Soft start circuit based on capacitor
Through the capacitor-based soft start circuit, the current limiting operation is controlled using the feedback signal of the capacitor trigger module, independent soft start for AC and DC power supply is achieved, solving the problems of complex and high cost in the existing technology, and improving the circuit Intelligence and efficiency.
Patent Information
- Application Number
- CN202420776655.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-16
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-04-16
AI Technical Summary
Existing soft start circuits require the use of multiple sets of relays and timing circuits when controlling AC power supply and DC power supply, resulting in complex control methods, increased circuit board size and cost, and it is difficult to independently control voltage overshoot and current surge phenomena.
Using a capacitor-based soft start circuit, the AC power output from the power supply module is regulated by the first soft start module, the second soft start control module cooperates with the capacitor trigger module to soft start protection of the DC power, and uses the feedback of the capacitor trigger module. The first soft start control module of signal control stops the current limit operation and realizes independent AC and DC power supply soft start.
It reduces the volume and cost of the circuit board, improves the intelligence of the soft start circuit, effectively avoids the impact of voltage overshoot and current surge on the circuit, and simplifies control methods.
Smart Images
Figure CN222192142U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of soft starting, in particular to a capacitor-based soft starting circuit. Background Art
[0002] Electrical equipment is prone to voltage overshoot and current surge at the moment of power-on, which may cause damage to the electrical equipment. Therefore, electrical equipment will use a soft start circuit, which uses a slowly rising voltage to control the slow rise of the output voltage. After the voltage reaches a predetermined value, the system enters a normal working state, avoiding the damage to the electrical equipment caused by the above-mentioned voltage overshoot and current surge. The existing soft start circuit generally adopts a timing device, a current limiting resistor and a relay, etc. The current limiting resistor performs current limiting work, and the timing device controls the switch closure of the relay at a fixed time, and then controls the current limiting resistor to stop working and restore power supply. When soft-start control is performed on AC power supply and DC power supply at the same time, multiple groups of relays and timing circuits are required, which makes the control method of the soft start circuit more complicated and increases the size and cost of the circuit board. Therefore, it needs to be improved. Utility Model Content
[0003] The embodiment of the utility model provides a capacitor-based soft start circuit to solve the problems raised in the above background technology.
[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0005] A capacitor-based soft start circuit comprises: a power supply module, a power supply control module, a first soft start module, a second soft start control module, a capacitor trigger module, a first soft start control module, a first output module and a second output module;
[0006] A power module is used to receive AC power and perform isolation, transformation, filtering and rectification on the AC power;
[0007] A power supply control module, connected to the power supply module and the second soft start control module, for transmitting the rectified electric energy to the second soft start control module, for stopping the transmission of electric energy;
[0008] A first soft start module, connected to the power module, for performing current limiting regulation on the electric energy after isolation and transformation and outputting the first electric energy;
[0009] a second soft start control module, connected to the capacitor trigger module, for performing voltage stabilization processing on the electric energy transmitted by the power supply control module and outputting second electric energy, and for receiving a feedback signal output by the capacitor trigger module and automatically increasing the voltage value of the second electric energy;
[0010] A capacitor trigger module, used for storing the second electric energy and outputting a feedback signal;
[0011] A first soft start control module is connected to the first output module, the capacitor trigger module and the power supply module, and is used to receive a feedback signal and, when the feedback signal is greater than a set breakdown threshold, control the first soft start module to stop current limiting and transmit the isolated and transformed electric energy to the first output module;
[0012] A first output module, connected to the first soft start module, used for receiving the first electric energy, used for receiving the isolated and changed electric energy transmitted by the first soft start control module;
[0013] The second output module is connected to the second soft start control module and is used to receive the second electric energy.
[0014] As a further solution of the utility model: the power supply module includes a power supply interface, a first transformer and a first capacitor; the first soft start module includes a first thyristor, a second thyristor, a first resistor and a second resistor; the first output module includes a first output port;
[0015] Preferably, the first end and the second end of the power interface are respectively connected to the first end and the second end of the primary side of the first transformer, the first end of the secondary side of the first transformer is connected to the first end of the first capacitor and the first end of the first thyristor, the second end of the first thyristor is connected to the first end of the first output port through the first resistor, the second end of the secondary side of the first transformer is connected to the second end of the first capacitor and the first end of the second thyristor, and the second end of the second thyristor is connected to the second end of the first output port through the second resistor.
[0016] As a further solution of the utility model: the power supply module also includes a first rectifier and a second capacitor; the power supply control module includes a third resistor, a fourth resistor, a first key switch, a first switch tube and a first power tube;
[0017] Preferably, the first input end and the second input end of the first rectifier are respectively connected to the first end and the second end of the first capacitor, the first output end of the first rectifier is connected to one end of the second capacitor, one end of the fourth resistor and the drain of the first power tube, and the gate of the first power tube and the collector of the first switch tube are connected through the third resistor, the other end of the fourth resistor is connected to the moving end of the first push switch, the fixed end of the first push switch is connected to the base of the first switch tube, the emitter of the first switch tube, the other end of the second capacitor and the second output end of the first rectifier are all grounded, and the source of the first power tube is connected to the second soft start control module.
[0018] As a further solution of the utility model: the second soft start control module includes a first voltage stabilizer, a first potentiometer, a fifth resistor and a second switch tube; the second output module includes a fourth capacitor and a second output port;
[0019] Preferably, the third end of the first voltage regulator is connected to the source of the first power tube, the first end of the first voltage regulator is connected to the emitter of the second switching tube, one end of the fifth resistor and one end of the first potentiometer, the second end of the first voltage regulator is connected to the other end of the fifth resistor, one end of the fourth capacitor and the first end of the second output port, the other end of the first potentiometer, the slider end of the first potentiometer, the collector of the second switching tube, the other end of the fourth capacitor and the second end of the second output port are all grounded, and the base of the second switching tube is connected to the capacitor trigger module.
[0020] As a further solution of the utility model: the capacitor trigger module includes a sixth resistor, a first diode and a third capacitor;
[0021] Preferably, the anode of the first diode is connected to the first end of the third capacitor, the base of the second switch tube and the first soft start control module and is connected to the emitter of the second switch tube through the sixth resistor, the cathode of the first diode is connected to the second end of the first regulator, and the second end of the third capacitor is grounded.
[0022] As a further solution of the utility model: the first soft start control module includes a seventh resistor, a second diode, a fourth diode, a third diode, a third switch tube, a first relay, a first power supply, a first logic chip, a second key switch and a first relay switch;
[0023] Preferably, the cathode of the second diode is connected to the first end of the third capacitor through the seventh resistor, the anode of the second diode is connected to the anode of the fourth diode, the cathode of the fourth diode is connected to the cathode of the third diode and the second end of the first logic chip, the first end of the first logic chip is connected to the moving end of the second push switch, the fixed end of the second push switch is connected to the first power supply and one end of the first relay, the other end of the first relay is connected to the collector of the third switch tube, the base of the third switch tube is connected to the anode of the third diode and the third end of the first logic chip, the emitter of the third switch tube is grounded, the first moving end and the second moving end of the first relay switch are respectively connected to the first end and the second end of the first capacitor, and the first fixed end and the second fixed end of the first relay switch are respectively connected to the first end and the second end of the first output port.
[0024] Compared with the prior art, the beneficial effects of the utility model are as follows: the capacitor-based soft start circuit of the utility model uses the first soft start module to perform current limiting regulation processing on the AC power output by the power supply module, and uses the second soft start control module to cooperate with the capacitor trigger module to perform soft start protection processing on the DC power transmitted by the power supply control module, thereby reducing the impact of impact voltage and surge current on the circuit. At the same time, when the electric energy stored in the capacitor trigger module exceeds the breakdown threshold set by the first soft start control module, the first soft start control module stops the current limiting regulation work of the first soft start module and performs normal power supply. The soft start work of AC power supply and DC power supply can be independently controlled without more relays, thereby reducing the volume and cost of the circuit board and improving the intelligence of the soft start circuit. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0026] Figure 1 The present invention provides a schematic block diagram of a capacitor-based soft start circuit.
[0027] Figure 2 A circuit diagram of a capacitor-based soft start circuit provided in an example of the utility model.
[0028] Figure 3 This is a connection circuit diagram of the first soft start control module provided in an example of the utility model. DETAILED DESCRIPTION
[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0030] In one embodiment, see Figure 1 , a capacitor-based soft start circuit, comprising: a power supply module 1, a power supply control module 2, a first soft start module 3, a second soft start control module 4, a capacitor trigger module 5, a first soft start control module 6, a first output module 7 and a second output module 8;
[0031] Specifically, the power module 1 is used to receive AC power and perform isolation, transformation, filtering and rectification on the AC power;
[0032] The power supply control module 2 is connected to the power supply module 1 and the second soft start control module 4, and is used to transmit the rectified electric energy to the second soft start control module 4, so as to stop the transmission of electric energy;
[0033] A first soft start module 3, connected to the power module 1, for performing current limiting and regulating processing on the electric energy after isolation and transformation and outputting the first electric energy;
[0034] The second soft start control module 4 is connected to the capacitor trigger module 5, and is used to stabilize the electric energy transmitted by the power supply control module 2 and output the second electric energy, and is used to receive the feedback signal output by the capacitor trigger module 5 and automatically increase the voltage value of the second electric energy;
[0035] The capacitor trigger module 5 is used to store the second electric energy and output a feedback signal;
[0036] A first soft start control module 6 is connected to the first output module 7, the capacitor trigger module 5 and the power supply module 1, and is used to receive a feedback signal and, when the feedback signal is greater than a set breakdown threshold, control the first soft start module 3 to stop current limiting and transmit the isolated and transformed electric energy to the first output module 7;
[0037] A first output module 7, connected to the first soft start module 3, for receiving the first electric energy, for receiving the isolated and changed electric energy transmitted by the first soft start control module 6;
[0038] The second output module 8 is connected to the second soft start control module 4 and is used for receiving the second electric energy.
[0039] In a specific embodiment, the power supply module 1 can adopt a power supply circuit composed of a power supply interface, a transformer, a rectifier, etc., can be connected to AC power, and isolate, transform, filter and rectify the AC power; the power supply control module 2 can adopt a power supply control circuit composed of a power tube, a resistor, a key switch, etc. to control the transmission and power-off control of electric energy; the first soft start module 3 can adopt a first soft start circuit composed of a thyristor and a current limiting resistor, in which the thyristor adjusts the transmitted electric energy and the current limiting resistor performs current limiting processing; the second soft start control module 4 can adopt a second soft start control circuit composed of a voltage stabilizer, a resistor, a triode, etc., which is controlled by the signal output by the capacitor trigger module 5 and can perform a slow voltage boost processing; the capacitor trigger module 5 can adopt a capacitor, a resistor, a diode, etc. The capacitor trigger circuit composed of a diode stores energy and triggers the operation of the second soft start control module 4 and the first soft start control module 6 when the stored electric energy reaches a certain level; the first soft start control module 6 can be composed of a diode, a resistor, a relay, a logic chip, a key switch, etc. to form a first soft start control circuit, and a breakdown threshold can be set, and when the electric energy stored in the capacitor trigger module 5 exceeds the breakdown threshold, the first soft start module 3 is self-locked and stops working; the first output module 7 can be composed of a first output circuit composed of a first output port, which can be connected to an electric device and provide AC power to the electric device; the second output module 8 can be composed of a second output circuit composed of a second output port and a capacitor, which can be connected to an electric device and provide DC power to the electric device.
[0040] In another embodiment, see Figure 1 , Figure 2 and Figure 3 The power module 1 includes a power interface, a first transformer B1 and a first capacitor C1; the first soft start module 3 includes a first thyristor SCR1, a second thyristor SCR2, a first resistor R1 and a second resistor R2; the first output module 7 includes a first output port;
[0041] Specifically, the first end and the second end of the power interface are respectively connected to the first end and the second end of the primary side of the first transformer B1, the first end of the secondary side of the first transformer B1 is connected to the first end of the first capacitor C1 and the first end of the first thyristor SCR1, the second end of the first thyristor SCR1 is connected to the first end of the first output port through the first resistor R1, the second end of the secondary side of the first transformer B1 is connected to the second end of the first capacitor C1 and the first end of the second thyristor SCR2, and the second end of the second thyristor SCR2 is connected to the second end of the first output port through the second resistor R2.
[0042] In a specific embodiment, the first thyristor SCR1 and the second thyristor SCR2 can both be bidirectional thyristors, which can be controlled by a related single chip microcomputer (not shown), and then AC-AC regulation is performed by simultaneously adjusting the conduction degree of the first thyristor SCR1 and the second thyristor SCR2, which will not be elaborated here.
[0043] Furthermore, the power supply module 1 further includes a first rectifier and a second capacitor; the power supply control module 2 includes a third resistor R3, a fourth resistor R4, a first key switch S1, a first switch tube VT1 and a first power tube Q1;
[0044] Specifically, the first input end and the second input end of the first rectifier are connected to the first end and the second end of the first capacitor C1 respectively, the first output end of the first rectifier is connected to one end of the second capacitor, one end of the fourth resistor R4 and the drain of the first power tube Q1, and connected to the gate of the first power tube Q1 and the collector of the first switch tube VT1 through the third resistor R3, the other end of the fourth resistor R4 is connected to the moving end of the first key switch S1, the fixed end of the first key switch S1 is connected to the base of the first switch tube VT1, the emitter of the first switch tube VT1, the other end of the second capacitor and the second output end of the first rectifier are all grounded, and the source of the first power tube Q1 is connected to the second soft start control module 4.
[0045] In a specific embodiment, the first push switch S1 is a normally open switch. When the first push switch S1 is controlled to be closed, the first switch tube VT1 is triggered to be turned on, and the power transmission work of the first power tube Q1 is stopped. The first switch tube VT1 can be an NPN transistor, and the first power tube Q1 can be an N-channel field effect tube.
[0046] Furthermore, the second soft start control module 4 includes a first voltage regulator IC1, a first potentiometer RP1, a fifth resistor R5 and a second switch tube VT2; the second output module 8 includes a fourth capacitor C4 and a second output port;
[0047] Specifically, the third end of the first voltage regulator IC1 is connected to the source of the first power tube Q1, the first end of the first voltage regulator IC1 is connected to the emitter of the second switch tube VT2, one end of the fifth resistor R5 and one end of the first potentiometer RP1, the second end of the first voltage regulator IC1 is connected to the other end of the fifth resistor R5, one end of the fourth capacitor C4 and the first end of the second output port, the other end of the first potentiometer RP1, the slider end of the first potentiometer RP1, the collector of the second switch tube VT2, the other end of the fourth capacitor C4 and the second end of the second output port are all grounded, and the base of the second switch tube VT2 is connected to the capacitor trigger module 5.
[0048] In a specific embodiment, the first voltage regulator IC1 may be a LM317 three-terminal voltage regulator; the first switch tube VT1 may be a PNP transistor to control the connection state between the first potentiometer RP1 and the fifth resistor R5, and then adjust the voltage value output by the first voltage regulator IC1.
[0049] Further, the capacitor trigger module 5 includes a sixth resistor R6, a first diode D1 and a third capacitor C3;
[0050] Specifically, the anode of the first diode D1 is connected to the first end of the third capacitor C3, the base of the second switch tube VT2 and the first soft start control module 6, and is connected to the emitter of the second switch tube VT2 through the sixth resistor R6, the cathode of the first diode D1 is connected to the second end of the first regulator IC1, and the second end of the third capacitor C3 is grounded.
[0051] In a specific embodiment, the third capacitor C3 stores energy, and the first diode D1 provides a discharge path for the third capacitor C3 when the first regulator IC1 stops supplying power.
[0052] Further, the first soft start control module 6 includes a seventh resistor R7, a second diode D2, a fourth diode D4, a third diode D3, a third switch tube VT3, a first relay K1, a first power supply VCC1, a first logic chip U1, a second key switch S2 and a first relay switch K1-1;
[0053] Specifically, the cathode of the second diode D2 is connected to the first end of the third capacitor C3 through the seventh resistor R7, the anode of the second diode D2 is connected to the anode of the fourth diode D4, the cathode of the fourth diode D4 is connected to the cathode of the third diode D3 and the second end of the first logic chip U1, the first end of the first logic chip U1 is connected to the moving end of the second key switch S2, the fixed end of the second key switch S2 is connected to the first power supply VCC1 and one end of the first relay K1, the other end of the first relay K1 is connected to the collector of the third switch tube VT3, the base of the third switch tube VT3 is connected to the anode of the third diode D3 and the third end of the first logic chip U1, the emitter of the third switch tube VT3 is grounded, the first moving end and the second moving end of the first relay switch K1-1 are respectively connected to the first end and the second end of the first capacitor C1, and the first fixed end and the second fixed end of the first relay switch K1-1 are respectively connected to the first end and the second end of the first output port.
[0054] In a specific embodiment, the seventh resistor R7 and the second diode D2 set the breakdown threshold; the first logic chip U1 can adopt an AND gate logic chip, cooperate with the fourth diode D4 and the third diode D3, and can perform signal self-locking processing on the signal input from the second end of the first logic chip U1 when the first end of the first logic chip U1 is at a high level; the second push switch S2 is a normally closed switch, and when the second push switch S2 is disconnected, the self-locking reset of the first logic chip U1 is controlled; the first relay switch K1-1 can select a double-pole double-throw normally open switch, which is controlled by the first relay K1 by magnetic attraction.
[0055] In a capacitor-based soft start circuit of the present embodiment, AC power is connected to the power interface, the first transformer B1 performs isolation and transformation, and the AC power after isolation and transformation is AC-AC regulated according to the conduction degree of the first thyristor SCR1 and the second thyristor SCR2, and then the first resistor R1 and the second resistor R2 perform current limiting processing, and finally transmit it to the first output port, and at the same time, the first rectifier and the second capacitor perform rectification and filtering, and then the first power tube Q1 transmits the DC power to the first voltage regulator IC1, at this time, the second switch tube VT2 is turned on, the first voltage regulator IC1 outputs with the lowest output voltage, and the third capacitor C3 stores the voltage output by the first voltage regulator IC1, the first voltage regulator IC1 slowly increases the voltage until the voltage stored in the third capacitor C3 controls the second switch tube VT2 to be turned off, the first voltage regulator IC1 will supply power normally according to the signal sampled by the fifth resistor R5 and the first potentiometer RP1, and provide DC power to the second output port, and at the same time, the third capacitor C3 After the stored electric energy exceeds the breakdown threshold set by the seventh resistor R7 and the second diode D2, the second end of the first logic chip U1 becomes a high level. Since the first end of the first logic chip U1 is provided with a high level by the first power supply VCC1, the first logic chip U1 cooperates with the fourth diode D4 and the fifth diode to self-lock and control the third switch tube VT3 to turn on. When the second key switch S2 is disconnected, the self-locking work can be stopped. The first relay K1 controls the first relay switch K1-1 to close, and stops the current limiting adjustment work of the first thyristor SCR1, the first resistor R1, the second thyristor SCR2 and the second resistor R2. If the DC power supply end needs to be soft-started again at this time, the first key switch S1 can be closed to turn on the first switch tube VT1, the first power tube Q1 is turned off, the first regulator IC1 stops working, and the third capacitor C3 is discharged through the first diode D1. After the third capacitor C3 is discharged, the first key switch S1 is disconnected again to soft-start the DC power supply end again.
[0056] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.
[0057] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.
Claims
1. A capacitor-based soft start circuit, characterized in that: The capacitor-based soft start circuit includes: a power supply module, a power supply control module, a first soft start module, a second soft start control module, a capacitor trigger module, a first soft start control module, a first output module and a second output module; The power module is used to receive AC power and perform isolation, transformation, filtering and rectification on the AC power; The power supply control module is connected to the power supply module and the second soft start control module, and is used to transmit the rectified electric energy to the second soft start control module, so as to stop the transmission of electric energy; The first soft start module is connected to the power module and is used to perform current limiting and regulating processing on the electric energy after isolation and transformation and output the first electric energy; The second soft start control module is connected to the capacitor trigger module, and is used to stabilize the electric energy transmitted by the power supply control module and output the second electric energy, and is used to receive the feedback signal output by the capacitor trigger module and automatically increase the voltage value of the second electric energy; The capacitor trigger module is used to store the second electric energy and output a feedback signal; The first soft start control module is connected to the first output module, the capacitor trigger module and the power supply module, and is used to receive a feedback signal and, when the feedback signal is greater than a set breakdown threshold, control the first soft start module to stop current limiting and transmit the isolated and transformed electric energy to the first output module; The first output module is connected to the first soft start module and is used to receive the first electric energy, and is used to receive the isolated and changed electric energy transmitted by the first soft start control module; The second output module is connected to the second soft start control module and is used for receiving second electric energy.
2. A capacitor-based soft start circuit according to claim 1, characterized in that: The power supply module includes a power supply interface, a first transformer and a first capacitor; the first soft start module includes a first thyristor, a second thyristor, a first resistor and a second resistor; the first output module includes a first output port; The first end and the second end of the power interface are respectively connected to the first end and the second end of the primary side of the first transformer, the first end of the secondary side of the first transformer is connected to the first end of the first capacitor and the first end of the first thyristor, the second end of the first thyristor is connected to the first end of the first output port through the first resistor, the second end of the secondary side of the first transformer is connected to the second end of the first capacitor and the first end of the second thyristor, and the second end of the second thyristor is connected to the second end of the first output port through the second resistor.
3. A capacitor-based soft start circuit according to claim 2, characterized in that: The power supply module also includes a first rectifier and a second capacitor; the power supply control module includes a third resistor, a fourth resistor, a first key switch, a first switch tube and a first power tube; The first input end and the second input end of the first rectifier are connected to the first end and the second end of the first capacitor respectively, the first output end of the first rectifier is connected to one end of the second capacitor, one end of the fourth resistor and the drain of the first power tube, and connected to the gate of the first power tube and the collector of the first switch tube through the third resistor, the other end of the fourth resistor is connected to the moving end of the first key switch, the fixed end of the first key switch is connected to the base of the first switch tube, the emitter of the first switch tube, the other end of the second capacitor and the second output end of the first rectifier are all grounded, and the source of the first power tube is connected to the second soft start control module.
4. A capacitor-based soft start circuit according to claim 3, characterized in that: The second soft start control module includes a first voltage stabilizer, a first potentiometer, a fifth resistor and a second switch tube; the second output module includes a fourth capacitor and a second output port; The third end of the first voltage regulator is connected to the source of the first power tube, the first end of the first voltage regulator is connected to the emitter of the second switching tube, one end of the fifth resistor and one end of the first potentiometer, the second end of the first voltage regulator is connected to the other end of the fifth resistor, one end of the fourth capacitor and the first end of the second output port, the other end of the first potentiometer, the slider end of the first potentiometer, the collector of the second switching tube, the other end of the fourth capacitor and the second end of the second output port are all grounded, and the base of the second switching tube is connected to the capacitor trigger module.
5. A capacitor-based soft start circuit according to claim 4, characterized in that: The capacitor trigger module includes a sixth resistor, a first diode and a third capacitor; The anode of the first diode is connected to the first end of the third capacitor, the base of the second switch tube and the first soft start control module and is connected to the emitter of the second switch tube through the sixth resistor, the cathode of the first diode is connected to the second end of the first regulator, and the second end of the third capacitor is grounded.
6. A capacitor-based soft start circuit according to claim 5, characterized in that: The first soft start control module includes a seventh resistor, a second diode, a fourth diode, a third diode, a third switch tube, a first relay, a first power supply, a first logic chip, a second key switch and a first relay switch; The cathode of the second diode is connected to the first end of the third capacitor through the seventh resistor, the anode of the second diode is connected to the anode of the fourth diode, the cathode of the fourth diode is connected to the cathode of the third diode and the second end of the first logic chip, the first end of the first logic chip is connected to the moving end of the second push switch, the fixed end of the second push switch is connected to the first power supply and one end of the first relay, the other end of the first relay is connected to the collector of the third switch tube, the base of the third switch tube is connected to the anode of the third diode and the third end of the first logic chip, the emitter of the third switch tube is grounded, the first moving end and the second moving end of the first relay switch are respectively connected to the first end and the second end of the first capacitor, and the first fixed end and the second fixed end of the first relay switch are respectively connected to the first end and the second end of the first output port.