CN210168272U

CN210168272U - Circuit for conducting anti-interference pulse in transient state of LED vehicle lamp

Info

Publication number: CN210168272U
Application number: CN201822230987.2U
Authority: CN
Inventors: 马冠群
Original assignee: Jiangsu Deyi Xiangyu Photoelectric Technology Co Ltd
Current assignee: Jiangsu Deyi Xiangyu Photoelectric Technology Co Ltd
Priority date: 2018-12-28
Filing date: 2018-12-28
Publication date: 2020-03-20
Anticipated expiration: 2028-12-28

Abstract

The utility model discloses anti-interference pulse's of LED car light transient state conduction circuit is provided with TVS transient voltage suppression diode with LED car light circuit parallel connection on the connecting line of the anodal, power cord negative pole of power cord, is provided with the resistance on the connecting line between TVS transient voltage suppression diode and the power cord is anodal, constitutes the crimping protection circuit, crimps the high transient voltage to the safe voltage of lower level, guarantees that follow-up circuit normally works; the power of the TVS transient voltage suppression diode is 1500W, the resistance power is larger than 2W, the resistance value is between 10 and 100 ohms, the internal resistance of P5A pulse is increased through the resistance, so that the current flowing through the TVS transient voltage suppression diode is reduced, the current can meet the relevant standard requirements of the ISO7637-2 standard on P5A pulse testing, the number of components is small, the TVS transient voltage suppression diode with the power of 1500W belongs to the medium power level, the appearance size is small, the structure is simple and compact, and the cost is low.

Description

Circuit for conducting anti-interference pulse in transient state of LED vehicle lamp

Technical Field

The utility model relates to a can satisfy the low-cost circuit that LED car light transient state conduction anti-interference pulse P5A required among the automotive lighting technology.

Background

At the present stage, various automobile electronic products are applied to the interior of an automobile in a large quantity, electromagnetic interference can be generated when the electronic products operate, and the electromagnetic interference can influence the normal work of electrical equipment in a conduction, coupling or radiation mode, so that the electromagnetic environment in the automobile is more and more severe; when various loads in vehicle electrical equipment, particularly inductive loads, are switched on and off, different types of transient interference pulses can be generated on a power supply line, and the load rejection transient phenomenon is particularly serious; when the battery is disconnected (in a power-deficient state), the alternating current generator generates charging current, and other loads still exist on the generator circuit to generate transient state, when the generator circuit is not disconnected, the current in a coil of the generator is large, and when the generator circuit is disconnected, the current suddenly decreases to generate reverse electromotive force; for example, the pulse amplitude of the waveform 5A is as high as 100-200V, the width is also as high as hundreds of milliseconds, the internal resistance is as low as a few ohms or even a few zero ohms, and the pulse belongs to a large-energy-level pulse, and an anti-interference circuit needs to be added at the input end of the circuit of the LED vehicle lamp to prevent the LED vehicle lamp from being damaged; the anti-interference circuit in the prior art adopts a Do-218AB type TVS tube, the power is more than 6000W, the structure is complex, the installation and connection operation is inconvenient, the overall dimension reaches 15.5 multiplied by 10 multiplied by 4.9, the occupied space is large, and the cost is high.

Disclosure of Invention

The utility model aims to solve the technical problem that a can be with the high transient voltage crimping to the safe voltage of lower level, guarantee follow-up circuit normal work, the circuit of the anti-interference pulse of LED car light transient state conduction is provided.

The utility model discloses full LED car light transient state conduction anti-interference pulse's circuit, its characterized in that: the device comprises an LED car lamp circuit, wherein two ends of the LED car lamp circuit are respectively connected to a positive pole of a power line and a negative pole of the power line, a TVS transient voltage suppression diode connected with the LED car lamp circuit in parallel is arranged on a connecting line of the positive pole of the power line and the negative pole of the power line, and a resistor is arranged on the connecting line between the TVS transient voltage suppression diode and the positive pole of the power line;

the TVS transient voltage suppression diode is an SMC/Do-214AB type fast recovery diode;

the power of the TVS transient voltage suppression diode is 1500W;

the power of the resistor is larger than 2W, and the resistance value range is 10-100 ohms.

Drawings

FIG. 1 is a schematic waveform of a test pulse 5A;

FIG. 2 is a table of parameters for test pulse 5A;

FIG. 3 is a schematic diagram of a prior art anti-jamming circuit using a Do-218AB TVS tube;

FIG. 4 is a schematic diagram of a transient voltage waveform generated by a Do-218AB TVS transistor in an anti-jamming circuit in the prior art;

FIG. 5 is a schematic diagram of a prior art anti-jamming circuit using a Do-218AB TVS tube;

FIG. 6 is a schematic bottom view of the structure of FIG. 6;

FIG. 7 is a rear view of the structure of FIG. 6;

fig. 8 is a schematic circuit diagram of the transient state conduction anti-interference pulse of the LED vehicle lamp according to the embodiment of the present invention;

fig. 9 is a schematic diagram of a clamping voltage waveform generated by a circuit for conducting an anti-interference pulse in a transient state of an LED vehicle lamp according to an embodiment of the present invention;

fig. 10 is a schematic plane structure diagram of an SMC/Do-214AB type TVS tube adopted by a circuit for transient conduction of an anti-interference pulse of an LED vehicle lamp according to an embodiment of the present invention;

FIG. 11 is a schematic top view of the structure;

fig. 12 is a parameter table of SMC/Do-214AB type TVS tube adopted by the circuit for transient conduction of anti-interference pulse of LED vehicle lamp according to the embodiment of the present invention.

Detailed Description

As shown in the figure, the circuit for conducting the anti-interference pulse in the transient state of the LED car lamp comprises an LED car lamp circuit, wherein two ends of the LED car lamp circuit are respectively connected to a positive pole of a power line and a negative pole of the power line; the internal resistance of the P5A pulse is increased through the resistor, so that the current flowing through the TVS transient voltage suppression diode is reduced to form a voltage-embedding protection circuit, the high transient voltage is embedded and pressed to a lower-level safe voltage, and the normal work of a subsequent circuit is ensured.

The TVS transient voltage suppression diode is an SMC/Do-214AB type fast recovery diode, the power is 1500W, the TVS transient voltage suppression diode belongs to a medium power level, the appearance size is small, the structure is simple and compact, and the cost is low.

The power of the resistor is more than 2W, the resistance range is 10-100 ohms, and the resistor belongs to the dozens of ohm level.

The specific design concept is as follows:

with the application of automobile electronic products in various automobiles in a large quantity and the severe electromagnetic environment in the automobiles, the electric equipment can generate electromagnetic interference during operation, and the electromagnetic interference can influence the normal operation of the electric equipment in a conduction, coupling or radiation mode. International standard ISO7637 proposes a method for conducting and testing electrical transients along a power line for electrical interference caused by conduction and coupling in road vehicles and their trailers, corresponding to the national standard GB/T21437.2. The method is suitable for 12V or 24V electric system vehicles.

The waveforms in the ISO7637 test are many, but the most strict test item is the P5A waveform, and the circuit is a low-cost circuit capable of meeting the requirement of conducting the anti-interference pulse P5A in the transient state of the LED vehicle lamp.

In the vehicle, due to the on-off of various loads, particularly inductive loads, different types of transient disturbance phenomena can be generated on a power supply line, the waveform in an ISO7637 test is a test waveform summarized by simulating some transient disturbance pulses which are actually present in the vehicle, the waveform 5 simulates a load rejection transient phenomenon, when a battery is disconnected (in a power-loss state), an alternating current generator generates charging current, and when other loads are still present on a generator circuit, the current in a coil of the generator is larger when the generator is not disconnected, and the sudden current is smaller when the generator is disconnected, so that reverse electromotive force is generated.

The waveform 5A pulse (fig. 1) has a high amplitude (100-. If an anti-interference circuit is not added at the circuit input end of the LED car lamp, the LED car lamp is damaged.

As shown in the figure, a TVS (transient voltage suppressor) is added at the power supply input end of an LED (light-emitting diode) car lamp circuit, the TVS is a professional device for overvoltage protection, and the parameter of the TVS is selected, so that high transient voltage can be clamped to lower safe voltage, and the normal work of a following circuit is ensured.

As described above, in order to pass the P5A pulse test in the ISO7637-2 standard, the TVS tube with power larger than 6000W must be selected, and the TVS tube with the specification has larger package size and higher price, namely, 5-6 RMB. And some low-power LED car lights, like license plate lamp, suitcase lamp, back position lamp etc. the cost of its LED car light module also several RMB, will pass P5A pulse test, adds a TVS pipe that is greater than 6KW, and material cost is just higher.

A low-cost protection circuit capable of meeting the requirement of transient conduction anti-interference pulse P5A. The TVS tube is a 1500W power TVS tube, the packaging overall dimension is small, the price is lower than 1 Yuan RMB, and the resistor R is a resistor with power larger than 2W and dozens of ohms. Because the internal resistance of the P5A pulse is low (several ohms, even a few tenths of ohms), adding a resistor R of several tens of ohms is equivalent to increasing the internal resistance of the P5A pulse, so that the current flowing through the TVS tube is greatly reduced, and the TVS tube with the power of 1500W can be selected.

The LED automobile lamp can be applied to low-power LED automobile lamps, such as license plate lamps, trunk lamps, rear position lamps and other products. And passes various pulse waveform tests required by the ISO7637-2 standard.

The advantages are that:

the circuit components are fewer, and the working reliability is good.

The TVS tube has the advantages of small power, small overall size and low cost.

The electromagnetic compatibility detection meets the test requirement of pulse P5A in the ISO7637-2 standard.

Key and protection points: the resistor R and the low-cost medium-power TVS tube form a voltage-clamping protection circuit which can pass the P5A pulse test in the ISO7637-2 standard.

Claims

1. The utility model provides a circuit of anti-interference pulse of LED car light transient state conduction which characterized in that: including LED car light circuit, LED car light circuit both ends are connected to the anodal, the power cord negative pole of power cord respectively, are provided with the TVS transient voltage suppression diode with LED car light circuit parallel connection on the connecting wire of the anodal, power cord negative pole of power cord, are provided with resistance on the connecting wire between TVS transient voltage suppression diode and the power cord is anodal.

2. The circuit for conducting anti-interference pulses to the transient state of the LED vehicle lamp according to claim 1, is characterized in that: the TVS transient voltage suppression diode is an SMC/Do-214AB type fast recovery diode.

3. The circuit for conducting anti-interference pulses to the transient state of the LED vehicle lamp according to claim 1, is characterized in that: the TVS transient voltage suppression diode has power of 1500W.

4. The circuit for conducting anti-interference pulses to the transient state of the LED vehicle lamp according to claim 1, is characterized in that: the power of the resistor is larger than 2W, and the resistance value range is 10-100 ohms.