Circuit design of automobile tail light controller

It's too professional, so it's recommended to write something of your own.

Drivers and friends all know that when driving at night, the rear of the car should be turned on, so which switch is the switch control of the light taillight? Let's take a detailed look at the tail light switch.

There is no independent switch for the rear lights of the car, and the tail lights of the car are automatically turned on with the use of the headlights. The switch of the headlamp connecting the headlight to the tail light is on the control lever on the left side of the steering wheel, and the switch is screwed forward for the marker light, and the control lever is turned forward for the high beam. As soon as you turn on the headlights, whether you turn on the low or high beams, the car's tail lights will be on.

When driving at night, the tail light of the car is used to remind the oncoming car behind to know the existence of the car in front, and can show the distance and position relationship between the two cars. The design of the car tail lights is very scientific, in addition to having enough brightness to allow others to clearly distinguish their driving signals, it will not cause a sense of glare or other non-trembling comfort to the drivers of other vehicles or pedestrians on the road.

1) Take a yellow LED on the left and one on the right to show the left and right turning. Take a red LED on the left and one on the right to show the brake.

Stop the car? Also has a light indication? What kind of lamp will it be? Then use white LEDs;

2) I don't see it in Table 2-1; Will it be so?

k1 、k0

0, 0 -- parking.

0, 1 -- right steering.

1, 0 -- left steering.

1, 1 -- brakes.

Automobile headlights are also called headlights, and headlights mainly include low beams and high beams. The control circuit is mainly composed of light switches, light switches, headlight relays and headlights.

Light switch: Turn the end of the switch to turn on the low beam of the headlamp, press forward to change to high beam, and press back back to low beam.

Car headlights, also known as car headlights, car LED daytime running lights, as the eyes of the car, are not only related to the external image of a car owner, but also closely related to safe driving at night or in bad weather conditions. The use and maintenance of car lights cannot be ignored.

This kind of headlight control circuit is relatively common and is often used in European cars.

The conventional headlight control circuit is to use the dimmer switch to control the filament power supply of the high beam and low beam of the headlight, and the common end of the filament is directly grounded (lap iron).

This type of headlight circuit enables the grounding (lap iron) of the high beam and low beam of the headlamp to be controlled by a dimmer switch, and the common end of the two-light filament is directly connected to the power supply through the fuse.

When the high beam is on, the high beam end is controlled to the ground, and the negative pole (lap iron) is connected when measuring, and the low beam end is suspended at this time, and the low beam is not lit because there is no loop, and the voltage of the low beam foot is measured through the positive power supply voltage of the filament, and the same is true after the light is changed.

Therefore, the exchange of positive and negative lines between those two lines is just a misunderstanding.

The automobile tail light control circuit comprises a decoding circuit and a display drive circuit. Its display drive circuit consists of 6 light-emitting diodes and 6 inverters (7404); The decoding circuit consists of a 3-8-line decoder 74138 and 6 NAND gates (7400). The three inputs A, B, and C of the 74138 are connected to the outputs 1q and 2q of the ternary counter and the steering control switch [2].

When [2]=0, the enable signal g=0 (decoder working), s=1, and the state of the counter is , the output terminals Y0, Y1, and Y2 corresponding to 74138 are valid for "0" in turn, that is, the output of the inverter G1 G3 is also 0 in turn, so the indicator lights are lit in the order of D3 D2 D1. If the above conditions remain unchanged, and [2]=1, then the output terminal Y4, Y5, and Y6 corresponding to 74138 are valid for 0 in turn, that is, the output of the inverter G4 G6 is 0 in turn, so the indicator lights are lit in the order of D4 D5 D6. When g=1 (the decoder prohibits decoding) and s=1, the output of 74138 is 1, and the output of g1 and g6 is also 1, and the indicator lights are all off. When g = 1 and s = cp, the indicator flashes with the frequency of cp.

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