High-voltage power supply starting circuit

Abstract

The utility model belongs to the technical field of switching power supplies, and relates to a high-voltage power supply starting circuit. In the circuit, a power supply end VDD of a chip U is simultaneously connected with a filter capacitor C1 and a cathode of a rectifier tube D2, and an anode of the rectifier tube D2 is grounded through an auxiliary winding NA. When the chip U is just powered on, the VDD pin of the chip U is at a low level, and input VCC is connected in series through the first voltage-sharing resistor and the second voltage-sharing resistor for voltage division; when the voltage on the two sides of the voltage-regulator tube D reaches the turn-on voltage of the switch tube Q, the switch tube Q is turned on. Thus, VCC voltage charges the filter capacitor C1 through the first starting resistor, the switching tube Q and the second starting resistor, and when the charging voltage reaches the starting voltage of the chip U, the chip U starts to work. When the output voltage is stable, the voltage generated by the auxiliary winding NA is rectified by the rectifier tube D2 and filtered by the filter capacitor C1 and then is supplied to the chip U. The efficiency of the starting circuit can be improved, the cost is reduced, and the starting circuit can be applied to occasions with higher input voltage.

Description

Technical Field

[0001] The utility model belongs to the technical field of switching power supplies and relates to a high-voltage power supply starting circuit. Background Art

[0002] In high-voltage and ultra-high-voltage system products such as photovoltaic and energy storage, the stable, efficient and reliable auxiliary power supply for each control unit is particularly important. As the auxiliary power supply used in such systems, the starting performance and starting power consumption of the switching power supply under high-voltage conditions directly affect the working state of the entire system. For a good system product, its power supply must have a good starting circuit to cooperate. However, the design of the high-voltage starting circuit is relatively difficult. It is necessary to reduce the circuit loss of the starting part to prevent key components from overheating and damage, and at the same time, find electronic components that can withstand high voltage.

[0003] The schematic diagram of the commonly used switching power supply starting circuit at present is as Figure 1 shown. After the power supply starts, the input voltage Vin charges the filter capacitor C1 through the power resistor R1. The charging speed of the filter capacitor C1 is related to the power resistor R1 and the filter capacitor C1. When the voltage on the filter capacitor C1 reaches the starting voltage of the main control chip, the switching power supply starts to work normally; when the output voltage is stable, the voltage generated by the auxiliary winding NA is rectified by the rectifier diode D2 and filtered by the filter capacitor C1 to supply power to the main control chip.

[0004] Figure 1 The disadvantages of the circuit are as follows: In order to reduce the starting time, the value of the power resistor R1 is taken to be small. Due to the power consumption generated by R1 this will increase the loss when the high voltage is input, reduce the power supply efficiency, and if a high-power resistor needs to be selected, the space occupied by the resistor is large and the cost is also high. Content of the Utility Model

[0005] The purpose of the present invention is to provide a high-voltage power supply starting circuit to solve the technical problems that the power resistor of the high-voltage starting circuit is too small, resulting in increased loss and reduced power supply efficiency, and the power resistor of the high-voltage starting circuit is too large, and the space occupied by the resistor is large. The utility model can reduce the starting loss, improve the efficiency of the starting circuit, and reduce the cost of the starting circuit.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] The utility model discloses a high-voltage power supply starting circuit, which includes a main control chip U. The power supply terminal VDD of the main control chip U is grounded through a filter capacitor C1. The power supply terminal VDD of the main control chip U is connected to the cathode of a rectifier diode D2, and the anode of the rectifier diode D2 is grounded through an auxiliary winding NA;

[0008] The power supply terminal VDD / start-up pin HV of the main control chip U is connected to the input VCC through a second start-up resistor, and at least one voltage-sharing start-up circuit is connected in series between the second start-up resistor and the input VCC.

[0009] Furthermore, the GND interface of the main control chip U is grounded.

[0010] Furthermore, the voltage-sharing start-up circuit includes a switching transistor Q. The drain of the switching transistor Q is connected to one end of the first start-up resistor; the gate of the switching transistor Q is simultaneously connected to the cathode of the voltage-regulator diode D, one end of the first voltage-sharing resistor, and one end of the second voltage-sharing resistor; the source of the switching transistor Q is respectively connected to the anode of the voltage-regulator diode D and one end of the second start-up resistor; the switching transistor Q and the first start-up resistor are connected in series and then in parallel with the first voltage-sharing resistor. The first voltage-sharing resistor and the first start-up resistor are used to connect to the input VCC / the next-stage voltage-sharing start-up circuit.

[0011] Furthermore, the specific connection of the first voltage-sharing resistor and the first start-up resistor to the input VCC / the next-stage voltage-sharing start-up circuit is as follows:

[0012] When there is one voltage-sharing start-up circuit, the first voltage-sharing resistor and the first start-up resistor are connected to the input VCC.

[0013] Furthermore, the specific connection of the first voltage-sharing resistor and the first start-up resistor to the input VCC / the next-stage voltage-sharing start-up circuit is as follows:

[0014] When there are several voltage-sharing start-up circuits, the first start-up resistor of the voltage-sharing start-up circuit is connected to the anode of the voltage-regulator diode D of the next voltage-sharing start-up circuit, the first voltage-sharing resistor of the voltage-sharing start-up circuit is connected to the cathode of the voltage-regulator diode D of the next voltage-sharing start-up circuit, and the first voltage-sharing resistor and the first start-up resistor of the last voltage-sharing start-up circuit are connected to the input VCC.

[0015] Furthermore, the first voltage-sharing resistor is several resistors connected in series.

[0016] Furthermore, the first start-up resistor is several resistors connected in series.

[0017] Furthermore, the cathode of the voltage-regulator diode D is grounded through the second voltage-sharing resistor.

[0018] Furthermore, the second voltage-sharing resistor is several resistors connected in series.

[0019] Furthermore, the second start-up resistor is several resistors connected in series.

[0020] Compared with the prior art, the present utility model has the following beneficial effects:

[0021] 1. The utility model filters through the capacitor C1, making the signal more stable and pure. The power supply terminal VDD of the main control chip U is connected to the cathode of the rectifier diode D2, and the anode of the rectifier diode D2 is grounded through the auxiliary winding NA. When the output voltage is stable, the voltage generated by the auxiliary winding NA is rectified by the rectifier diode D2 and filtered by the filter capacitor C1 to supply power to the main control chip. The utility model is beneficial to reducing the starting loss, improving the efficiency of the starting circuit, reducing the cost of the starting circuit, and can be applied to occasions with higher input voltages.

[0022] 2. The first starting resistor of the utility model plays a current limiting role for the drain of the switching transistor Q to protect the switching transistor Q. The first voltage-sharing resistor and the second voltage-sharing resistor equalize the voltage of the input VCC, and the divided voltage is connected to the gate of the switching transistor Q. The source of the switching transistor Q is respectively connected to the anode of the voltage stabilizing diode D and the second starting resistor. The second starting resistor plays a current limiting role for the source of the switching transistor Q to protect the switching transistor Q, which is beneficial to improving the stability of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the starting circuit diagram of the existing switching power supply;

[0024] Figure 2 is the circuit structure block diagram of the utility model;

[0025] Figure 3 is the starting circuit diagram of the switching power supply of an embodiment of the utility model;

[0026] Figure 4 is the starting circuit diagram of the switching power supply of another embodiment of the utility model;

[0027] Figure 5 is the circuit schematic diagram of an embodiment of the utility model;

[0028] Figure 6 is the circuit schematic diagram of another embodiment of the utility model.

[0029] Wherein: 1. The first voltage-sharing resistor; 2. The second voltage-sharing resistor; 3. The first starting resistor; 4. The second starting resistor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the utility model.

[0031] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present utility model are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0032] The following further describes the present utility model in detail with reference to the drawings:

[0033] See Figure 2 and Figure 3 , the present utility model discloses a high-voltage power supply startup circuit, which includes a main control chip U. The power supply terminal VDD of the main control chip U is grounded through a filter capacitor C1. Filtering is performed through the capacitor C1 to make the signal more stable and pure. The power supply terminal VDD of the main control chip U is connected to the cathode of a rectifier diode D2. The anode of the rectifier diode D2 is grounded through an auxiliary winding NA. When the output voltage is stable, the auxiliary winding NA couples the voltage of the secondary side. One side is grounded, and the other side is rectified by the rectifier diode D2 and filtered by the filter capacitor C1 to supply power to the main control chip;

[0034] The power supply terminal VDD / startup pin HV of the main control chip U is connected to the input VCC through a second startup resistor 4. At least one voltage-sharing startup circuit is connected in series between the second startup resistor 4 and the input VCC. After the power supply is started, the input voltage Vin charges the filter capacitor C1 through the power resistor R1. The charging speed of the filter capacitor C1 is related to the power resistor R1 and the filter capacitor C1. When the voltage on the filter capacitor C1 reaches the startup voltage of the main control chip, the switching power supply starts to work normally; when the output voltage is stable, the voltage generated by the auxiliary winding NA is rectified by the rectifier diode D2 and filtered by the filter capacitor C1 to supply power to the main control chip. The present utility model is beneficial to reducing startup losses, improving the efficiency of the startup circuit, reducing the cost of the startup circuit, and can be applied to occasions with higher input voltages.

[0035] Embodiment 1:

[0036] See Figure 3 , the present utility model discloses a high-voltage power supply startup circuit, which includes a main control chip U. The power supply terminal VDD of the main control chip U is grounded through a filter capacitor C1. The power supply terminal VDD of the main control chip U is connected to the cathode of a rectifier diode D2. The anode of the rectifier diode D2 is grounded through an auxiliary winding NA;

[0037] The power supply terminal VDD of the main control chip U is connected to the input VCC through the second startup resistor 4. A voltage equalizing startup circuit is connected in series between the second startup resistor 4 and the input VCC, and the startup of the chip is realized through the voltage equalizing startup circuit.

[0038] Preferably, the GND interface of the main control chip U is grounded.

[0039] Preferably, the voltage equalizing startup circuit includes a switching tube Q. The drain of the switching tube Q is connected to the first startup resistor 3. The first startup resistor 3 limits the current of the drain of the switching tube Q to protect the switching tube Q. The first voltage equalizing resistor 1 and the second voltage equalizing resistor 2 equalize the input VCC, and the divided voltage is connected to the gate of the switching tube Q. The source of the switching tube Q is respectively connected to the anode of the voltage stabilizing diode D and the second startup resistor 4. The second startup resistor 4 limits the current of the source of the switching tube Q to protect the switching tube Q, which is beneficial to improving the stability of the circuit. The switching tube Q and the first startup resistor 3 are connected in series and then in parallel with the first voltage equalizing resistor 1. The first voltage equalizing resistor 1 and the first startup resistor 3 are used to connect the input VCC / the next-stage voltage equalizing startup circuit.

[0040] Preferably, the first voltage equalizing resistor 1 and the first startup resistor 3 are connected to the input VCC.

[0041] Preferably, the first voltage equalizing resistor 1 is a number of resistors connected in series.

[0042] Preferably, the first startup resistor 3 is a number of resistors connected in series.

[0043] Preferably, the cathode of the voltage stabilizing diode D is connected to the second voltage equalizing resistor 2, and the second voltage equalizing resistor 2 is grounded.

[0044] Preferably, the second voltage equalizing resistor 2 is a number of resistors connected in series.

[0045] Preferably, the second startup resistor 4 is a number of resistors connected in series.

[0046] The working process of this embodiment is as follows:

[0047] When just powered on, the filter capacitor C1 has no voltage, the VDD pin of the chip U is at a low level, the anode of the voltage stabilizing diode D is at a low level, and the input VCC is divided in series by the first voltage equalizing resistor 1 and the second voltage equalizing resistor 2; when the cathode potential of the voltage stabilizing diode D is higher than the anode and this reverse voltage reaches the breakdown voltage of the voltage stabilizing diode D, the voltage across the voltage stabilizing diode D is clamped and does not change; when the voltage across the voltage stabilizing diode D reaches the turn-on voltage of the switching tube Q, the switching tube Q will turn on. In this way, the input VCC voltage will charge the filter capacitor C1 through the first startup resistor 3, the switching tube Q, and the second startup resistor 4. When the voltage of the filter capacitor C1 reaches the startup voltage of the chip U, the chip U starts to work.

[0048] Embodiment 2:

[0049] See Figure 4 , the present utility model discloses a high-voltage power supply startup circuit, which includes a main control chip U. The power supply terminal VDD of the main control chip U is grounded through a filter capacitor C1. The power supply terminal VDD of the main control chip U is connected to the cathode of a rectifier diode D2, and the anode of the rectifier diode D2 is grounded through an auxiliary winding NA.

[0050] The startup pin HV of the main control chip U is connected to the input VCC through a second startup resistor 4, and at least one voltage-sharing startup circuit is connected in series between the second startup resistor 4 and the input VCC.

[0051] Preferably, the GND interface of the main control chip U is grounded.

[0052] Preferably, the voltage-sharing startup circuit includes a switching tube Q. The drain of the switching tube Q is connected to one end of a first startup resistor 3; the gate of the switching tube Q is simultaneously connected to the cathode of a zener diode D, one end of a first voltage-sharing resistor 1, and one end of a second voltage-sharing resistor 2; the source of the switching tube Q is respectively connected to the anode of the zener diode D and one end of the second startup resistor 4; the switching tube Q and the first startup resistor 3 are connected in series and then in parallel with the first voltage-sharing resistor 1. The first voltage-sharing resistor 1 and the first startup resistor 3 are used to connect the input VCC / the next-stage voltage-sharing startup circuit.

[0053] Preferably, the cathode of the zener diode D is connected to the second voltage-sharing resistor 2, and the second voltage-sharing resistor 2 is grounded.

[0054] The working process of this embodiment is as follows:

[0055] Similar to the working principle of Embodiment 1, when just powered on, the HV pin of the chip U is at a low level, and the anode of the zener diode D is at a low level. The input VCC is divided by the first voltage-sharing resistor 1 and the second voltage-sharing resistor 2 in series; when the potential of the cathode of the zener diode D is higher than the anode and this reverse voltage reaches the breakdown voltage of the zener diode D, the voltage across the zener diode D is clamped and does not change; when the voltage across the zener diode D reaches the turn-on voltage of the switching tube Q, the switching tube Q will turn on. In this way, the input VCC voltage will charge the HV pin of the chip U through the first startup resistor 3, the switching tube Q, and the second startup resistor 4. When the voltage of the HV pin of the chip U is greater than the undervoltage protection threshold, the chip U starts to work.

[0056] Embodiment 3:

[0057] See Figure 5 , the high-voltage power supply startup circuit diagram of Embodiment 3 of the present utility model. U3 represents the main control chip, C1 represents the filter capacitor, NA represents the auxiliary winding, D2 represents the rectifier diode, VDD represents the chip power supply terminal, and HV represents the high-voltage connection terminal. A high-voltage power supply startup circuit includes a power supply circuit and a voltage-sharing startup circuit. The connection relationship between these two circuits is as follows:

[0058] a. Connection mode of the power supply circuit:

[0059] The power supply circuit includes a main control chip U3, an auxiliary winding NA, a rectifier diode D2, and a filter capacitor C1.

[0060] One end of the filter capacitor C1 is connected to the chip power supply terminal VDD of the main control chip U3, and the other end of the filter capacitor C1 is connected to the ground.

[0061] The anode of the rectifier diode D2 is connected to the auxiliary winding NA, and the cathode of the rectifier diode D2 is connected to the chip power supply terminal VDD of the main control chip U3.

[0062] One end of the auxiliary winding NA is connected to the anode of the rectifier diode D2, and the other end is connected to the ground.

[0063] b. Connection mode of the voltage equalization starting circuit:

[0064] The voltage equalization starting circuit includes a voltage equalization circuit and a starting circuit;

[0065] The voltage equalization circuit mentioned above includes a first voltage equalization resistor 1, a second voltage equalization resistor 2, and a third voltage equalization resistor 3. The first voltage equalization resistor 1 is the resistor RA, the second voltage equalization resistor 2 is the resistor RB, and the third voltage equalization resistor 3 is the resistor RC;

[0066] The first voltage equalization resistor 1 includes resistors R1, R2, and R3 connected in series;

[0067] The second voltage equalization resistor 2 includes resistors R4, R5, and R6 connected in series;

[0068] The third voltage equalization resistor 3 includes resistors R7, R8, and R9 connected in series;

[0069] Among them, the upper end of the resistor R1 is connected to the input VCC, the lower end of the resistor R3 is connected to the upper end of the resistor R4, the lower end of the resistor R6 is connected to the upper end of the resistor R7, and the lower end of the resistor R9 is grounded.

[0070] The starting circuit mentioned above includes a first starting circuit QA, a second starting circuit QB, and a resistor circuit RX.

[0071] The first starting circuit QA includes a switching tube Q1, a voltage stabilizing diode D3, and resistors Ra and Rb;

[0072] The second starting circuit QB includes a switching tube Q2, a voltage stabilizing diode D4, and resistors Rc and Rd;

[0073] The resistor circuit RX includes resistors Re and Rf;

[0074] The upper end of the Ra resistor is connected to the input VCC. The resistors Ra and Rb are in series. The lower end of the Rb resistor is connected to the drain of the switching transistor Q1. The source of the switching transistor Q1 is connected to the anode of the voltage regulator diode D3. The gate of the switching transistor Q1 is connected to the cathode of the voltage regulator diode D3 and to the lower end of the R3 resistor.

[0075] The upper end of the resistor Rc is connected to the anode of the voltage regulator diode D3. The resistors Rc and Rd are in series. The lower end of the Rd resistor is connected to the drain of the switching transistor Q2. The source of the switching transistor Q2 is connected to the anode of the voltage regulator diode D4. The gate of the switching transistor Q2 is connected to the cathode of the voltage regulator diode D4 and to the lower end of the R6 resistor.

[0076] The upper end of the Re resistor is connected to the anode of the voltage regulator diode D4. The resistors Re and Rf are in series. The lower end of the Rf resistor leads out the VDD line.

[0077] In the power supply circuit, the main control chip U3 has a power supply pin VDD. The VDD line of the voltage equalizing startup circuit is directly connected to the VDD pin of the main control chip U3. The VDD is connected to the capacitor C1 to the ground.

[0078] The working process of this embodiment is as follows:

[0079] When just powered on, the filter capacitor C1 has no voltage. The VDD pin of the chip U is at a low level. The anodes of the voltage regulator diodes D3 and D4 are both at a low level. The input VCC is divided by the series connection of the first voltage equalizing resistor 1, the second voltage equalizing resistor 2, and the third voltage equalizing resistor 3. When the cathode potentials of the voltage regulator diodes D3 and D4 are both higher than the anodes and the reverse voltages both reach the breakdown voltages of the voltage regulator diodes D3 and D4, the voltages across the voltage regulator diodes D3 and D4 are clamped and do not change. When the voltages across the voltage regulator diodes D3 and D4 both reach the turn-on voltages of the switching transistors Q1 and Q2, the switching transistors Q1 and Q2 will both turn on. In this way, the input VCC voltage will charge the filter capacitor C1 through the first startup circuit QA, the second startup circuit QB, and the resistor circuit RX. When the voltage of the filter capacitor C1 reaches the startup voltage of the chip U, the chip U starts to work.

[0080] Embodiment 4:

[0081] As Figure 6 shown, it is the circuit schematic diagram of this embodiment. To adapt to a higher input voltage, the difference between this embodiment and Embodiment 3 is that the main control chip U4 not only has a power supply pin VDD, but also has a startup pin HV. The HV line of the voltage equalizing startup circuit is directly connected to the HV pin of the chip.

[0082] The working process of this embodiment is as follows:

[0083] When just powered on, the HV pin of chip U is at low level. The anodes of voltage stabilizing diodes D3 and D4 are both at low level. The input VCC is divided in series by the first voltage-sharing resistor 1, the second voltage-sharing resistor 2, and the third voltage-sharing resistor 3. When the cathode potentials of voltage stabilizing diodes D3 and D4 are both higher than the anodes, and the reverse voltages both reach the breakdown voltages of voltage stabilizing diodes D3 and D4, the voltages across voltage stabilizing diodes D3 and D4 are clamped and do not change. When the voltages across voltage stabilizing diodes D3 and D4 both reach the turn-on voltages of switching transistors Q1 and Q2, switching transistors Q1 and Q2 will both turn on. In this way, the input VCC voltage will charge the HV pin of chip U through the first startup circuit QA, the second startup circuit QB, and the resistor circuit RX. When the voltage of the HV pin of chip U is greater than the undervoltage protection threshold, chip U starts to work.

[0084] Figure 5 and Figure 6 For the circuits of and

[0084] , since they are both divided by voltage-sharing resistors with two or more stages, they can withstand a higher input voltage range and achieve high voltage and wide-range input.

[0085] In summary, the present utility model has the following advantages:

[0086] 1. It can reduce startup losses;

[0087] 2. It can be applied to occasions with higher input voltages;

[0088] 3. Low cost: Since the circuits all use commonly used electronic components on the market, it is very easy for designers to select components, and the raw material cost is low.

[0089] In the above specific embodiments, the switching MOS transistor Q can also be replaced by any device with switching characteristics, and the resistor voltage-dividing circuit can also be composed of embodiments such as capacitors in series. Therefore, except for the specific circuits described above, those implemented by technical means with the same concept, such as those belonging to those skilled in the art according to the solutions and drawings described in the present utility model, by using transistors with different characteristics and replacing the main power circuit topology, all fall within the protection scope of the present utility model.

[0090] The above content is only to illustrate the technical idea of the present utility model, and the protection scope of the present utility model cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present utility model falls within the protection scope of the claims of the present utility model.

Claims

1. A high-voltage power supply startup circuit, characterized in that, It includes a main control chip U. The power supply terminal VDD of the main control chip U is grounded through a filter capacitor C1. The power supply terminal VDD of the main control chip U is connected to the cathode of a rectifier diode D2, and the anode of the rectifier diode D2 is grounded through an auxiliary winding NA. The power supply terminal VDD / start pin HV of the main control chip U is connected to the input VCC through a second start resistor (4), and at least one voltage equalizing start circuit is connected in series between the second start resistor (4) and the input VCC.

2. The high-voltage power supply startup circuit according to claim 1, characterized in that, The GND interface of the main control chip U is grounded.

3. The high-voltage power supply starting circuit according to claim 1, characterized in that, The voltage equalizing start circuit includes a switching tube Q. The drain of the switching tube Q is connected to one end of a first start resistor (3); the gate of the switching tube Q is simultaneously connected to the cathode of a zener diode D, one end of a first voltage equalizing resistor (1), and one end of a second voltage equalizing resistor (2); the source of the switching tube Q is respectively connected to the anode of the zener diode D and one end of the second start resistor (4); the switching tube Q and the first start resistor (3) are connected in series and then paralleled with the first voltage equalizing resistor (1), and the first voltage equalizing resistor (1) and the first start resistor (3) are used to connect the input VCC / the next-stage voltage equalizing start circuit.

4. A high-voltage power supply startup circuit according to claim 3, wherein The specific connection of the first voltage equalizing resistor (1) and the first start resistor (3) to the input VCC / the next-stage voltage equalizing start circuit is as follows: When there is one voltage equalizing start circuit, the first voltage equalizing resistor (1) and the first start resistor (3) are connected to the input VCC.

5. The high-voltage power supply starting circuit according to claim 3, wherein The specific connection of the first voltage equalizing resistor (1) and the first start resistor (3) to the input VCC / the next-stage voltage equalizing start circuit is as follows: When there are several voltage equalizing start circuits, the first start resistor (3) of the voltage equalizing start circuit is connected to the anode of the zener diode D of the next voltage equalizing start circuit, the first voltage equalizing resistor (1) of the voltage equalizing start circuit is connected to the cathode of the zener diode D of the next voltage equalizing start circuit, and the first voltage equalizing resistor (1) and the first start resistor (3) of the last voltage equalizing start circuit are connected to the input VCC.

6. A high-voltage power supply startup circuit according to any one of claims 4 and 5, characterized in that The first voltage equalizing resistor (1) is several resistors connected in series.

7. A high-voltage power supply startup circuit according to any one of claims 4 and 5, characterized in that, The first start resistor (3) is several resistors connected in series.

8. A high-voltage power supply starting circuit according to claim 3, characterized in that The cathode of the zener diode D is grounded through the second voltage equalizing resistor (2).

9. The high-voltage power supply starting circuit according to claim 8, characterized in that, The second voltage equalizing resistor (2) is several resistors connected in series.

10. The high-voltage power supply startup circuit according to claim 1, wherein, The second start resistor (4) is several resistors connected in series.

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