An electromagnetic compatibility circuit based on aluminum substrate

Abstract

The utility model discloses an electromagnetic compatibility circuit based on an aluminum substrate, belonging to the field of electromagnetic compatibility technology, comprising a circuit board and a power supply circuit, wherein the power supply circuit is arranged on the upper surface of the circuit board, the circuit board comprises an aluminum substrate, and the power ground GND1 of the power supply circuit is electrically connected to the aluminum substrate; the power supply circuit comprises an inrush current suppression module, and the inrush current suppression module comprises a resistor R15, a resistor R16, a resistor R21, a resistor R22, a resistor R23, a capacitor C30, a voltage regulator ZD1, an NPN transistor Q5 and a P-channel field effect transistor Q1. The electromagnetic compatibility circuit based on the aluminum substrate solves the problem that the existing vehicle-mounted LED lamp is easily interfered by the vehicle-mounted electrical equipment, resulting in flickering brightness, which affects the normal use of the LED lamp.

Description

Technical Field

[0001] The utility model relates to the technical field of electromagnetic compatibility, in particular to an electromagnetic compatibility circuit based on an aluminum substrate. Background Art

[0002] LED lights are installed on cars for lighting and decoration. With the increase of on-board electrical equipment, LED lights will receive electromagnetic interference from various electrical equipment. When the interference is strong, the brightness of the LED lights will flicker, affecting the normal use of the LED lights and even causing visual discomfort to users. Utility Model Content

[0003] In order to overcome the defects of the prior art, the utility model provides an electromagnetic compatibility circuit based on an aluminum substrate to solve the above problems.

[0004] The technical solution adopted by the utility model to solve the technical problem is: an electromagnetic compatibility circuit based on an aluminum substrate, comprising a circuit board and a power supply circuit, wherein the power supply circuit is arranged on the upper surface of the circuit board, the circuit board comprises an aluminum substrate, and a power ground GND1 of the power supply circuit is electrically connected to the aluminum substrate;

[0005] The power supply circuit includes an inrush current suppression module, which includes a resistor R15, a resistor R16, a resistor R21, a resistor R22, a resistor R23, a capacitor C30, a voltage regulator ZD1, an NPN transistor Q5 and a P-channel field effect transistor Q1. The first end of the resistor R21 is electrically connected to the output end of the built-in power supply of the vehicle, the second end of the resistor R21 is electrically connected to the first end of the resistor R22 and the first end of the capacitor C30 respectively, the second end of the resistor R22 is electrically connected to the first end of the resistor R23, the second end of the capacitor C30 is electrically connected to the second end of the resistor R23, the first end of the resistor R23 is electrically connected to the base of the NPN transistor Q5, and the NP The emitter of the N-type transistor Q5 and the second end of the resistor R23 are commonly grounded, the collector of the NPN-type transistor Q5 is electrically connected to the first end of the resistor R16, the second end of the resistor R16 is electrically connected to the gate of the P-channel field effect transistor Q1, the drain of the P-channel field effect transistor Q1 serves as the output end of the surge current suppression module, the first end of the resistor R15 is electrically connected to the output end of the built-in power supply of the vehicle and the negative electrode of the voltage regulator ZD1 respectively, the second end of the resistor R15 is electrically connected to the positive electrode of the voltage regulator ZD1, the negative electrode of the voltage regulator ZD1 is electrically connected to the source of the P-channel field effect transistor Q1, and the positive electrode of the voltage regulator ZD1 is electrically connected to the gate of the P-channel field effect transistor Q1.

[0006] It is worth noting that an insulating layer is provided on the upper surface of the aluminum substrate, and the power circuit is arranged on the insulating layer. The electrical connection between the electrical components of the power circuit is achieved by setting a wiring layer on the upper surface of the insulating layer, and the power ground GND1 is electrically connected to the lower surface of the aluminum substrate through rivets.

[0007] Optionally, the aluminum substrate is provided with a through hole, and the through hole penetrates the aluminum substrate from top to bottom, and the rivet is electrically connected to the lower surface of the aluminum substrate after passing through the through hole.

[0008] Preferably, the power supply circuit also includes a common-mode inductor CL2; the first end of the first coil of the common-mode inductor CL2 is electrically connected to the output end of the built-in power supply of the vehicle, the second end of the first coil of the common-mode inductor CL2 is electrically connected to the first end of the resistor R21 and the first end of the resistor R15, the first end of the second coil of the common-mode inductor CL2 is electrically connected to the power ground GND1, and the second end of the second coil of the common-mode inductor CL2 is electrically connected to the digital ground line DGND.

[0009] Specifically, the power supply circuit also includes a π-type filtering module and a three-terminal filter. The π-type filtering module includes an inductor L1, a capacitor C20 and a capacitor C21. The first end of the inductor L1 is electrically connected to the source of the P-channel field effect transistor Q1, the first end of the inductor L1 is also electrically connected to the first end of the capacitor C20, the second end of the capacitor C20 is electrically connected to the digital ground line DGND, the second end of the inductor L1 is respectively electrically connected to the first end of the capacitor C21 and the input end of the three-terminal filter, the second end of the capacitor C21 is electrically connected to the digital ground line DGND, and the output end of the three-terminal filter serves as the output end of the power supply circuit.

[0010] It is worth noting that the output end of the built-in power supply of the vehicle is electrically connected to the positive electrode of the Schottky diode D4, and the negative electrode of the Schottky diode D4 is electrically connected to the first end of the first coil of the common mode inductor CL2.

[0011] Preferably, the output end of the built-in power supply of the car is electrically connected to the power ground GND1 through the transient voltage suppression diode TVS2, the ground end of the built-in power supply of the car is electrically connected to the power ground GND1, and the power ground GND1 is electrically connected to the aluminum substrate through the transient voltage suppression diode TVS4.

[0012] The beneficial effect of the utility model is that in the electromagnetic compatibility circuit based on the aluminum substrate, the power circuit is used to power the LED lamp, and the power ground GND1 of the power circuit is guided to the aluminum substrate by rivets, and then electrically connected to the aluminum substrate, which has the effect of electrostatic shielding, effectively avoiding electromagnetic interference from other electrical equipment, thereby ensuring that the LED lamp can work stably. The RC circuit composed of the resistors R21, R22, R23 and the capacitor C30 cooperates with the NPN transistor Q5 and the P-channel field effect transistor Q1 to suppress the surge current, thereby improving the stability of the output of the power circuit, and further ensuring that the LED lamp can work stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A circuit diagram of a power supply circuit in one embodiment of the utility model;

[0014] Figure 2 An exploded diagram of a circuit board corresponding to an electromagnetic compatibility circuit in an embodiment of the utility model;

[0015] Figure 3 This is a schematic diagram of the structure of a circuit board corresponding to an electromagnetic compatibility circuit in an embodiment of the utility model;

[0016] Figure 4 A cross-sectional view of a circuit board corresponding to an electromagnetic compatibility circuit in an embodiment of the utility model;

[0017] In the figure: 1 aluminum substrate; 11 through hole; 2 insulation layer; 3 wiring layer; 4 electrical component. DETAILED DESCRIPTION

[0018] The specific implementation methods of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these implementation methods is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each implementation method of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0019] like Figure 1-4 As shown, an electromagnetic compatibility circuit based on an aluminum substrate includes a circuit board and a power supply circuit, wherein the power supply circuit is arranged on the upper surface of the circuit board, the circuit board includes an aluminum substrate 1, and a power ground GND1 of the power supply circuit is electrically connected to the aluminum substrate 1;

[0020] like Figure 1As shown, the power supply circuit includes an inrush current suppression module, which includes a resistor R15, a resistor R16, a resistor R21, a resistor R22, a resistor R23, a capacitor C30, a voltage regulator ZD1, an NPN transistor Q5 and a P-channel field effect transistor Q1. The first end of the resistor R21 is electrically connected to the output end of the built-in power supply of the vehicle, the second end of the resistor R21 is electrically connected to the first end of the resistor R22 and the first end of the capacitor C30 respectively, the second end of the resistor R22 is electrically connected to the first end of the resistor R23, the second end of the capacitor C30 is electrically connected to the second end of the resistor R23, the first end of the resistor R23 is electrically connected to the base of the NPN transistor Q5, and the The emitter of the NPN transistor Q5 and the second end of the resistor R23 are commonly grounded, the collector of the NPN transistor Q5 is electrically connected to the first end of the resistor R16, the second end of the resistor R16 is electrically connected to the gate of the P-channel field effect transistor Q1, the drain of the P-channel field effect transistor Q1 serves as the output end of the surge current suppression module, the first end of the resistor R15 is electrically connected to the output end of the built-in power supply of the vehicle and the negative electrode of the voltage regulator ZD1 respectively, the second end of the resistor R15 is electrically connected to the positive electrode of the voltage regulator ZD1, the negative electrode of the voltage regulator ZD1 is electrically connected to the source of the P-channel field effect transistor Q1, and the positive electrode of the voltage regulator ZD1 is electrically connected to the gate of the P-channel field effect transistor Q1.

[0021] In the electromagnetic compatibility circuit based on aluminum substrate, the power circuit is used to power the LED lamp. The power ground GND1 of the power circuit is guided to the aluminum substrate 1 by rivets, and then electrically connected to the aluminum substrate 1, which has the effect of electrostatic shielding, effectively avoiding electromagnetic interference from other electrical equipment, thereby ensuring that the LED lamp can work stably. The RC circuit composed of the resistors R21, R22, R23 and the capacitor C30 cooperates with the NPN transistor Q5 and the P-channel field effect transistor Q1 to suppress the surge current, thereby improving the stability of the output of the power circuit, and further ensuring that the LED lamp can work stably.

[0022] The resistors R21, R22, R23 and the capacitor C30 form an RC circuit with a slow charging and discharging function, so that the capacitor C30 can provide a voltage to the base of the NPN transistor Q5 and can slowly increase the voltage. After the voltage of the base of the NPN transistor Q5 exceeds the threshold, the emitter and collector of the NPN transistor Q5 are turned on, and the output voltage of the built-in power supply of the vehicle passes through the resistor R15 and then passes through the emitter and collector of the NPN transistor Q5 to be grounded to form a loop. The gate of the P-channel field effect transistor Q1 is energized, the drain and source of the P-channel field effect transistor Q1 are turned on, and the output voltage of the built-in power supply of the vehicle can flow through the P-channel field effect transistor Q1. In this way, even if the built-in power supply of the vehicle has an impact current and a surge current, due to the slow charging and discharging effect of the RC circuit, the impact current and the surge current can be suppressed through the P-channel field effect transistor Q1, thereby improving the output stability of the power supply circuit.

[0023] Preferably, Figure 2 , 3 As shown in Figure 4, an insulating layer 2 is provided on the upper surface of the aluminum substrate 1, and the power circuit is arranged on the insulating layer 2. The electrical connection between the electrical components 4 of the power circuit is achieved by arranging a wiring layer 3 on the upper surface of the insulating layer 2, and the power ground GND1 is electrically connected to the lower surface of the aluminum substrate 1 through rivets.

[0024] The insulating layer 2 is made of insulating material, and the wiring layer 3 is metal copper. In this way, except for the power ground GND1 of the electrical components 4 of the power circuit which can be electrically connected to the lower surface of the aluminum substrate 1, other ports can be insulated from the aluminum substrate 1, thereby avoiding short circuit of the driving circuit.

[0025] Specifically, the aluminum substrate 1 is provided with a through hole 11, and the through hole 11 penetrates the aluminum substrate 1 from top to bottom, and the rivet is electrically connected to the lower surface of the aluminum substrate 1 after passing through the through hole 11. The through hole 11 can facilitate the rivet to be inserted, so that the rivet can pass from the upper surface of the aluminum substrate 1 to the lower surface of the aluminum substrate 1.

[0026] Optional, such as Figure 1As shown, the power supply circuit also includes a common-mode inductor CL2; the first end of the first coil of the common-mode inductor CL2 is electrically connected to the output end of the built-in power supply of the car, the second end of the first coil of the common-mode inductor CL2 is electrically connected to the first end of the resistor R21 and the first end of the resistor R15, the first end of the second coil of the common-mode inductor CL2 is electrically connected to the power ground GND1, and the second end of the second coil of the common-mode inductor CL2 is electrically connected to the digital ground DGND. Common-mode inductors, also called common-mode chokes, are used to filter common-mode electromagnetic interference signals in switching power supplies and to suppress the electromagnetic waves generated by high-speed signal lines from radiating outward. By electrically connecting the first end of the second coil of the common-mode inductor CL2 to the aluminum substrate 1 through the power ground GND, electromagnetic wave interference can be further suppressed.

[0027] Preferably, the power supply circuit also includes a π-type filtering module and a three-terminal filter, the π-type filtering module includes an inductor L1, a capacitor C20 and a capacitor C21, the first end of the inductor L1 is electrically connected to the source of the P-channel field effect transistor Q1, the first end of the inductor L1 is also electrically connected to the first end of the capacitor C20, the second end of the capacitor C20 is electrically connected to the digital ground line DGND, the second end of the inductor L1 is respectively electrically connected to the first end of the capacitor C21 and the input end of the three-terminal filter, the second end of the capacitor C21 is electrically connected to the digital ground line DGND, and the output end of the three-terminal filter serves as the output end of the power supply circuit. The π-type filtering module formed by the inductor L1, the capacitor C20 and the capacitor C21 has the functions of filtering, filtering noise, stabilizing current and suppressing electromagnetic interference. The model of the three-terminal filter is YFF31HC2A105M00, and its function is to make the output signal purer and more stable by filtering out the clutter and noise in the input signal. The three-terminal filter is composed of a filter capacitor and a filter resistor. By selecting reasonable resistance and capacitance values, signal filtering in different frequency ranges can be achieved, that is, low-pass filtering, high-pass filtering or band-pass filtering can be achieved.

[0028] It is worth noting that the output end of the built-in power supply of the vehicle is electrically connected to the positive electrode of the Schottky diode D4, and the negative electrode of the Schottky diode D4 is electrically connected to the first end of the first coil of the common mode inductor CL2. The Schottky diode D4 plays a role in preventing reverse connection, thereby preventing the current from flowing back and damaging the electrical component 4.

[0029] Specifically, the output end of the built-in power supply of the car is electrically connected to the power ground GND1 through the transient voltage suppression diode TVS2, the ground end of the built-in power supply of the car is electrically connected to the power ground GND1, and the power ground GND1 is electrically connected to the aluminum substrate 1 through the transient voltage suppression diode TVS4. The transient voltage suppression diode TVS2 and the transient voltage suppression diode TVS4 both play the role of anti-static and surge voltage suppression.

[0030] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. An electromagnetic compatibility circuit based on an aluminum substrate, characterized in that: It includes a circuit board and a power supply circuit, wherein the power supply circuit is arranged on the upper surface of the circuit board, the circuit board includes an aluminum substrate, and a power ground GND1 of the power supply circuit is electrically connected to the aluminum substrate; The power supply circuit includes an inrush current suppression module, which includes a resistor R15, a resistor R16, a resistor R21, a resistor R22, a resistor R23, a capacitor C30, a voltage regulator ZD1, an NPN transistor Q5 and a P-channel field effect transistor Q1. The first end of the resistor R21 is electrically connected to the output end of the built-in power supply of the vehicle, the second end of the resistor R21 is electrically connected to the first end of the resistor R22 and the first end of the capacitor C30 respectively, the second end of the resistor R22 is electrically connected to the first end of the resistor R23, the second end of the capacitor C30 is electrically connected to the second end of the resistor R23, the first end of the resistor R23 is electrically connected to the base of the NPN transistor Q5, and the NP The emitter of the N-type transistor Q5 and the second end of the resistor R23 are commonly grounded, the collector of the NPN-type transistor Q5 is electrically connected to the first end of the resistor R16, the second end of the resistor R16 is electrically connected to the gate of the P-channel field effect transistor Q1, the drain of the P-channel field effect transistor Q1 serves as the output end of the surge current suppression module, the first end of the resistor R15 is electrically connected to the output end of the built-in power supply of the vehicle and the negative electrode of the voltage regulator ZD1 respectively, the second end of the resistor R15 is electrically connected to the positive electrode of the voltage regulator ZD1, the negative electrode of the voltage regulator ZD1 is electrically connected to the source of the P-channel field effect transistor Q1, and the positive electrode of the voltage regulator ZD1 is electrically connected to the gate of the P-channel field effect transistor Q1.

2. The electromagnetic compatibility circuit based on an aluminum substrate according to claim 1, characterized in that: An insulating layer is provided on the upper surface of the aluminum substrate, and the power circuit is arranged on the insulating layer. The electrical connection between the electrical components of the power circuit is achieved by providing a wiring layer on the upper surface of the insulating layer. The power ground GND1 is electrically connected to the lower surface of the aluminum substrate through rivets.

3. The electromagnetic compatibility circuit based on an aluminum substrate according to claim 2, characterized in that: The aluminum substrate is provided with a through hole, and the through hole penetrates the aluminum substrate from top to bottom. The rivet passes through the through hole and is electrically connected to the lower surface of the aluminum substrate.

4. The electromagnetic compatibility circuit based on an aluminum substrate according to claim 1, characterized in that: The power supply circuit also includes a common-mode inductor CL2; a first end of the first coil of the common-mode inductor CL2 is electrically connected to the output end of the built-in power supply of the vehicle, a second end of the first coil of the common-mode inductor CL2 is electrically connected to the first end of the resistor R21 and the first end of the resistor R15, a first end of the second coil of the common-mode inductor CL2 is electrically connected to the power ground GND1, and a second end of the second coil of the common-mode inductor CL2 is electrically connected to the digital ground line DGND.

5. The electromagnetic compatibility circuit based on an aluminum substrate according to claim 4, characterized in that: The power supply circuit also includes a π-type filtering module and a three-terminal filter. The π-type filtering module includes an inductor L1, a capacitor C20 and a capacitor C21. The first end of the inductor L1 is electrically connected to the source of the P-channel field effect transistor Q1, the first end of the inductor L1 is also electrically connected to the first end of the capacitor C20, the second end of the capacitor C20 is electrically connected to the digital ground line DGND, the second end of the inductor L1 is electrically connected to the first end of the capacitor C21 and the input end of the three-terminal filter respectively, the second end of the capacitor C21 is electrically connected to the digital ground line DGND, and the output end of the three-terminal filter serves as the output end of the power supply circuit.

6. The electromagnetic compatibility circuit based on an aluminum substrate according to claim 5, characterized in that: The output end of the built-in power supply of the vehicle is electrically connected to the positive electrode of the Schottky diode D4, and the negative electrode of the Schottky diode D4 is electrically connected to the first end of the first coil of the common mode inductor CL2.

7. The electromagnetic compatibility circuit based on an aluminum substrate according to claim 6, characterized in that: The output end of the built-in power supply of the car is electrically connected to the power ground GND1 through the transient voltage suppression diode TVS2, the ground end of the built-in power supply of the car is electrically connected to the power ground GND1, and the power ground GND1 is electrically connected to the aluminum substrate through the transient voltage suppression diode TVS4.

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