Vehicle-mounted projector LED RGB power supply switching port filtering protection circuit

Abstract

The utility model relates to a filtering protection circuit for an LED RGB power supply switching port of a vehicle-mounted projector. The filtering protection circuit comprises an R lamp filtering protection circuit connected with an R lamp interface, a G lamp filtering protection circuit connected with a G lamp interface, and a B lamp filtering protection circuit connected with a B lamp interface. Each of the R lamp filtering protection circuit, the G lamp filtering protection circuit and the B lamp filtering protection circuit comprises a plug-in common mode inductor, a BDL filter and a TVS tube which are sequentially arranged in parallel; the plug-in common-mode inductor is used for providing a common-mode noise suppression capability, the BDL filter is used for providing a common-mode filtering capability and a relatively good low-frequency differential-mode noise filtering capability, and the TVS tube is used for providing a surge plugging impact prevention capability; the differential-common-mode noise suppression filtering and surge protection capabilities are integrated, the filtering performance is not easily influenced, and the EMI intensity suppression capability is relatively remarkable, so that EMI noise radiation can be effectively suppressed.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of vehicle-mounted equipment electromagnetic compatibility, more particularly to a kind of vehicle-mounted projector LED RGB power supply switching port filter protection circuit. BACKGROUND

[0002] With the rapid development of new energy automobile industry, relevant vehicle-mounted products are increasingly diversified, for example, vehicle-mounted projector is one of emerging vehicle-mounted products. At present, in the EMI problem processing of each module of vehicle-mounted projector, it is found that the main problem is that when LED RGB light source power supply switches, the EMI noise problem of driving power supply. This is because the running current of vehicle-mounted projector is large, when MOS tube is on / off during the switching process of LED RGB light source power supply, the dithering of large current will radiate noise to the outside through the external harness of light source, so as to cause the emission intensity of EMI, and the noise suppression difficulty is high, which puts forward higher requirements for the processing measures of suppressing EMI.

[0003] And the existing EMI problem processing mode when LED RGB light source power supply switches still has shortcomings: because the current of LED RGB switching is large, many filtering methods cannot be used, for example, traditional circuit uses magnetic beads to suppress noise, but due to current limitation, the impedance of magnetic beads is selected to be relatively low, basically without noise suppression effect, so that the ability of suppressing EMI intensity is not enough significant, so as to effectively suppress EMI noise. UTILITY MODEL CONTENTS

[0004] The technical problem to be solved by the utility model is to provide a kind of vehicle-mounted projector LED RGB power supply switching port filter protection circuit for the above-mentioned defects of prior art.

[0005] The technical scheme adopted by the utility model to solve its technical problem is: a kind of vehicle-mounted projector LED RGB power supply switching port filter protection circuit, including the R lamp filter protection circuit connected with R lamp interface, G lamp filter protection circuit connected with G lamp interface and B lamp filter protection circuit connected with B lamp interface;The R lamp filter protection circuit, G lamp filter protection circuit and B lamp filter protection circuit all include the plug-in common mode inductor, BDL filter and TVS tube that are sequentially connected in parallel.

[0006] In some embodiments, the R lamp filter protection circuit includes first plug-in common mode inductor, first BDL filter and first TVS tube;The first end of the first plug-in common mode inductor, the A pole of the first BDL filter and the negative pole of the first TVS tube are all connected with the positive pole of R lamp interface respectively, and the second end of the first plug-in common mode inductor, the B pole of the first BDL filter and the positive pole of the first TVS tube are all connected with the negative pole of R lamp interface respectively.

[0007] In some embodiments, the first terminal of the first plug-in common mode inductor is interconnected with its third terminal, and the third terminal of the first plug-in common mode inductor is connected to the power supply terminal; the second terminal of the first plug-in common mode inductor is interconnected with its fourth terminal, and the fourth terminal of the first plug-in common mode inductor is grounded.

[0008] In some embodiments, the G-lamp filtering protection circuit includes a second plug-in common-mode inductor, a second BDL filter, and a second TVS diode; the first terminal of the second plug-in common-mode inductor, the A terminal of the second BDL filter, and the negative terminal of the second TVS diode are all connected to the positive terminal of the G-lamp interface, and the second terminal of the second plug-in common-mode inductor, the B terminal of the second BDL filter, and the positive terminal of the second TVS diode are all connected to the negative terminal of the G-lamp interface.

[0009] In some embodiments, the first terminal of the second plug-in common mode inductor is interconnected with its third terminal, and the third terminal of the second plug-in common mode inductor is connected to the power supply terminal; the second terminal of the second plug-in common mode inductor is interconnected with its fourth terminal, and the fourth terminal of the second plug-in common mode inductor is grounded.

[0010] In some embodiments, the B-lamp filtering protection circuit includes a third plug-in common-mode inductor, a third BDL filter, and a third TVS diode; the first terminal of the third plug-in common-mode inductor, the A terminal of the third BDL filter, and the negative terminal of the third TVS diode are all connected to the positive terminal of the B-lamp interface, and the second terminal of the third plug-in common-mode inductor, the B terminal of the third BDL filter, and the positive terminal of the third TVS diode are all connected to the negative terminal of the B-lamp interface.

[0011] In some embodiments, the first terminal of the third plug-in common mode inductor is interconnected with its third terminal, and the third terminal of the third plug-in common mode inductor is connected to the power supply terminal; the second terminal of the third plug-in common mode inductor is interconnected with its fourth terminal, and the fourth terminal of the third plug-in common mode inductor is grounded.

[0012] The beneficial effects of this utility model are as follows: Unlike the prior art, the LED RGB power supply switching port filtering and protection circuit of this utility model for vehicle projectors includes a plug-in common-mode inductor, a BDL filter, and a TVS diode arranged in parallel in sequence in the R lamp filtering and protection circuit, the G lamp filtering and protection circuit, and the B lamp filtering and protection circuit. The plug-in common-mode inductor is used to provide common-mode noise suppression capability, the BDL filter is used to provide common-mode filtering capability and good low-frequency differential-mode noise filtering capability, and the TVS diode is used to provide surge protection against plugging and unplugging impact. By integrating differential and common-mode noise suppression filtering and surge protection capabilities, the filtering performance is not easily affected when switching the power supply of LED RGB light sources, and the ability to suppress EMI intensity is also more significant, thereby effectively suppressing EMI noise radiation. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the filtering and protection circuit for the LED RGB power supply switching port of the vehicle-mounted projector in this embodiment of the present invention;

[0014] Figure 2 This is a schematic diagram of the equivalent circuit of the BDL filter in this embodiment of the present invention;

[0015] Figure 3 This is a schematic diagram of the noise change state before the application of the LED RGB power supply switching port filtering protection circuit of the vehicle projector in this embodiment of the utility model.

[0016] Figure 4 This is a schematic diagram of the noise change state after applying the LED RGB power supply switching port filtering and protection circuit of the vehicle projector in this embodiment of the utility model;

[0017] The labels and numbers in the diagram are as follows: R lamp filter protection circuit-10; G lamp filter protection circuit-20; B lamp filter protection circuit-30. Detailed Implementation

[0018] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this utility model are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0019] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0020] "Multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0021] Furthermore, the terms indicating orientation, such as "up," "down," "front," "back," "left," "right," "upper end," and "lower end," are all based on the posture and position of the device or equipment described in this solution during normal use.

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of this utility model. Obviously, the described embodiments are some, but not all, embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] This utility model embodiment provides a filtering and protection circuit for the LED RGB power supply switching port of a vehicle-mounted projector, such as... Figure 1 As shown, the LED RGB power supply switching port filtering and protection circuit of the vehicle projector includes an R-lamp filtering and protection circuit 10 connected to the R-lamp interface J1, a G-lamp filtering and protection circuit 20 connected to the G-lamp interface J2, and a B-lamp filtering and protection circuit 30 connected to the B-lamp interface J3; the R-lamp filtering and protection circuit 10, the G-lamp filtering and protection circuit 20, and the B-lamp filtering and protection circuit 30 all include a plug-in common mode inductor, a BDL filter, and a TVS diode arranged in parallel in sequence.

[0024] In the LED RGB power supply switching port filtering protection circuit of the vehicle projector in this embodiment of the utility model, a plug-in common-mode inductor, a BDL filter and a TVS diode are designed and incorporated. The plug-in common-mode inductor is used to provide common-mode noise suppression capability, the BDL filter is used to provide common-mode filtering capability and good low-frequency differential-mode noise filtering capability, and the TVS diode is used to provide surge protection against plugging and unplugging impacts; thus, differential and common-mode noise suppression filtering and surge protection capabilities are integrated.

[0025] The equivalent circuit of the BDL filter is as follows: Figure 2 As shown, it can be simplified to a combination of one X capacitor and two Y capacitors. According to the internal structure diagram of X2Y, two Y capacitors are formed between the A / B electrodes and the shielding layer to filter out common-mode noise, which is filtered out through the path of lowest impedance; while an X capacitor is formed between the A and B electrodes, which is specifically used to filter out differential-mode noise.

[0026] Specifically, in this embodiment, the R-lamp filtering and protection circuit 10 includes a first plug-in common-mode inductor L1, a first BDL filter BDL1, and a first TVS diode TVS1. The first terminal of the first plug-in common-mode inductor L1, the A terminal of the first BDL filter BDL1, and the negative terminal of the first TVS diode TVS1 are all connected to the positive terminal of the R-lamp interface J1. The second terminal of the first plug-in common-mode inductor L1, the B terminal of the first BDL filter BDL1, and the positive terminal of the first TVS diode TVS1 are all connected to the negative terminal of the R-lamp interface J1. The first terminal of the first plug-in common-mode inductor L1 is interconnected with its third terminal, which is connected to the power supply. The second terminal of the first plug-in common-mode inductor L1 is interconnected with its fourth terminal, which is grounded.

[0027] The primary purpose of the first plug-in common-mode inductor L1 is to suppress common-mode noise radiated from the R-lamp interface J1 through the wiring harness. The A and B terminals of the first BDL filter BDL1 are connected to the positive and negative terminals of the power supply to the R-lamp interface J1, respectively. The G1 and G2 terminals of the first BDL filter BDL1 (not shown in the attached diagram) are grounded, effectively filtering out differential-mode and common-mode noise. The addition of the first TVS diode TVS1 provides surge protection capability for the R-lamp filter protection circuit 10, protecting the downstream chip circuitry from voltage surges during R-lamp interface J1 plugging and unplugging and from external interference surge voltages flowing into the port.

[0028] Specifically, in this embodiment, the G-lamp filtering and protection circuit 20 includes a second plug-in common-mode inductor L2, a second BDL filter BDL2, and a second TVS diode TVS2. The first terminal of the second plug-in common-mode inductor L2, the A terminal of the second BDL filter BDL2, and the negative terminal of the second TVS diode TVS2 are all connected to the positive terminal of the G-lamp interface J2. The second terminal of the second plug-in common-mode inductor L2, the B terminal of the second BDL filter BDL2, and the positive terminal of the second TVS diode TVS2 are all connected to the negative terminal of the G-lamp interface J2. The first terminal of the second plug-in common-mode inductor L2 is interconnected with its third terminal, which is connected to the power supply. The second terminal of the second plug-in common-mode inductor L2 is interconnected with its fourth terminal, which is grounded.

[0029] The primary purpose of the second plug-in common-mode inductor L2 is to suppress common-mode noise radiated from the G lamp interface J2 through the wiring harness. The A and B terminals of the second BDL filter BDL2 are connected to the positive and negative terminals of the power supply to the G lamp interface J2, respectively. The G1 and G2 terminals of the second BDL filter BDL2 (not shown in the attached diagram) are grounded, effectively filtering out differential-mode and common-mode noise. The addition of the second TVS diode TVS2 provides surge protection capability for the G lamp filter protection circuit 20, protecting the downstream chip circuitry from voltage surges during the insertion and removal of the G lamp interface J2 and from external interference surge voltages flowing into the port.

[0030] Specifically, in this embodiment, the B-lamp filtering and protection circuit 30 includes a third plug-in common-mode inductor L3, a third BDL filter BDL3, and a third TVS diode TVS3. The first terminal of the third plug-in common-mode inductor L3, the A terminal of the third BDL filter BDL3, and the negative terminal of the third TVS diode TVS3 are all connected to the positive terminal of the B-lamp interface J3. The second terminal of the third plug-in common-mode inductor L3, the B terminal of the third BDL filter BDL3, and the positive terminal of the third TVS diode TVS3 are all connected to the negative terminal of the B-lamp interface J3. The first terminal of the third plug-in common-mode inductor L3 is interconnected with its third terminal, and the third terminal of the third plug-in common-mode inductor L3 is connected to the power supply terminal. The second terminal of the third plug-in common-mode inductor L3 is interconnected with its fourth terminal, and the fourth terminal of the third plug-in common-mode inductor L3 is grounded.

[0031] The main purpose of the third plug-in common-mode inductor L3 is to suppress common-mode noise radiated from the B-lamp interface J3 through the wiring harness. The A and B terminals of the third BDL filter BDL3 are connected to the positive and negative terminals of the power supply to the B-lamp interface J3, respectively. The G1 and G2 terminals of the third BDL filter BDL3 (not shown in the attached diagram) are grounded, effectively filtering out differential-mode and common-mode noise. The addition of the third TVS diode TVS3 provides surge protection capability for the B-lamp filter protection circuit 30, protecting the downstream chip circuitry from voltage surges during the insertion and removal of the B-lamp interface J3 and from external interference surge voltages flowing into the port.

[0032] The LED RGB power supply switching port filtering and protection circuit for vehicle-mounted projectors, as described in this embodiment, allows large current to pass through. On the one hand, the filtering performance is not easily affected when switching the power supply to the LED RGB light source, and the ability to suppress EMI intensity is also significant, thus effectively suppressing EMI noise radiation. On the other hand, even with wide power supply traces, the filtering performance of small-package filtering devices is not affected, effectively ensuring the filtering and protection effect.

[0033] For example, Figure 3 The table below shows the noise changes before applying the LED RGB power supply switching port filtering and protection circuit to the vehicle-mounted projector. Relevant test data can be found in Table 1 below.

[0034]

[0035] Combination Figure 3 As can be seen from the test data in Table 1, there is significant noise exceeding the standard in the 40MHz-100MHz frequency range, with the highest exceeding the standard by nearly 12dB at points M7 and M8. After elimination, it was found that the excessive power supply noise envelope was caused by the RGB light source power supply switching module.

[0036] For example, Figure 4 The noise change status after applying the filtering and protection circuit of the LED RGB power supply switching port of the vehicle projector is shown. Please refer to Table 2 below for relevant test data:

[0037]

[0038] Combination Figure 4 As can be seen from the test data in Table 2, after applying the LED RGB power supply switching port filter protection circuit of the vehicle projector, the excessive noise in the 40MHz-100MHz frequency range has been significantly reduced, and the test data has a margin of about 11dB compared with the standard limit.

[0039] It is evident that the noise suppression effect after applying the LED RGB power supply switching port filtering and protection circuit of the vehicle projector is more significant than before the application.

[0040] It should be noted that the test data listed in Tables 1 and 2 at different frequency values ​​are mainly to show the noise change status corresponding to different frequency values ​​in a specific frequency range (e.g., 40MHz-100MHz frequency range), and do not involve noise comparison at a specific frequency value.

[0041] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A filtering and protection circuit for the LED RGB power supply switching port of a vehicle-mounted projector, characterized in that: It includes an R-lamp filter protection circuit connected to the R-lamp interface, a G-lamp filter protection circuit connected to the G-lamp interface, and a B-lamp filter protection circuit connected to the B-lamp interface; each of the R-lamp filter protection circuit, G-lamp filter protection circuit, and B-lamp filter protection circuit includes a plug-in common-mode inductor, a BDL filter, and a TVS diode arranged in parallel in sequence.

2. The filtering and protection circuit for the LED RGB power supply switching port of the vehicle-mounted projector according to claim 1, characterized in that: The R-lamp filtering and protection circuit includes a first plug-in common-mode inductor, a first BDL filter, and a first TVS diode; the first terminal of the first plug-in common-mode inductor, the A terminal of the first BDL filter, and the negative terminal of the first TVS diode are all connected to the positive terminal of the R-lamp interface, and the second terminal of the first plug-in common-mode inductor, the B terminal of the first BDL filter, and the positive terminal of the first TVS diode are all connected to the negative terminal of the R-lamp interface.

3. The filtering and protection circuit for the LED RGB power supply switching port of the vehicle-mounted projector according to claim 2, characterized in that: The first terminal of the first plug-in common mode inductor is interconnected with its third terminal, and the third terminal of the first plug-in common mode inductor is connected to the power supply terminal; the second terminal of the first plug-in common mode inductor is interconnected with its fourth terminal, and the fourth terminal of the first plug-in common mode inductor is grounded.

4. The filtering and protection circuit for the LED RGB power supply switching port of the vehicle-mounted projector according to claim 1, characterized in that: The G-lamp filtering and protection circuit includes a second plug-in common-mode inductor, a second BDL filter, and a second TVS diode; the first terminal of the second plug-in common-mode inductor, the A terminal of the second BDL filter, and the negative terminal of the second TVS diode are all connected to the positive terminal of the G-lamp interface, and the second terminal of the second plug-in common-mode inductor, the B terminal of the second BDL filter, and the positive terminal of the second TVS diode are all connected to the negative terminal of the G-lamp interface.

5. The filtering and protection circuit for the LED RGB power supply switching port of the vehicle-mounted projector according to claim 4, characterized in that: The first terminal of the second plug-in common mode inductor is interconnected with its third terminal, and the third terminal of the second plug-in common mode inductor is connected to the power supply terminal; the second terminal of the second plug-in common mode inductor is interconnected with its fourth terminal, and the fourth terminal of the second plug-in common mode inductor is grounded.

6. The filtering and protection circuit for the LED RGB power supply switching port of the vehicle-mounted projector according to claim 1, characterized in that: The B-lamp filtering and protection circuit includes a third plug-in common-mode inductor, a third BDL filter, and a third TVS diode. The first terminal of the third plug-in common-mode inductor, the A terminal of the third BDL filter, and the negative terminal of the third TVS diode are all connected to the positive terminal of the B-lamp interface. The second terminal of the third plug-in common-mode inductor, the B terminal of the third BDL filter, and the positive terminal of the third TVS diode are all connected to the negative terminal of the B-lamp interface.

7. The filtering and protection circuit for the LED RGB power supply switching port of the vehicle-mounted projector according to claim 6, characterized in that: The first terminal of the third plug-in common mode inductor is interconnected with its third terminal, and the third terminal of the third plug-in common mode inductor is connected to the power supply terminal; the second terminal of the third plug-in common mode inductor is interconnected with its fourth terminal, and the fourth terminal of the third plug-in common mode inductor is grounded.

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