DC-DC module and light source combined control circuit for suppressing electromagnetic interference

Abstract

The utility model discloses a DC-DC module and light source combined control circuit for suppressing electromagnetic interference, which comprises a dial switch circuit, a first common-mode coil suppression common-mode signal module, an anti-reverse connection filter circuit, a PWM (Pulse-Width Modulation) switch type step-down circuit, a second common-mode coil suppression common-mode signal module and an LED (Light Emitting Diode) light source plate which are connected in sequence, the LED light source plate is provided with a magnetic bead B1 and a magnetic bead B2. According to the utility model, the common-mode coil is additionally arranged at the input end of the DC-DC module, so that not only can a filtering effect be achieved, but also the influence of noise on an internal circuit of the DC-DC module can be effectively reduced, and the common-mode coil is arranged at the output end, so that the propagation of common-mode current can be effectively inhibited; therefore, the load and other circuits are protected from electromagnetic interference, the efficiency and the stability of the power supply are improved, the lamp panel with the magnetic beads is low in loss and small in size, the circuit layout is more compact, the overall cost is reduced, the production efficiency is improved, and the service life of the lamp panel is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of control circuits, and particularly relates to a DC-DC module and light source combined control circuit for suppressing electromagnetic interference. Background Art

[0002] During the detection process of lamps, it is usually necessary to detect electromagnetic interference and pass the EMC test to meet international standards and achieve a stable lighting effect. The DC-DC power supply may generate common-mode current during operation. If these currents are not controlled, they may interfere with other circuits. Therefore, electronic components for suppressing electromagnetic interference often need to be added to the control circuit. The existing technical solutions for suppressing electromagnetic interference are as follows: 1. A large number of capacitors and resistors are added to absorb the electromagnetic waves of the circuit to suppress electromagnetic interference, but this reduces the efficiency of the DC-DC module. 2. The input uses an I-shaped inductor for filtering, which has a certain effect, but the effect is not obvious. A magnetic ring is wound around the output, but the magnetic ring is large in volume, high in cost, and inconvenient to operate. Therefore, in order to avoid the disadvantages existing in the prior art, it is necessary to improve the prior art. Summary of the Utility Model

[0003] The purpose of the utility model is to overcome the disadvantages and deficiencies in the prior art, and provide a DC-DC module and light source combined control circuit for suppressing electromagnetic interference.

[0004] The utility model is realized by the following technical solutions:

[0005] A DC-DC module and light source combined control circuit for suppressing electromagnetic interference includes a DIP switch circuit, a first common-mode coil for suppressing common-mode signals, an anti-reverse connection filter circuit, a PWM switching step-down circuit, a second common-mode coil for suppressing common-mode signals, and an LED light source board, which are connected in sequence. The PWM switching step-down circuit is connected to an external power control circuit. The PWM switching step-down circuit includes a chip U1. The first common-mode coil for suppressing common-mode signals includes a common-mode coil LF1. The second common-mode coil for suppressing common-mode signals includes a common-mode coil LF2. The LED light source board is provided with a bead B1 and a bead B2.

[0006] Further, the DIP switch circuit includes a DIP switch SW1D. The input positive pole of the common-mode coil LF1 is connected to the fourth pin of the DIP switch SW1D, and the input negative pole of the common-mode coil LF1 is connected to the positive pole DC+ of the power input.

[0007] Further, the anti-reverse connection filter circuit includes a rectifier bridge DB1. The input positive pole of the rectifier bridge DB1 is connected to the output positive pole of the common-mode coil LF1, and the input negative pole of the rectifier bridge DB1 is connected to the output negative pole of the common-mode coil LF1.

[0008] Further, the anti-reverse connection filtering circuit includes an I-shaped inductor L3, a polarized capacitor EC1, and a polarized capacitor EC3. The negative electrodes of the polarized capacitor EC1 and the polarized capacitor EC3 are respectively connected to the sixth pin and the seventh pin of the chip U1, and the positive electrodes of the polarized capacitor EC1 and the polarized capacitor EC3 are respectively connected to the output positive electrode of the rectifier bridge DB1 through the I-shaped inductor L3.

[0009] Further, the PWM switching step-down circuit further includes a polarized capacitor EC2. The third pin of the chip U1 is connected to the input positive electrode of the common-mode coil LF2 through an inductor L4. The positive electrode of the polarized capacitor EC2 is connected to the input positive electrode of the common-mode coil LF2, and the negative electrode of the polarized capacitor EC2 is connected to the output positive electrode of the rectifier bridge DB1 through a resistor R7 and a resistor R9.

[0010] Further, the PWM switching step-down circuit further includes a diode D6. The positive electrode of the diode D6 is connected to the input positive electrode of the common-mode coil LF2 through an inductor L4, and the negative electrode of the diode D6 is connected to the output positive electrode of the rectifier bridge DB1 through an inductor L2 and a resistor R9.

[0011] Further, the second pin of the chip U1 is connected to the output positive electrode of the rectifier bridge DB1 through a resistor R9. The second pin of the chip U1 is grounded through a capacitor C20, a resistor R22, and a capacitor C6. The fourth pin of the chip U1 is grounded through a resistor R10.

[0012] Further, the external power adjustment control circuit includes a triode Q1, a triode Q2, a triode Q3, and an adjustment switch RP1. The C terminal of the triode Q1 is connected to the eighth pin of the chip U1. The C terminal of the triode Q1 is connected to the E terminal of the triode Q3 through a resistor R13. The C terminal of the triode Q3 is connected to the E terminal of the triode Q2. The C terminal of the triode Q2 is connected to the output positive electrode of the rectifier bridge DB1 through a resistor R25 and a resistor R9. The A terminal of the adjustment switch RP1 is connected to the B terminal of the triode Q3. The C terminal of the triode Q3 is connected to the B terminal of the adjustment switch RP1 through a resistor R19.

[0013] Further, the external power adjustment control circuit further includes a diode D5 and a zener diode ZD1. The positive electrode of the zener diode ZD1 is connected to the negative electrode of the diode D5 through a resistor R5 and a resistor R6. The positive electrode of the zener diode ZD1 is connected to the B terminal of the triode Q2.

[0014] Further, the model of the chip U1 is OC5266.

[0015] Compared with the prior art, the common-mode signal suppression module of the present utility model by the first common-mode coil includes a common-mode coil LF1, the common-mode signal suppression module of the second common-mode coil includes a common-mode coil LF2, the LED light source board is provided with a bead B1 and a bead B2, adding a common-mode coil at the input end of the DC-DC module can not only play a filtering role, but also effectively reduce the influence of these noises on the internal circuit of the DC-DC module. Its main purpose is to prevent the common-mode noise generated by the power supply from spreading to the load or other circuits. Placing a common-mode coil at the output end can effectively suppress the propagation of these common-mode currents, thereby protecting the load and other circuits from electromagnetic interference, thus improving the efficiency and stability of the power supply. Placing the common-mode coil at the output end of the DC-DC power supply, its main purpose is to prevent the common-mode noise generated by the power supply from spreading to the load or other circuits. By placing a common-mode coil at the output end, the propagation of these common-mode currents can be effectively suppressed, thereby protecting the load and other circuits from electromagnetic interference. The lamp board with beads has low loss, small volume, and more compact circuit layout, which is beneficial to reducing the overall cost and improving production efficiency. Moreover, the lamp board clamped by the beads is also a lamp board with independent protection and anti-interference functions. When a transient overvoltage appears in the circuit, the chip bead can effectively absorb this energy, thereby reducing the damage to the lamp beads and extending their service life. Therefore, when this lamp board is matched with other DC-DC modules for application, it also has good compatibility and anti-interference ability. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is the circuit schematic diagram of the DC-DC module and the light source combination control circuit for suppressing electromagnetic interference of the present utility model.

[0018] In the figure: A - DIP switch circuit; B - Common-mode signal suppression module of the first common-mode coil; C - Reverse connection prevention and filtering circuit; D - External power adjustment control circuit; E - Common-mode signal suppression module of the second common-mode coil; F - PWM switching buck circuit; G - LED light source board. Detailed Embodiments

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] As Figure 1 shown, a DC-DC module and light source combined control circuit for suppressing electromagnetic interference of the present invention includes a DIP switch circuit A, a first common-mode coil for suppressing common-mode signals module B, an anti-reverse connection filter circuit C, a PWM switching step-down circuit F, a second common-mode coil for suppressing common-mode signals module E, and an LED light source board G connected in sequence. The PWM switching step-down circuit F is connected to an external power adjustment control circuit D. The PWM switching step-down circuit F includes a chip U1. The first common-mode coil for suppressing common-mode signals module B includes a common-mode coil LF1. The second common-mode coil for suppressing common-mode signals module E includes a common-mode coil LF2. The LED light source board G is provided with a bead B1 and a bead B2. By the first common-mode coil for suppressing common-mode signals module B including a common-mode coil LF1, the second common-mode coil for suppressing common-mode signals module E including a common-mode coil LF2, and the LED light source board G being provided with a bead B1 and a bead B2, adding a common-mode coil at the input end of the DC-DC module can not only play a filtering role, but also effectively reduce the influence of these noises on the internal circuit of the DC-DC module. Its main purpose is to prevent the common-mode noise generated by the power supply from spreading to the load or other circuits. Placing a common-mode coil at the output end can effectively suppress the propagation of these common-mode currents, thereby protecting the load and other circuits from electromagnetic interference, thereby improving the efficiency and stability of the power supply. Placing the common-mode coil at the output end of the DC-DC power supply, its main purpose is to prevent the common-mode noise generated by the power supply from spreading to the load or other circuits. By placing a common-mode coil at the output end, the propagation of these common-mode currents can be effectively suppressed, thereby protecting the load and other circuits from electromagnetic interference. The lamp board with beads has low loss, small volume, and a more compact circuit layout, which is beneficial to reducing the overall cost and improving production efficiency. Moreover, the lamp board clamped by the beads is also a lamp board with independent protection and anti-interference functions. When a transient overvoltage appears in the circuit, the chip bead can effectively absorb this energy, thereby reducing the damage to the lamp beads and extending their service life. Therefore, when this lamp board is matched with other DC-DC modules for application, it also has good compatibility and anti-interference ability.

[0021] The DIP switch circuit includes a DIP switch SW1D. The positive input of the common-mode coil LF1 is connected to the fourth pin of the DIP switch SW1D. The negative input of the common-mode coil LF1 is connected to the positive power input DC+. By switching the voltage through the DIP switch, the stability of the connection between the DIP switch circuit and the common-mode coil LF1 is ensured, and at the same time, the connection and operation of the DIP switch SW1D are facilitated.

[0022] The reverse-connection protection filter circuit C includes a rectifier bridge DB1. The positive input of the rectifier bridge DB1 is connected to the positive output of the common-mode coil LF1, and the negative input of the rectifier bridge DB1 is connected to the negative output of the common-mode coil LF1. After being filtered by the common-mode coil LF1, it passes through the bridge rectifier DB1 to provide protection against reverse connection of the DC power supply.

[0023] The reverse-connection protection filter circuit C includes an I-shaped inductor L3, a polarized capacitor EC1, and a polarized capacitor EC3. The negative electrodes of the polarized capacitor EC1 and the polarized capacitor EC3 are respectively connected to the sixth pin and the seventh pin of the chip U1. The positive electrodes of the polarized capacitor EC1 and the polarized capacitor EC3 are respectively connected to the positive output of the rectifier bridge DB1 through the I-shaped inductor L3. The circuit composed of the I-shaped inductor L3, the polarized capacitor EC1, and the polarized capacitor EC3 filters the current into pulsating direct current and then supplies power to the entire circuit.

[0024] The PWM switching step-down circuit F also includes a polarized capacitor EC2. The third pin of the chip U1 is connected to the positive input of the common-mode coil LF2 through an inductor L4. The positive electrode of the polarized capacitor EC2 is connected to the positive input of the common-mode coil LF2. The negative electrode of the polarized capacitor EC2 is connected to the positive output of the rectifier bridge DB1 through a resistor R7 and a resistor R9. The current is stepped down through the PWM switching step-down circuit to achieve a constant current output.

[0025] The PWM switching step-down circuit F also includes a diode D6. The positive electrode of the diode D6 is connected to the positive input of the common-mode coil LF2 through an inductor L4. The negative electrode of the diode D6 is connected to the positive output of the rectifier bridge DB1 through an inductor L2 and a resistor R9. The reverse-connection protection filter circuit supplies power to the LED light source board through the common-mode coil LF2.

[0026] The second pin of the chip U1 is connected to the positive output of the rectifier bridge DB1 through a resistor R9. The second pin of the chip U1 is grounded through a capacitor C20, a resistor R22, and a capacitor C6. The fourth pin of the chip U1 is grounded through a resistor R10 to improve the stability and safety of the input operating voltage of the chip U1.

[0027] The external power adjustment control circuit D includes a triode Q1, a triode Q2, a triode Q3 and an adjustment switch RP1. The C terminal of the triode Q1 is connected to the eighth pin of the chip U1. The C terminal of the triode Q1 is connected to the E terminal of the triode Q3 through a resistor R13. The C terminal of the triode Q3 is connected to the E terminal of the triode Q2. The C terminal of the triode Q2 is connected to the positive output of the rectifier bridge DB1 through a resistor R25 and a resistor R9. The A terminal of the adjustment switch RP1 is connected to the B terminal of the triode Q3. The C terminal of the triode Q3 is connected to the B terminal of the adjustment switch RP1 to achieve the stability of power adjustment and accurately achieve the adjustment of power output.

[0028] The external power adjustment control circuit D further includes a diode D5 and a zener diode ZD1. The positive pole of the zener diode ZD1 is connected to the negative pole of the diode D5 through a resistor R5 and a resistor R6. The positive pole of the zener diode ZD1 is connected to the B terminal of the triode Q2 to improve the stability and safety of the operation of the external power adjustment control circuit D.

[0029] As a specific implementation manner, the model of the chip U1 is OC5266, with stable control and high control efficiency.

[0030] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A DC-DC module and light source combination control circuit for suppressing electromagnetic interference, characterized in that: It includes a DIP switch circuit, a first common-mode coil common-mode signal suppression module, an anti-reverse connection filter circuit, a PWM switch-type buck circuit, a second common-mode coil common-mode signal suppression module and an LED light source board connected in sequence, the PWM switch-type buck circuit is connected to an external power adjustment control circuit, the PWM switch-type buck circuit includes a chip U1, the first common-mode coil common-mode signal suppression module includes a common-mode coil LF1, the second common-mode coil common-mode signal suppression module includes a common-mode coil LF2, and the LED light source board is provided with magnetic beads B1 and B2.

2. The DC-DC module and light source combination control circuit for suppressing electromagnetic interference according to claim 1, characterized in that: The dip switch circuit includes a dip switch SW1D, the input positive pole of the common mode coil LF1 is connected to the fourth pin of the dip switch SW1D, and the input negative pole of the common mode coil LF1 is connected to the power input positive pole DC+.

3. The DC-DC module and light source combination control circuit for suppressing electromagnetic interference according to claim 1, characterized in that: The anti-reverse connection filter circuit includes a rectifier bridge DB1, an input positive pole of the rectifier bridge DB1 is connected to an output positive pole of the common mode coil LF1, and an input negative pole of the rectifier bridge DB1 is connected to an output negative pole of the common mode coil LF1.

4. The DC-DC module and light source combination control circuit for suppressing electromagnetic interference according to claim 3, characterized in that: The anti-reverse connection filter circuit includes an I-shaped inductor L3, a polarity capacitor EC1 and a polarity capacitor EC3. The negative electrode of the polarity capacitor EC1 and the negative electrode of the polarity capacitor EC3 are respectively connected to the sixth pin and the seventh pin of the chip U1, and the positive electrode of the polarity capacitor EC1 and the positive electrode of the polarity capacitor EC3 are respectively connected to the output positive electrode of the rectifier bridge DB1 through the I-shaped inductor L3.

5. The DC-DC module and light source combination control circuit for suppressing electromagnetic interference according to claim 3, characterized in that: The PWM switching buck circuit also includes a polarity capacitor EC2. The third pin of the chip U1 is connected to the input positive electrode of the common mode coil LF2 through the inductor L4. The positive electrode of the polarity capacitor EC2 is connected to the input positive electrode of the common mode coil LF2. The negative electrode of the polarity capacitor EC2 is connected to the output positive electrode of the rectifier bridge DB1 through the resistors R7 and R9.

6. The DC-DC module and light source combination control circuit for suppressing electromagnetic interference according to claim 3, characterized in that: The PWM switching buck circuit further includes a diode D6, the anode of the diode D6 is connected to the input anode of the common mode coil LF2 through an inductor L4, and the cathode of the diode D6 is connected to the output anode of the rectifier bridge DB1 through an inductor L2 and a resistor R9.

7. The DC-DC module and light source combination control circuit for suppressing electromagnetic interference according to claim 3, characterized in that: The second pin of the chip U1 is connected to the positive output electrode of the rectifier bridge DB1 through a resistor R9, the second pin of the chip U1 is grounded through a capacitor C20, a resistor R22 and a capacitor C6, and the fourth pin of the chip U1 is grounded through a resistor R10.

8. The DC-DC module and light source combination control circuit for suppressing electromagnetic interference according to claim 3, characterized in that: The external power regulation control circuit includes a transistor Q1, a transistor Q2, a transistor Q3 and an adjustment switch RP1. The C end of the transistor Q1 is connected to the eighth pin of the chip U1, the C end of the transistor Q1 is connected to the E end of the transistor Q3 through a resistor R13, the C end of the transistor Q3 is connected to the E end of the transistor Q2, the C end of the transistor Q2 is connected to the output positive electrode of the rectifier bridge DB1 through resistors R25 and R9, the A end of the adjustment switch RP1 is connected to the B end of the transistor Q3, and the C end of the transistor Q3 is connected to the B end of the adjustment switch RP1 through a resistor R19.

9. The DC-DC module and light source combination control circuit for suppressing electromagnetic interference according to claim 8, characterized in that: The external power regulation control circuit further includes a diode D5 and a voltage regulator diode ZD1, wherein the anode of the voltage regulator diode ZD1 is connected to the cathode of the diode D5 via resistors R5 and R6, and the anode of the voltage regulator diode ZD1 is connected to the B terminal of the transistor Q2.

10. The DC-DC module and light source combined control circuit for suppressing electromagnetic interference according to claim 1, characterized in that: The model of the chip U1 is OC5266.

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