the LED is broken, it is possible to prevent the phenomenon that the normal LED other than the failed LED flicker even if power is supplied to the LED lamp.

2 is a circuit diagram illustrating a tell-tail circuit of a vehicle LED lamp according to a preferred embodiment of the present invention.

2, the Tel-tail circuit 200 of the vehicle LED lamp includes a constant voltage unit 210, a constant current unit 220, and an equalizer 230. ), A light emitting device power supply unit 240, an error detection unit 250, a teltail power supply unit 260 and a control unit 270.

The constant voltage unit 210 receives a vehicle power and outputs a constant voltage which is a constant output voltage. The constant voltage output from the constant voltage unit 210 becomes a reference voltage Vref which is a constant voltage for checking whether the equalization unit 230 is normally operated using the size ratio of the plurality of resistors R1 and R2.

The reference voltage Vref is preferably a voltage (LED1, LED2, LED3) of each of the light emitting element portions LED1, LED2, LED3, and LED4 when the light emitting element portions LED1, LED2, LED3, and LED4 operate normally. It is set to be smaller than the LED4, and is set to be larger than when one of the light emitting elements (LED1, LED2, LED3, LED4) is open to consume no current.

The constant voltage unit 210 includes a capacitor 212 to stabilize the output. When power is supplied to the constant voltage unit 210 by the capacitor 212, first, the capacitor 212 is charged, and while the capacitor 212 is charged, power is first applied to the teltail power supply unit 260 which will be described later. That is, the power is applied to the teltail power supply unit 260 before the constant voltage unit 210 by using the time constant value of the capacitor 212 itself. The capacitance of the capacitor 212 used herein may vary according to a necessary difference in the time for which the power is applied to the teltail power supply unit 260 before the constant voltage unit 210.

The constant current unit 220 generates a constant current using the voltage generated by the constant voltage unit 210. The constant current unit 220 is electrically connected to the TR unit 234 of the equalizer 230 to be described later.

In addition, the constant current unit 220 outputs a constant current that is a constant output current by the power of the vehicle and an enable signal applied by the controller 270 to be described later. At this time, the constant current unit 220 is enabled when a high level enable signal is applied, and outputs a constant constant current, and when a low level enable signal is applied, it is disabled and does not output a constant current. The constant current unit 220 is disabled when a low level enable signal is applied, and thus does not output a constant current, thereby turning off all of the plurality of light emitting devices of the equalizer 230.

The constant current unit 220 may be made of a buck controller for outputting a constant current by the on / off operation of the switching element, or may be made of a linear controller for outputting a constant current by consuming voltage as heat, but the present invention It is not intended to limit this.

The equalizing unit 230 includes a plurality of light emitting element units 232 and a TR unit 234 composed of a plurality of transistors.

In detail, the equalizing unit 230 includes a plurality of light emitting device units LED1, LED2, LED3, and LED4 including a plurality of light emitting devices L connected in series. The plurality of light emitting element units LED1, LED2, LED3, and LED4 are connected in parallel with each other. Each of the light emitting devices L of the equalizing unit 230 including the plurality of light emitting device units LED1, LED2, LED3, and LED4 emits light by a constant current applied from the constant current unit 220. That is, the equalizer 230 emits light by the constant current when the constant current is output from the constant current unit 220, and turns off when the constant current is not output.

The lighting unit 230 may be a lighting device mounted on a vehicle such as a headlight, a taillight, a fog light, a stop light, and a turn signal.

The TR unit 234 maintains a constant current applied from the electrically connected constant current.

In addition, in FIG. 2, the equalizing unit 230 has four light emitting device units LED1, LED2, LED3, and LED4, and one light emitting device unit is illustrated as consisting of three light emitting devices L. It is not intended to limit this.

The constant voltage unit 210 receives a vehicle power and outputs a constant voltage which is a constant output voltage. The constant voltage output from the constant voltage unit 210 is a reference voltage Vref which is a constant constant voltage that checks whether the equalizer 230 is operating normally by using the size ratio of the plurality of resistors R1 and R2. The reference voltage Vref is preferably a voltage (LED1, LED2, LED3) of each of the light emitting element portions LED1, LED2, LED3, and LED4 when the light emitting element portions LED1, LED2, LED3, and LED4 operate normally. It is set to be smaller than the LED4, and is set to be larger than when one of the light emitting elements (LED1, LED2, LED3, LED4) is open to consume no current.

Here, the voltages LED1, LED2, LED3, and LED4 of each light emitting device may include, for example, a first light emitting device L1, a second light emitting device L2, and a third light emitting device L3 sequentially connected in series. In the case of the light emitting device unit LED1, when a constant current is applied to the anode electrode of the first light emitting device L1, the voltage of the cathode electrode of the third light emitting device L3 becomes LED1. That is, the voltages LED1, LED2, LED3, and LED4 of the light emitting element portion are the voltages after being consumed by each of the light emitting element portions LED1, LED2, LED3, and LED4 when a constant current is applied.

The equalizer 230 is electrically connected to the light emitting device power supply unit 240 for supplying power to the plurality of light emitting devices.

The light emitting device power supply unit 240 receives power from the vehicle and supplies power to the plurality of light emitting devices of the equalizer 230.

The error detecting unit 250 compares the voltages LED1, LED2, LED3, and LED4 of the light emitting device units with the reference voltages Vref output from the constant voltage unit 210, respectively, so that the plurality of light emitting devices L may malfunction. It outputs an error output value as to whether it has been opened and turned off.

The error detector 250 may include a comparator 252 including a plurality of comparators and an end gate part 254 including one or more end gates for comparison.

The error detection unit 250 includes a comparison unit 252 for comparing the voltages LED1, LED2, LED3, and LED4 of the plurality of light emitting device units with the reference voltage Vref, respectively. For example, if the comparators of the comparator 252 are Co1, Co2, Co3, and Co4, respectively, the first comparator Co1 may determine the voltage LED1 and the reference voltage Vref of the first light emitting device LED1. The comparison result is output, and the second comparator Co2 compares the voltage LED2 of the second light emitting device unit LED2 with the reference voltage Vref and outputs the result value. At this time, the first comparator Co1 outputs a high level result value when the voltage LED1 of the first light emitting device unit LED1 is greater than the reference voltage Vref, and is smaller than the reference voltage Vref. Output the low level result. The second comparator Co2 to the fourth comparator Co4 also output a high level result value when the voltage of the light emitting device unit is greater than the reference voltage Vref, similarly to the first comparator Co1.

And an end gate unit 254 for checking whether all of the result values output from the comparison unit 252 of the error detection unit 250 are high level. For example, when the gates of the gate unit 254 are AND1, AND2, and AND3, respectively, the first end gate AND1 may determine the result of the first comparator Co1 and the result of the second comparator Co2. In comparison, the second end gate AND2 compares the output value of the first end gate AND1 with the result value of the third comparator Co3, and the third end gate AND3 is the second end gate AND2. Compare the output value of with and the result value of the fourth comparator (Co4) to output the error output value.

When the equalization unit 230 is normally driven, the error detection unit 250 has the voltages LED1, LED2, LED3, and LED4 of each light emitting device unit being greater than the reference voltage Vref, so that the equalization unit 230 is operated. It outputs a high level error output (Tell tale) indicating that all are normal.

When the at least one light emitting device L of the lighter 230 is open and does not emit light, the error detection unit 250 includes voltages of the light emitting device unit corresponding to the lighter 230 (LED1, LED2, LED3). , LED4) becomes smaller than the reference voltage Vref and outputs a low level error output value (Tell tale).

In FIG. 2, the end gates AND1, AND2, and3 show three end gates of two inputs, but one end gate of four inputs may be used.

The error detection unit 250 operates by receiving power from the teltail power supply unit 260.

The Teltail power supply unit 260 receives the vehicle power to generate power supplied to the error detection unit 250.

The error detection unit 250 described in FIG. 1 is supplied with power from the constant voltage unit 210 to detect an error. As a result, when any one or more of the LED lamps fail, an LED lamp that does not fail to detect a failure is There was a flickering phenomenon.

In the case of the tel-tail circuit 200 of the vehicle LED lamp according to the present invention, the error detection unit 250 is supplied with power from the teltail power supply unit 260 instead of being supplied with power from the constant voltage unit 210. In addition, by using the time LEDay characteristic due to the capacitor 212 included in the constant voltage unit 210, the teltail power supply unit 260 receives the vehicle power before the constant voltage unit 210 receives the error detection unit 250. To the power supply. As a result, the error detection unit 250 may detect a state such as an LED failure while the LED lamp is turned off, and thus no flicker occurs.

The error output value (Tell tale) output from the error detection unit 250 is applied to the control unit 270.

The controller 270 includes a transistor, and an error output value (tale tale) output from the error detection unit 250 is applied to the base of the transistor. When a high level error output value (Tell tale) is applied to the transistor, the transistor is turned off to output a high level enable signal, which is a high level input power supply Vcc applied to the emitter of the transistor, of the constant current unit 220. It is applied to the enable terminal En. When the low level error output value (Tell tale) is applied, the transistor is turned on and the input power supply Vcc applied to the emitter is applied to the collector connected to the ground GND, and the input of the constant current unit 220 is applied. A low level enable signal is applied to the enable terminal En.

That is, when a high level error output value (Tell tale) is applied, the controller 270 applies the high level enable signal to the constant current unit 220 so that the constant current unit 220 normally drives and outputs a constant current. When enabled and a low level error output value (Tell tale) is applied, a low level enable signal is applied to the constant current unit 220 to stop driving of the constant current unit 220 so as not to output a constant current. Enable it.

Since the constant current unit 220 does not output a constant current when at least one light emitting element L of the equalizer 230 is open due to a failure or the like and consumes no current, the constant current unit 220 turns off the entire equalizer 230. (Off)

As such, when the entire lighter 230 is turned off, no current flows in the lighter 230, and thus, the lighter 230 may be detected as not normal through a current sensor (not shown) that senses current. have. When the failure state of the equalizer 230 is detected through the current sensor as described above, the Tell-dale may be notified to the driver through the cluster, and thus the driver may be caused by the equalizer 230. The accident can be prevented in advance.

The Tel-tail circuit 200 of the vehicle LED lamp according to the present invention prevents the phenomenon of turning on and off for a while to detect a failure in the process of forcibly turning off all the LED lamps in the event of a failure of some of the vehicle LED lamps.

This prevents the user from mistaken the LED lamp for malfunction.

It will be apparent to those skilled in the art that various modifications, substitutions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. . The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

210-Constant Voltage Section 220-Constant Current Section
230-Equalization part 232-A plurality of light emitting element parts
234-TR 240-Light-emitting element power supply
250-Error Detection Unit 252-Comparison Unit
254-End Gate Section 260-Tel Tail Power Section
270 -

Claims (7)

A constant voltage unit including a capacitor and generating a reference voltage by receiving a vehicle power;
A constant current unit generating a constant current using the voltage generated by the constant voltage unit;
An equalizing unit including a plurality of light emitting device units connected in parallel with a light emitting device unit including a transistor for maintaining the constant current applied from the constant current unit and a plurality of light emitting devices connected in series;
A light emitting device power supply unit receiving the vehicle power to supply power to a plurality of light emitting devices of the light emitting unit; And
Teller of the vehicle LED lamp, characterized in that for comparing the voltage of the plurality of light emitting elements and the reference voltage, respectively, and outputs an error output value for whether at least one of the plurality of light emitting elements failure. -Tail circuit. The method of claim 1,
The tell-tail circuit of the vehicle LED lamp,
And a control unit electrically connected to the error detecting unit to control the enable signal applied to the enable end of the constant current unit by receiving the error output value. Circuit. The method of claim 1,
Tell-tail circuit of vehicle LED lamp is
Further comprising a teltail power supply for receiving the vehicle power, generating a power supplied to the error detection unit,
And the error detection unit operates by receiving power from the teltail power supply unit. The method of claim 1,
The error detector determines that the equalizer is normally driven when the voltages of the plurality of light emitting device parts are greater than the reference voltage, and outputs a high level error output value, and at least one of the plurality of light emitting device voltages. And if the voltage is less than the reference voltage, determine that the equalizer is abnormally driven, and output a low level error output value. 5. The method of claim 4,
The error detector includes: a comparison unit configured to compare voltages of the plurality of light emitting device units with the reference voltages, and output a result value; And
Tel-tail circuit of the vehicle LED lamp, characterized in that it comprises an end gate for checking whether all of the result values output from the plurality of comparison unit is a high level. 5. The method of claim 4,
When the high level error output value is applied, the controller applies the high level enable signal to the constant current unit to enable the constant current unit. When the low level error output value is applied, the control unit transmits the low level enable signal to the constant current unit. Tel-tail circuit of a vehicle LED lamp, characterized in that for applying to disable the constant current (Disable). 3. The method of claim 2,
And the control unit stops or drives an operation of the constant current unit by controlling an enable signal applied to the enable terminal of the constant current unit according to the error output value.

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