CN-224205286-U - Far-near light switching circuit based on NMOS tube

Abstract

The utility model relates to a far-near light switching circuit based on an NMOS tube. The LED lamp panel comprises an interface unit, a constant current driving unit and a lamp panel unit which are sequentially connected, and further comprises a switching unit connected with the lamp panel unit, wherein the switching unit comprises a magnetic bead B1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a triode Q1, an NMOS tube Q2, a zener tube Z1, a voltage stabilizing tube Z2, a diode D1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7.

Inventors

• DAI JIAN

Assignees

• 上海晨阑光电器件有限公司

Dates

Publication Date

20260505

Application Date

20250509

Claims (4)

1. 1. The far and near light switching circuit based on the NMOS tube comprises an interface unit, a constant current driving unit and a lamp panel unit which are sequentially connected, and is characterized by further comprising a switching unit connected with the lamp panel unit, wherein the switching unit comprises a magnetic bead B1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a triode Q1, an NMOS tube Q2, a zener tube Z1, a voltage stabilizing tube Z2, a diode D1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7; one end of the magnetic bead B1 is connected with the lamp panel unit, the other end of the magnetic bead B1 is respectively connected with one end of the third capacitor C3 and the drain electrode of the NMOS tube Q2, and the other end of the third capacitor C3 is grounded; The grid electrode of the NMOS tube Q2 is respectively connected with one end of the second capacitor C2, one end of the fifth resistor R5, the negative electrode of the voltage stabilizing tube Z2, one end of the fourth resistor R4 and the collector electrode of the triode Q1, and the other end of the second capacitor C2 is connected with the other end of the fifth resistor R5 and the positive electrode of the voltage stabilizing tube Z2 and then grounded; The emitter of the triode Q1 is grounded, the base of the triode Q1 is respectively connected with one end of the third resistor R3, one end of the first capacitor C1 and one end of the first resistor R1, the other end of the third resistor R3 is connected with the other end of the first capacitor C1 and then grounded, the other end of the first resistor R1 is respectively connected with one end of the second resistor R2 and the positive electrode of the zener diode Z1, the other end of the second resistor R2 is grounded, the negative electrode of the zener diode Z1 is connected with the negative electrode of the diode D1, and the positive electrode of the diode D1 is connected with the positive electrode HB of the interface unit.
2. 2. The NMOS tube-based far and near light switching circuit according to claim 1, wherein said lamp panel unit comprises a first lamp group and a second lamp group connected in series, and one end of said magnetic bead B1 is connected between said first lamp group and said second lamp group.
3. 3. The high beam and low beam switching circuit based on NMOS tubes of claim 2, wherein said first lamp set is turned on individually to form a low beam light on state and said first lamp set is turned on simultaneously with said second lamp set to form a high beam light on state.
4. 4. The switching circuit of the high beam and low beam lamp based on the NMOS tube of claim 1, wherein when the HB positive signal of the interface unit is at a low level, the triode Q1 is turned off, the grid of the NMOS tube Q2 is divided by the fourth resistor R4 and the fifth resistor R5 to form a high level, the NMOS tube Q2 is turned on, and is in a low beam lamp lighting working state at the moment, when the HB positive signal of the interface unit is at a high level, the triode Q1 is turned on, the grid of the NMOS tube Q2 is grounded through the triode Q1, and the NMOS tube Q2 is turned off, and is in a high beam lamp lighting working state at the moment.

Description

Far-near light switching circuit based on NMOS tube Technical Field The utility model relates to a car lamp circuit, in particular to a far-near light switching circuit based on NMOS (N-channel metal oxide semiconductor) tubes. Background With the development of the automobile industry, the requirements on the intelligence and the reliability of a vehicle lighting system are increasing. The rapid and stable switching of the high beam and low beam is an important guarantee for night driving safety. At present, a switching circuit of a high beam and a low beam of an automobile mainly depends on a traditional relay or a transistor driving scheme, but the following problems exist in the practical application of the technologies: Limitations of relay scheme: The relay is switched on and off by means of a mechanical contact, and has the problems of low response speed, usually millisecond delay, short service life caused by mechanical abrasion, easy failure due to frequent switching and the like; The volume is large, and the integration requirement of compact vehicle-mounted electronic equipment is difficult to meet; Contact sparks can cause electromagnetic interference (EMI) that affects the stability of the vehicle electronics system. The shortcomings of the common transistor scheme: The bipolar transistor (BJT) has higher conduction voltage drop, so that the energy consumption is high, the heat generation is serious, and an additional heat dissipation design is needed; the switching speed is limited, high-frequency switching is difficult to realize, and short flicker can be caused when lamplight is switched; the circuit is easily damaged by sudden load change or short circuit fault due to perfect protection functions such as overcurrent, overvoltage and temperature protection. Based on the above, there is a need for an efficient, reliable and integrated high and low beam switching scheme. Disclosure of Invention The utility model aims to overcome the defects in the prior art and provides an NMOS (N-channel metal oxide semiconductor) -based high and low beam switching circuit which improves the response speed of high and low beam switching and improves the energy efficiency and the reliability. The utility model is realized in that the far and near light lamp switching circuit based on the NMOS tube comprises an interface unit, a constant current driving unit and a lamp panel unit which are sequentially connected, and further comprises a switching unit connected with the lamp panel unit, wherein the switching unit comprises a magnetic bead B1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a triode Q1, an NMOS tube Q2, a zener tube Z1, a voltage stabilizing tube Z2, a diode D1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7; one end of the magnetic bead B1 is connected with the lamp panel unit, the other end of the magnetic bead B1 is respectively connected with one end of the third capacitor C3 and the drain electrode of the NMOS tube Q2, and the other end of the third capacitor C3 is grounded; The grid electrode of the NMOS tube Q2 is respectively connected with one end of the second capacitor C2, one end of the fifth resistor R5, the negative electrode of the voltage stabilizing tube Z2, one end of the fourth resistor R4 and the collector electrode of the triode Q1, and the other end of the second capacitor C2 is connected with the other end of the fifth resistor R5 and the positive electrode of the voltage stabilizing tube Z2 and then grounded; The emitter of the triode Q1 is grounded, the base of the triode Q1 is respectively connected with one end of the third resistor R3, one end of the first capacitor C1 and one end of the first resistor R1, the other end of the third resistor R3 is connected with the other end of the first capacitor C1 and then grounded, the other end of the first resistor R1 is respectively connected with one end of the second resistor R2 and the positive electrode of the zener diode Z1, the other end of the second resistor R2 is grounded, the negative electrode of the zener diode Z1 is connected with the negative electrode of the diode D1, and the positive electrode of the diode D1 is connected with the positive electrode HB of the interface unit. The lamp panel unit comprises a first lamp group and a second lamp group which are connected in series, and one end of the magnetic bead B1 is connected between the first lamp group and the second lamp group. The low beam light-on operation state is formed when the first lamp group is individually lighted, and the high beam light-on operation state is formed when the first lamp group and the second lamp group are simultaneously lighted. When the HB positive signal of the interface unit is at a low level, the triode Q1 is turned off, the grid electrode of the NMOS tube Q2 is divided by the fourth resistor R4 and the fi