Slow-start and slow-charge circuit of capacitor
By introducing a mutual constraint mechanism between the first and second switching modules in the capacitor slow-start and slow-charge circuit, combined with current limiting and voltage regulation modules, stable charging of the capacitor is achieved, solving the problem of unstable slow-start and slow-charge current, improving the slow-start speed and reducing inrush current.
Patent Information
- Application Number
- CN202422879535.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2034-11-25
AI Technical Summary
Existing capacitor slow-start and slow-charge circuits suffer from unstable current during the slow-start process, resulting in limited slow-start speed or excessive inrush current, making it difficult to control simultaneously.
Through the mutual constraint of the first and second switching modules, the first switching module enters the balanced linear region working state, realizing constant current charging of the downstream capacitor. Combined with the current limiting module and voltage regulation module, the slow start charging current and time are precisely controlled.
Stable current control was achieved during the slow start-up and slow charging process, which improved the slow start-up speed and reduced the inrush current, ensuring the safe charging of the capacitor.
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Figure CN223599498U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to electronic circuit technical field, concretely relates to a capacitor's slow start slow charging circuit. BACKGROUND
[0002] The static capacitance voltage is zero, if suddenly adding a voltage to the capacitor, due to the capacitor voltage cannot suddenly change, in the voltage addition instant similar short circuit, will produce huge impact current and damage the device on the path, generally needs to increase a capacitor slow start slow charging circuit to limit current and charge steadily.
[0003] The existing capacitor slow start slow charging circuit as shown in the figure, its working logic is as follows: after voltage Vin is connected, first close switch K2, charges the back-end capacitor through switch K2 and resistance R1, due to the current limiting effect of resistance R1, the impact current can be controlled, when the back-end capacitor voltage Vo is charged to close to input voltage Vin, close switch K1, and voltage slow start slow charging is completed. Figure 1
[0004] But since the slow start slow charging current limiting is through the current limiting resistance R1, the slow start current is (Vin-Vo) / R1. In the slow start initial stage, since the voltage difference is large, the slow start current is also large, when the capacitor is slowly started to a certain voltage, the voltage difference becomes small, and the slow start slow charging current is also small, and the slow start speed is greatly limited. To solve the slow start speed problem, the resistance R1 value can be reduced. The resistance R1 value is small, which can speed up the slow start speed, but the impact current is large. Therefore, how to stably control the charging current during the slow start process becomes a key problem to be solved. UTILITY MODEL CONTENTS
[0005] Therefore, the utility model provides a capacitor's slow start slow charging circuit to solve the problem of unstable control of the slow start slow charging circuit.
[0006] The utility model provides a capacitor's slow start slow charging circuit, the slow start slow charging circuit includes: first switch module, second switch module, third switch module, current limiting module and capacitor group, wherein,
[0007] The control end of first switch module is connected with the positive pole of input power supply, the first end of capacitor group and the first end of second switch module respectively, the first end of first switch module is connected with the first end of current limiting module, the control end of second switch module respectively, the second end of first switch module is connected with the second end of capacitor group, the second end of third switch module respectively,
[0008] The control end of third switch module receives external driving voltage, the first end of third switch module, the second end of second switch module and the second end of current limiting module are connected with the negative pole of input power supply.
[0009] The slow start and slow charging circuit of the capacitor has the advantages that the first switch module is controlled by the second switch module, the first switch module is in a balanced linear working state, constant current is supplied to the rear-end capacitor for charging, the slow start and slow charging current and the slow start and slow charging time are accurately controlled, and the problem of unstable slow start and slow charging is solved.
[0010] In an alternative embodiment, the first switch module comprises a first resistor and a first transistor, wherein,
[0011] The first end of the first resistor is connected with the positive pole of the input power supply and the first end of the capacitor group respectively, the second end of the first resistor is connected with the control end of the first transistor and the first end of the second switch module respectively, the first end of the first transistor is connected with the first end of the current limiting module and the control end of the second switch module respectively, and the second end of the first transistor is connected with the second end of the capacitor group and the second end of the third switch module respectively.
[0012] In an alternative embodiment, the slow start and slow charging circuit further comprises a voltage stabilizing module, the first end of the voltage stabilizing module is connected with the control end of the first switch module, and the second end of the voltage stabilizing module is connected with the negative pole of the input power supply.
[0013] In an alternative embodiment, the current limiting module comprises a second resistor.
[0014] In an alternative embodiment, the first transistor is a MOS transistor.
[0015] In an alternative embodiment, the second switch module comprises a second transistor.
[0016] In an alternative embodiment, the second transistor is a triode.
[0017] In an alternative embodiment, the third switch module comprises a third transistor.
[0018] In an alternative embodiment, the third transistor is a MOS transistor.
[0019] In an alternative embodiment, the voltage stabilizing module comprises a voltage stabilizing diode, the negative pole of the voltage stabilizing diode is connected with the second end of the first resistor and the control end of the first transistor respectively, and the positive pole of the voltage stabilizing diode is connected with the negative pole of the input power supply. BRIEF DESCRIPTION OF DRAWINGS
[0020] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.
[0021] Figure 1 is the existing slow start slow charging circuit diagram;
[0022] Figure 2 is the principle block diagram of the slow start slow charging circuit of the capacitor according to the embodiments of the present application;
[0023] Figure 3 is the slow start slow charging circuit diagram of the capacitor according to the embodiments of the present application;
[0024] Figure 4 is the principle block diagram of the slow start slow charging circuit of the capacitor according to the embodiments of the present application. Specific embodiments
[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0026] In the description of the present application, it should be noted that the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.
[0027] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements, or it can be wireless connection or wired connection. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0028] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict.
[0029] Referring toFigure 1 Since the slow rise and slow charge current limiting is achieved by the current limiting resistor R1, the slow rise current is (Vin-Vo) / R1. In the slow rise initial stage, the slow rise current is large due to large pressure difference. After the capacitor is charged to a certain voltage, the pressure difference becomes small, and the slow rise and slow charge current is also small, so the slow rise speed is greatly limited. If the resistance value of the resistor R1 is small, the slow rise speed can be accelerated, but the impact current is large. If the resistance value of the resistor R1 is large, the impact current can be greatly improved, but the slow rise and slow charge speed is greatly limited, and if there is other load at the rear end, the slow rise voltage will not be sufficient, and a large impact current will be generated when the K1 switch is closed.
[0030] Therefore, the utility model provides a kind of slow rise and slow charge circuit of capacitor, by the mutual restriction of first switch module and second switch module, slow rise and slow charge circuit can constant current charge rear end capacitor.As shown in Figure 2 The slow rise and slow charge circuit of capacitor includes: first switch module, second switch module, third switch module, current limiting module and capacitor group. The control end of the first switch module is connected with the positive pole of input power supply, the first end of capacitor group and the first end of second switch module respectively, the first end of the first switch module is connected with the first end of current limiting module and the control end of second switch module respectively, and the second end of the first switch module is connected with the second end of capacitor group and the second end of third switch module respectively. The control end of the third switch module receives external driving voltage, and the first end of the third switch module, the second end of the second switch module and the second end of current limiting module are connected with the negative pole of input power supply.
[0031] Specifically, the positive pole of input power supply charges the control end of the first switch module until the control end driving level is reached, and the first switch module is turned on. The slow rise and slow charge circuit charges the capacitor through the loop formed by input power supply→capacitor→first switch module→current limiting module. In this process, a current limiting voltage is generated across the current limiting module when the current is turned on, and when the current limiting voltage reaches the turn-on threshold of the second switch module, the second switch module is closed, thereby pulling down the control end driving level of the first switch module, so that the first switch module enters a balanced linear region working state, and the slow rise and slow charge current is constant at a certain value.
[0032] The utility model provides a kind of slow start slow charging circuit of capacitor, comprising: first switch module, second switch module, third switch module, current limiting module and capacitor group, wherein the control end of first switch module is connected with the anode of input power supply, the first end of capacitor group and the first end of second switch module respectively, the first end of first switch module is connected with the first end of current limiting module, the control end of second switch module respectively, the second end of first switch module is connected with the second end of capacitor group, the second end of third switch module respectively;The control end of third switch module receives external driving voltage, the first end of third switch module, the second end of second switch module, the second end of current limiting module are connected with the cathode of input power supply.
[0033] In an alternative embodiment, as shown in Figure 3 The first switch module includes a first resistor R3 and a first transistor Q2. Wherein, the first end of the first resistor R3 is connected with the anode of input power supply and the first end of capacitor group respectively, the second end of the first resistor R3 is connected with the control end of the first transistor Q2 and the first end of the second switch module respectively, the first end of the first transistor Q2 is connected with the first end of the current limiting module and the control end of the second switch module respectively, the second end of the first transistor Q2 is connected with the second end of the capacitor group and the second end of the third switch module respectively.
[0034] Specifically, referring to Figure 3 The input voltage Vin in the figure is the input power supply. The capacitor group includes capacitor C1, capacitor C2, capacitor C3 and capacitor C4, wherein the capacitor C1, capacitor C2, capacitor C3 and capacitor C4 are connected in parallel. When the input voltage Vin is connected, the positive electrode of the power supply charges the gate of the first transistor Q2 through the first resistor R3 until the gate drive level is reached, and the first transistor Q2 is turned on. The slow start slow charging circuit charges the capacitor through the loop composed of input voltage Vin→capacitor→first transistor Q2→current limiting module. In the embodiment of the utility model, the first transistor Q2 is a MOS tube.
[0035] In an alternative embodiment, as shown in Figure 3 The current limiting module includes a second resistor R2.
[0036] Specifically, after the slow start slow charging circuit is turned on, the capacitor is charged through the loop of input voltage Vin-capacitor-first transistor Q2-second resistor R2. In this process, the conduction current generates a current-limiting voltage across the second resistor R2, and when the second resistor R2 reaches the turn-on threshold of the second switch module, the second switch module is closed, thereby pulling down the gate drive level of the first transistor Q2, so that the first transistor Q2 enters a balanced linear region working state, so that the slow start slow charging current is constant at a certain value I limit , and the specific current limiting value I limit is equal to the turn-on threshold voltage Vth_Q3 / R2 of Q3. The second switch module includes a second transistor Q3. The second transistor Q3 is a triode.
[0037] In an alternative embodiment, as shown in Figure 3 , the third switch module includes a third transistor Q1.
[0038] Specifically, when the voltage across the capacitor is charged to near the input voltage Vin, the third transistor Q1 is closed, and the voltage slow start slow charging is completed. The drive voltage of the third transistor Q1 comes from an external control device. The third transistor Q1 is a MOS transistor.
[0039] In an alternative embodiment, as shown in Figure 4 , the slow start slow charging circuit further includes a voltage stabilizing module, the first end of the voltage stabilizing module is connected with the control end of the first switch module, and the second end of the voltage stabilizing module is connected with the negative electrode of the input power supply.
[0040] Specifically, as shown in Figure 3 , the voltage stabilizing module includes a voltage stabilizing diode D1, the negative electrode of the voltage stabilizing diode D1 is connected with the second end of the first resistor R3 and the control end of the first transistor Q2 respectively, and the positive electrode of the voltage stabilizing diode D1 is connected with the negative electrode of the input power supply. By setting the voltage stabilizing diode D1, the voltage across the second resistor R2 is stabilized.
[0041] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.
Claims
1. A slow-start, slow-charge circuit for a capacitor, characterized in that, The soft-start and soft-charge circuit includes: a first switch module, a second switch module, a third switch module, a current limiting module, and a capacitor bank, wherein, The control terminal of the first switch module is connected to the positive terminal of the input power supply, the first terminal of the capacitor bank, and the first terminal of the second switch module. The first terminal of the first switch module is connected to the first terminal of the current limiting module and the control terminal of the second switch module. The second terminal of the first switch module is connected to the second terminal of the capacitor bank and the second terminal of the third switch module. The control terminal of the third switch module receives an external driving voltage, and the first terminal of the third switch module, the second terminal of the second switch module, and the second terminal of the current limiting module are all connected to the negative terminal of the input power supply.
2. The capacitor slow-start slow-charge circuit according to claim 1, characterized in that, The first switching module includes a first resistor and a first transistor, wherein, The first end of the first resistor is connected to the positive terminal of the input power supply and the first end of the capacitor bank, respectively. The second end of the first resistor is connected to the control terminal of the first transistor and the first end of the second switching module, respectively. The first end of the first transistor is connected to the first end of the current limiting module and the control terminal of the second switching module, respectively. The second end of the first transistor is connected to the second end of the capacitor bank and the second end of the third switching module, respectively.
3. The capacitor slow-start slow-charge circuit according to claim 2, characterized in that, The slow-start and slow-charge circuit further includes a voltage regulator module, the first end of which is connected to the control terminal of the first switching module, and the second end of which is connected to the negative terminal of the input power supply.
4. The capacitor slow-start slow-charge circuit according to claim 1, characterized in that, The current limiting module includes a second resistor.
5. The capacitor slow-start slow-charge circuit according to claim 2, characterized in that, The first transistor is a MOS transistor.
6. The capacitor slow-start slow-charge circuit according to claim 1, characterized in that, The second switching module includes a second transistor.
7. The capacitor slow-start slow-charge circuit according to claim 6, characterized in that, The second transistor is a bipolar transistor.
8. The capacitor slow-start slow-charge circuit according to claim 1, characterized in that, The third switching module includes a third transistor.
9. The capacitor slow-start slow-charge circuit according to claim 8, characterized in that, The third transistor is a MOS transistor.
10. The capacitor slow-start slow-charge circuit according to claim 3, characterized in that, The voltage regulator module includes a Zener diode, the negative terminal of which is connected to the second terminal of the first resistor and the control terminal of the first transistor, and the positive terminal of which is connected to the negative terminal of the input power supply.