Discrete lamp driving system

Abstract

The utility model discloses a discrete lamp driving system, which belongs to the technical field of automobile electronic control, and comprises an MCU (Microprogrammed Control Unit), a partial pressure sampling module, a lamp driving control module, an overcurrent protection module and a lamp, and the lamp driving control module is electrically connected with the MCU, the overcurrent protection module and the lamp respectively; and the partial pressure sampling module is electrically connected with the MCU. The discrete lamp driving system is simple in structure, high safety is guaranteed, and meanwhile the problems of resource waste and cost increase caused by a common lamp driving scheme in the market can be solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of automobile electronic control technology especially to a discrete lamp drive system. BACKGROUND

[0002] In prior art, with the continuous development of automobile industry, higher requirements are put forward for automobile electronic component industry, which is embodied in lower cost, higher safety and the like, at present, most lamp drive schemes are based on integrated chip design, utilize integrated chip to receive control signal sent by single-chip microcomputer to realize lamp drive, but for application scene requiring only single lamp, resource waste of integrated chip and unnecessary cost loss are caused easily. Therefore, the paper proposes a lamp drive scheme with simple structure and high safety, which aims at solving the above problems. SUMMARY

[0003] The utility model discloses a discrete lamp drive system, simple structure can solve the problem of resource waste and cost increase caused by the common lamp drive scheme on the market while guaranteeing higher safety.

[0004] To realize the above-mentioned purpose, the utility model provides a discrete lamp drive system, including MCU, voltage division sampling module, lamp drive control module, overcurrent protection module and lamp, the lamp drive control module is connected with MCU, overcurrent protection module and lamp electricity respectively, voltage division sampling module and MCU electricity are connected.

[0005] Preferably, the circuit structure of the lamp drive control module is: the IO port M1_DEMAND_CTRL of the MCU is connected to the base of the triode Q1 through the current limiting resistor R1, the current limiting resistor R1 is connected to the gate of the MOS tube Q2A through the current limiting resistor R2 and the diode D1, the external power supply V12 is connected to the collector of the triode Q1 and the gate of the MOS tube Q2B through the pull-up resistor R4, the external power supply V12 is connected to the drain of the MOS tube Q2B, the output voltage VOUT interface is connected to the source of the MOS tube Q2B, the output voltage VOUT is also connected to the drain of the MOS tube Q2A through the pull-down resistor R3, the emitter of the triode Q1 and the source of the MOS tube Q2A are grounded.

[0006] Preferably, the circuit structure of the lamp driving control module further comprises: the power supply ACTIVITY_LAMP of the lamp is connected with a voltage dividing resistor R9 through a current limiting resistor R11 and connected with the ground through a pull-down resistor R8, the positive pole of the lamp is connected to the ADC sampling port M1_DEMAND_MON of the MCU through the voltage dividing resistor R9 and a current limiting resistor R7 and a filter capacitor C1, the power supply ACTIVITY_LAMP of the lamp is connected with the positive pole of the lamp through the current limiting resistor R11, the negative pole of the lamp is connected with the drain of a MOS tube Q3, the source of the MOS tube Q3 is connected with the ground through an overcurrent resistor R10, the output voltage VOUT is connected with the gate of the MOS tube Q3 and the collector of a triode Q5 through a current limiting resistor R5, the base and the emitter of the triode Q5 are connected across the overcurrent resistor R10, in addition, the gate and the source of the MOS tube Q3 are further connected with a bias resistor R6, and the emitter of the triode Q5 is connected with the ground.

[0007] Therefore, the utility model adopts the above-mentioned kind of discrete lamp driving system, simple structure, can solve the problem of resource waste and cost increase brought by the common lamp driving scheme on market while ensuring higher safety.

[0008] The technical scheme of the utility model will be described in further detail below with reference to the drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 It is the whole connection scheme schematic diagram of a discrete lamp driving system embodiment of the utility model;

[0010] Figure 2 It is the first part of the lamp driving control module circuit diagram of a discrete lamp driving system embodiment of the utility model;

[0011] Figure 3 It is the second part of the lamp driving control module circuit diagram of a discrete lamp driving system embodiment of the utility model. DETAILED DESCRIPTION

[0012] The technical scheme of the utility model will be described in further detail below with reference to the drawings and embodiments.

[0013] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the usual meanings understood by persons of ordinary skill in the field to which this utility model belongs. The words "first", "second" and similar terms used in this utility model do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0014] Example 1

[0015] like Figure 1 As shown, the utility model provides a discrete lamp driving system, including an MCU, a voltage divider sampling module, a lamp driving control module, an overcurrent protection module and a lamp. The lamp driving control module is electrically connected to the MCU, the overcurrent protection module and the lamp respectively, and the voltage divider sampling module is electrically connected to the MCU.

[0016] The lamp drive control module uses MOS tubes to turn the lamp on and off. To meet the MOS tube's requirements for drive current, a totem pole circuit is used to improve the MCU's drive capability and avoid the problem of insufficient MCU drive current. The overcurrent protection module uses transistors to implement overcurrent protection for the circuit's drive control module. When the current exceeds the designed threshold, the drive control module is shut down by the transistor. The voltage divider sampling module divides the voltage through resistors and sends it to the MCU to monitor the lamp's power supply voltage and report abnormal lamp power supply voltage failures. Among them, the MCU, voltage divider sampling module, overcurrent protection module, and lamp structure are all existing technologies, so they will not be described in detail here.

[0017] like Figure 2As shown, the circuit structure of a portion of the lamp drive control module is as follows: the MCU's IO port M1_DEMAND_CTRL is connected to the base of the transistor Q1 through the current-limiting resistor R1 to control the on / off of the transistor Q1. The current-limiting resistor R1 is connected to the gate of the MOS transistor Q2A through the current-limiting resistor R2 and the diode D1 to control the on / off of the MOS transistor Q2A. The external power supply V12 is connected to the collector of the transistor Q1 and the gate of the MOS transistor Q2B through the pull-up resistor R4. The external power supply V12 is connected to the drain of the MOS transistor Q2B to provide a high-level output for the output voltage VOUT (the output voltage VOUT interface is connected to the source of the MOS transistor Q2B). The output voltage VOUT is also connected to the drain of the MOS transistor Q2A through the pull-down resistor R3 to provide a low-level output. The emitter of the transistor Q1 and the source of the MOS transistor Q2A are grounded.

[0018] like Figure 2 As shown, the circuit structure of a portion of the lamp drive control module is as follows: the lamp power supply ACTIVITY_LAMP is connected to the voltage divider resistor R9 through the current limiting resistor R11 and is grounded through the pull-down resistor R8. The positive electrode of the lamp passes through the voltage divider resistor R9, then through the current limiting resistor R7 and the filter capacitor C1 to be connected to the MCU's ADC sampling port M1_DEMAND_MON to monitor the lamp power supply fluctuation. The lamp power supply ACTIVITY_LAMP is connected to the positive electrode of the lamp through the current limiting resistor R11. The negative electrode of the lamp is connected to the drain of the MOS transistor Q3. The source of the MOS transistor Q3 is grounded through the overcurrent resistor R10. The output voltage VOUT is connected to the gate of the MOS transistor Q3 through the current limiting resistor R5 to control the on and off of the MOS transistor Q3. It is also connected to the collector of the transistor Q5 to implement the overcurrent protection function. The base and emitter of the transistor Q5 are connected to both ends of the overcurrent resistor R10. In addition, a bias resistor R6 is connected between the gate and source of the MOS transistor Q3 to ensure reliable conduction of the MOS transistor Q3. The emitter of the transistor Q5 is reliably grounded.

[0019] When controlling the lamp, when the MCU's IO port M1_DEMAND_CTRL sends a high level, a voltage difference is formed between pin 1 (base) and pin 2 (emitter) of transistor Q1, causing pin 2 (emitter) and pin 3 (collector) of transistor Q1 to be turned on. As a result, there is no voltage difference between pin 1 (source) and pin 2 (gate) of MOS tube Q2B, making it unable to be turned on. However, a voltage difference is formed between pin 5 (gate) and pin 4 (source) of MOS tube Q2A, causing MOS tube Q2A to be turned on, making the VOUT voltage 0V. The entire circuit is in an inoperative state, and the lamp is in an off state.

[0020] When the single-chip microcomputer IO port (M1_DEMAND_CTRL) sends a low level, the 1st pin and the 2nd pin of Q1 have no voltage difference, Q1 cannot be turned on, so that the 1st pin and the 2nd pin of Q2B form a voltage difference, Q2B is turned on, and the 5th pin and the 4th pin of Q2A have no voltage difference, Q2A cannot be turned on, so that the output voltage VOUT is V12 (the power supply voltage of the lamp, generally 12V), the whole circuit is in a working state, and the lamp is in a lighting state, when the lamp is in the lighting state, if the current through the MOS tube Q3 abnormally increases at this time, exceeds the threshold value of the circuit design, then the voltage across the overcurrent resistor R10 abnormally increases, so that the voltage difference between the 1st pin (base) and the 2nd pin (emitter) of the triode Q5 abnormally increases, exceeds the turn-on voltage of the triode Q5, the triode Q5 is turned on, and the gate voltage of the MOS tube Q3 is forcibly pulled down to 0V, so that there is no voltage drop between the gate and the source of the MOS tube Q3, and the MOS tube Q3 is turned off, thereby protecting the whole circuit.

[0021] The overcurrent threshold value can be calculated by the following formula:

[0022] The overcurrent threshold value (A) = the turn-on voltage (V) of the triode Q5 / the resistance (Ω) of the overcurrent resistor R10.

[0023] When the lamp power supply voltage is abnormally too low or too high, M1_DEMAND_MON is also too low or too high, the MCU can be designed to have an overlow threshold value and an overhigh threshold value, when the threshold value is exceeded, the MCU cuts off the control signal, and reports a fault, thereby realizing protection and diagnosis of the circuit.

[0024] Therefore, the lamp driving system has the advantages of simple structure, high safety, and the problems of resource waste and cost increase caused by the common lamp driving scheme on the market can be solved.

[0025] Finally, it should be noted that: the above embodiments are only used to illustrate the technical scheme of the utility model and not to limit it, although the utility model has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical scheme of the utility model can still be modified or replaced, and these modifications or replacements cannot make the modified technical scheme deviate from the spirit and scope of the technical scheme of the utility model.

Claims

1. A discrete lamp driving system, characterized in that: It includes an MCU, a voltage-dividing sampling module, a lamp driving control module, an overcurrent protection module and a lamp, wherein the lamp driving control module is electrically connected to the MCU, the overcurrent protection module and the lamp respectively; the voltage-dividing sampling module is electrically connected to the MCU; The IO port M1_DEMAND_CTRL of the MCU is connected to the base of the transistor Q1 through a current-limiting resistor R1. The current-limiting resistor R1 is connected to the gate of the MOS transistor Q2A through a current-limiting resistor R2 and a diode D1. The external power supply V12 is connected to the collector of the transistor Q1 and the gate of the MOS transistor Q2B through a pull-up resistor R4. The external power supply V12 is connected to the drain of the MOS transistor Q2B. The output voltage VOUT interface is connected to the source of the MOS transistor Q2B. The output voltage VOUT is also connected to the drain of the MOS transistor Q2A through a pull-down resistor R3. The emitter of the transistor Q1 and the source of the MOS transistor Q2A are grounded.

2. The discrete lamp driving system according to claim 1, characterized in that: The circuit structure of the lamp drive control module also includes: the lamp power supply ACTIVITY_LAMP is connected to the voltage divider resistor R9 through the current limiting resistor R11 and is grounded through the pull-down resistor R8. The positive electrode of the lamp is connected to the ADC sampling port M1_DEMAND_MON of the MCU through the current limiting resistor R7 and the filter capacitor C1 after passing through the voltage divider resistor R9. The lamp power supply ACTIVITY_LAMP is connected to the positive electrode of the lamp after passing through the current limiting resistor R11. The negative electrode of the lamp is connected to the drain of the MOS transistor Q3. The source of the MOS transistor Q3 is grounded through the overcurrent resistor R10. The output voltage VOUT is connected to the gate of the MOS transistor Q3 and the collector of the transistor Q5 through the current limiting resistor R5. The base and emitter of the transistor Q5 are connected to both ends of the overcurrent resistor R10. In addition, a bias resistor R6 is connected between the gate and source of the MOS transistor Q3, and the emitter of the transistor Q5 is grounded.

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