CN101239598A - Car light multiplexing control method and car light multiplexing control circuit - Google Patents

Abstract

The invention discloses a lights multiplexing control method and the relative lights multiplexing control circuit, which can use stop lights to imitate the working conditions of latter position lights or latter changing lights which have breakdowns when the latter position lights or the latter changing lights get breakdowns, so as to replace the latter position lights or latter changing lights which have breakdowns. The lights multiplexing control circuit includes main chips and stop lights drive chips, wherein, the main chips send out switch control signals to the drive chips of the latter position lights or the latter changing lights which have breakdowns when the latter position lights or the latter changing lights have breakdowns, and the powers of the latter position lights or the latter changing lights are turned off; PWM signals are outputted to the drive chips of the stop lights by the main chips, and the frequency and the duty cycle of the PWM signals are controlled, so that the working conditions of the latter position lights or the latter changing lights can be imitated. The invention controls the working conditions of the stop lights by the PWM signals, and can imitate the working conditions of the latter position lights or the latter changing lights which have breakdowns.

Description

Car light multiplexing control method and car light multiplexing control circuit

Technical field

The present invention relates to a kind of vehicle light control method and correspondent control circuits thereof, particularly a kind of control method and correspondent control circuits thereof that is used for the motor vehicle rear car light

Background technology

On express highway, the catastrophic discontinuityfailure of car light is the one of the main reasons that causes traffic accident, wherein makes the rear-end collision that forms and increases gradually because of Rear Position Lamp or rear directional damage, and this problem be there is no suitable solution at present.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of car light multiplexing control method, can be when Rear Position Lamp or rear directional break down, the Rear Position Lamp that breaks down with stoplight stop lamp simulation or the mode of operation of rear directional are with temporary transient this Rear Position Lamp that breaks down or rear directional of substituting.

For solving the problems of the technologies described above, car light multiplexing control method of the present invention comprises the steps: when Rear Position Lamp or rear directional break down, master chip sends the chip for driving of switch controlling signal to Rear Position Lamp that breaks down or rear directional, closes Rear Position Lamp or rear directional power supply; The master chip output pwm signal is to the stoplight stop lamp chip for driving, and the frequency and the dutycycle of control pwm signal, makes the Rear Position Lamp that the stoplight stop lamp simulation breaks down or the mode of operation of rear directional.

When described Rear Position Lamp breaks down, the frequency that described master chip exports the described pwm signal of described stoplight stop lamp chip for driving to is 20KHz～30KHz, the dutycycle of described pwm signal is 0.4～0.6, and aforementioned dutycycle calculates according to the principle that power equates.

When described rear directional broke down, the frequency that described master chip exports the described pwm signal of described stoplight stop lamp chip for driving to was 90KHz～110KHz, and the dutycycle of described pwm signal is 0.5.

The present invention is by the mode of operation of pwm signal control stoplight stop lamp, can make the Rear Position Lamp that its simulation breaks down or the mode of operation of rear directional.

Another technical matters to be solved by this invention provides a kind of car light multiplexing control circuit, can be when Rear Position Lamp or rear directional break down, make the Rear Position Lamp that the stoplight stop lamp simulation breaks down or the mode of operation of rear directional.

For addressing the above problem, the present invention includes master chip, master chip can be accepted the breakdown signal that the chip for driving of Rear Position Lamp or rear directional is sent; And after accepting this breakdown signal, send the chip for driving of switch controlling signal to Rear Position Lamp that breaks down or rear directional, close Rear Position Lamp or rear directional power supply; Output pwm signal is to the stoplight stop lamp chip for driving then, and the frequency and the dutycycle of control pwm signal, makes the Rear Position Lamp that the stoplight stop lamp simulation breaks down or the mode of operation of rear directional; Comprise the stoplight stop lamp chip for driving, can accept from the pwm signal of master chip and control the mode of operation of stoplight stop lamp.

Master chip of the present invention can send pwm signal to the stoplight stop lamp chip for driving, the Rear Position Lamp that the simulation of control stoplight stop lamp is broken down or the mode of operation of rear directional.

Description of drawings

Fig. 1 is that the present invention is applied to the multiplexing schematic block circuit diagram of Rear Position Lamp;

Fig. 2 is that the present invention is applied to the multiplexing schematic block circuit diagram of rear directional.

The specific embodiment

The present invention is further detailed explanation below in conjunction with accompanying drawing.

Car light multiplexing control circuit of the present invention comprises master chip and stoplight stop lamp chip for driving as depicted in figs. 1 and 2, and wherein master chip is monitored rear directional and Rear Position Lamp in real time in running state.By car light multiplexing control method of the present invention, as find Rear Position Lamp or rear directional fault, master chip promptly sends pwm signal to the stoplight stop lamp chip for driving, open stoplight stop lamp, and the frequency by adjusting pwm signal and dutycycle make stoplight stop lamp serve as the Rear Position Lamp or the rear directional of et out of order with the mode of operation of control stoplight stop lamp temporarily.The stoplight stop lamp chip for driving can be accepted from the pwm signal of master chip and control the mode of operation of stoplight stop lamp.

When chaufeur was opened certain car light, the master chip in the car light multiplexing control circuit of the present invention was monitored Rear Position Lamp and rear directional by the fault diagnosis signal of Rear Position Lamp chip for driving or rear directional chip for driving feedback.

For the brightness that guarantees stoplight stop lamp consistent with superseded Rear Position Lamp brightness, master chip by the PWM mode to stoplight stop lamp brightness adjust.When Rear Position Lamp broke down, for security consideration, master chip at first was changed to low level with the input pin of two Rear Position Lamp chip for driving, closes the Rear Position Lamp power supply, and output pwm signal is to the chip for driving input pin of stoplight stop lamp, as shown in Figure 1 then.Master chip makes the brightness of stoplight stop lamp consistent with Rear Position Lamp brightness by adjusting the frequency and the dutycycle of pwm signal, serves as Rear Position Lamp and uses.The control of pwm signal requires as follows: the frequency requirement of pwm signal is controlled at 20KHz～30KHz scope, and the underfrequency car light will scintillation, and frequency is too high, can cause the temperature rise of stoplight stop lamp chip for driving too fast; The pwm signal dutycycle calculates according to the principle that power equates, is generally 0.4～0.6.Concerning power was the Rear Position Lamp of 5W, the frequency of pwm signal was 22KHz, and the pwm signal dutycycle is 0.5.

When Rear Position Lamp broke down, the calculating principle of dutycycle was by adjusting the PWM dutycycle, make stoplight stop lamp identical with the brightness of not under command light, promptly keeping both power to equate.If stoplight stop lamp power is X watt, hot stable state internal resistance is Rx; Not under command light power is Y watt, and hot stable state internal resistance is Ry; The car load cell pressure is the V volt.Then have: X=(V*V)/Rx, Y=(V*V)/Ry.After using pwm signal that stoplight stop lamp is controlled, the dutycycle of establishing the pwm signal of control stoplight stop lamp is P, and then the power of stoplight stop lamp is: Xp=(P*V) * (P*V)/Rx=(P*P) X.For concrete car light, X and Y numerical value are known, according to the principle of setting previously, can draw Xp=Y, and promptly (P*P) X=Y separates this equation, can get pwm signal dutycycle P,$P=\sqrt{Y/X}.$

When rear directional broke down, master chip at first sent switch controlling signal and gives the rear directional chip for driving, closes the rear directional power supply; Start timer then, every the input pin state of a stoplight stop lamp chip for driving of time change of 1/90 second～1/110 second, as shown in Figure 2, stoplight stop lamp will be realized the steering indicating light function with the frequency scintillation of 90Hz～110Hz; The dutycycle of pwm signal is 0.5, and dutycycle is 0.5 can guarantee stoplight stop lamp when flicker, and the light and shade time equates.Concerning general rear directional, the flicker frequency of stoplight stop lamp can be 100Hz, and dutycycle is 0.5.

The car light multiplexing function that car light multiplexing control method and car light multiplexing control circuit of the present invention provided can avoid because the potential safety hazard that Rear Position Lamp or rear directional catastrophic failure are caused, the safety that improves car load.

Claims (6)

1. a car light multiplexing control method is characterized in that, comprises the steps:

When Rear Position Lamp or rear directional broke down, master chip sent the chip for driving of switch controlling signal to Rear Position Lamp that breaks down or rear directional, closes Rear Position Lamp or rear directional power supply;

The master chip output pwm signal is to the stoplight stop lamp chip for driving, and the frequency and the dutycycle of control pwm signal, makes the Rear Position Lamp that the stoplight stop lamp simulation breaks down or the mode of operation of rear directional.

2. car light multiplexing control method according to claim 1, it is characterized in that, when described Rear Position Lamp breaks down, the frequency that described master chip exports the described pwm signal of described stoplight stop lamp chip for driving to is 20KHz～30KHz, the dutycycle of described pwm signal is 0.4～0.6, and aforementioned dutycycle calculates according to the principle that power equates.

3. car light multiplexing control method according to claim 2 is characterized in that, the frequency of described pwm signal is 22KHz, and the dutycycle of described pwm signal is 0.5.

4. car light multiplexing control method according to claim 1, it is characterized in that, when described rear directional broke down, the frequency that described master chip exports the described pwm signal of described stoplight stop lamp chip for driving to was 90KHz～110KHz, and the dutycycle of described pwm signal is 0.5.

5. car light multiplexing control method according to claim 4 is characterized in that, the frequency of described pwm signal is 100KHz.

6. a car light multiplexing control circuit is characterized in that, comprising:

Master chip, master chip can be accepted the breakdown signal that the chip for driving of Rear Position Lamp or rear directional is sent; And after accepting this breakdown signal, send the chip for driving of switch controlling signal to Rear Position Lamp that breaks down or rear directional, close Rear Position Lamp or rear directional power supply; Output pwm signal is to the stoplight stop lamp chip for driving then, and the frequency and the dutycycle of control pwm signal, makes the Rear Position Lamp that the stoplight stop lamp simulation breaks down or the mode of operation of rear directional;

The stoplight stop lamp chip for driving can be accepted from the pwm signal of master chip and controls the mode of operation of stoplight stop lamp.

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