Peak voltage absorption circuit and power supply circuit

Abstract

A peak voltage absorption circuit and a power supply circuit, by adding a main absorption circuit, a first discharge circuit and a second discharge circuit, can repeatedly absorb and discharge the peak voltage. Moreover, this circuit does not need to discharge the peak voltage absorbed by the main absorption circuit through the original circuit that generates the peak voltage in the reverse direction. Therefore, the parameter selection of this peak voltage absorption circuit only needs to consider the absorption effect of the peak voltage without considering the impact current generated by the reverse discharge on the original circuit that generates the peak voltage, thereby shortening the circuit debugging period and improving the absorption effect of the peak voltage, and solving the problems of long debugging period and poor peak voltage absorption effect existing in the technical solution.

Description

Technical Field

[0001] The present invention belongs to the technical field of circuit protection, and particularly relates to a spike voltage absorption circuit and a power supply circuit. Background Art

[0002] In a semiconductor switch tube circuit, due to the action of line parasitic inductance or leakage inductance, oscillatory spike voltages will be generated at both ends of the switch tube. Therefore, a spike voltage absorption circuit needs to be connected at both ends of the switch tube to absorb the spike voltage. Currently, there are mainly three traditional spike voltage absorption circuit solutions: connecting a non-polar capacitor in parallel at both ends of the switch tube, connecting an RC branch in parallel at both ends of the switch tube, or connecting an RCD branch in parallel at both ends of the switch tube. However, in these solutions, the switch tube that generates the spike voltage is responsible for discharging the spike voltage. As a result, when selecting the parameters of the spike voltage absorption circuit, the impact current generated by the discharge of the absorbed voltage needs to be considered for its impact on the switch tube. That is, when selecting components inside the spike voltage absorption circuit, there are many factors that need to be balanced, and part of the spike voltage absorption effect needs to be sacrificed to avoid damage to the switch tube by the impact current. Therefore, the traditional technical solutions have problems of long debugging cycles and poor spike voltage absorption effects. Summary of the Invention

[0003] In view of this, the embodiments of the present invention provide a spike voltage absorption circuit and a power supply circuit, aiming to solve the problems of long debugging cycles and poor spike voltage absorption effects in traditional technical solutions.

[0004] The first aspect of the embodiments of the present invention provides a spike voltage absorption circuit, connected to a power transmission line, and the spike voltage absorption circuit includes:

[0005] A main absorption circuit, the high-potential end of the main absorption circuit is connected to the positive transmission line, the low-potential end of the main absorption circuit is connected to the negative transmission line, and the main absorption circuit is used to absorb the spike voltage;

[0006] A first discharge circuit, the input end of the first discharge circuit is connected to the high-potential end of the main absorption circuit, the output end of the first discharge circuit is connected to the low-potential end of the main absorption circuit, and the first discharge circuit is used to release the spike voltage absorbed by the main absorption circuit at a first target rate; and

[0007] A second discharge circuit, the first end of the second discharge circuit is connected to the high-potential end of the main absorption circuit, the second end of the second discharge circuit is connected to the low-potential end of the main absorption circuit, and the second discharge circuit is used to release the voltage absorbed by the main absorption circuit at a second target rate when the peak value of the spike voltage is greater than the clamping voltage of the power transmission line.

[0008] The second aspect of the embodiments of the present invention provides a power supply circuit, including a switching power supply circuit, and further including a spike voltage absorption circuit as described in the first aspect of the embodiments of the present invention, and the spike voltage absorption circuit is connected to the switching power supply circuit.

[0009] The above spike voltage absorption circuit realizes repeated absorption and discharge of spike voltage by adding a main absorption circuit, a first discharge circuit and a second discharge circuit. Moreover, this circuit does not need to discharge the spike voltage absorbed by the main absorption circuit through the original circuit that generates the spike voltage in the reverse direction. Therefore, the parameter selection of this spike voltage absorption circuit only needs to consider the absorption effect of the spike voltage and does not need to consider the impact current generated by the reverse discharge on the original circuit that generates the spike voltage, thereby shortening the circuit debugging period and improving the absorption effect of the spike voltage, and solving the problems of long debugging period and poor spike voltage absorption effect existing in the technical solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0011] Figure 1 It is a circuit schematic diagram of a spike voltage absorption circuit provided by an embodiment of the present invention;

[0012] Figure 2 For Figure 1 The specific example circuit schematic diagram of the spike voltage absorption circuit shown;

[0013] Figure 3 It is another circuit schematic diagram of a spike voltage absorption circuit provided by an embodiment of the present invention;

[0014] Figure 4 For Figure 3 The example circuit schematic diagram of the slave absorption circuit of the spike voltage absorption circuit shown;

[0015] Figure 5 It is another circuit schematic diagram of a spike voltage absorption circuit provided by an embodiment of the present invention;

[0016] Figure 6 For Figure 5 The example circuit schematic diagram of the slave absorption circuit of the spike voltage absorption circuit shown;

[0017] Figure 7 For Figure 5 The example circuit schematic diagram of the slave absorption circuit of the spike voltage absorption circuit shown;

[0018] Figure 8 is Figure 5 an example circuit schematic diagram of the slave absorption circuit of the spike voltage absorption circuit shown;

[0019] Figure 9 is Figure 5 an example circuit schematic diagram of the slave absorption circuit of the spike voltage absorption circuit shown. Specific Embodiments

[0020] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] Please refer to Figure 1 , a circuit schematic diagram of the spike voltage absorption circuit provided by an embodiment of the present invention. For the sake of convenience of description, only the parts related to this embodiment are shown and are described in detail as follows:

[0022] The spike voltage absorption circuit in this embodiment is connected to the power transmission line 10. It should be understood that the power transmission line 10 can be the lead-out wire of any circuit that generates spike voltage and needs to eliminate spike voltage, such as an inverter welding power supply, a UPS power supply, a three-phase or single-phase grid-connected inverter power supply, etc. that include semiconductor switching tubes or rectifier diodes. It should be understood that when the switching tube in the semiconductor switching tube circuit is turned off, due to the action of line parasitic inductance or leakage inductance, oscillatory spike voltage will be generated at both ends of the switching tube. It should be understood that when the main device generating the spike voltage is the switching tube in this circuit, one end of the positive transmission line 11 of the power transmission line 10 is connected to the input end of the switching tube, the other end of the positive transmission line 11 of the power transmission line 10 is connected to this spike voltage absorption circuit, one end of the negative transmission line 12 of the power transmission line 10 is connected to the output end of the switching tube, and the other end of the negative transmission line 12 of the power transmission line 10 is connected to this spike voltage absorption circuit. The power transmission line 10 is used to transmit the spike voltage in the circuit generating the spike voltage to the spike voltage absorption circuit, and the spike voltage absorption circuit completes the absorption of the spike voltage to eliminate the spike voltage in the circuit generating the spike voltage.

[0023] The peak voltage absorption circuit includes: a main absorption circuit 200, a first discharge circuit 300 and a second discharge circuit 400. The high potential end of the main absorption circuit 200 is connected to the positive transmission line 11 of the power transmission line 10, the low potential end of the main absorption circuit 200 is connected to the negative transmission line 12 of the power transmission line 10, the first end of the second discharge circuit 400 is connected to the high potential end of the main absorption circuit 200, and the second end of the second discharge circuit 400 is connected to the low potential end of the main absorption circuit 200; the main absorption circuit 200 is used to absorb the peak voltage; the input end of the first discharge circuit 300 is connected to the high potential end of the main absorption circuit 200, the output end of the first discharge circuit 300 is connected to the low potential end of the main absorption circuit 200, the first discharge circuit 300 is used to release the peak voltage absorbed by the main absorption circuit 200 at a first target rate; the second discharge circuit 400 is used to release the voltage absorbed by the main absorption circuit 200 at a second target rate when the peak value of the peak voltage is greater than the clamping voltage of the power transmission line 10.

[0024] It should be understood that the first target rate in the present embodiment is lower than the second target rate. When the peak value of the spike voltage of the power transmission line 10 is lower than the clamping voltage of the power transmission line 10, the spike voltage absorbed by the main absorption circuit 200 is released through the first discharge circuit 300, so that the main absorption circuit 200 can continuously absorb the spike voltage. When the peak value of the spike voltage of the power transmission line 10 is higher than its clamping voltage, the second discharge circuit 400 is opened, and the main absorption circuit 200 is discharged through the second discharge circuit 400. At this time, the residual voltage of the main absorption circuit 200 is released through the first discharge circuit 300. It should be understood that the main absorption circuit 200 in the present embodiment continues to absorb the spike voltage after being discharged through the second discharge circuit 400 and the first discharge circuit 300, and this is repeated. That is, when the spike voltage is higher than the clamping voltage of the circuit in which it is located, the spike voltage absorption circuit in the present embodiment repeatedly absorbs and discharges the spike voltage until the spike voltage is lower than the clamping voltage of the circuit in which the device is located.

[0025] The spike absorption circuit in this embodiment adds a main absorption circuit 200, a first discharge circuit 300 and a second discharge circuit 400 to achieve repeated absorption and discharge of the spike voltage. Moreover, this circuit does not need to reversely discharge the spike voltage absorbed by the main absorption circuit through the original circuit that generates the spike voltage. Therefore, the parameter selection of this spike voltage absorption circuit only needs to consider the absorption effect of the spike voltage without considering the influence of the impact current generated by the reverse discharge on the original circuit that generates the spike voltage, thereby shortening the circuit debugging cycle and improving the peak voltage absorption effect, solving the problems of long debugging cycle and poor spike voltage absorption effect in the technical solution.

[0026] It should be understood that the main absorption circuit 200 includes at least one capacitor. The first ends of the capacitors are commonly connected as the high-potential end of the main absorption circuit 200, and the second ends of the capacitors are commonly connected as the low-potential end of the main absorption circuit 200. The number and capacitance value of the capacitors can be determined according to the absorption capacity of the specific circuit. Please refer to Figure 2 , in one embodiment, the main absorption circuit 200 includes: capacitor C1 and capacitor C2. The first end of capacitor C1 and one end of capacitor C2 are commonly connected as the high-potential end of the main absorption circuit 200, and the second end of capacitor C1 and the second end of capacitor C2 are commonly connected as the low-potential end of the main absorption circuit 200.

[0027] It should be understood that capacitor C1 and capacitor C2 in this embodiment can be a non-polar capacitor and an electrolytic capacitor respectively. The capacitance values of capacitor C1 and capacitor C2 can be determined by the debugger during debugging according to the absorption effect of the spike voltage at both ends of the power transmission line 10. Since the spike voltage absorbed by capacitor C1 and capacitor C2 does not need to be discharged reversely through the power transmission line 10, the impact current generated when capacitor C1 and capacitor C2 discharge does not need to be considered for the load connected to the power transmission line 10. It should be understood that in other embodiments, the main absorption circuit 200 can include one capacitor or two or more capacitors connected in parallel according to the spike voltage and the absorption requirements of the spike voltage of its actual circuit.

[0028] In the main absorption circuit of this embodiment, by adding capacitor C1 and capacitor C2, it is realized that only the resistance values of capacitor C1 and capacitor C2 need to be debugged according to the absorption effect of the spike voltage, thus solving the problems such as poor spike voltage absorption effect, long debugging period and complex parameter design caused by compromise processing due to the need to consider multiple factors in the traditional technical solution.

[0029] Please refer to Figure 2 , in one embodiment, the first discharge circuit 300 includes: resistor R1. The first end of resistor R1 is used as the input end of the first discharge circuit 300, and the second end of resistor R1 is used as the output end of the first discharge circuit 300. It should be understood that resistor R1 in this embodiment is used to release the spike voltage absorbed by the main absorption circuit 200, so that the main absorption circuit 200 can accelerate the absorption of the spike voltage.

[0030] Please refer to Figure 2, in one embodiment, the second discharge circuit 400 includes: a clamping unit 410, a switching transistor Q1, and a negative feedback discharge unit 420. The clamping unit 410 is connected to the positive transmission line 11 of the power transmission line 10. The control end of the switching transistor Q1 is connected to the output end of the clamping unit 410. The input end of the switching transistor Q1 is connected to the high-potential end of the main absorption circuit. The first end of the negative feedback discharge unit 420 is connected to the output end of the switching transistor Q1, and the second end of the negative feedback discharge unit 420 is connected to the negative transmission line 12 of the power transmission line 10. The clamping unit 410 is configured to conduct and output a high level when the peak value of the spike voltage is higher than the clamping voltage of the power transmission line 10, and to cut off and output a low level when the peak value of the spike voltage is lower than the clamping voltage of the power transmission line 10. The switching transistor Q1 is configured to conduct according to the high level to provide a discharge path for the main absorption circuit 200 to release the spike voltage or to cut off according to the low level. The negative feedback discharge unit 420 is configured to discharge, and to generate a feedback voltage according to the discharge current of the switching transistor Q1 and feedback the feedback voltage to the control end of the switching transistor Q1. The feedback voltage is used to adjust the conduction degree of the switching transistor Q1.

[0031] It should be understood that the clamping unit 410 can be composed of a device with a clamping function, such as a transient voltage suppression diode. The switching transistor Q1 can be a MOS transistor, a bipolar transistor, an IGBT thyristor, etc. The negative feedback discharge unit 420 can be composed of a resistor, etc.

[0032] It should be understood that the conduction degree of the switching transistor Q1 includes a linear region (i.e., a variable resistance region), a saturation region, a breakdown region, and a cut-off region, etc. The negative feedback discharge unit 420 generates a feedback voltage according to the discharge current of the switching transistor Q1 and feeds it back to the control end of the switching transistor Q1, thereby adjusting the control voltage of the control end of the switching transistor Q1, so that the switching transistor Q1 is in the linear region, thereby sharing the power loss of the negative feedback discharge unit 420, and at the same time preventing the switching transistor Q1 and the negative feedback discharge unit 420 from being in a conducting state all the time and overheating and damaging. The negative feedback function enhances the self-protection ability of the spike voltage absorption circuit and improves the stability and reliability of the entire circuit.

[0033] Please refer to Figure 2 , in one embodiment, the clamping unit 410 includes a resistor R2, a resistor R3, a first transient voltage suppression diode TVS1, and a second transient voltage suppression diode TVS2. The first end of the first transient voltage suppression diode TVS1 is connected to the positive transmission line 11 of the power transmission line 10. The second end of the first transient voltage suppression diode TVS1, the first end of the resistor R2, and the first end of the resistor R3 are connected. The second end of the resistor R2 and the second end of the second transient voltage suppression diode TVS2 are commonly connected to the control end of the switching transistor Q1. The second end of the second transient voltage suppression diode TVS2 is connected to the output end of the switching transistor Q1. The second end of the resistor R3 is connected to the negative transmission line 12 of the power transmission line 10.

[0034] It should be understood that the first transient voltage suppression diode TVS1 and the second transient voltage suppression diode TVS2 in this embodiment can be bidirectional transient voltage suppression diodes. The breakdown voltage of the first transient voltage suppression diode TVS1 can be selected according to the absorption clamping voltage of the spike voltage. The breakdown voltage of the second transient voltage suppression diode TVS2 can be fixedly selected as any voltage lower than the absorption clamping voltage of the spike voltage, such as a bidirectional transient voltage suppression diode with a breakdown voltage of 18V.

[0035] When the peak value of the spike voltage is less than the breakdown voltage of the first transient voltage suppression diode TVS1, the output of the clamping unit 410 to the control terminal of the switching transistor Q1 is at a low level. At this time, the switching transistor Q1 is turned off, and the spike voltage absorbed by the main absorption circuit 200 is slowly released through the first discharge circuit 300, accelerating the absorption of the spike voltage. When the peak value of the spike voltage is greater than the sum of the breakdown voltages of the first transient voltage suppression diode TVS1 and the second transient voltage diode TVS2, the output of the clamping unit 410 to the control terminal of the switching transistor Q1 is at a high level. At this time, the switching transistor Q1 is turned on, and the spike voltage absorbed by the main absorption circuit 200 is quickly discharged through the switching transistor Q1 and the negative feedback discharge unit 420. Moreover, the residual voltage of the main absorption circuit 200 is discharged through the first discharge circuit 300. After the main absorption circuit 200 is quickly discharged, it continues to absorb the spike voltage, and the absorption and discharge of the main absorption circuit 200 are repeated.

[0036] Please refer to Figure 2 , in one embodiment, the negative feedback discharge unit 420 includes a resistor R4. The first end of the resistor R4 is connected to the output terminal of the switching transistor Q1, and the second end of the resistor R4 is connected to the negative transmission line 12 of the power transmission line 10.

[0037] It should be understood that the resistor R4 is a power consumption resistor, and the resistance value of the resistor R4 should be less than that of the resistor R1. The resistance value of the resistor R4 can be determined according to the discharge current of the spike voltage absorption circuit in actual application and the breakdown voltage of the second transient voltage suppressor TVS2, that is, R resistor R4 = breakdown voltage of UTVS2 / I discharge current. Among them, the discharge current can be determined according to the absorption effect of the spike voltage selected independently and the spike voltage situation of the actual circuit. In addition to the discharge function, the resistor R4 also has a negative feedback function during the discharge process. During the discharge process, the resistor R4 forms a voltage corresponding to the magnitude of the discharge current of the switching transistor Q1, and this voltage is fed back negatively to the control end of the switching transistor Q1 to control the conduction degree of the switching transistor Q1, so that the switching transistor Q1 is in the linear region (i.e., the variable resistance region) to share the power loss of the resistor R4 during discharge, thereby reducing the volume of the resistor R4. At the same time, it also prevents the switching transistor Q1 and the resistor R4 from being in the conducting state all the time and overheating and being damaged, strengthening the self-protection ability of the circuit and improving the stability and reliability of the entire circuit.

[0038] Please refer to Figure 3 , in one embodiment, the spike voltage absorption circuit further includes: a first unidirectional transmitter 110 and / or a second unidirectional transmitter 120. The main absorption circuit 200, the first discharge circuit 300, and the second discharge circuit 400 are connected to the positive transmission line 11 through the first unidirectional transmitter 110, and the main absorption circuit 200, the first discharge circuit 300, and the second discharge circuit 400 are connected to the negative transmission line 12 through the second unidirectional transmitter 120. The first unidirectional transmitter 110 and the second unidirectional transmitter 120 are respectively used to unidirectionally access the spike voltage of the power transmission line.

[0039] It should be understood that the spike voltage absorption circuit in this embodiment can include both the first unidirectional transmitter 110 and the second unidirectional transmitter 120, or only include the first unidirectional transmitter 110, or only include the second unidirectional transmitter 120.

[0040] The spike voltage absorption circuit in this embodiment realizes unidirectional access to the spike voltage by adding the first unidirectional transmitter 110 and / or the second unidirectional transmitter 120, and avoids the spike voltage from being reversely discharged back to the original circuit that generates the spike voltage.

[0041] Please refer to Figure 4, in one embodiment, the first unidirectional transmitter 110 includes a diode D1, the second unidirectional transmitter 120 includes a diode D2. The positive electrode of the diode D1 serves as the input terminal of the first unidirectional transmitter 110 and is connected to the positive electrode transmission line 11. The negative electrode of the diode D1 serves as the input terminal of the first unidirectional transmitter 110 and is connected to the high potential terminal of the main absorption circuit 200, the input terminal of the first discharge circuit 300, and the first end of the second discharge circuit 400. The positive electrode of the diode D2 serves as the input terminal of the second unidirectional transmitter 120 and is connected to the low potential terminal of the main absorption circuit 200, the output terminal of the first discharge circuit 300, and the second end of the second discharge circuit 400. The negative electrode of the diode D2 serves as the output terminal of the second unidirectional transmitter 120 and is connected to the negative electrode transmission line 12.

[0042] Please refer to Figure 5 , in one embodiment, it further includes a slave absorption circuit. The first end of the slave absorption circuit is connected to the positive electrode transmission line, the second end of the slave absorption circuit is connected to the negative electrode transmission line, and the slave absorption circuit is used to assist in absorbing the spike voltage.

[0043] It should be understood that the spike voltage in this embodiment is mainly absorbed by the main absorption circuit 200, and the slave absorption circuit 500 only assists in absorbing the spike voltage, but the main absorption circuit 200 and the slave absorption circuit 500 do not interfere with each other.

[0044] The spike voltage absorption circuit in this embodiment adds a slave absorption circuit to assist in absorbing the spike voltage, so that the spike voltage absorption circuit can absorb various types of spike voltages, making the circuit versatility of the spike voltage absorption circuit strong.

[0045] Please refer to Figure 6 , in one embodiment, the slave absorption circuit 500 includes: a resistor R5 and a capacitor C3. The first end of the resistor R5 serves as the first end of the slave absorption circuit 500, the second end of the resistor R5 is connected to the first end of the capacitor C3, and the second end of the capacitor C3 serves as the second end of the slave absorption circuit 500.

[0046] Please refer to Figure 7 , in one embodiment, the slave absorption circuit 500 includes: a diode D3, a resistor R6, and a capacitor C4. The positive electrode of the diode D3 serves as the first end of the slave absorption circuit 500, the negative electrode of the diode D3 is connected to the first end of the resistor R6 and the first end of the capacitor C4, and the second end of the resistor R6 and the second end of the capacitor C4 are commonly connected as the second end of the slave absorption circuit 500.

[0047] Please refer to Figure 8, in one embodiment, the slave absorption circuit 500 includes: a diode D4, a resistor R7, and a capacitor C5. The positive electrode of the diode D4 and the first end of the resistor R7 are commonly connected as the first end of the slave absorption circuit 500. The negative electrode of the diode D4 and the second end of the resistor R7 are commonly connected to the first end of the capacitor C5. The second end of the capacitor C5 serves as the second end of the slave absorption circuit 500.

[0048] Please refer to Figure 9 , in one embodiment, the first end of the capacitor C6 serves as the first end of the slave absorption circuit 500, and the second end of the capacitor C6 serves as the second end of the slave absorption circuit 500.

[0049] It should be understood that the slave absorption circuit 500 may include Figure 4 , Figure 5 , Figure 6 and Figure 7 any one of the circuit components, and the slave absorption circuit 500 may also include Figure 4 , Figure 5 , Figure 6 and Figure 7 any two or more of the circuit components.

[0050] The second aspect of the embodiments of the present invention provides a power supply circuit, including a switching power supply circuit, and further including a spike voltage absorption circuit as in the first aspect of the embodiments of the present invention. The spike voltage absorption circuit is connected to the switching power supply circuit. It should be understood that the power transmission line 10 may be a lead-out wire of the switching power supply circuit for transmitting the spike voltage of the switching power supply circuit to the spike voltage absorption circuit.

[0051] Various embodiments of various devices, circuits, devices, systems, and / or methods are described herein. Many specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the drawings. However, those skilled in the art will understand that the embodiments may be practiced without such specific details. In other instances, well-known operations, components, and elements have been described in detail to avoid obscuring the embodiments in the specification. Those skilled in the art will understand that the embodiments described herein and shown are non-limiting examples, and thus it can be recognized that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments.

[0052] References throughout this specification to "various embodiments", "in an embodiment", "one embodiment" or "an embodiment" etc. mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in various embodiments", "in some embodiments", "in one embodiment" or "in an embodiment" etc. in appropriate places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Accordingly, a particular feature, structure, or characteristic shown or described in connection with one embodiment may be incorporated in whole or in part with the features, structures, or characteristics of one or more other embodiments, without assuming that such combination is illogical or non-functional. Any directional references (e.g., plus, minus, upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise and counterclockwise) are used for identification purposes to assist the reader in understanding the disclosure and do not create a limitation, particularly as to the position, orientation, or use of an embodiment.

[0053] Although certain embodiments have been described above in some detail, those skilled in the art may make many variations to the disclosed embodiments without departing from the scope of the disclosure. Connection references (e.g., attached, coupled, connected, etc.) should be construed broadly and may include intermediate members between the connection of elements and relative movement between elements. Thus, a connection reference does not necessarily imply that two elements are directly connected / coupled and in a fixed relationship to each other. The use of "for example" throughout this specification should be construed broadly and is used to provide non-limiting examples of embodiments of the disclosure, and the disclosure is not limited to such examples. It is intended that all matters included in the above description or shown in the accompanying drawings be construed as illustrative and not restrictive. Changes may be made in details or structure without departing from the disclosure.

[0054] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A spike voltage absorption circuit is connected to a power transmission line. It is characterized in that it is applied to spike voltage absorption in a semiconductor switch tube circuit. The spike voltage absorption circuit includes: A main absorption circuit, the high-potential end of the main absorption circuit is connected to the positive transmission line, the low-potential end of the main absorption circuit is connected to the negative transmission line, and the main absorption circuit is used to absorb the spike voltage; A first discharge circuit, the input end of the first discharge circuit is connected to the high-potential end of the main absorption circuit, the output end of the first discharge circuit is connected to the low-potential end of the main absorption circuit, and the first discharge circuit is used to release the spike voltage absorbed by the main absorption circuit at a first target rate; and A second discharge circuit, the first end of the second discharge circuit is connected to the high-potential end of the main absorption circuit, the second end of the second discharge circuit is connected to the low-potential end of the main absorption circuit, and the second discharge circuit is used to release the voltage absorbed by the main absorption circuit at a second target rate when the peak value of the spike voltage is greater than the clamping voltage of the power transmission line; The second discharge circuit includes: A clamping unit, the clamping unit is connected to the positive transmission line, and the clamping unit is used to conduct and output a high level when the peak value of the spike voltage is higher than the clamping voltage of the power transmission line, and cut off and output a low level when the peak value of the spike voltage is lower than the clamping voltage of the power transmission line; A switching tube, the control end of the switching tube is connected to the output end of the clamping unit, the input end of the switching tube is connected to the high-potential end of the main absorption circuit, and the switching tube is used to conduct according to the high level to provide a discharge channel for the main absorption circuit to release the spike voltage or cut off according to the low level; and A negative feedback discharge unit, the first end of the negative feedback discharge unit is connected to the output end of the switching tube, the second end of the negative feedback discharge unit is connected to the negative transmission line, and the negative feedback discharge unit is used for discharging and generating a feedback voltage according to the discharge current of the switching tube and feeding the feedback voltage back to the control end of the switching tube, and the feedback voltage is used to adjust the conduction degree of the switching tube.

2. The spike voltage absorption circuit according to claim 1, It is characterized in that the main absorption circuit includes: at least one capacitor, the first ends of the capacitors are commonly connected as the high-potential end of the main absorption circuit, and the second ends of the capacitors are commonly connected as the low-potential end of the main absorption circuit.

3. The spike voltage absorption circuit according to claim 1, It is characterized in that the first discharge circuit includes: a first resistor, the first end of the first resistor is used as the input end of the first discharge circuit, and the second end of the first resistor is used as the output end of the first discharge circuit.

4. The spike voltage absorption circuit according to claim 1, It is characterized in that The clamping unit includes a second resistor, a third resistor, a first transient voltage suppression diode, and a second transient voltage suppression diode. The first end of the first transient voltage suppression diode is connected to the positive electrode transmission line. The second end of the first transient voltage suppression diode, the first end of the second resistor, and the first end of the third resistor are connected. The second end of the second resistor and the second end of the second transient voltage suppression diode are commonly connected to the control end of the switching tube. The second end of the second transient voltage suppression diode is connected to the output end of the switching tube. The second end of the third resistor is connected to the negative electrode transmission line.

5. The spike voltage absorption circuit according to claim 1, wherein, the negative feedback discharge unit includes a fourth resistor. The first end of the fourth resistor is connected to the output end of the switching tube. The second end of the fourth resistor is connected to the negative electrode transmission line.

6. The spike voltage absorption circuit according to any one of claims 1-5, wherein, further comprising: a first unidirectional transmitter and / or a second unidirectional transmitter. The main absorption circuit, the first discharge circuit, and the second discharge circuit are connected to the positive electrode transmission line through the first unidirectional transmitter. The main absorption circuit, the first discharge circuit, and the second discharge circuit are connected to the negative electrode transmission line through the second unidirectional transmitter. The first unidirectional transmitter and the second unidirectional transmitter are respectively used to unidirectionally access the spike voltage of the power transmission line.

7. The spike voltage absorption circuit according to claim 6, wherein, further comprising a slave absorption circuit. The first end of the slave absorption circuit is connected to the positive electrode transmission line. The second end of the slave absorption circuit is connected to the negative electrode transmission line. The slave absorption circuit is used to assist in absorbing the spike voltage.

8. The spike voltage absorption circuit according to claim 7, wherein, the slave absorption circuit includes: a fifth resistor and a first capacitor. The first end of the fifth resistor serves as the first end of the slave absorption circuit. The second end of the fifth resistor is connected to the first end of the first capacitor. The second end of the first capacitor serves as the second end of the slave absorption circuit.

9. A power supply circuit includes a switching power supply circuit, wherein, further comprising the spike voltage absorption circuit according to any one of claims 1-8. The spike voltage absorption circuit is connected to the switching power supply circuit.

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