High-voltage output DCDC power supply module

Abstract

The utility model discloses a high voltage output DCDC power supply module, which comprises a shell, a PCB and an installation epoxy board, the shell is a cavity structure with an opening at the bottom, the PCB is arranged in the shell and is fixed by pouring AB glue, four pins are arranged on the PCB, the four pins penetrate out of the installation epoxy board, and the installation epoxy board covers the bottom of the shell and is fixed with the AB glue in the shell in a contact and bonding manner. The PCB is encapsulated in the cavity of the shell through AB glue by adopting the shell and the mounting epoxy board, so that the power module can be protected and prevented from being influenced by the outside, the mounting epoxy board plays a role in stabilizing the pins and prevents the connection reliability of the PCB from being influenced, the electrical connection between the pins and the PCB is more stable, and the AB glue is encapsulated inside, so that the reliability of the power module is improved. On one hand, an elastic buffering effect is achieved, internal components are prevented from being damaged due to huge vibration, on the other hand, an effect of isolating external influence can be achieved, and the service life is prolonged.

Description

Technical Field

[0001] The utility model relates to a high-voltage output DCDC power supply module, belonging to the technical field of switch power supplies. Background Art

[0002] In the field of switching power supplies, low-voltage to low-voltage power modules are the mainstream products in the market, and low-voltage to kilovolt high-voltage power supplies are relatively rare. This is because in traditional switching power supply technology, if you want to convert a low voltage of 28V into a high voltage of 3600V or above, the transformer ratio must reach 1:130, and the number of turns on the secondary side of the high-frequency transformer needs to be 650 turns. It is large in size and heavy in weight. When it is installed on the PCB board using pin plug-in, it is subject to vibration and other reasons, resulting in poor stability and connection reliability. Summary of the invention

[0003] The technical problem to be solved by the utility model is to provide a high-voltage output DCDC power supply module to solve the problems existing in the above-mentioned prior art.

[0004] The technical solution adopted by the utility model is: a high-voltage output DCDC power supply module, including a shell, a PCB board and a mounting epoxy board. The shell is a cavity structure with an opening at the bottom. The PCB board is placed in the shell and is fixed by AB glue encapsulation. Four pins are arranged on the PCB board. The four pins pass through the mounting epoxy board. The mounting epoxy board covers the bottom of the shell and is fixed by contact with the AB glue in the shell.

[0005] Furthermore, the above-mentioned shell dimensions are 40.0mm long × 27.0mm wide × 15.0mm high, with a wall thickness of 1mm. A 2mm high step is set at the bottom end, and the wall thickness at the step is 0.5mm. The dimensions of the installed epoxy board are 39mm long × 26mm wide × 2mm high.

[0006] Furthermore, the circuit of the above-mentioned high-voltage output DCDC power supply module includes an input end, a flyback conversion circuit, a voltage doubler rectifier circuit, an output sampling circuit, an error amplifier circuit, a drive circuit and an output end, the input end is connected to the flyback conversion circuit, the voltage doubler rectifier circuit and the output end in sequence, the output sampling circuit is connected to the output end and the error amplifier circuit, the error amplifier circuit is connected to the drive circuit, and the drive circuit is connected to the flyback conversion circuit.

[0007] Furthermore, the high-voltage circuit part and the low-voltage circuit part are arranged on the left and right sides of the PCB board respectively, and a high-frequency transformer is installed between the high-voltage circuit part and the low-voltage circuit part.

[0008] Beneficial effects of the utility model: Compared with the prior art, the effects of the utility model are as follows:

[0009] 1) The PCB board is potted into the shell cavity with AB glue using a shell and an epoxy board. This can protect the power module from external influences. The epoxy board is installed to stabilize the pins, avoiding affecting the connection reliability of the connection on the PCB board. The electrical connection between the pins and the PCB board is more stable. The internal potting of AB glue can, on the one hand, play an elastic buffering role to prevent internal components from being damaged due to huge vibrations. On the other hand, it can isolate the external influences and increase the service life.

[0010] 2) The use of flyback conversion circuit and voltage doubler rectifier circuit can minimize the types and quantities of components. If the traditional solution wants to achieve 3600V high-voltage output without using voltage doubler rectifier circuit, the transformer ratio will reach 1:130, and the number of turns of the secondary side of the high-frequency transformer used will need to be 650 turns. Therefore, the use of flyback conversion circuit and voltage doubler rectifier circuit reduces the number of turns of the high-frequency transformer, and only 110 turns are needed on the secondary side, thereby realizing the miniaturization of the power module. The size of the module is miniaturized to 40.0mm long × 27.0mm wide × 15.0mm high, which meets the input voltage range of DC 22V~35V, can work normally in the temperature range of -40℃~85℃, and has the characteristics of low power consumption, high output voltage stability, and high output voltage accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a three-dimensional structural diagram of a high-voltage output DCDC power module;

[0012] Figure 2 This is a three-dimensional structural diagram of the high-voltage output DCDC power module (without the mounting epoxy board);

[0013] Figure 3 This is a front view structural diagram of a high voltage output DCDC power module;

[0014] Figure 4 yes Figure 3 Schematic diagram of the AA section structure;

[0015] Figure 5 yes Figure 3 Schematic diagram of the structure of the middle BB section;

[0016] Figure 6 yes Figure 3 Schematic diagram of the CC cross-section structure;

[0017] Figure 7 It is a schematic diagram of the three-dimensional structure of the PCB board;

[0018] Figure 8 This is a schematic diagram of the circuit principle of the high-voltage output DCDC power module;

[0019] Fig. 9It is a circuit topology diagram;

[0020] Fig.10 It is the PWM control circuit diagram;

[0021] Fig.11 It is the PCB layout diagram;

[0022] Fig.12 This is the installation diagram of epoxy board PCB. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] Example 1: Figure 1-7 As shown, a high-voltage output DCDC power supply module includes a shell 1, a PCB board 2 and a mounting epoxy board 3. The shell 1 is a cavity structure with an opening at the bottom. The PCB board 2 is placed in the shell 1 and is fixed by encapsulation with AB glue. Four pins 4 are arranged on the PCB board 2. The four pins 4 pass through the mounting epoxy board 3. The mounting epoxy board 3 covers the bottom of the shell 1 and is bonded and fixed with the AB glue in the shell. The mounting epoxy board 3 is made of the material of the PCB board.

[0025] Furthermore, the dimensions of the above-mentioned shell 1 are 40.0mm long×27.0mm wide×15.0mm high, with a wall thickness of 1mm. A 2mm high step 5 is set at the bottom end, and the wall thickness of the step 5 is 0.5mm. The dimensions of the installed epoxy board 3 are 39mm long×26mm wide×2mm high.

[0026] like Figure 8 As shown, the circuit of the above-mentioned high-voltage output DCDC power supply module includes an input end, a flyback conversion circuit, a voltage doubler rectifier circuit, an output sampling circuit, an error amplifier circuit, a drive circuit and an output end, the input end is connected to the flyback conversion circuit, the voltage doubler rectifier circuit and the output end in sequence, the output sampling circuit is connected to the output end and the error amplifier circuit, the error amplifier circuit is connected to the drive circuit, and the drive circuit is connected to the flyback conversion circuit.

[0027] like Fig. 9As shown, in the circuit in which the flyback conversion circuit is connected to the voltage doubler rectifier circuit: one end of the inductor L1 is connected to the 28V power input terminal, and the other end is connected to the drain of the transformer T1 and the MOS tube Q1, the source of the MOS tube Q1 is grounded, and the gate of the drain of the MOS tube Q1 is connected to the PWM terminal of the drive circuit, and the output end of the transformer T1 is connected to the voltage doubler rectifier circuit, which includes a diode D1, a diode D3, a diode D5, a diode D2, a diode D4, a diode D6, a capacitor C1, a capacitor C3, a capacitor C5, a capacitor C2, a capacitor C4 and a capacitor C6, one end of the capacitor C1 is connected to an output terminal of the secondary side of the transformer T1, and the other end is connected to the The cathode of the transformer T1 is connected to the anode of the diode D2 and one end of the capacitor C3. The anode of the diode D1 is connected to the other output end of the secondary side of the transformer T1, the ground terminal GND and one end of the capacitor C2. The cathode of the diode D2 is connected to the other end of the capacitor C2, the anode of the diode D3 and one end of the capacitor C4. The other end of the capacitor C3 is connected to the cathode of the diode D3, the anode of the diode D4 and one end of the capacitor C5. The other end of the capacitor C4 is connected to the cathode of the diode D4, the anode of the diode D5 and one end of the capacitor C6. The other end of the capacitor C5 is connected to the cathode of the diode D5 and the anode of the diode D6. The other end of the capacitor C6 is connected to the cathode of the diode D6 and the output terminal OUT.

[0028] Among them, the inductor L1 plays the role of input filtering, controlling the on and off of the MOS tube Q1, and the energy is converted through the transformer T1; when the MOS tube Q1 is on, the current on the primary side of the transformer T1 rises, and the secondary side induces a voltage of the same phase, the diodes D1, D3, and D5 in the voltage doubler rectifier circuit are turned on, and the capacitors C1, C3, and C5 are charged. At the same time, D2, D4, and D6 are turned off, and the capacitors C2, C4, and C6 are connected in series to supply power to the output load.

[0029] During the cut-off period of MOS tube Q1, the induced voltage on the secondary side of transformer T1 is reversed, diodes D1, D3, and D5 are cut off, and the induced voltage on the secondary side of transformer T1 is superimposed on the voltage on capacitors C1, C3, and C5 to charge capacitors C2, C4, and C6 respectively. Capacitor C6 also supplies power to the output load.

[0030] like Fig.10 The driving circuit for the controller shown has PWM as the output terminal and VCC as the input terminal. A 555 time base circuit is selected to form a PWM control circuit. The duty cycle of the PWM signal in the 555 time base circuit is controlled by collecting the high-voltage output voltage to form a negative feedback, thereby realizing closed-loop control of the high-voltage DC output. It has the advantages of a small number of components and a small size.

[0031] Furthermore, the high-voltage circuit part and the low-voltage circuit part are arranged on the left and right sides of the PCB board 2, respectively, and a high-frequency transformer is installed between the high-voltage circuit part and the low-voltage circuit part for isolation.

[0032] Embodiment 2: A method for manufacturing a high-voltage output DCDC power module, the method comprising the following steps:

[0033] 1) Step 1: Circuit topology selection. The main circuit board is the core of the power module. Its main function is to convert the 28V low-voltage DC input into a 3600V high-voltage DC output. It uses a flyback conversion topology and a voltage doubler rectifier circuit. Fig. 9 The front-stage flyback circuit boosts the 28V low-voltage DC to a high-voltage DC of about 600V, and the back-stage uses a 6-fold voltage rectifier to achieve a 3600V high-voltage DC output;

[0034] 2) Step 2: Selection of control circuit. The control circuit uses a PWM controller built with a 555 time base circuit, which can perform closed-loop control of the output voltage. The 555 time base circuit is used to form a PWM control circuit. By collecting the high-voltage output voltage to form a negative feedback control of the duty cycle of the PWM signal in the 555 time base circuit, the closed-loop control of the high-voltage DC output is achieved. It has the advantages of a small number of components and a small size. Fig.10 As shown;

[0035] 3) Step 3: PCB layout, using high voltage and low voltage partition layout, with high frequency transformer in the middle to isolate the two sides; PCB layout as follows Figure 11-12 As shown, the high voltage (left) and low voltage (right) partition layout is adopted, and the high-frequency transformer is used in the middle to isolate the two sides, which well realizes the function of the module and avoids the influence of high voltage signal on low voltage signal;

[0036] 4) Step 4: Install the epoxy board PCB design. The epoxy board should fit the size of the main circuit printed board and the shell. At the same time, let the 4 electrical pins pass through the epoxy board and insulate the pins. The size of the epoxy board is 39mm long × 26mm wide × 2mm high. The 4 corners are rounded, and the rounded size is R2.

[0037] 5) Step 5: Design of the shell. The shell material is 6061 aluminum. 6061 aluminum has good strength and oxidation resistance and is a good material choice. The shell dimensions are 40.0mm×27.0mm wide×15.0mm high. The middle is hollowed out with a wall thickness of 1mm. The inner wall is milled to 0.5mm thick 2mm from the top, and the inner wall corners are rounded 2mm, just enough to embed the epoxy board in the top of the shell.

[0038] 6) Step 6: Install and fix. After the welding test of the main circuit printed board is completed, place it in the shell, pour AB glue into the shell, and then cover it with the epoxy board to fix it together with the shell;

[0039] 7) Step 7: Baking. After completing step 6, place the power module in an oven at 70℃±5℃ for baking to solidify the potting glue.

[0040] The above description is only a specific implementation method of the present utility model, but the protection scope of the present utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present utility model, which should be included in the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims

1. A high voltage output DCDC power supply module, characterized in that: The invention comprises a housing (1), a PCB board (2) and a mounting epoxy board (3); the housing (1) is a cavity structure with an opening at the bottom; the PCB board (2) is placed in the housing (1) and is fixed by encapsulation with AB glue; four plug pins (4) are arranged on the PCB board (2); the four plug pins (4) extend through the mounting epoxy board (3); the mounting epoxy board (3) covers the bottom of the housing (1) and is fixed by contacting with the AB glue in the housing.

2. A high voltage output DCDC power supply module according to claim 1, characterized in that: The dimensions of the housing (1) are 40.0 mm long × 27.0 mm wide × 15.0 mm high, with a wall thickness of 1 mm. A 2 mm high step is provided at the bottom end, and the wall thickness at the step is 0.5 mm. The dimensions of the mounting epoxy plate (3) are 39 mm long × 26 mm wide × 2 mm high.

3. A high voltage output DCDC power supply module according to claim 1, characterized in that: The circuit of the high-voltage output DCDC power supply module includes an input end, a flyback conversion circuit, a voltage doubler rectifier circuit, an output sampling circuit, an error amplifier circuit, a drive circuit and an output end. The input end is connected to the flyback conversion circuit, the voltage doubler rectifier circuit and the output end in sequence, the output sampling circuit is connected to the output end and the error amplifier circuit, the error amplifier circuit is connected to the drive circuit, and the drive circuit is connected to the flyback conversion circuit.

4. A high voltage output DCDC power supply module according to claim 1, characterized in that The high-voltage circuit part and the low-voltage circuit part are arranged on the left and right sides of the PCB board respectively, and a high-frequency transformer is installed between the high-voltage circuit part and the low-voltage circuit part.

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