Tail lamp circuit

Abstract

The invention relates to the technical field of vehicle lamp control, in particular to a tail lamp circuit which comprises a capacitor diode module, an MOS tube module, a signal conversion module, a triode brightness comparison module, a brightness multiplexing LED load and a position lamp load. The triode brightness comparison module is connected with the capacitance diode module and the signal conversion module, and is used for controlling a brightness multiplexing LED load to carry out brightness adjustment according to the input combination of the position lamp power line, the brake power line and the tail gate opening signal line; and the brightness multiplexing LED load is connected with the triode brightness comparison module, adjusts the brightness through the triode brightness comparison module, independently realizes the brightness of the brake lamp, or realizes the brightness of the position lamp or the brightness of the brake lamp through superposition lightening with the position lamp load. According to the invention, the brightness of the position lamp is increased through the brightness multiplexing LED load; and the logic control of brightness adjustment is realized through discrete components, so that the cost is reduced on the premise of ensuring the quality.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle light control, and in particular to a tail light circuit. Background Art

[0002] Taillights are lamps installed at the rear of a vehicle. Some taillights are either fixed or movable. Movable taillights are mounted on the trunk, while fixed taillights are mounted on the vehicle's bodywork outside the tailgate. Typical functions include position lights, turn signals, brake lights, fog lights, and reverse lights. Position lights facilitate visibility for vehicles behind, indicating the vehicle's current state. Turn signals alert vehicles behind to impending left or right turns. Brake lights warn vehicles behind that the vehicle is braking and urge them to maintain a safe distance. Fog lights are used in foggy conditions to provide a timely warning to vehicles behind. Reverse lights indicate that vehicles behind are about to reverse or have already reversed. Existing technology typically uses a single LED to achieve two different brightness levels. For example, the position and brake lights use the same LED model and number to achieve two brightness levels. If the movable position light LED is off, the fixed position light needs to increase its brightness to ensure that the position light meets regulatory requirements. Increasing the brightness of the position lights on the fixed side generally requires a circuit solution with a chip, which is relatively expensive. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: In order to overcome the above technical problems, the present invention provides a taillight circuit.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a taillight circuit, in which a body control module (BCM) provides a brake power line, a position light power line, and a tailgate opening signal line. The taillight circuit includes a capacitor diode module, a MOS tube module, a signal conversion module, a transistor brightness comparison module, a brightness multiplexing LED load, and a position light load;

[0005] The MOS tube module is connected to the position light power line and is used to separate the position light power line state into a power supply line and a signal line;

[0006] The capacitor diode module is connected to the MOS tube module and the brake power line, and is used to perform front-end preprocessing on the brake power output by the brake power line, and the front-end preprocessing includes capacitor filtering and diode voltage division;

[0007] The signal conversion module is connected to the capacitor diode module and the tailgate opening signal line, and is used to convert the tailgate opening signal output by the tailgate opening signal line into a processing signal required by the subsequent circuit;

[0008] The transistor brightness comparison module is connected to the capacitor diode module and the signal conversion module, and is used to control the brightness of the brightness multiplexing LED load to adjust the brightness according to the input combination of the position light power line, the brake power line and the tailgate opening signal line;

[0009] The position light load provides basic position light brightness; the basic position light brightness can be set or adjusted according to actual conditions and regulations.

[0010] The brightness-multiplexing LED load is connected to a transistor brightness comparison module, which adjusts the brightness to achieve the brightness of the brake light alone or in combination with the position light load to achieve the brightness of either the position light or the brake light. The brightness-multiplexing LED load is an LED that meets the optical requirements of the position light, the brake light, and the tailgate opening. The position light load is a combination of red LEDs that meet the chromaticity requirements of the position light.

[0011] The transistor brightness comparison module is configured to control the brightness multiplexing LED load to present three brightness levels according to the input combination of the position light power line, the brake power line and the tailgate opening signal line; the brightness multiplexing LED load:

[0012] When only the brake power line is input, the brake light brightness is output separately;

[0013] When the position light power is input, it is lit in conjunction with the position light load to achieve the basic brightness of the position light or the increased brightness of the position light.

[0014] The transistor brightness comparison module controls the brightness of the multiplexed LED load to present:

[0015] When only brake power is input, the output is brake light brightness;

[0016] When only the position light power line is input and the tailgate is closed, the first brightness is output, and together with the position light load, the first position light brightness is provided to achieve the brightness of the position light function;

[0017] When only the position light power line is input and the tailgate is open, the second brightness is output, and together with the position light load, the second position light brightness is provided to achieve increased brightness of the position light.

[0018] The capacitor-diode module includes a filter capacitor, an anti-pulse diode D3 and a voltage-dividing resistor R1. The filter capacitor, anti-pulse diode D3 and the voltage-dividing resistor R1 are all connected in parallel to the brake power line. The capacitor-diode module outputs a STOP / POS signal network and a STOP power network.

[0019] The MOS tube module includes a position light power front-end processing circuit and a separation circuit. The position light power front-end processing circuit is connected to the position light power line to perform front-end processing and output the POS power network.

[0020] The separation circuit includes:

[0021] A first PMOS transistor Q6 has a source coupled to the position light power line and a drain coupled to the STOP / POS signal network;

[0022] A first NMOS transistor Q7, a gate of which is coupled to the POS power network via a first resistor R26;

[0023] a second NMOS transistor Q8 , having a gate coupled to the STOP power supply network and a drain coupled to the gate of the first NMOS transistor Q7 ;

[0024] When the brake power is input, the second NMOS transistor Q8 is turned on to turn off the first NMOS transistor Q7 and turn on the first PMOS transistor Q6; when the position light power is input, the first NMOS transistor Q7 is turned on to turn on the first PMOS transistor Q6.

[0025] The signal conversion module includes a first transistor Q15, a second transistor Q19, a third transistor Q9, and a second PMOS transistor Q10. The base of the first transistor Q15 is coupled to the tailgate opening signal line. The collector of the first transistor Q15 outputs a control signal to the collector of the second transistor Q19 and the base of the third transistor Q9. The first transistor Q15, the second transistor Q19, and the third transistor Q9 are all provided with a base bias circuit.

[0026] The source of the second PMOS transistor Q10 is coupled to the POS power network, the gate of the second PMOS transistor Q10 is coupled to the collector of the third transistor Q9, and the drain of the second PMOS transistor Q10 outputs the Open_Sig network;

[0027] A base of the second transistor Q19 is coupled to the STOP power network, and a collector of the second transistor Q19 is coupled to the POS network.

[0028] The position light load includes several groups of serially connected LEDs, each group of serially connected LEDs includes multiple LEDs connected in series, and the positive poles of each group of serially connected LEDs are connected to the POS power supply network through independent driver chips.

[0029] The transistor brightness comparison module includes:

[0030] A third NMOS transistor Q11 has a gate coupled to the STOP / POS signal network and a source grounded;

[0031] A fourth NMOS transistor Q12 has a gate coupled to the Open_Sig network and a source grounded;

[0032] A fifth NMOS transistor Q5 has a gate coupled to the STOP power supply network and a source grounded;

[0033] a fourth transistor Q1 , having a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the third NMOS transistor Q11 ;

[0034] a fifth transistor Q2 , having a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the fourth NMOS transistor Q12 ;

[0035] a sixth transistor Q3 , having a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the fifth NMOS transistor Q5 ;

[0036] The seventh transistor Q4 has a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the fifth NMOS transistor Q5 .

[0037] The first resistor group is connected in series between the emitter of the fourth transistor Q1 and the drain of the third NMOS transistor Q11. The second resistor group is connected in series between the emitter of the fourth NMOS transistor Q2 and the drain of the fourth NMOS transistor Q12. The third resistor group is connected in series between the emitter of the sixth transistor Q3 and the drain of the fifth NMOS transistor Q5. The fourth resistor group is connected in series between the emitter of the seventh transistor Q4 and the drain of the fifth NMOS transistor Q5. The sixth and seventh transistors Q3 and Q4 are both coupled to the fifth NMOS transistor Q5, forming a two-way switching circuit. When the brake light receives power, two current paths can be used to increase current.

[0038] When only the position light power supply is input and the tailgate is closed, the third NMOS transistor Q11 is turned on, causing the fourth transistor Q1 to be turned on. The brightness multiplexing LED load forms a current loop through the first resistor group, outputting a first brightness, and jointly providing the first position light brightness with the position light load to achieve the brightness of the position light function.

[0039] When only the position light power supply is input and the tailgate is open, the third NMOS transistor Q11 and the fourth NMOS transistor Q12 are turned on, so that the fourth transistor Q1 and the fourth NMOS transistor Q2 are turned on. The brightness multiplexing LED load forms a current loop through the first resistor group and the second resistor group connected in parallel, outputs a second brightness, and together with the position light load provides the second position light brightness, thereby achieving increased brightness of the position light.

[0040] When the brake power is input, the fifth NMOS tube Q5 and the seventh transistor Q4 are both turned on, and the brightness multiplexing LED load forms a current loop through the first resistor group, the second resistor group, the third resistor group and the fourth resistor group connected in parallel, and outputs the third brightness. At this time, the brightness is the maximum, corresponding to the brightness of the brake light.

[0041] The brightness multiplexing LED load includes 4 groups of series LEDs, each group of series LEDs is composed of 2 LEDs in series, and the positive electrode of each group of series LEDs is connected to the STOP / POS signal network through a buffer resistor, and the negative electrode of each group of series LEDs is connected to the STOP / POS-network through a balancing resistor.

[0042] The beneficial effects of the present invention are as follows: in a taillight circuit of the present invention, when the active side position light is off, the brightness of the position light is increased by brightness multiplexing LED load to ensure the brightness of the active side position light; the logic control of adjusting the brightness is realized by discrete components, and the cost is reduced while ensuring the quality; by multiplexing the braking LED into the position light brightness, it is possible to use fewer position light LEDs and low-power position light LEDs to meet position regulations; the solution is simple and has great cost advantages, and there is no need to use complex microprocessor units and linear chips. The transistor brightness comparison module uses a logic circuit and a transistor constant current circuit, and the same LED can achieve three brightness changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a system block diagram of the taillight circuit of the present invention.

[0044] Figure 2 1 is a circuit diagram of the capacitor-diode module of the present invention.

[0045] Figure 3 This is a circuit diagram of the MOS tube module of the present invention.

[0046] Figure 4 It is a circuit diagram of the signal conversion module of the present invention.

[0047] Figure 5 This is a circuit diagram of the position lamp load-1 of the present invention.

[0048] Figure 6 This is a circuit diagram of the position lamp load-2 of the present invention.

[0049] Figure 7 This is a circuit diagram of the position light driving module-1 of the present invention.

[0050] Figure 8 This is a circuit diagram of the position light driver module-2 of the present invention.

[0051] Figure 9 This is a circuit diagram of the position light driver module-3 of the present invention.

[0052] Figure 10 It is a circuit diagram of the triode brightness comparison module of the present invention.

[0053] Figure 11 1 is a circuit diagram of a brightness multiplexing LED load according to the present invention.

[0054] Figure 12 It is the comprehensive truth value diagram of the position light, brake light and tailgate opening of the present invention. DETAILED DESCRIPTION

[0055] The present invention will now be described in further detail with reference to the accompanying drawings. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope of the present invention and its application.

[0056] like Figure 1 As shown, a taillight circuit of the present invention is provided with a brake power line, a ground line, a position light power line and a tailgate opening signal line by a body control module. The taillight circuit includes a capacitor diode module, a MOS tube module, a signal conversion module, a transistor brightness comparison module, a brightness multiplexing LED load and a position light load.

[0057] The MOS tube module is connected to the position light power line and is used to separate the position light power line status into the power supply line and the signal line.

[0058] The capacitor diode module connects the MOS tube module and the brake power line and is used to perform front-end preprocessing on the brake power output by the brake power line. The front-end preprocessing includes capacitor filtering and diode voltage division.

[0059] The signal conversion module is connected to the capacitor diode module and the tailgate opening signal line, and is used to convert the tailgate opening signal output by the tailgate opening signal line into a processing signal required by the subsequent circuit.

[0060] The transistor brightness comparison module is connected to the capacitor diode module and the signal conversion module, and is used to control the brightness multiplexing LED load to adjust the brightness according to the input combination of the position light power line, the brake power line and the tailgate opening signal line.

[0061] Position light load provides basic position light brightness; basic position light brightness can be set or adjusted according to actual conditions and regulations.

[0062] A brightness-multiplexing LED load is connected to a transistor brightness comparison module. The module adjusts the brightness to achieve the brightness of the brake light alone, or to illuminate the position light load in combination with the position light load to achieve the brightness of either the position light or the brake light. The brightness-multiplexing LED load is an LED that meets the optical requirements of the position light, the brake light, and the tailgate opening. The position light load is a combination of red LEDs that meet the chromaticity requirements of the position light.

[0063] In this embodiment, the transistor brightness comparison module is configured to control the brightness multiplexing LED load to present three brightness levels according to the input combination of the position light power line, the brake power line and the tailgate opening signal line; the brightness multiplexing LED load:

[0064] When only the brake power line is input, the brake light brightness is output separately;

[0065] When the position light power is input, it is lit in conjunction with the position light load to achieve the basic brightness of the position light or the increased brightness of the position light.

[0066] The transistor brightness comparison module controls the brightness of the multiplexed LED load to present:

[0067] When only brake power is input, the output is brake light brightness;

[0068] When only the position light power line is input and the tailgate is closed, the first brightness is output, and together with the position light load, the first position light brightness is provided to achieve the brightness of the position light function;

[0069] When only the position light power line is input and the tailgate is open, the second brightness is output, and together with the position light load, the second position light brightness is provided to achieve increased brightness of the position light.

[0070] The present invention can adjust the brightness of the brightness multiplexing LED load in three different working conditions. Among them, the brightness of the brightness multiplexing LED load is the highest when the brake light function is in operation, followed by the brightness of the position light boost, and finally the brightness of the position light function.

[0071] like Figure 2 As shown in the figure, the brake power input first passes through the front-end anti-pulse protection of anti-pulse diode D3, and then is filtered by large capacitor C1 and small capacitor C2. R1 is a shunt resistor. The capacitor-diode module forms the STOP / POS signal network and the STOP power network.

[0072] like Figure 3 As shown, the MOS tube module includes a position light power front-end processing circuit and a separation circuit. The position light power front-end processing circuit is connected to the position light power line to perform front-end processing and output the POS power network.

[0073] The separation circuit includes:

[0074] A first PMOS transistor Q6 has a source coupled to the position light power line and a drain coupled to the STOP / POS signal network;

[0075] A first NMOS transistor Q7, a gate of which is coupled to the POS power network via a first resistor R26;

[0076] The second NMOS transistor Q8 has a gate coupled to the STOP power network, and a drain coupled to the gate of the first NMOS transistor Q7.

[0077] D7 is a 9.1V Zener diode. The source of pin 2 of the first PMOS transistor Q6 is connected to the input voltage, and the drain of pin 3 is connected to the STOP / POS signal network. When the source potential of the first PMOS transistor Q6 is greater than the gate potential, and the voltage difference is greater than the gate-source turn-on voltage, the first PMOS transistor Q6 turns on, i.e., the switch closes, outputting the STOP / POS network. The gate of pin 1 of the first PMOS transistor Q6 is connected to pin 3 of the first NMOS transistor Q7 through resistor R22. The first pin of the second NMOS transistor Q8 is connected to the STOP power line, and the third pin is connected to the first resistor R26. When the brake light power supply is input, the source of the second NMOS transistor Q8 is grounded. When the gate-source voltage exceeds the turn-on voltage threshold, the second NMOS transistor Q8 turns on, closing the switch. At this time, the drain of the second NMOS transistor Q8 is at a low level. When the position light power is input, the other end of the first resistor R26 has a voltage, and at this time, the gate of the first NMOS transistor Q7 has a voltage. When the gate-source voltage of the first NMOS transistor Q7 is greater than the turn-on voltage threshold, the first NMOS transistor Q7 is turned on, and the switch is closed. That is, the drain of the first NMOS transistor Q7 is at a low level, and the first PMOS transistor Q6 is turned on.

[0078] like Figure 4 As shown, the signal conversion module includes a first transistor Q15, a second transistor Q19, a third transistor Q9 and a second PMOS transistor Q10. The base of the first transistor Q15 is coupled to the tailgate opening signal line, and the collector of the first transistor Q15 outputs a control signal to the collector of the second transistor Q19 and the base of the third transistor Q9. The first transistor Q15, the second transistor Q19 and the third transistor Q9 all have a base bias circuit; the source of the second PMOS transistor Q10 is coupled to the POS power network, the gate of the second PMOS transistor Q10 is coupled to the collector of the third transistor Q9, and the drain of the second PMOS transistor Q10 outputs the Open_Sig network; the base of the second transistor Q19 is coupled to the STOP power network, and the collector of the second transistor Q19 is coupled to the POS network.

[0079] The tailgate opening signal line first passes through diode T4 and anti-reverse diode D6, and is then divided by resistor R71. C42 is the base bias capacitor for the first transistor Q15, and R72 is the base control resistor for the first transistor Q15. The STOP power network is first connected to the base of the second transistor Q19 through R79. Capacitor C43 and resistor R81 are the base bias components for the second transistor Q19. The collector of the second transistor Q19 is connected to the POS power network through resistor R46. D8 is a Zener diode. The source of the second pin of the second PMOS transistor Q10 is connected to the POS power network. The gate of the first pin of the second PMOS transistor Q10 is connected to the collector of the third transistor Q9 through resistor R62. Similarly, capacitor C52 and resistor R47 are the base bias components for Q9. When the position light power is input, the source of the second PMOS transistor Q10 is connected to the POS power network. When the gate-source voltage is greater than the minimum turn-on voltage, the second PMOS transistor Q10 is turned on, i.e., the switch is closed. The third pin of the second PMOS transistor Q10 outputs the Open_Sig network.

[0080] like Figure 5 、 Figure 6 The following are two sets of position light loads. Each set of position light loads contains three sets of series-connected LEDs. Each set of series-connected LEDs contains 2-3 LEDs connected in series. Figure 5 As shown, PL1, PL2, and PL3 form a group of LEDs connected in series. Small capacitors PC1, PC2, and PC3 are connected in parallel next to each LED, serving as protective components during anti-interference testing. The positive terminal of PL1 is connected to the TL1+ network. The negative terminal of PL3 is connected to the GND network. Similarly, PL4, PL5, and PL6 are also connected in series as a group. PC4, PC5, and PC6 are the filter capacitors for the LEDs. The positive terminal of PL4 is connected to the TL2+ network, and the negative terminal of PL6 is connected to the GND network. PL7 and PL8 are connected in series to ensure the same average current across each group, ensuring uniform brightness. Resistors R66 and R63 are connected in parallel to share a certain voltage. The positive terminal of PL7 is connected to the TL3+ network, and R66 and R63, in parallel, are connected to the GND network. Figure 6In the diagram, PL9, PL10, and PL11 are connected in series as a group, while PC9, PC10, and PC11 are parallel capacitors. PL9's positive terminal is connected to the TL4+ network, and PL11's negative terminal is connected to the GND network. PL12, PL13, and PL14 are connected in series as a group, with PC12, PC13, and PC14 acting as parallel capacitors. PL12's positive terminal is connected to the TL5+ network, and PL14's negative terminal is connected to the GND network. PL15 and PL16 are connected in series, with resistors R65 and R65 connected in parallel. PL15's positive terminal is connected to the TL6+ network, and the parallel resistors are connected to the GND network. Each of the TL1+, TL2+, TL3+, TL4+, TL5+, and TL6+ networks has a capacitor to ground.

[0081] The position light load is driven by the position light driver module, which connects the MOS tube module and the position light load. Figure 7 、 Figure 8 、 Figure 9 As shown, the position light driver module uses a linear chip. The position light load uses 6 sets of series-connected LEDs. In order to ensure that the power of a single chip does not exceed the maximum temperature resistance, this embodiment uses Figure 7 、 Figure 8 The two chips shown are used to drive the position light load. Figure 7 In the diagram, the first pin of driver chip U3 is connected to a large ground capacitor C32. Sampling resistors R31, R34, R38, and R33 are connected to the POS power network at one end, and their other ends are connected to pins 2 through 5 of driver chip U3. By adjusting the resistor values, the brightness of the LEDs in the position light load can be adjusted. R39 is a pull-down resistor for pin 5 of driver chip U3. R36 is a pull-up resistor for output voltage diagnosis of driver chip U3, and R40 is a pull-down resistor. Pin 9 of driver chip U3 is the open circuit diagnostic feedback pin and is connected to capacitor C25. Pin 10 is the enable pin of driver chip U3. R75 is connected to the POS power network at one end and to R77 and pin 10 of driver chip U3 at the other end. R77 is an enable pull-down resistor. By varying the resistance values ​​of resistors R75 and R77, the enable voltage of driver chip U3 can be adjusted. Pins 11 and 12 of driver chip U3 are connected to the TL3+ network. The 13th and 14th pins of the driver chip U3 are connected to the TL2+ network, and the 15th and 16th pins of the driver chip U3 are connected to the TL1+ network. The driver chip U3 can control the brightness of the 8 LEDs in the position light load. Similarly, Figure 8In the diagram, pin 1 of driver chip U2 is connected to capacitor C12, which is connected to ground. Sampling resistors R21, R23, R29, and R30 are connected to the POS network at one end, and their other ends are connected to pins 2 through 5 of driver chip U2. By adjusting the resistor values, the brightness of the LED in the position light load can be adjusted. R35 is a pull-down resistor for pin 5 of driver chip U2. R37 is a pull-up resistor for output voltage diagnosis of driver chip U2, and R41 is a pull-down resistor. Pin 9 of driver chip U2 is the open circuit diagnostic feedback pin and is connected to capacitor C26. Pin 10 is the enable pin of driver chip U2. R76 is connected to the POS power network at one end and to R78 and pin 10 of driver chip U2 at the other end. R78 is an enable pull-down resistor. By varying the resistance values ​​of resistors R76 and R78, the enable voltage of driver chip U2 can be adjusted. Pins 11 and 12 of driver chip U2 are connected to the TL6+ network. The 13th and 14th pins of driver chip U2 are connected to the TL5+ network, and the 15th and 16th pins of driver chip U2 are connected to the TL4+ network. Driver chip U2 can control the brightness of the eight LEDs in the position light load. To ensure that if one LED in the position light load opens, the remaining LEDs will not light. The ninth pin of driver chip U3 and the ninth pin of driver chip U2 are connected together, connected to the FAULT-2 network. The FAULT-2 network is an error cascade pin. If one LED in each channel of each driver chip opens, the FAULT-2 network tells the remaining driver chips to turn off all LEDs, thus achieving a one-out-all-out situation. Figure 9 In Figure 1, the base of transistor Q17 is connected to the FAULT-2 network, the emitter is connected to the POS power network, and the collector of transistor Q17 is connected to the ground resistor R89. The base of transistor Q18 is connected to the resistor R88, the collector is connected to the Zener diode D16, and the emitter is connected to the GND network. Figure 7-9 In the figure, the FAULT-2 network is represented by F.

[0082] like Figure 10 As shown, the transistor brightness comparison module includes:

[0083] A third NMOS transistor Q11 has a gate coupled to the STOP / POS signal network and a source grounded;

[0084] A fourth NMOS transistor Q12 has a gate coupled to the Open_Sig network and a source grounded;

[0085] A fifth NMOS transistor Q5 has a gate coupled to the STOP power supply network and a source grounded;

[0086] a fourth transistor Q1 , having a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the third NMOS transistor Q11 ;

[0087] a fifth transistor Q2 , having a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the fourth NMOS transistor Q12 ;

[0088] a sixth transistor Q3 , having a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the fifth NMOS transistor Q5 ;

[0089] The seventh transistor Q4 has a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the fifth NMOS transistor Q5 .

[0090] The sixth transistor Q3 and the seventh transistor Q4 are both coupled to the fifth NMOS transistor Q5 to form a two-way switch circuit. When the brake light has power input, two current paths can be used to increase the current.

[0091] The STOP / POS network is connected to the first pin of diode D9 through resistor R2. D9 is a small-signal diode that provides a stable base voltage for the fourth transistor Q1. C23 is the base-steering capacitor for Q1. The emitter of the fourth transistor Q1 is connected to resistors R55 and R56. The collector of the fourth transistor Q1 is connected to the collector of the fifth transistor Q2. The base of the fifth transistor Q2 is connected to the base of the fourth transistor Q1. C24 is the base-steering capacitor for the fifth transistor Q2. The emitter of the fifth transistor Q2 is connected to resistors R57 and R58. The collector of the fifth transistor Q2 is connected to the collector of Q3. PC25 is the base-steering capacitor for the sixth transistor Q3. The emitter of the sixth transistor Q3 is connected to resistors R51 and R52. The collector of the sixth transistor Q3 is connected to the collector of the seventh transistor Q4. The STOP / POS signal network is connected to the gate pin 1 of the third NMOS transistor Q11 through resistor R42, with the source connected to ground. R59 is a gate-to-ground resistor, and C28 is a gate filter capacitor. The Open_Sig network is connected to the gate pin 1 of the fourth NMOS transistor Q12 through resistor R43, with the source connected to ground. R60 is a gate-to-ground resistor, and C29 is a gate filter capacitor. The STOP power supply network is connected to the gate pin 1 of the fifth NMOS transistor Q5 through resistor R44, with the source connected to ground. R61 is a gate-to-ground resistor, and C30 is a gate filter capacitor. When the vehicle body receives position light power, the STOP / POS signal network is energized. When the potential difference between the gate pin 1 and the source pin 2 of the third NMOS transistor Q11 exceeds the gate-source turn-on voltage, the MOS transistor conducts, closing the switch. At this point, the emitter of the fourth transistor Q1 is at a low level. The base of the fourth transistor Q1 is at a high level, turning on the emitter junction and the transistor, closing the switch. Similarly, when the tailgate is open, the Open_Sig network is active. When the potential difference between the gate and source terminals of the fourth NMOS transistor Q12 (pin 1) exceeds the gate-source turn-on voltage, the MOS transistor conducts, effectively closing the switch. At this point, the emitter of the fifth transistor Q2 is at a low level. The base of the fifth transistor Q2 is connected to the other end of resistor R50, effectively turning the transistor on. When the brake power line is input to the vehicle, the STOP power network is active. When the potential difference between the gate and source terminals of the fifth NMOS transistor Q5 (pin 1) exceeds the gate-source turn-on voltage, the MOS transistor conducts, effectively closing the switch. At this point, the emitter of the seventh transistor Q4 is at a low level. The base of the seventh transistor Q4 is at a high level, conducting the emitter junction and the transistor, effectively closing the switch. The collectors of the fourth transistor Q1, the fifth transistor Q2, the sixth transistor Q3, and the seventh transistor Q4 are connected together and divided by resistors R7, R20, R4, and R5 to the STOP / POS- network. The STOP / POS- network is connected to the cathode of the function-multiplexing LED.A logic circuit composed of transistors and MOSFETs adjusts the brightness of the same reused LED to three levels: the brake light LED, the position light LED, and the position light boost LED, based on the different combinations of the brake light power supply, position light power supply, and tailgate release signal lines. Under functional safety requirements, the brake light has the highest priority. There are eight possible combinations of the position light power supply, brake light power supply, and tailgate release signal lines, such as... Figure 11 As shown:

[0092] 1. When there is no power input to the position lights, no power input to the brakes, and the tailgate is not open, neither the position lights nor the brightness multiplexing LED load will light up.

[0093] 2. When the position light power supply is off, the brake power supply is off, and the tailgate is open, the position light and the brightness multiplexing LED load will not light up.

[0094] 3. When the position light power is not input, the position light LED is off. When the brake power is input, Q11 is cut off and Q1 is disconnected. When the tailgate is not open, Q12 is cut off and Q2 is disconnected. Q5 is turned on. By adjusting R51, R52, R53, and R54, the brightness of the LED load can be adjusted to function as a brake light.

[0095] 4. When the position light power supply is not input, the position light LED is off. When the brake power supply is input and the tailgate is open, Q5 is on and Q4 is closed. The brightness of the LED load is the current of the brake light function.

[0096] 5. When the position light power is applied, Q11 conducts, Q1 conducts, and the position light LED illuminates. When the brake light power is not applied, Q5 is cut off and Q4 is disconnected. When the tailgate is closed, the brightness of the multiplexed LED load is set to the position light current through resistors R55 and R56.

[0097] 6. When the position light is powered, Q11 conducts, Q1 is on, and the position light LED illuminates. When the brake light is powered, Q5 is off, and Q4 is off. When the tailgate is open, the brightness of the LED load is adjusted to the current required for the position light function through resistors R55 and R56.

[0098] 7. When the position light power is applied, Q11 conducts, Q1 conducts, and the position light LED illuminates. When the brake light power is applied, Q5 conducts, and Q4 closes. When the tailgate is closed, the brightness of the multiplexed LED load is set to the brake light current through resistors R51, R52, R53, and R54.

[0099] 8. When the position light power is applied, Q11 conducts, Q1 conducts, and the position light LED illuminates. When the brake light power is applied, Q5 conducts, and Q4 closes. When the tailgate is opened, the brightness of the multiplexed LED load is set to the brake light current through resistors R51, R52, R53, and R54.

[0100] like Figure 12 As shown, the brightness multiplexing LED load includes 4 groups of series LEDs, each group of series LEDs consists of 2 LEDs in series, and the positive electrode of each group of series LEDs is connected to the STOP / POS signal network through a buffer resistor (R82-R85), and the negative electrode of each group of series LEDs is connected to the STOP / POS-network through a balancing resistor (R67-R70). Figure 12 In the embodiment, the brightness multiplexing LED load consists of 8 LEDs. SL1 and SL2 are connected in series as a group, and SC1 and SC2 are electrostatic protection capacitors. The positive pole of SL1 is connected to the ST1+ network. SL3 and SL4 are connected in series as a group, and SC3 and SC4 are electrostatic protection capacitors. The positive pole of SL3 is connected to the ST2+ network. SL5 and SL6 are connected in series as a group, and SC5 and SC6 are electrostatic protection capacitors. The positive pole of SL5 is connected to the ST3+ network. SL7 and SL8 are connected in series as a group, and SC7 and SC8 are electrostatic protection capacitors. The positive pole of SL7 is connected to the ST4+ network. In each group, the negative pole of SL2 is connected to the STOP / POS- network through resistor R67, the negative pole of SL4 is connected to the resistor R68, the negative pole of SL6 is connected to the resistor R69, and the negative pole of SL8 is connected to the resistor R70. The role of the four resistors is to balance the relative current values ​​of each group to ensure the consistency of brightness. The ST1+, ST2+, ST3+, ST4+, and STOP / POS- networks each have a capacitor connected to ground. Resistors R82, R83, R84, and R85 are connected together to form the STOP / POS network. The other ends are connected to the ST1+, ST2+, ST3+, and ST4+ networks, respectively. These resistors act as buffers and isolation for the power input network, improving the circuit's voltage stability and reliability.

[0101] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A taillight circuit, characterized in that: The body control module provides brake power lines, position light power lines, and tailgate opening signal lines. The taillight circuit includes a capacitor diode module, a MOS tube module, a signal conversion module, a transistor brightness comparison module, a brightness multiplexing LED load, and a position light load. The MOS tube module is connected to the position light power line and is used to separate the position light power line state into a power supply line and a signal line; The capacitor diode module is connected to the MOS tube module and the brake power line, and is used to perform front-end preprocessing on the brake power output by the brake power line; The signal conversion module is connected to the capacitor diode module and the tailgate opening signal line, and is used to convert the tailgate opening signal output by the tailgate opening signal line into a processing signal required by the subsequent circuit; The transistor brightness comparison module is connected to the capacitor diode module and the signal conversion module, and is used to control the brightness of the brightness multiplexing LED load to adjust the brightness according to the input combination of the position light power line, the brake power line and the tailgate opening signal line; The position lamp load provides basic position lamp brightness; The brightness multiplexing LED load is connected to the transistor brightness comparison module, and the brightness is adjusted by the transistor brightness comparison module to realize the brightness of the brake light alone, or to realize the brightness of the position light or the brake light by lighting it in combination with the position light load.

2. The taillight circuit according to claim 1, wherein: The transistor brightness comparison module is configured to control the brightness multiplexing LED load to present three brightness levels according to the input combination of the position light power line, the brake power line and the tailgate opening signal line; the brightness multiplexing LED load: When only the brake power line is input, the brake light brightness is output separately; When the position light power is input, it is lit in conjunction with the position light load to achieve the basic brightness of the position light or the increased brightness of the position light.

3. The taillight circuit according to claim 2, wherein: The transistor brightness comparison module controls the brightness of the multiplexed LED load to present: When only brake power is input, the output is brake light brightness; When only the position light power line is input and the tailgate is closed, the first brightness is output, and together with the position light load, the first position light brightness is provided; When only the position lamp power line is input and the tailgate is open, the second brightness is output, and together with the position lamp load, the second position lamp brightness is provided.

4. The taillight circuit according to claim 1, wherein: The capacitor-diode module includes a filter capacitor, an anti-pulse diode D3 and a voltage-dividing resistor R1. The filter capacitor, anti-pulse diode D3 and the voltage-dividing resistor R1 are all connected in parallel to the brake power line. The capacitor-diode module outputs a STOP / POS signal network and a STOP power network.

5. The taillight circuit according to claim 4, characterized in that: The MOS tube module includes a position light power front-end processing circuit and a separation circuit. The position light power front-end processing circuit is connected to the position light power line to perform front-end processing and output the POS power network. The separation circuit includes: A first PMOS transistor Q6 has a source coupled to the position light power line and a drain coupled to the STOP / POS signal network; A first NMOS transistor Q7, a gate of which is coupled to the POS power network via a first resistor R26; a second NMOS transistor Q8 , having a gate coupled to the STOP power supply network and a drain coupled to the gate of the first NMOS transistor Q7 ; When the brake power is input, the second NMOS transistor Q8 is turned on to turn off the first NMOS transistor Q7 and turn on the first PMOS transistor Q6; when the position light power is input, the first NMOS transistor Q7 is turned on to turn on the first PMOS transistor Q6.

6. The taillight circuit according to claim 5, wherein: The signal conversion module includes a first transistor Q15, a second transistor Q19, a third transistor Q9, and a second PMOS transistor Q10. The base of the first transistor Q15 is coupled to the tailgate opening signal line. The collector of the first transistor Q15 outputs a control signal to the collector of the second transistor Q19 and the base of the third transistor Q9. The first transistor Q15, the second transistor Q19, and the third transistor Q9 are all provided with a base bias circuit. The source of the second PMOS transistor Q10 is coupled to the POS power network, the gate of the second PMOS transistor Q10 is coupled to the collector of the third transistor Q9, and the drain of the second PMOS transistor Q10 outputs the Open_Sig network; A base of the second transistor Q19 is coupled to the STOP power network, and a collector of the second transistor Q19 is coupled to the POS network.

7. The taillight circuit according to claim 6, wherein: The position light load includes several groups of serially connected LEDs, each group of serially connected LEDs includes multiple LEDs connected in series, and the positive poles of each group of serially connected LEDs are connected to the POS power supply network through independent driver chips.

8. The taillight circuit according to claim 7, wherein: The transistor brightness comparison module includes: A third NMOS transistor Q11 has a gate coupled to the STOP / POS signal network and a source grounded; A fourth NMOS transistor Q12 has a gate coupled to the Open_Sig network and a source grounded; A fifth NMOS transistor Q5 has a gate coupled to the STOP power supply network and a source grounded; a fourth transistor Q1 , having a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the third NMOS transistor Q11 ; a fifth transistor Q2 , having a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the fourth NMOS transistor Q12 ; a sixth transistor Q3 , having a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the fifth NMOS transistor Q5 ; The seventh transistor Q4 has a base coupled to the STOP / POS signal network, a collector coupled to the STOP / POS signal network, and an emitter coupled to the drain of the fifth NMOS transistor Q5 .

9. The taillight circuit according to claim 8, wherein: The first resistor group is connected in series between the emitter of the fourth transistor Q1 and the drain of the third NMOS transistor Q11, the second resistor group is connected in series between the emitter of the fourth NMOS transistor Q2 and the drain of the fourth NMOS transistor Q12, the third resistor group is connected in series between the emitter of the sixth transistor Q3 and the drain of the fifth NMOS transistor Q5, and the fourth resistor group is connected in series between the emitter of the seventh transistor Q4 and the drain of the fifth NMOS transistor Q5; When only the position light power is input and the tailgate is closed, the third NMOS transistor Q11 is turned on to turn on the fourth transistor Q1, and the brightness multiplexing LED load forms a current loop through the first resistor group to output the first brightness; When only the position light power is input and the tailgate is open, the third NMOS transistor Q11 and the fourth NMOS transistor Q12 are turned on, so that the fourth transistor Q1 and the fourth NMOS transistor Q2 are turned on. The brightness multiplexing LED load forms a current loop through the first resistor group and the second resistor group connected in parallel, and outputs the second brightness. When the braking power is input, the fifth NMOS tube Q5 and the seventh transistor Q4 are both turned on, and the brightness multiplexing LED load forms a current loop through the first resistor group, the second resistor group, the third resistor group and the fourth resistor group connected in parallel to output the third brightness.

10. The taillight circuit according to claim 1, wherein: The brightness multiplexing LED load includes 4 groups of series LEDs, each group of series LEDs is composed of 2 LEDs in series, and the positive electrode of each group of series LEDs is connected to the STOP / POS signal network through a buffer resistor, and the negative electrode of each group of series LEDs is connected to the STOP / POS-network through a balancing resistor.

Images