A DC-DC converter

Abstract

An embodiment of the present invention discloses a DC-DC converter. The DC-DC converter includes a main conversion circuit, a power supply circuit, a control circuit, and a feedback circuit. The main conversion circuit converts high-voltage DC power from an external power grid into low-voltage DC power. The power supply circuit provides a startup voltage for the control circuit when the external power grid is connected to high-voltage DC power. It also provides a stable operating voltage for the control circuit when the main conversion circuit outputs low-voltage DC power. The feedback circuit outputs a voltage feedback signal based on the low-voltage DC power output by the main conversion circuit to the control circuit. The control circuit then outputs a pulse wave signal based on the voltage feedback signal to control the shutdown of the main conversion circuit, thereby achieving independent startup, a wide voltage input range, and a low-cost design for the DC / DC converter.

Description

Technical Field

[0001] The embodiments of the present invention relate to power electronics technology, and in particular to a DC-DC converter. Background Art

[0002] With the rapid development of power electronics technology, power electronics are becoming increasingly intertwined with people's lives and work. These devices rely on reliable switching power supplies. Switching power supplies are capacitor-input circuits. Phase differences between current and voltage can cause power loss, necessitating a PFC control circuit to improve the power factor. Switching power supplies can be categorized into two main types: AC / DC and DC / DC converters.

[0003] In the prior art, when a switching power supply DC / DC converter is used in a PFC control circuit and the BOOST main circuit output voltage reaches 950V or above, the auxiliary switching power supply DC / DC converter generally uses an independently designed switching power supply including a transformer to power the PFC control circuit. This complicates the design of the entire switching power supply when matching a high-input, wide-voltage power grid, and increases the cost of the entire switching power supply. Summary of the Invention

[0004] The embodiment of the present invention provides a DC-DC converter to achieve independent startup of the DC / DC converter, wide voltage range input, and low-cost design.

[0005] In a first aspect, an embodiment of the present invention provides a DC-DC converter, the DC-DC converter comprising: a main conversion circuit, a power supply circuit, a control circuit, and a feedback circuit;

[0006] The input end of the main conversion circuit is electrically connected to the external power grid; the output end of the main conversion circuit is electrically connected to the first input end of the power supply circuit and the input end of the feedback circuit respectively, and the freewheeling end of the main conversion circuit is electrically connected to the ground end of the control circuit; the external power grid is electrically connected to the second input end of the power supply circuit;

[0007] The power supply terminal of the control circuit is electrically connected to the output terminal of the power supply circuit, the output terminal of the control circuit is electrically connected to the control terminal of the main conversion circuit, and the feedback terminal of the control circuit is electrically connected to the output terminal of the feedback circuit;

[0008] The main conversion circuit is used to convert high-voltage direct current power connected to the external power grid into low-voltage direct current power;

[0009] The power supply circuit is used to provide a starting voltage for the control circuit when the external power grid is connected to high-voltage direct current; and is also used to provide a stable operating voltage for the control circuit when the main conversion circuit outputs low-voltage direct current;

[0010] The feedback circuit is used to feed back a signal to the control circuit based on the low-voltage direct current output voltage output by the main conversion circuit;

[0011] The control circuit is used to output a pulse wave signal according to the voltage signal fed back by the feedback circuit to control the shutdown of the main conversion circuit.

[0012] Optionally, the main conversion circuit includes a first transistor, a first inductor, a first capacitor and a first unidirectional diode;

[0013] The output end of the first transistor is electrically connected to the external power grid, the input end of the first transistor is electrically connected to the first end of the first inductor and the output end of the first unidirectional diode respectively, the control end of the first transistor is electrically connected to the output end of the control circuit, and the output end of the first unidirectional diode is the freewheeling end of the main conversion circuit;

[0014] The second end of the first inductor is electrically connected to the first end of the first capacitor, and the second end of the first capacitor is electrically connected to the input end of the first unidirectional diode; the second end of the first inductor is a low-voltage direct current output end.

[0015] Optionally, the power supply circuit includes a first resistor, a second unidirectional diode and a second capacitor;

[0016] A first end of the first resistor is electrically connected to the external power grid, and a second end of the first resistor is electrically connected to a power supply terminal of the control circuit;

[0017] The input end of the second unidirectional diode is electrically connected to the output end of the main conversion circuit, and the output end of the second unidirectional diode is electrically connected to the first end of the second capacitor and the power supply end of the control circuit respectively; the second end of the second capacitor is electrically connected to the ground end of the control circuit.

[0018] Optionally, the power supply circuit further includes a third unidirectional diode, a second resistor and a first optocoupler isolator;

[0019] The input end of the third unidirectional diode is electrically connected to the output end of the main conversion circuit, the output end of the third unidirectional diode is electrically connected to the first end of the second resistor, the second end of the second resistor is electrically connected to the input end of the first optocoupler isolator, and the output end of the first optocoupler isolator is electrically connected to the freewheeling end of the main conversion circuit and the ground end of the control circuit, respectively.

[0020] Optionally, the feedback circuit includes a third resistor, a fourth resistor, a comparator, a second optocoupler isolator and a fifth resistor;

[0021] The first end of the third resistor is electrically connected to the output end of the main conversion circuit and the first end of the second optocoupler isolator, respectively; the second end of the third resistor is electrically connected to the first end of the fourth resistor and the input end of the comparator, respectively; the second end of the fourth resistor is electrically connected to the ground end of the comparator; the output end of the comparator is electrically connected to the second end of the second optocoupler isolator; the third end of the second optocoupler isolator is electrically connected to the first end of the fifth resistor; the second end of the fifth resistor is grounded; and the fourth end of the second optocoupler isolator is electrically connected to the voltage stabilizing end of the control circuit.

[0022] Optionally, the control circuit includes a third capacitor and a sixth resistor;

[0023] The main conversion circuit further includes a seventh resistor;

[0024] The current feedback end of the control circuit is electrically connected to the first end of the third capacitor and the first end of the sixth resistor respectively, the second end of the third capacitor is grounded, the second end of the sixth resistor is electrically connected to the first end of the seventh resistor, and the second end of the seventh resistor is electrically connected to the output end of the first unidirectional diode.

[0025] Optionally, the control circuit further includes a fourth capacitor and an eighth resistor;

[0026] The oscillation frequency end of the control circuit is electrically connected to the first end of the fourth capacitor and the first end of the eighth resistor respectively, the second end of the fourth capacitor is grounded, and the second end of the eighth resistor is electrically connected to the voltage stabilization end of the control circuit.

[0027] Optionally, the power supply circuit further includes a voltage regulator tube,

[0028] The first end of the voltage-stabilizing diode is electrically connected to the second end of the first resistor, and the second end of the voltage-stabilizing diode is electrically connected to the second end of the second capacitor.

[0029] Optionally, the feedback circuit further includes a fifth capacitor,

[0030] A first end of the fifth capacitor is electrically connected to a first end of the fifth resistor, and a second end of the fifth capacitor is electrically connected to a second end of the fifth resistor.

[0031] Optionally, the main conversion circuit further includes a sixth capacitor;

[0032] A first end of the sixth capacitor is electrically connected to the external power grid, and a second end of the sixth capacitor is electrically connected to the input end of the first unidirectional diode.

[0033] The present invention converts high-voltage direct current (DC) power connected to an external power grid into low-voltage DC power through a main conversion circuit; provides a starting voltage for a control circuit when the high-voltage DC power is connected to the external power grid through a power supply circuit; also provides a stable operating voltage for the control circuit when the main conversion circuit outputs low-voltage DC power; also feeds back a voltage signal to the control circuit based on the output voltage of the low-voltage DC power output by the main conversion circuit through a feedback circuit; the control circuit outputs a pulse wave signal based on the voltage feedback signal to control the shutdown of the main conversion circuit to achieve independent startup, wide voltage range input, and low-cost design of the DC / DC converter, thereby solving the problem in the prior art that a DC / DC converter generally uses an independently designed switching power supply including a transformer to power a PFC control circuit, which complicates the design of the entire switching power supply and increases the cost of the entire switching power supply when matching a power grid with high input and a wide voltage range. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A circuit block diagram of a DC-DC converter provided in an embodiment of the present invention;

[0035] Figure 2 This is a circuit diagram of a DC-DC converter provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0037] Figure 1 A circuit block diagram of a DC-DC converter provided in an embodiment of the present invention is shown in FIG. Figure 1As shown, the DC-DC converter includes a main conversion circuit 10, a power supply circuit 20, a control circuit 30 and a feedback circuit 40; the input end of the main conversion circuit 10 is electrically connected to the external power grid; the output end of the main conversion circuit 10 is electrically connected to the first input end of the power supply circuit 20 and the input end of the feedback circuit 40 respectively, and the freewheeling end of the main conversion circuit 10 is electrically connected to the ground end of the control circuit 30; the external power grid is electrically connected to the second input end of the power supply circuit 20; the power supply end of the control circuit 30 is electrically connected to the output end of the power supply circuit 20, the output end of the control circuit 30 is electrically connected to the control end of the main conversion circuit 10, and the feedback end of the control circuit 30 is electrically connected to the output end of the feedback circuit 40. The main conversion circuit 10 is used to convert high-voltage direct current power connected to the external power grid into low-voltage direct current power; the power supply circuit 20 is used to provide a starting voltage for the control circuit 30 when the external power grid is connected to high-voltage direct current power; it is also used to provide a stable operating voltage for the control circuit 30 when the main conversion circuit 10 outputs low-voltage direct current power; the feedback circuit 40 is used to feedback a signal to the control circuit 30 based on the output voltage of the low-voltage direct current power output by the main conversion circuit 10; the control circuit 30 is used to output a pulse wave signal based on the voltage signal fed back by the feedback circuit to control the shutdown of the main conversion circuit 10.

[0038] Among them, in the switching power supply DC / DC converter of the PFC control circuit, the main conversion circuit 10 can control the high input grid voltage of up to 950V or more through the pulse wave signal output by the control circuit 30 to output a stable low-voltage DC voltage; specifically, the working principle of the DC-DC converter is: when the input end of the main conversion circuit 10 inputs high-voltage DC power, the power supply circuit 20 provides a starting voltage for the control circuit 30, and the output end of the control circuit 30 outputs a pulse wave signal to control the conduction time of the main conversion circuit 10 so that the main conversion circuit 10 outputs a low-voltage DC voltage; when the main conversion circuit 10 outputs a low-voltage DC voltage, the power supply circuit 20 continues to provide a stable working voltage for the control circuit 30; it should be noted here that due to the high voltage input at the input end of the main conversion circuit 10 The DC power energy is not fixed, and the low-voltage DC voltage output from the output end of the main conversion circuit 10 is unstable. The feedback circuit 40 can output a feedback voltage signal in real time based on the low-voltage DC voltage output by the main conversion circuit 10. The control circuit 30 outputs a pulse wave signal with different duty cycles based on the feedback voltage signal to control the output end of the main conversion circuit 10 to output a stable low-voltage DC power to complete the power supply of the PFC control circuit. This realizes independent startup, wide voltage range input, and low-cost design of the DC / DC converter, and solves the problem in the prior art that the DC / DC converter generally uses an independently designed switching power supply including a transformer to power the PFC control circuit. This complicates the design of the entire switching power supply and increases the cost of the entire switching power supply when matching a high-input, wide-voltage range power grid.

[0039] Optional, Figure 2 is a circuit diagram of a DC-DC converter provided by an embodiment of the present invention, such as Figure 2 As shown, the main conversion circuit 10 includes a first transistor Q1, a first inductor L1, a first capacitor C1 and a first unidirectional diode D1; the input end of the first transistor Q1 is electrically connected to the external power grid, the output end of the first transistor Q1 is electrically connected to the first end of the first inductor L1 and the output end of the first unidirectional diode D1 respectively, the control end of the first transistor Q1 is electrically connected to the output end of the control circuit 30, and the output end of the first unidirectional diode D1 is the freewheeling end of the main conversion circuit 10; the second end of the first inductor L1 is electrically connected to the first end of the first capacitor C1, and the second end of the first capacitor C1 is electrically connected to the input end of the first unidirectional diode D1; the second end of the first inductor L1 is a low-voltage DC output end.

[0040] Optional, see Figure 2 The power supply circuit 20 includes a first resistor R1, a second unidirectional diode D2 and a second capacitor C2; a first end of the first resistor R1 is electrically connected to the external power grid, and a second end of the first resistor R1 is electrically connected to the power supply terminal of the control circuit 30; an input end of the second unidirectional diode D2 is electrically connected to the output end of the main conversion circuit 10, and an output end of the second unidirectional diode D2 is electrically connected to the first end of the second capacitor C2 and the power supply terminal of the control circuit 30 respectively; a second end of the second capacitor C2 is electrically connected to the ground terminal of the control circuit 30.

[0041] Optional, continue to refer to Figure 2 The power supply circuit 20 also includes a third unidirectional diode D3, a second resistor R2 and a first optocoupler isolator U1; the input end of the third unidirectional diode D3 is electrically connected to the output end of the main conversion circuit 10, the output end of the third unidirectional diode D3 is electrically connected to the first end of the second resistor R2, the second end of the second resistor R2 is electrically connected to the input end of the first optocoupler isolator U1, and the output end of the first optocoupler isolator U1 is electrically connected to the freewheeling end of the main conversion circuit 10 and the ground end of the control circuit 30, respectively.

[0042] When high-voltage DC power is input to the +BUS input terminal of the main conversion circuit 10, the high-voltage DC power is first fully charged to the power supply terminal VCC of the control circuit 30 through the first resistor R1 and the second capacitor C2. The control circuit 30 then starts operating, and then the output terminal OUT of the control circuit 30 outputs a pulse wave signal with different duty cycles to the control terminal of the first transistor Q1, thereby controlling the conduction duration of the first transistor Q1. When the first transistor Q1 is on, the output terminal of the main conversion circuit 10 outputs low-voltage DC power, illustratively outputting a low-voltage DC power of +15V. The low-voltage DC power then flows through the second unidirectional diode D2 and the second capacitor C2 to continuously power the control circuit 30, thus achieving the independent self-powering function of the DC-DC converter.

[0043] At the same time, when the first transistor Q1 is disconnected, the low-voltage DC voltage passes through the first capacitor C1 and the first unidirectional diode D1 to form a freewheeling circuit. To ensure that the first transistor Q1 of the main conversion circuit 10 is in the off state during the freewheeling phase, the low-voltage DC current passes through the third unidirectional diode D3, the second resistor R2, and the first optocoupler isolator U1. This lowers the voltage at the ground terminal of the control circuit 30, thereby causing the output terminal of the first unidirectional diode D1 to be in a zero voltage state. This prevents the reverse recovery current generated when the output terminal of the first unidirectional diode D1 is at a high voltage, causing the first transistor Q1 to turn on and generate an excessive current spike. This ensures that the first capacitor C1 and the first unidirectional diode D1 are always in the freewheeling phase, and the first transistor Q1 in the main conversion circuit 10 is disconnected. The voltage regulator D can stabilize the startup voltage and operating voltage of the control circuit 30.

[0044] Because the first inductor L1 and the first capacitor C1 are used in the main conversion circuit 10 to control energy output, a wide range of high-voltage DC voltages can be input to the input end of the main conversion circuit 10, and a stable low-voltage DC voltage can be output through the first inductor L1 and the first capacitor C1. This achieves a wide voltage input for the DC-DC converter. Compared with the prior art, in which a transformer is used in the main conversion circuit 10 to control energy output, the voltage range of the input end of the main conversion circuit 10 is limited. In addition, a power grid with a wide voltage range complicates the design of the entire switching power supply and increases the cost of the entire switching power supply.

[0045] The main conversion circuit 10 further includes a sixth capacitor C6. A first end of the sixth capacitor C6 is connected to the external power grid +BUS, and a second end of the sixth capacitor C6 is electrically connected to the input end of the first unidirectional diode D1. The sixth capacitor C6 provides filtering, improving the reliability of the main conversion circuit 10.

[0046] Optional, continue to refer to Figure 2 The feedback circuit 30 includes a third resistor R3, a fourth resistor R4, a comparator U, a second optocoupler isolator U2 and a fifth resistor R5; a first end of the third resistor R3 is electrically connected to the output end of the main conversion circuit 10 and the first end of the second optocoupler isolator U2, respectively; a second end of the third resistor R3 is electrically connected to the first end of the fourth resistor R4 and the input end of the comparator U, respectively; a second end of the fourth resistor R4 is electrically connected to the ground end of the comparator U; an output end of the comparator U is electrically connected to the second end of the second optocoupler isolator U2; a third end of the second optocoupler isolator U2 is electrically connected to the first end of the fifth resistor R5; a second end of the fifth resistor R5 is grounded; and a fourth end of the second optocoupler isolator U2 is electrically connected to the voltage stabilizing end of the control circuit 30.

[0047] Since the high-voltage DC power connected to the input of the main conversion circuit 10 is not fixed, the low-voltage DC power output by the main conversion circuit 10 is unstable. To ensure that the main conversion circuit 10 outputs a stable low-voltage DC power, the feedback circuit 40 outputs a feedback voltage signal to the control circuit 30 based on the low-voltage DC voltage output by the main conversion circuit 10, so that the control circuit 30 outputs a pulse wave signal with different duty cycles to the main conversion circuit 10 to adjust the energy output. Specifically, the low-voltage DC power output by the main conversion circuit 10 is divided by the third resistor R3 and the fourth resistor R4, and then input to the input of the comparator U. The comparator U controls the output of a certain current after comparison with the reference voltage source. The current is then output through the second optoelectronic isolator U2, and the current is converted to a certain voltage value through the fifth resistor R5 and output to the feedback pin of the control circuit 10. When the control circuit 30 receives a smaller voltage, it controls the output of a larger duty cycle signal to the main conversion circuit 10. When the control circuit 30 receives a larger voltage, it controls the output of a smaller duty cycle signal to the main conversion circuit 10. In this way, the main conversion circuit 10 can be adjusted to output a stable low-voltage DC voltage. The feedback circuit 40 further includes a fifth capacitor C5, a first end of the fifth capacitor C5 being electrically connected to a first end of a fifth resistor R5, and a second end of the fifth capacitor C5 being electrically connected to a second end of the fifth resistor R5. The fifth capacitor C5 plays a filtering role.

[0048] Optional, see Figure 2 The control circuit 30 includes a third capacitor C3 and a sixth resistor R6; the main conversion circuit 10 also includes a seventh resistor R7; a current feedback terminal ISEN of the control circuit 30 is electrically connected to the first end of the third capacitor C3 and the first end of the sixth resistor R6, respectively, a second end of the third capacitor C3 is grounded, a second end of the sixth resistor R6 is electrically connected to the first end of the seventh resistor R7, and a second end of the seventh resistor R7 is electrically connected to the output end of the first unidirectional diode D1.

[0049] When the main conversion circuit 10 is in the freewheeling phase, the freewheeling current outputted through the seventh resistor R7 and the sixth resistor R6 is fed back to the control circuit 30 to provide real-time feedback on the current magnitude of the main conversion circuit 10 in the freewheeling phase, thereby further adjusting the pulse wave signals outputted by the control circuit 30 to have different duty cycles. The third capacitor C3 also serves as a filter.

[0050] Optional, continue to refer to Figure 2The control circuit 30 further includes a fourth capacitor C4 and an eighth resistor R8. An oscillation frequency terminal RT / CT of the control circuit 30 is electrically connected to a first terminal of the fourth capacitor C4 and a first terminal of the eighth resistor R8, respectively. A second terminal of the fourth capacitor C4 is grounded, and a second terminal of the eighth resistor R8 is electrically connected to a voltage regulator terminal VREF of the control circuit 30. The fourth capacitor C4 and the eighth resistor R8 can determine the oscillation frequency of the pulse wave signal output by the control circuit 30.

[0051] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A DC-DC converter, characterized in that: include: Main conversion circuit, power supply circuit, control circuit and feedback circuit; The input end of the main conversion circuit is electrically connected to the external power grid; The output end of the main conversion circuit is electrically connected to the first input end of the power supply circuit and the input end of the feedback circuit respectively, and the freewheeling end of the main conversion circuit is electrically connected to the ground end of the control circuit; the external power grid is electrically connected to the second input end of the power supply circuit; The power supply terminal of the control circuit is electrically connected to the output terminal of the power supply circuit, the output terminal of the control circuit is electrically connected to the control terminal of the main conversion circuit, and the feedback terminal of the control circuit is electrically connected to the output terminal of the feedback circuit; The main conversion circuit is used to convert high-voltage direct current power connected to the external power grid into low-voltage direct current power; The power supply circuit is used to provide a starting voltage for the control circuit when the external power grid is connected to high-voltage direct current; and is also used to provide a stable operating voltage for the control circuit when the main conversion circuit outputs low-voltage direct current; The feedback circuit is used to feed back a signal to the control circuit based on the low-voltage direct current output voltage output by the main conversion circuit; The control circuit is configured to output a pulse wave signal according to the voltage feedback signal to control the shutdown of the main conversion circuit; The power supply circuit includes a first resistor, a second unidirectional diode and a second capacitor; A first end of the first resistor is electrically connected to the external power grid, and a second end of the first resistor is electrically connected to a power supply terminal of the control circuit; The input end of the second unidirectional diode is electrically connected to the output end of the main conversion circuit, and the output end of the second unidirectional diode is electrically connected to the first end of the second capacitor and the power supply end of the control circuit respectively; the second end of the second capacitor is electrically connected to the ground end of the control circuit; The power supply circuit further includes a third unidirectional diode, a second resistor and a first optocoupler isolator; The input end of the third unidirectional diode is electrically connected to the output end of the main conversion circuit, the output end of the third unidirectional diode is electrically connected to the first end of the second resistor, the second end of the second resistor is electrically connected to the input end of the first optocoupler isolator, and the output end of the first optocoupler isolator is electrically connected to the freewheeling end of the main conversion circuit and the ground end of the control circuit, respectively.

2. The DC-DC converter according to claim 1, wherein: The main conversion circuit includes a first transistor, a first inductor, a first capacitor and a first unidirectional diode; The input end of the first transistor is electrically connected to the external power grid, the output end of the first transistor is electrically connected to the first end of the first inductor and the output end of the first unidirectional diode respectively, the control end of the first transistor is electrically connected to the output end of the control circuit, and the output end of the first unidirectional diode is the freewheeling end of the main conversion circuit; The second end of the first inductor is electrically connected to the first end of the first capacitor, and the second end of the first capacitor is electrically connected to the input end of the first unidirectional diode; the second end of the first inductor is a low-voltage direct current output end.

3. The DC-DC converter according to claim 1, wherein: The feedback circuit includes a third resistor, a fourth resistor, a comparator, a second optocoupler isolator and a fifth resistor; The first end of the third resistor is electrically connected to the output end of the main conversion circuit and the first end of the second optocoupler isolator, respectively; the second end of the third resistor is electrically connected to the first end of the fourth resistor and the input end of the comparator, respectively; the second end of the fourth resistor is electrically connected to the ground end of the comparator; the output end of the comparator is electrically connected to the second end of the second optocoupler isolator; the third end of the second optocoupler isolator is electrically connected to the first end of the fifth resistor; the second end of the fifth resistor is grounded; and the fourth end of the second optocoupler isolator is electrically connected to the voltage stabilizing end of the control circuit.

4. The DC-DC converter according to claim 2, wherein: The control circuit includes a third capacitor and a sixth resistor; The main conversion circuit further includes a seventh resistor; The current feedback end of the control circuit is electrically connected to the first end of the third capacitor and the first end of the sixth resistor respectively, the second end of the third capacitor is grounded, the second end of the sixth resistor is electrically connected to the first end of the seventh resistor, and the second end of the seventh resistor is electrically connected to the output end of the first unidirectional diode.

5. The DC-DC converter according to claim 1, wherein: The control circuit further includes a fourth capacitor and an eighth resistor; The oscillation frequency end of the control circuit is electrically connected to the first end of the fourth capacitor and the first end of the eighth resistor respectively, the second end of the fourth capacitor is grounded, and the second end of the eighth resistor is electrically connected to the voltage stabilization end of the control circuit.

6. The DC-DC converter according to claim 1, wherein: The power supply circuit also includes a voltage regulator tube, The first end of the voltage-stabilizing diode is electrically connected to the second end of the first resistor, and the second end of the voltage-stabilizing diode is electrically connected to the second end of the second capacitor.

7. The DC-DC converter according to claim 3, wherein: The feedback circuit further includes a fifth capacitor, A first end of the fifth capacitor is electrically connected to a first end of the fifth resistor, and a second end of the fifth capacitor is electrically connected to a second end of the fifth resistor.

8. The DC-DC converter according to claim 2, wherein: The main conversion circuit further includes a sixth capacitor; A first end of the sixth capacitor is electrically connected to the external power grid, and a second end of the sixth capacitor is electrically connected to the input end of the first unidirectional diode.

Images