A high-efficiency capacitor charging peak current limiting circuit

Abstract

This application relates to a high-efficiency capacitor charging peak current limiting circuit, comprising: a main controller, a sensing resistor, a first comparator, a second comparator, a MOSFET switch, and a load module. In implementation, the first comparator compares the voltage across the sensing resistor in real time to obtain the current change; the second comparator compares the reference voltage provided by the main controller with the output of the first comparator, and quickly drives the gate of the MOSFET switch according to the result, causing the MOSFET to turn off when the current exceeds a threshold and turn on when the current is below the threshold. Through the division of labor and cooperation between the first and second comparators, the circuit can achieve rapid detection and effective limitation of the capacitor charging peak current, avoiding the impact of instantaneous large current on the devices, while reducing heat loss in the resistor and switching devices, thereby improving the reliability and efficiency of the entire circuit.

Description

Technical Field

[0001] This application relates to the field of circuit control technology, and in particular to a high-efficiency capacitor charging peak current limiting circuit. Background Technology

[0002] With the increasing power and integration of electronic devices, capacitors are widely used in various circuits as energy storage and filtering components. During the initial charging phase, capacitors experience a large instantaneous current, known as the peak current. If this peak current is too large, it can not only cause a transient drop in the circuit's power supply voltage but also potentially pull the battery out of balance, thus affecting other sensitive components and reducing the overall stability and reliability of the device. Therefore, effectively limiting the peak current is a crucial problem to be solved in capacitor charging technology.

[0003] In existing technologies, common current-limiting methods include connecting a current-limiting resistor in series in the capacitor charging circuit or using a simple constant current source structure. While these methods can suppress peak currents to some extent, they generally suffer from drawbacks such as slow response speed, high energy loss, and severe heat generation, making them unsuitable for high-current, high-power devices. For example, large detectors are typically battery-powered. If excessive transient current occurs during capacitor charging, it will not only increase charging losses but also shorten battery life and may even affect the normal operation of the detector.

[0004] Therefore, there is an urgent need to provide a new type of capacitor charging peak current limiting circuit that can meet the current control requirements of large detectors during capacitor charging, effectively limit peak current while reducing heat loss during charging, thereby improving the overall safety and efficiency of the circuit. Utility Model Content

[0005] To at least partially overcome the problem of excessive peak current during capacitor charging of large detectors leading to power supply voltage deviation and increased heat loss, thus affecting the overall stability of the device, this application provides an efficient capacitor charging peak current limiting circuit.

[0006] The proposed solution is as follows:

[0007] A high-efficiency capacitor charging peak current limiting circuit includes:

[0008] Main controller, sensing resistor, first comparator, second comparator, MOSFET switch and load module;

[0009] The first end of the detection resistor is connected to the power supply, and the second end is connected to the drain of the MOSFET switch.

[0010] The positive input terminal of the first comparator is connected to the first terminal of the detection resistor, and the negative input terminal of the first comparator is connected to the second terminal of the detection resistor;

[0011] The positive input of the second comparator is connected to the main controller, and the negative input of the second comparator is connected to the output of the first comparator.

[0012] The gate of the MOSFET switch is connected to the output of the second comparator, and the source of the MOSFET switch is connected to the load module.

[0013] The first comparator is used to compare the voltage across the detection resistor, and the second comparator is used to compare the output voltage of the main controller with the output result of the first comparator and drive the MOSFET switch.

[0014] Preferably, the source of the MOSFET switch is grounded after being connected to the load module.

[0015] Preferably, the main controller is used to provide an adjustable reference voltage.

[0016] Preferably, the load module is a capacitor charging module.

[0017] Preferably, the detection resistor is a low-temperature drift sampling resistor.

[0018] Preferably, the first comparator and the second comparator are high-speed operational amplifier comparators.

[0019] Preferably, the MOSFET switch is a fast low internal resistance MOSFET.

[0020] The technical solution provided in this application may include the following beneficial effects:

[0021] The first comparator compares the voltage across the sensing resistor in real time to obtain the current change. The second comparator compares the reference voltage provided by the main controller with the output of the first comparator and quickly drives the gate of the MOSFET switch based on the result. This causes the MOSFET to turn off when the current exceeds the threshold and turn on when the current is below the threshold. Through the division of labor and cooperation between the first and second comparators, the circuit can quickly detect and effectively limit the peak current of capacitor charging, avoiding the impact of instantaneous large current on the devices, while reducing heat loss in the resistor and switching devices, thereby improving the reliability and efficiency of the entire circuit.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0024] Figure 1 This is a schematic diagram of a high-efficiency capacitor charging peak current limiting circuit provided in one embodiment of this application.

[0025] Figure reference numerals: Main controller - MCU; Sensing resistor - RS; First comparator - U1; Second comparator - U2; MOSFET switch - U3; Load module - ESC. Detailed Implementation

[0026] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0027] Figure 1 This is a schematic diagram of a high-efficiency capacitor charging peak current limiting circuit according to an embodiment of this application, referring to... Figure 1 A high-efficiency capacitor charging peak current limiting circuit includes:

[0028] The main controller MCU, sensing resistor RS, first comparator U1, second comparator U2, MOSFET switch U3, and load module ESC;

[0029] The first end of the sensing resistor RS is connected to the power supply, and the second end is connected to the drain of the MOSFET switch U3;

[0030] The positive input terminal of the first comparator U1 is connected to the first terminal of the sensing resistor RS, and the negative input terminal of the first comparator U1 is connected to the second terminal of the sensing resistor RS.

[0031] The positive input of the second comparator U2 is connected to the main controller MCU, and the negative input of the second comparator U2 is connected to the output of the first comparator U1.

[0032] The gate of MOSFET switch U3 is connected to the output of the second comparator U2, and the source of MOSFET switch U3 is connected to the load module ESC.

[0033] The first comparator U1 is used to compare the voltage across the detection resistor RS, and the second comparator U2 is used to compare the output voltage of the main controller MCU with the output result of the first comparator U1 and drive the MOSFET switch U3.

[0034] It should be noted that the source of MOSFET switch U3 is grounded after being connected to the load module ESC.

[0035] The source of MOSFET switch U3 is connected not only to the input terminal of the load module ESC, but also to the circuit ground after the load module ESC. This connection method creates a complete current loop for the load module ESC during charging: power supply—sensing resistor RS—MOSFET switch U3—load module ESC—ground. This structure ensures a stable current path, allowing current to flow smoothly through the load module ESC to charge the capacitor when MOSFET switch U3 is on, and cutting off the current loop when MOSFET switch U3 is off, thus effectively controlling the peak charging current of the capacitor.

[0036] It should be noted that the main controller MCU is used to provide an adjustable reference voltage.

[0037] The main controller MCU can output an adjustable reference voltage signal, which is input to the positive input of the second comparator U2. By adjusting the reference voltage, the current threshold during capacitor charging can be flexibly set, allowing the second comparator U2 to operate under different current limiting conditions. When the actual current exceeds the threshold, the second comparator U2 outputs a control signal to turn off the MOSFET, thereby effectively achieving peak current control under different operating conditions. This structure enables the circuit to adapt to the power requirements of large detectors in different operating modes, improving the controllability and adaptability of the circuit.

[0038] It should be noted that the load module ESC is a capacitor charging module.

[0039] When the MOSFET switch U3 is turned on, current is allowed to flow through the sensing resistor RS into the capacitor charging module, and the capacitor begins to charge. When the MOSFET is turned off, the current path is interrupted, and the capacitor stops charging. By setting this current-limiting structure in the capacitor charging circuit, excessive transient current can be avoided during the initial charging of the capacitor, ensuring the stable operation of the detector power supply circuit, and extending the service life of the capacitor and the power supply battery.

[0040] It should be noted that the sensing resistor RS is a low-temperature drift sampling resistor.

[0041] The sensing resistor RS is a low-temperature drift sampling resistor, whose resistance remains stable despite temperature changes. Because large detectors easily generate heat during prolonged operation or high-power charging, ordinary resistors will experience resistance drift due to temperature variations, introducing current detection errors. This embodiment, by employing a low-temperature drift sampling resistor, reduces the impact of temperature on sampling accuracy, ensuring a more accurate and reliable current detection signal acquired by the comparator module, thereby improving the stability and control accuracy of the entire current limiting circuit.

[0042] It should be noted that the first comparator U1 and the second comparator U2 are high-speed operational amplifier comparators.

[0043] Both the first comparator U1 and the second comparator U2 employ high-speed operational amplifiers (op-amps). Compared to ordinary comparators, high-speed op-amps have the advantages of short response time and fast switching speed, enabling them to output control signals promptly when the capacitor charging current surges. Through this design, the MOSFET switch U3 can quickly switch between on and off, ensuring the real-time performance of the current limiting control and preventing peak current lag from impacting the circuit and power supply.

[0044] It should be noted that the MOSFET switch U3 is a fast low internal resistance MOSFET.

[0045] MOSFET switch U3 is a fast-acting, low-resistance MOSFET. Low-resistance MOSFETs have extremely low on-resistance when turned on, significantly reducing power loss in the current path and heat generation during charging. Simultaneously, their fast switching speed facilitates rapid response to the comparator's output control signal. Using this type of MOSFET further improves the efficiency and reliability of the capacitor charging circuit, making it particularly suitable for applications such as large-scale detectors that have high requirements for power efficiency and safety.

[0046] In implementation, the first comparator U1 compares the voltage across the sensing resistor RS in real time to obtain the current change. The second comparator U2 compares the reference voltage provided by the main controller MCU with the output of the first comparator U1, and quickly drives the gate of the MOSFET switch U3 according to the result, so that the MOSFET turns off when the current exceeds the threshold and turns on when the current is below the threshold. Through the division of labor and cooperation between the first comparator U1 and the second comparator U2, the circuit can quickly detect and effectively limit the peak current of capacitor charging, avoid the impact of instantaneous large current on the device, and reduce the heat loss of energy in the resistor and switching device, thereby improving the reliability and efficiency of the entire circuit.

[0047] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0048] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means at least two.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A high-efficiency capacitor charging peak current limiting circuit, characterized in that, include: Main controller, sensing resistor, first comparator, second comparator, MOSFET switch and load module; The first end of the detection resistor is connected to the power supply, and the second end is connected to the drain of the MOSFET switch. The positive input terminal of the first comparator is connected to the first terminal of the detection resistor, and the negative input terminal of the first comparator is connected to the second terminal of the detection resistor; The positive input of the second comparator is connected to the main controller, and the negative input of the second comparator is connected to the output of the first comparator. The gate of the MOSFET switch is connected to the output of the second comparator, and the source of the MOSFET switch is connected to the load module. The first comparator is used to compare the voltage across the detection resistor, and the second comparator is used to compare the output voltage of the main controller with the output result of the first comparator and drive the MOSFET switch.

2. The high-efficiency capacitor charging peak current limiting circuit according to claim 1, characterized in that, The source of the MOSFET switch is grounded after being connected to the load module.

3. The high-efficiency capacitor charging peak current limiting circuit according to claim 1, characterized in that, The main controller is used to provide an adjustable reference voltage.

4. The high-efficiency capacitor charging peak current limiting circuit according to claim 1, characterized in that, The load module is a capacitor charging module.

5. The high-efficiency capacitor charging peak current limiting circuit according to claim 1, characterized in that, The detection resistor is a low-temperature drift sampling resistor.

6. The high-efficiency capacitor charging peak current limiting circuit according to claim 1, characterized in that, The first comparator and the second comparator are high-speed operational amplifier comparators.

7. The high-efficiency capacitor charging peak current limiting circuit according to claim 1, characterized in that, The MOSFET switch is a fast low internal resistance MOSFET.

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