A voltage switching control circuit and a voltage switching control device

Abstract

The present application relates to the technical field of voltage conversion, and provides a voltage switching control circuit and a voltage switching control device, wherein a transformer module operates under the enabling action of an enabling module, and after voltage conversion of a first voltage output by a DC power supply, a second voltage is output, then a voltage divider module divides the second voltage and feeds back to the transformer module to instruct the transformer module to adjust the second voltage, and at the same time, a control module outputs a control voltage to the voltage divider module to adjust the voltage divider module to divide the second voltage, wherein the voltage divider module includes a nonlinear resistor, a second resistor, a third resistor, a third capacitor and a diode, thereby the scheme adds a nonlinear resistor and a diode to the original voltage switching control technology, the design variable is only a nonlinear resistor, which is relatively easy to select, and the electronic components are also relatively simple, and are widely used in set-top boxes or switch products that require voltage switching.

Description

Technical Field

[0001] The present application relates to the technical field of voltage conversion, and in particular to a voltage switching control circuit and a voltage switching control device. Background Art

[0002] At present, in the DC-DC fixed voltage output circuit, such as Figure 1 As shown, chip U1 is a DC-DC power supply chip, which is connected to a reference voltage through an input terminal Vin. After chip U1 performs voltage conversion on the reference voltage, its final output voltage can be obtained according to the following formula: Vout = Vfb*(1+R2 / R3). It can be obtained that this solution can achieve a fixed output voltage by selecting the ratio of resistor R2 to resistor R3.

[0003] If the above output voltage needs to be adjusted and switched, the first method is to connect a resistor Rb to the control voltage terminal through the feedback control terminal FB of the DC-DC power supply chip to realize the voltage switching control function, such as Figure 2 As shown, when the control voltage terminal is grounded and connected to the power supply terminal, different voltages will be output, specifically using the following formula: when Vctl=0V, Vout=Vfb*(1+(R21 / (R31 / / Rb))); when Vctl is approximately equal to Vout, Vout=Vfb*(1+((R21 / / Rb) / R31)); thereby achieving the effect of changing the output voltage of the DC-DC power supply chip.

[0004] Of course, the second method can also directly use the variable resistor Rc to replace the above-mentioned resistor R2, such as Figure 3 As shown, when the control voltage terminal is grounded or connected to the power supply terminal, different voltages will be output, specifically using the following formula: when Vctl=0V, Vout=Vfb*(1+(Rc1 / R3)); when Vctl is approximately equal to Vout, Vout=Vfb*(1+(Rc2 / R3)).

[0005] However, in the first method mentioned above, after an external resistor Rb is connected, the original two voltage-dividing resistors (resistors R2 and R3) are modified to new voltage-dividing resistors. Because the original voltage-dividing resistors (i.e., resistors R31 and R21) and the newly added control resistor Rb, a total of three resistance values, need to be changed at the same time, it is difficult to select a suitable value, and it is not easy to upgrade the original non-switching power supply circuit. In the second method, although there is no need to change the voltage-dividing resistance value to ground (the value of resistor R3), the cost of the variable resistor Rc is relatively high. If the required value is selected and the resistance change meets the requirements, it is difficult to find and purchase.

[0006] Therefore, how to reduce the design variables that need to be considered during design and use simple electronic components has become a technical problem that urgently needs to be solved. Summary of the invention

[0007] The purpose of the present application is to provide a voltage switching control circuit and a voltage switching control device, aiming to solve the technical problems of traditional voltage switching control technology having many design variables and relatively complex electronic components.

[0008] A first aspect of an embodiment of the present application provides a voltage switching control circuit, the voltage switching control circuit comprising:

[0009] A voltage transformation module, connected to a DC power supply, and configured to output a second voltage after performing voltage transformation on a first voltage output by the DC power supply;

[0010] an enabling module, connected to the DC power supply and the transformer module, and configured to enable the transformer module to operate when receiving the first voltage;

[0011] a current limiting protection module, connected to the voltage transformation module and configured to perform current limiting protection on the second voltage;

[0012] a voltage dividing module, connected to the voltage transformation module and the current limiting protection module, and configured to divide the second voltage and feed back the voltage to the voltage transformation module to instruct the voltage transformation module to adjust the second voltage;

[0013] a control module connected to the voltage dividing module and configured to output a control voltage to the voltage dividing module to adjust the voltage dividing module to divide the second voltage;

[0014] Wherein, the voltage division module comprises:

[0015] A nonlinear resistor, a second resistor, a third resistor, a third capacitor and a diode;

[0016] The first end of the second resistor and the first end of the third capacitor are connected to the current limiting protection module, the second end of the second resistor, the second end of the third capacitor, the first end of the third resistor and the first end of the nonlinear resistor are connected together and connected to the transformer module, and the second end of the nonlinear resistor is connected to the control module through the diode.

[0017] Therefore, the voltage switching control circuit adds a nonlinear resistor and a diode to the original voltage switching control technology. The design variable is only the nonlinear resistor, which is easier to select and the electronic components are also simpler.

[0018] In one embodiment, the second end of the nonlinear resistor is connected to the control module through the diode, comprising:

[0019] The second end of the nonlinear resistor is connected to the cathode of the diode, and the anode of the diode is connected to the control module; or

[0020] The second end of the nonlinear resistor is connected to the anode of the diode, and the cathode of the diode is connected to the control module. This embodiment specifically defines that the diode can be connected either forward or reverse.

[0021] In one embodiment, it also includes:

[0022] The input filter module is connected to the DC power supply, the enabling module and the voltage conversion module, and is configured to filter the first voltage. This embodiment provides an input filter module to filter a specific frequency band in the first voltage to reduce or even eliminate interference.

[0023] In one embodiment, it also includes:

[0024] The output filter module is connected to the current limiting protection module and the voltage dividing module, and is configured to filter the adjusted second voltage. This embodiment provides an output filter module to filter a specific frequency band of the adjusted second voltage to further reduce or even eliminate interference.

[0025] In one embodiment, the transformer module includes a DC-DC power supply chip. This embodiment specifically defines the selection characteristics of the transformer module.

[0026] In one embodiment, the enabling module includes:

[0027] a first resistor and a first capacitor;

[0028] The first end of the first resistor is connected to the DC power supply, the second end of the first resistor is connected to the first end of the first capacitor and connected to the voltage conversion module, and the second end of the first capacitor is grounded. This embodiment defines the specific circuit structure of the enabling module.

[0029] In one embodiment, the current limiting protection module includes:

[0030] a second capacitor and a first inductor;

[0031] The first end of the second capacitor is connected to the voltage transformation module, the second end of the second capacitor is connected to the first end of the first inductor, and the second end of the first inductor is connected to the voltage division module. This embodiment defines the specific circuit structure of the current limiting protection module.

[0032] In one embodiment, the input filtering module includes:

[0033] a fourth capacitor and a fifth capacitor;

[0034] The first end of the fourth capacitor and the first end of the fifth capacitor are connected to the voltage conversion module, and the second end of the fourth capacitor and the second end of the fifth capacitor are grounded. This embodiment defines the specific circuit structure of the input filter module.

[0035] In one embodiment, the output filtering module includes:

[0036] a sixth capacitor, a seventh capacitor and an eighth capacitor;

[0037] The first end of the sixth capacitor is connected to the first end of the seventh capacitor and the first end of the eighth capacitor and is connected to the voltage divider module, and the second end of the sixth capacitor is connected to the second end of the seventh capacitor and the second end of the eighth capacitor and is grounded. This embodiment defines the specific circuit structure of the output filter module.

[0038] A second aspect of an embodiment of the present application provides a voltage switching control device, including a DC power supply and also including the voltage switching control circuit as described above.

[0039] The above-mentioned voltage switching control device adds nonlinear resistors and diodes to the original voltage switching control technology. The design variable is only nonlinear resistors, which are relatively easy to select, and the electronic components are also relatively simple. It is widely used in set-top boxes or switch products that require voltage switching.

[0040] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the above-mentioned voltage switching control circuit and voltage switching control device work under the enabling action of the enabling module through the transformer module, and output a second voltage after voltage conversion of the first voltage output by the DC power supply. Then, the voltage divider module divides the second voltage and feeds it back to the transformer module to instruct the transformer module to adjust the second voltage. At the same time, the control module outputs a control voltage to the voltage divider module to adjust the voltage divider module to divide the second voltage. The voltage divider module includes a nonlinear resistor, a second resistor, a third resistor, a third capacitor and a diode. Therefore, the scheme adds a nonlinear resistor and a diode to the original voltage switching control technology. The design variable is only a nonlinear resistor, which is easier to select, and the electronic components are also simpler. It is widely used in set-top boxes or switch products that require voltage switching. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 An exemplary circuit diagram of a fixed voltage output circuit according to the prior art;

[0042] Figure 2 An exemplary circuit diagram of a DC-DC switching control circuit involved in the prior art;

[0043] Figure 3 Another exemplary circuit diagram of a DC-DC switching control circuit involved in the prior art;

[0044] Figure 4 A schematic diagram of the module structure of a voltage switching control circuit provided in the best embodiment of the present application;

[0045] Figure 5 For the corresponding Figure 4 An example circuit diagram of a voltage switching control circuit;

[0046] Figure 6 For the corresponding Figure 4 Another exemplary circuit diagram of a voltage switching control circuit;

[0047] Figure 7 A schematic diagram of a module structure of a voltage switching control circuit provided in another embodiment of the present application;

[0048] Figure 8 For the corresponding Figure 7 An example circuit diagram of a voltage switching control circuit;

[0049] Fig. 9 For the corresponding Figure 7 Another example circuit diagram of a voltage switching control circuit. DETAILED DESCRIPTION

[0050] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0052] See also Figure 4 , is a schematic diagram of a structural module of a voltage switching control circuit provided by the present application, and Figure 5 and Figure 6 Two exemplary circuits of the voltage switching control circuit are shown. For the sake of convenience, only the parts related to the present embodiment are shown, which are described in detail as follows:

[0053] The present application provides a voltage switching control circuit, including a voltage transformation module 102 , an enabling module 101 , a current limiting protection module 103 , a voltage dividing module 104 and a control module 105 .

[0054] The transformer module 102 and the DC power supply ( Figure 4 The voltage transformation module 102 is used to transform the first voltage output by the DC power supply and output a second voltage.

[0055] Specifically, the function of the transformer module 102 is to perform voltage conversion on the first voltage output by the DC power supply, including voltage step-up and voltage step-down processing, and the first voltage and the second voltage are both DC voltages. The transformer module 102 is implemented using a DC-DC power supply chip U1.

[0056] The enabling module 101 is connected to the DC power supply and the transformer module 102 . The enabling module 101 is configured to enable the transformer module 102 to operate when receiving a first voltage.

[0057] Specifically, the enabling module 101 controls the start-up and working time of the transformer module 102 so that the transformer module 102 performs voltage conversion on the first voltage output by the DC power supply.

[0058] Wherein, the enabling module 101 includes a first resistor R1 and a first capacitor C1;

[0059] A first end of the first resistor R1 is connected to a DC power supply, a second end of the first resistor R1 is connected to a first end of the first capacitor C1 and connected to the transformer module 102 , and a second end of the first capacitor C1 is grounded.

[0060] The current limiting protection module 103 is connected to the voltage transformation module 102 , and the current limiting protection module 103 is used to perform current limiting protection on the second voltage.

[0061] Specifically, the current limiting protection module 103 controls the current corresponding to the second voltage within a preset current range to avoid current overload or short circuit, thereby avoiding damage to the connected load.

[0062] Wherein, the current limiting protection module 103 includes a second capacitor C2 and a first inductor L1;

[0063] A first terminal of the second capacitor C2 is connected to the voltage transformation module 102 , a second terminal of the second capacitor C2 is connected to a first terminal of the first inductor L1 , and a second terminal of the first inductor L1 is connected to the voltage division module 104 .

[0064] The voltage dividing module 104 is connected to the voltage transformation module 102 and the current limiting protection module 103 . The voltage dividing module 104 is used to divide the second voltage and feed back the voltage to the voltage transformation module 102 to instruct the voltage transformation module 102 to adjust the second voltage.

[0065] Specifically, the voltage dividing module 104 functions to provide feedback so that the voltage transformation module 102 can timely adjust the output of the second voltage according to the feedback.

[0066] The control module 105 is connected to the voltage dividing module 104 , and is used to output a control voltage to the voltage dividing module 104 , so as to adjust the voltage dividing module 104 to divide the second voltage.

[0067] Specifically, the control module 105 is used to control the output voltage of the voltage divider module 104 to adjust the voltage divider module 104 to divide the second voltage, thereby enabling the transformer module 102 to adjust the output of the second voltage. It should be understood that when the control module 105 changes the control voltage of the voltage divider module 104, the second voltage output by the transformer module 102 will be changed. The control module 104 is implemented by a central processing unit (CPU).

[0068] like Figure 5 and Figure 6 As shown, the voltage dividing module 104 includes a non-linear resistor Rc, a second resistor R2, a third resistor R3, a third capacitor C3 and a diode D1.

[0069] The first end of the second resistor R2 and the first end of the third capacitor C3 are connected to the current limiting protection module 103, the second end of the second resistor R2, the second end of the third capacitor C3, the first end of the third resistor R3 and the first end of the nonlinear resistor Rc are connected together and connected to the transformer module 102, and the second end of the nonlinear resistor Rc is connected to the control module 105 through the diode D1.

[0070] It should be understood that the nonlinear resistor Rc is a variable resistor, and nonlinearity means that the resistance value of the resistor will change sharply under certain conditions. Therefore, the voltage divider module in the original voltage switching control technology is added with a nonlinear resistor Rc and a diode D1. When the control voltage of the control module 105 to the voltage divider module 104 is low or high, it will not affect the original circuit. The design variable is only the nonlinear resistor, which is easier to select, and the electronic components are also simpler.

[0071] The diode D1 may be a silicon diode or a germanium diode, but is not limited to these two types. The above solution is not limited to only one diode, and may be implemented with two or more diodes.

[0072] Furthermore, the second end of the nonlinear resistor Rc is connected to the control module 105 via the diode D1, including two situations:

[0073] The first case is: Figure 5As shown, the second terminal of the nonlinear resistor Rc is connected to the cathode of the diode D1, and the anode of the diode D1 is connected to the control module 105;

[0074] The second situation is: Figure 6 As shown, the second terminal of the nonlinear resistor Rc is connected to the anode of the diode D1 , and the cathode of the diode D1 is connected to the control module 105 .

[0075] For example, in the first case above, when Vc is at a high level, the diode D1 is turned on, and the on-resistance of the diode D1 is extremely small and can be ignored. The total resistance of the series branch formed by the nonlinear resistor Rc and the diode D1 is Rc, and the second voltage Vout is:

[0076] Vout=Vfb*(1+((R2 / / Rc) / R3))

[0077] When Vc is at a low level of zero, the diode D1 is not conducting, and the on-resistance of the diode D1 is extremely large, much higher than the second resistor R2, the third resistor R3 and the nonlinear resistor Rc. The effect of the access circuit composed of the accessed nonlinear resistor Rc and the diode D1 on the voltage switching control circuit can be ignored. The output second voltage Vout of the voltage switching control circuit is only related to the voltage division ratio of the second resistor R2 and the third resistor R3:

[0078] Vout=Vfb*(1+R2 / R3)

[0079] As can be seen from the above, when the CPU output is controlled at a low level, the original DC-DC power supply chip maintains the second voltage of the original output unchanged. Therefore, it is only necessary to select a suitable nonlinear resistor Rc to ensure that when the CPU output is controlled at a high level, the voltage switching control circuit obtains the required reduced voltage output.

[0080] Similarly, in the second case above, when Vc is at a high level, the diode D1 is not conducting, and the on-resistance of the diode D1 is extremely large, much higher than the second resistor R2, the third resistor R3, and the nonlinear resistor Rc. The effect of the access circuit composed of the connected nonlinear resistor Rc and the diode D1 on the voltage switching control circuit can be ignored. The output voltage of the voltage switching control circuit is only related to the voltage division ratio of the second resistor R2 and the third resistor R3:

[0081] Vout=Vfb*(1+(R2 / R3))

[0082] When Vc is at zero level, diode D1 is turned on, and the on-resistance of diode D1 is extremely small and can be ignored. The total resistance of the series branch composed of nonlinear resistor Rc and diode D1 is Rc, and the second voltage Vout is:

[0083] Vout=Vfb*(1+(R2 / (R3 / / Rc))

[0084] As can be seen from the above, when the CPU output is controlled at a high level, the original DC-DC power supply chip maintains the original output second voltage unchanged. Therefore, it is only necessary to select a suitable nonlinear resistor Rc to ensure that when the CPU output is controlled at a low level, the voltage switching control circuit obtains the required increased voltage output.

[0085] See also Figure 7 , is a module structure of a voltage switching control circuit provided by another embodiment of the present application. For the sake of convenience, only the part related to this embodiment is shown, which is described in detail as follows:

[0086] As an embodiment of the present application, Figure 4 Based on the illustrated embodiment, the voltage switching control circuit further includes an input filtering module 106;

[0087] The input filter module 106 is connected to the DC power supply, the enabling module 101 and the voltage transformation module 102 , and the input filter module 106 is used to filter the first voltage.

[0088] Specifically, an input filtering module 106 is provided to filter out a specific frequency band in the first voltage, so as to reduce or even eliminate interference.

[0089] As an embodiment of the present application, Figure 4 Based on the illustrated embodiment, the voltage switching control circuit further includes an output filtering module 107;

[0090] The output filter module 107 is connected to the current limiting protection module 103 and the voltage dividing module 104 , and is configured to perform filtering processing on the regulated second voltage.

[0091] Specifically, the output filtering module 107 is provided to filter out a specific frequency band of the adjusted second voltage, so as to further reduce or even eliminate interference.

[0092] Figure 8 and Fig. 9 Shows the corresponding Figure 7 Two example circuits of the voltage switching control circuit are shown. For the sake of convenience, only the parts related to this embodiment are shown. The details are as follows:

[0093] As an embodiment of the present application, the input filter module 106 includes a fourth capacitor C4 and a fifth capacitor C5.

[0094] A first end of the fourth capacitor C4 and a first end of the fifth capacitor C5 are connected to the transformer module 102 , and a second end of the fourth capacitor C4 and a second end of the fifth capacitor C5 are grounded.

[0095] As an embodiment of the present application, the output filter module 107 includes a sixth capacitor C6, a seventh capacitor C7 and an eighth capacitor C8.

[0096] The first end of the sixth capacitor C6 is connected to the first end of the seventh capacitor C7 and the first end of the eighth capacitor C8 and is connected to the voltage divider module 104 . The second end of the sixth capacitor C6 and the second end of the seventh capacitor C7 and the second end of the eighth capacitor C8 are grounded.

[0097] like Figure 8 As described above, the cathode of the diode D1 is connected to the nonlinear resistor Rc, and the anode of the diode D1 is connected to the control module 105. Therefore, when the control voltage output by the control module 105 to the voltage divider module 104 is high, the second voltage output by the DC-DC power chip U1 is reduced.

[0098] like Fig. 9 As described above, the anode of the diode D1 is connected to the nonlinear resistor Rc, and the cathode of the diode D1 is connected to the control module 105. Therefore, when the control voltage output by the control module 105 to the voltage divider module 104 is at a low level, the second voltage output by the DC-DC power chip U1 is increased.

[0099] In a second aspect, the present application provides a voltage switching control device, including a DC power supply and the voltage switching control circuit as described above. The voltage switching control device is widely used in set-top boxes or switch products that require voltage switching.

[0100] It should be noted that the voltage switching control device adds a DC power supply to the above-mentioned voltage switching control circuit. Therefore, the functional description and principle description of the enabling module 101, the voltage transformation module 102, the current limiting protection module 103, the voltage dividing module 104, the control module 105, the input filtering module 106 and the output filtering module 107 of the voltage switching control circuit can be referred to. Figure 4-Figure 9 The embodiments of the present invention will not be described in detail here.

[0101] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the above-mentioned voltage switching control circuit and voltage switching control device work under the enabling action of the enabling module through the transformer module, and output a second voltage after voltage conversion of the first voltage output by the DC power supply. Then, the voltage divider module divides the second voltage and feeds it back to the transformer module to instruct the transformer module to adjust the second voltage. At the same time, the control module outputs a control voltage to the voltage divider module to adjust the voltage divider module to divide the second voltage. The voltage divider module includes a nonlinear resistor, a second resistor, a third resistor, a third capacitor and a diode. Therefore, the scheme adds a nonlinear resistor and a diode to the original voltage switching control technology. The design variable is only a nonlinear resistor, which is easier to select, and the electronic components are also simpler. It is widely used in set-top boxes or switch products that require voltage switching.

[0102] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0103] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A voltage switching control circuit, characterized in that: The voltage switching control circuit comprises: A voltage transformation module, connected to a DC power supply, and configured to output a second voltage after performing voltage transformation on a first voltage output by the DC power supply; an enabling module, connected to the DC power supply and the transformer module, and configured to enable the transformer module to operate when receiving the first voltage; a current limiting protection module, connected to the voltage transformation module and configured to perform current limiting protection on the second voltage; a voltage dividing module, connected to the voltage transformation module and the current limiting protection module, and configured to divide the second voltage and feed back the voltage to the voltage transformation module to instruct the voltage transformation module to adjust the second voltage; a control module connected to the voltage dividing module and configured to output a control voltage to the voltage dividing module to adjust the voltage dividing module to divide the second voltage; Wherein, the voltage division module comprises: A nonlinear resistor, a second resistor, a third resistor, a third capacitor and a diode; The first end of the second resistor and the first end of the third capacitor are connected to the current limiting protection module, the second end of the second resistor, the second end of the third capacitor, the first end of the third resistor and the first end of the nonlinear resistor are connected together and connected to the transformer module, and the second end of the nonlinear resistor is connected to the control module through the diode.

2. The voltage switching control circuit according to claim 1, characterized in that: The second end of the nonlinear resistor is connected to the control module through the diode, comprising: The second end of the nonlinear resistor is connected to the cathode of the diode, and the anode of the diode is connected to the control module; or The second end of the nonlinear resistor is connected to the anode of the diode, and the cathode of the diode is connected to the control module.

3. The voltage switching control circuit according to claim 1, characterized in that: Also includes: An input filtering module is connected to the DC power supply, the enabling module and the voltage transformation module, and is configured to filter the first voltage.

4. The voltage switching control circuit according to claim 1, characterized in that: Also includes: The output filtering module is connected to the current limiting protection module and the voltage dividing module, and is configured to filter the adjusted second voltage.

5. The voltage switching control circuit according to claim 1, characterized in that: The voltage conversion module includes a DC-DC power supply chip.

6. The voltage switching control circuit according to claim 1, characterized in that: The enabling module comprises: a first resistor and a first capacitor; A first end of the first resistor is connected to the DC power supply, a second end of the first resistor is connected to a first end of the first capacitor and connected to the transformer module, and a second end of the first capacitor is grounded.

7. The voltage switching control circuit according to claim 1, characterized in that: The current limiting protection module comprises: a second capacitor and a first inductor; A first end of the second capacitor is connected to the voltage transformation module, a second end of the second capacitor is connected to a first end of the first inductor, and a second end of the first inductor is connected to the voltage division module.

8. The voltage switching control circuit according to claim 3, characterized in that: The input filtering module comprises: a fourth capacitor and a fifth capacitor; The first end of the fourth capacitor and the first end of the fifth capacitor are connected to the transformer module, and the second end of the fourth capacitor and the second end of the fifth capacitor are grounded.

9. The voltage switching control circuit according to claim 4, characterized in that: The output filtering module comprises: a sixth capacitor, a seventh capacitor and an eighth capacitor; The first end of the sixth capacitor is connected to the first end of the seventh capacitor and the first end of the eighth capacitor and is connected to the voltage divider module, and the second end of the sixth capacitor and the second end of the seventh capacitor and the second end of the eighth capacitor are grounded.

10. A voltage switching control device, comprising a DC power supply, characterized in that: It also includes the voltage switching control circuit as described in any one of claims 1-9.

Images