JP2005205968A - Lamp control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lamp control device capable of saving power. <P>SOLUTION: Plus power supply from a high voltage battery 11 is supplied to a lamp 31 with built-in headlight. A lamp ground line 15 from the lamp 31 is connected to a collector 33 of a power transistor 32 with built-in PWM driver 12. A base 35 of the power transistor 32 is connected to an output of a pulse transmission circuit 36. A first input 41 of the pulse transmission circuit 36 and a second input 42 are connected to a contact 18a for Lo beam of a light switch 17a and a contact 18b for Hi beam, respectively. The pulse transmission circuit 36 outputs pulse signals of different duty ratios at the first input 41 "L" time and the second input 42 "L" time to the power transistor 32, intermits and pulses DC voltage from the high voltage battery 11 and supplies the pulses to the lamp 31. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lamp control device that supplies power to a lamp provided in an automobile.

  Conventionally, automobiles have been provided with lamps such as headlights, and these lamps have been lit by an installed battery.

  Here, in a gasoline engine vehicle equipped with a 12V or 24V battery, the lamp can be turned on by using a general 12V or 24V lamp, but only a high voltage battery for driving the vehicle is provided. In an electric vehicle, the lamp described above cannot be directly connected and used.

  Therefore, such an electric vehicle is equipped with a lamp control device 101 as shown in FIG.

  That is, the output from the high voltage battery 111 is first input to the DC / DC converter 112 and supplied to the lamps 114 such as a headlight and a tail lamp via the switches 113. As a result, the high-voltage DC voltage from the high-voltage battery 111 is stepped down to a DC voltage of 12V, and the 12V lamp is lit.

  However, in such a lamp control device 101, when a 12V55W lamp is lit, it is necessary to mount a DC / DC converter 112 having an output of 55W. Here, in a normal vehicle, a head lamp, a tail lamp, a stop lamp, and the like are provided, and the total output thereof reaches 250 W, and a DC / DC converter 112 of 250 W or more is required.

  Further, when considering the conversion efficiency of the DC / DC converter 112, power of 300 W or more is consumed on the input side, and the internal loss of the DC / DC converter 112 always occurs even when there is no load, which is an obstacle to power saving. Can be.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a lamp control device capable of saving power.

  In order to solve the above-mentioned problem, in the lamp control device according to claim 1 of the present invention, in the lamp control device for lighting a lamp provided in an electric vehicle with a battery that outputs a high voltage for driving the vehicle, A PWM control unit is provided that intermittently pulses the output DC voltage and adjusts the width of each pulse according to the lamp and supplies the pulse to the lamp.

  That is, an electric vehicle is equipped with a battery that outputs a high voltage to drive the vehicle, and the battery cannot be lit by directly connecting it to a normal lamp.

  Therefore, by providing the PWM control unit, the DC voltage output from the battery is pulsed and the width of each pulse is adjusted according to the lamp, so that the supply power, that is, the work amount per unit time can be reduced. Adjustments are made. Then, the adjusted electric power is supplied to the lamp, and the lamp is turned on.

  In the lamp control device according to claim 2, the PWM control unit includes a high duty output in which the pulse occupies a high ratio per unit time, and a low duty output in which the pulse occupies a lower ratio than the high duty output. Is selectively output.

  For this reason, the brightness | luminance of the lighted lamp can be raised by performing a high duty output from a PWM control part. Moreover, the brightness | luminance of the lighted lamp can be made low by performing a low duty output from the said PWM control part.

  Thereby, the brightness | luminance of the lamp to light is varied.

  As described above, in the lamp control device according to the first aspect of the present invention, a normal lamp for low voltage can be turned on without stepping down the high voltage power output from the battery by the DC / DC converter. it can.

  As a result, the circuit can be reduced in size and cost as compared with the conventional case requiring a large DC / DC converter.

  In addition, since a large DC / DC converter that constantly generates internal loss even when there is no load can be eliminated, power loss can be reduced and power saving can be achieved.

  In the lamp control device according to the second aspect, the luminance of the lamp to be lit can be varied by selectively outputting the high duty output or the low duty output. Thereby, when this lamp is applied to a headlight that illuminates the front of the vehicle, it is possible to selectively use a high-luminance Hi beam and a low-luminance Lo beam.

  Further, the tail lamp provided at the rear of the vehicle is normally composed of a double filament lamp so that the brightness can be varied between when the light is turned on and when the brake is operated. Therefore, in the present invention, since the brightness of the lamp to be turned on can be varied, the function of the tail lamp can be realized by using a single filament lamp.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a lamp control device 1 according to the present embodiment. The lamp control device 1 is mounted on an electric vehicle, and is a device that supplies power to lamps such as a headlight, a tail lamp, a stop lamp, and a blinker lamp provided on the electric vehicle to light them.

  That is, the electric vehicle is equipped with only a high voltage battery 11 that outputs a high voltage to drive a large motor for traveling. The power source from the high voltage battery 11 is PWM (pulse width modulation). It is supplied to the PWM driver 12 constituting the control unit. Further, the supply line 13 connected to the positive electrode of the high voltage battery 11 is connected to the lamp loads 14,... Composed of the lamps, and the lamp grounds of the lamp loads 14,. The line 15 is connected to the PWM driver 12. The input lines 16,... Connected to the PWM driver 12 are connected to the contacts 18,... Of the switches 17,. The common terminals 19 are connected to the negative terminal of the high-voltage battery 11 through a ground line 21.

  On the other hand, as one of the switches 17, there is a light switch 17a for turning on the headlight. The light switch 17a includes a Lo beam contact 18a for lighting the lamp with low brightness and a Hi beam contact 18b for lighting the lamp with high brightness. The contacts 18a and 18b are connected to the input line 16 respectively. , 16 to the PWM driver 12.

  FIG. 2 is a diagram showing the details, and only a circuit for turning on the headlight will be described as an example.

  That is, positive power from the high voltage battery 11 is supplied to a lamp 31 with a built-in headlight via a supply line 13, and a lamp ground line 15 from the lamp 31 is a power transistor with a built-in PWM driver 12. 32 collectors 33 are connected. The emitter 34 of the power transistor 32 is connected to the ground line 21, and the base 35 is connected to the output of the pulse transmission circuit 36 built in the PWM driver 12.

  The first input 41 of the pulse transmission circuit 36 is connected to the Lo beam contact 18a of the light switch 17a, and the second input 42 of the pulse transmission circuit 36 is connected to the Hi beam of the light switch 17a. The contact 18b is connected. Thus, when the light switch 17a is switched to the Lo beam, the first input 41 changes from “H” to “L”, while when the light switch 17a is switched to the Hi beam. The second input 18b changes from “H” to “L”.

  The pulse transmission circuit 36 is configured to output a pulse signal to the power transistor 32 when “L” is input to the first input 41 or the second input 42. It is configured to output pulse signals having different duty ratios when the input 41 is “L” and when the second input 42 is “L”.

  The power transistor 32 to which this pulse signal is input is configured to be turned on / off in response to the pulse signal, and is configured to supply power to the lamp 31 when turned on and to shut off the power when turned off. . As a result, the DC voltage from the high voltage battery 11 can be intermittently pulsed and supplied to the lamp 31.

  In the PWM modulation output 51 supplied to the lamp 31 by the power transistor 32 that is turned on / off according to the pulse signal from the pulse transmission circuit 36, the width W of each pulse 52 is set to the lamp 31 used. It has been adjusted accordingly.

  More specifically, when the voltage supplied from the high voltage battery 11 is 83.6V and the standard value of the lamp 31 is 24V55W, the power consumed per unit time when the lamp 31 is lit is 55W. Thus, the width W of each pulse 52 in the PWM modulation output 51 is set.

  At this time, in the PWM modulation output 51, the duty ratio indicating the ratio of the pulse 52 per unit time is set when the light switch 17a is switched to the Lo beam and when switched to the Hi beam. When the Hi beam is selected, the high duty output 61 that the pulse 52 occupies is high, and when the Lo beam is selected, the pulse 52 occupies the high duty output 61. The low-duty output 62 with a low output is output. That is, when the Hi beam is selected, the high duty output 61 is set so that the power consumed when the lamp 31 is lit is 55 W. When the Lo beam is selected, the power consumed when the lamp 31 is lit The low duty output 62 is set to be less than 55W.

  In the present embodiment according to the above configuration, a normal electric vehicle is equipped with only a high voltage battery 11 that outputs a high voltage to drive a large motor for traveling. The 24V55W type lamp 31 cannot be directly lit.

  Therefore, by using the PWM driver 12 described above, the DC voltage output from the high voltage battery 11 is converted into a continuous pulse signal by pulsing, and the width W of each pulse 52 is adjusted according to the lamp 31. Thus, the supply power, that is, the work amount per unit time can be adjusted, and then supplied to the lamp 31.

  As a result, the general and easily available lamp 31 for 24V can be lit without trouble without stepping down the high-voltage power source output from the high-voltage battery 11 with a DC / DC converter. Therefore, the circuit can be reduced in size and cost as compared with the conventional case requiring a large DC / DC converter.

  In addition, since a large DC / DC converter that constantly generates internal loss even when there is no load can be eliminated, power loss can be reduced and power saving can be achieved.

  The luminance of the lit lamp 31 can be increased by performing the high duty output 61 from the PWM driver 12. Further, the luminance of the lit lamp 31 can be lowered by performing the low duty output 62 from the PWM driver 12.

  Thus, by selectively outputting the high duty output 61 or the low duty output 62, the luminance of the lamp 31 to be lit can be varied. Therefore, in the present embodiment in which the lamp 31 is applied to a headlight that illuminates the front of the vehicle, it is possible to selectively use a high-intensity Hi beam and a low-intensity Lo beam.

  Further, the present invention can be applied to a tail lamp provided at the rear of the vehicle. In other words, this tail lamp is usually composed of a double filament lamp, and is configured so that the luminance can be varied between when the light is turned on and when the brake is operated. Therefore, since the brightness of the lamp 31 to be lit can be varied as described above, the function of the tail lamp can be realized by using a single filament lamp.

  In this case, the selection range of the red lens in the tail lamp can be widened, and the degree of design freedom can be increased.

It is a block diagram which shows one embodiment of this invention. It is explanatory drawing which shows the detail of the principal part of the embodiment. It is a block diagram which shows the conventional lamp control apparatus.

Explanation of symbols

1 Lamp Controller 11 High Voltage Battery 12 PWM Driver 31 Lamp 51 PWM Modulation Output 52 Pulse 61 High Duty Output 62 Low Duty Output W Width

Claims (2)

In a lamp control device for lighting a lamp provided in an electric vehicle with a battery that outputs a high voltage for driving the vehicle,
A lamp control device comprising: a PWM control unit that intermittently pulses a DC voltage output from the battery and adjusts the width of each pulse according to the lamp and supplies the pulse to the lamp. The PWM control unit selectively outputs a high duty output with a high ratio of the pulses per unit time and a low duty output with a low ratio of the pulses with respect to the high duty output. Item 2. A lamp control device according to item 1.

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