Power supply power-on transient current control circuit

Abstract

The utility model relates to a power supply power-on transient current control circuit which comprises an MOS tube, a current-limiting resistor, an electrolytic capacitor, a first diode, a first resistor and a first capacitor. The first end of the MOS tube is suitable for being electrically connected to a power supply input end; one end of the current-limiting resistor is electrically connected to the first end of the MOS tube, and the other end of the current-limiting resistor is electrically connected to the second end of the MOS tube; the cathode of the electrolytic capacitor is electrically connected to the other end of the current-limiting resistor, and the anode of the electrolytic capacitor is suitable for being electrically connected to the power output end; the cathode of the first diode is electrically connected to the anode of the electrolytic capacitor; the anode of the first diode is electrically connected to one end of the first resistor; one end of the first resistor is electrically connected to one end of the first capacitor, and the other end of the first resistor is electrically connected to the other end of the first capacitor; one end of the first capacitor is electrically connected to the third end of the MOS tube, and the other end of the first capacitor is electrically connected to the first end of the MOS tube. The connection mode is simple, the instantaneous power-on current is effectively reduced, and the instantaneous power-on safety of the whole power supply system is improved.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a power supply power-on transient current control circuit. Background Art

[0002] In critical devices and system chassis boards with high power requirements, the power supply will stably provide power to the entire system under ideal conditions. However, in real-world applications, the system faces challenges during power-up due to the complexity of system design and various factors, particularly the presence of capacitive loads such as energy storage capacitors.

[0003] First, when the energy storage capacitor is initially powered on, its charging process has not yet been completed. At this point, the capacitor's impedance is very low, approaching a short-circuit state. In this state, the capacitor acts like a momentary current sink, causing the system to generate a transient surge current at power-on that is much higher than during normal operation. This transient surge current can not only exceed the rated output capacity of the power supply but also place significant load pressure on the entire power supply system.

[0004] This transient surge current has multiple negative impacts. First, excessive current can cause the power supply's output voltage to become unstable or even exceed its safe range, damaging the power supply equipment. Second, the power supply system can become overloaded due to the transient surge current, resulting in startup anomalies, hiccups (where the system briefly starts and then immediately stops), or even complete failure. Furthermore, excessive current can damage other sensitive electronic components in the system, affecting overall system performance and reliability. Utility Model Content

[0005] In view of this, the present application proposes a power supply power-on transient current control circuit to solve the above problems.

[0006] According to one aspect of the present application, a power supply power-on transient current control circuit is provided, comprising: a MOS tube, a current limiting resistor, an electrolytic capacitor and a first capacitor;

[0007] The first end of the MOS tube is suitable for being electrically connected to the power input end;

[0008] One end of the current limiting resistor is electrically connected to the first end of the MOS transistor, and the other end of the current limiting resistor is electrically connected to the second end of the MOS transistor, so as to reduce the transient impact current of the power supply system;

[0009] The negative electrode of the electrolytic capacitor is electrically connected to the other end of the current limiting resistor, the positive electrode of the electrolytic capacitor is suitable for being electrically connected to the power output end, and both ends of the electrolytic capacitor are suitable for being electrically connected to the load;

[0010] One end of the first capacitor is electrically connected to the positive electrode of the electrolytic capacitor, one end of the first capacitor is electrically connected to the third end of the MOS tube, and the other end of the first capacitor is electrically connected to the first end of the MOS tube to control the opening of the MOS tube.

[0011] In a possible implementation, the device further includes: a first diode, wherein a cathode of the first diode is electrically connected to a positive electrode of the electrolytic capacitor, and a positive electrode of the first diode is electrically connected to one end of the first capacitor.

[0012] In a possible implementation, the device further includes: a first resistor, one end of the first resistor being electrically connected to one end of the first capacitor, and the other end of the first resistor being electrically connected to the other end of the first capacitor.

[0013] In a possible implementation, the MOS transistor is an N-channel MOS field-effect transistor, the gate of the MOS transistor is electrically connected to one end of the first capacitor, the source of the MOS transistor is electrically connected to the other end of the first capacitor, and the drain of the MOS transistor is electrically connected to one end of the electrolytic capacitor.

[0014] In a possible implementation, the device further includes: a second capacitor, one end of the second capacitor is electrically connected to one end of the electrolytic capacitor, and the other end of the second capacitor is electrically connected to the other end of the electrolytic capacitor.

[0015] In a possible implementation, the capacitance of the second capacitor is 0.1 uF.

[0016] In a possible implementation, the model of the MOS tube is FQB34N20.

[0017] In a possible implementation, the resistance of the current-limiting resistor is 10Ω, the capacitance of the electrolytic capacitor is 330 uF, and the capacitance of the first capacitor is 0.1 uF.

[0018] In a possible implementation, the first diode is a voltage stabilizing diode, and a voltage stabilizing parameter of the first diode is 6.2V.

[0019] In a possible implementation, the resistance of the first resistor is 100K.

[0020] Beneficial effects of this application:

[0021] The power-on transient current control circuit proposed in this embodiment has a simple connection method. A current-limiting resistor is electrically connected between the power supply and the load to limit the current of the entire system when it is instantly powered on, preventing the instantaneous power-on current from directly impacting the load, thereby better protecting the entire system. Furthermore, an electrolytic capacitor is electrically connected across the load so that the instantaneous power-on current first enters the electrolytic capacitor for charging, thereby controlling the time it takes for the instantaneous charging current to reach the load. Secondly, the current-limiting resistor is connected in parallel with the MOS tube. When the V gs When the conduction voltage range of the MOS tube is reached, the current preferably flows into the MOS tube, causing the current limiting resistor to stop working, thereby reducing the power consumption and heat generation of the entire system.

[0022] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the application and, together with the description, serve to explain the principles of the application.

[0024] Figure 1 A circuit diagram of a power supply power-on transient current control circuit according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0025] Various exemplary embodiments, features, and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0026] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application or simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0028] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0029] In addition, numerous specific details are provided in the detailed description below to better illustrate the present application. Those skilled in the art will appreciate that the present application can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0030] like Figure 1 As shown, the power supply power-on transient current control circuit includes: a MOS transistor Q11, a current-limiting resistor R169, an electrolytic capacitor C7, a first resistor R168, and a first capacitor C175. The first end of the MOS transistor Q11 is adapted to be electrically connected to a power supply input terminal; one end of the current-limiting resistor R169 is electrically connected to the first end of the MOS transistor Q11, and the other end of the current-limiting resistor R169 is electrically connected to the second end of the MOS transistor Q11, thereby reducing transient surge current in the power supply system; the negative electrode of the electrolytic capacitor C7 is electrically connected to the other end of the current-limiting resistor R169, the positive electrode of the electrolytic capacitor C7 is adapted to be electrically connected to the power supply output terminal, and both ends of the electrolytic capacitor C7 are adapted to be electrically connected to a load; one end of the first capacitor C175 is electrically connected to the electrolytic capacitor C7, one end of the first capacitor C175 is electrically connected to the third end of the MOS transistor Q11, and the other end of the first capacitor C175 is electrically connected to the first end of the MOS transistor Q11, thereby controlling the turning on of the MOS transistor Q11.

[0031] The power-on transient current control circuit proposed in this embodiment has a simple connection method. A current-limiting resistor R169 is electrically connected between the power supply and the load to limit the current of the entire system when it is instantly powered on, preventing the transient power-on current from directly impacting the load, thereby better protecting the entire system. Furthermore, an electrolytic capacitor C7 is electrically connected across the load so that the instantaneous power-on current first enters the electrolytic capacitor C7 for charging, thereby controlling the time it takes for the transient charging current to reach the load. Secondly, the current-limiting resistor R169 is connected in parallel with the MOS tube Q11. When the V gs， That is, when the voltage between the source and gate of the MOS tube reaches the conduction voltage range of the MOS tube Q11, current flows into the MOS tube Q11, causing the current limiting resistor R169 to stop working, thereby reducing the power consumption and heat generation of the entire system.

[0032] In one specific embodiment, the first diode D34 is further included. The cathode of the first diode D34 is electrically connected to the anode of the electrolytic capacitor C7. The anode of the first diode D34 is electrically connected to one end of the first resistor R168. It should be noted that the first diode D34 is electrically connected between the electrolytic capacitor C7 and the first resistor R168 to better protect the entire power supply system. When the conduction voltage of the diode is reached, the first capacitor C175 is charged again to control the V gs , so that the running time of the entire system can be controlled.

[0033] Furthermore, in one specific embodiment, one end of the first resistor R168 is electrically connected to one end of the first capacitor C175, and the other end of the first resistor R168 is electrically connected to the other end of the first capacitor C175. Here, it should be noted that the first resistor R168 is connected in parallel across the first capacitor C175. When the first diode D34 is turned on and the first capacitor C175 is charged, and the rated voltage of the first resistor R168 limits the charge amount of the first capacitor C175, the V of the MOS tube Q11 is indirectly controlled. gs .

[0034] In one specific embodiment, the MOS transistor Q11 is an N-channel MOS field-effect transistor. The gate of the MOS transistor Q11 is electrically connected to one end of the first capacitor C175, the source of the MOS transistor Q11 is electrically connected to the other end of the first capacitor C175, and the drain of the MOS transistor Q11 is electrically connected to one end of the electrolytic capacitor C7. It should be noted that an insulating material is provided between the source and drain of the MOS transistor Q11. The MOS transistor Q11 turns on and begins operation only when the Vgs voltage of the MOS transistor Q11 reaches a predetermined range.

[0035] In one specific embodiment, the device further includes a second capacitor, one end of which is electrically connected to one end of the electrolytic capacitor C7, and the other end of which is electrically connected to the other end of the electrolytic capacitor C7, to further filter the instantaneous power-on current, thereby making the current delivered to the load cleaner.

[0036] In one specific embodiment, the capacitance of the second capacitor is 0.1 uF.

[0037] In one specific embodiment, the model of the MOS transistor Q11 is FQB34N20.

[0038] In one specific embodiment, the resistance of the current limiting resistor R169 is 10Ω.

[0039] In one specific embodiment, the capacitance of the electrolytic capacitor C7 is 330uF.

[0040] In one specific embodiment, the first diode D34 is a voltage stabilizing diode, and the voltage stabilizing parameter of the first diode D34 is 6.2V. It should be noted that the voltage stabilizing diode can be

[0041] In one specific embodiment, the capacitance of the first capacitor C175 is 0.1 uF.

[0042] In one specific embodiment, the resistance of the first resistor R168 is 100K.

[0043] In summary, it should be noted that when the power supply voltage of the power board is 110VDC, the average current of the setting operation is I p When the power is first turned on, the power supply card supplies 110V voltage. After the current is limited by the current limiting resistor R169, the electrolytic capacitor C7 is charged to slow down the charging speed of the electrolytic capacitor C7. Among them, the transient surge current within the control time of limiting the transient surge current of power on is I=U / R+I p =110V / 10ohm+I p =11A+I p It should be noted that U is the supply voltage of the power supply card, and R is the resistance of the current-limiting resistor. Therefore, the larger the resistance of the current-limiting resistor R169, the further the transient inrush current can be reduced, thereby reducing the transient power-up current of the system.

[0044] Secondly, when the value of electrolytic capacitor C7 is 330uF, the theoretical charging time is t=5*RC. It should be noted here that R refers to the resistance of the current limiting resistor in series with the electrolytic capacitor. C refers to the capacity of the electrolytic capacitor. After substituting the actual value, the theoretical charging time of electrolytic capacitor C7 is calculated as t=5*10ohm*330uF=16.5ms. t is used to describe the time required for the capacitor voltage to reach 63.2% of its final value (here is the voltage of the charging power supply). In practical applications, in order to ensure that the capacitor is fully charged and reaches a stable voltage value, a time constant of 5 times (i.e. 5*RC) is usually selected to ensure that the capacitor voltage reaches most of its final value (close to 100%), thereby meeting the needs of most applications.

[0045] In addition, in order to further control the instantaneous power-on time of this power supply system, an additional RC control unit can be set; wherein the RC control unit includes: a resistor group and a capacitor group, and the resistor group is arranged between the first diode D34 and the electrolytic capacitor C7. The resistor group includes: a resistor R165 and a resistor R167, and the resistor R165 and the resistor R167 are arranged in series. Further, the capacitor group includes: a capacitor C173 and a capacitor C174, and the capacitor C173 and the capacitor C174 are arranged in parallel, and one end of the capacitor C173 is electrically connected to the negative electrode of the first diode D34, and the other end is electrically connected to the other end of the first capacitor C175. And the voltage of the capacitor C173 and the capacitor C174 is the same. When the 110V power supply voltage is divided and limited by the resistor R165 and the resistor R167, the first capacitor C175 is charged through the voltage regulator diode D34 (the voltage regulator value is 6.2V). Since the turn-on parameter of the N-MOS field effect transistor Q11 is 3V <V gs <5V, when the voltage across the first capacitor C175 reaches 5V, the N-MOS field effect transistor Q11 is turned on; at the same time, since the Zener diode parameter of the first diode D34 is 6.2V, when the voltage across the capacitor C175 reaches 5V, the sum of the voltages is 5V+6.2V=11.2V;

[0046] It can be seen that after the electrolytic capacitor C7 is charged, the 110V supply voltage is limited by the resistor R165 and the resistor R167, and then the capacitor C173 and the capacitor C174 (selected as 4.7uF) are charged. When the capacitors C173 and C174 are charged to 11.2V, the first diode D34 reaches the breakdown voltage, and the first capacitor C175 starts charging. Among them, the voltage V across the capacitors C173 and C174 is t Satisfying the formula, V t =V u *[1–exp(-t / RC)]. V t is the voltage across capacitor C173 and capacitor C174, and V t V changes with time t. u is the final charging voltage of capacitors C173 and C174, that is, the voltage across them when the capacitors are fully charged. t is the time elapsed from the start of charging to a certain moment. RC is the circuit's time constant.

[0047] In ideal conditions, when V u =110V, it can be calculated that when V t =11.2V, the charging time of capacitor C173 and capacitor C174 is t, and V u =110V, V t=11.2V into the calculation formula, we can solve for the charging time t = 0.1074 * RC. It should be noted that since the electrolytic capacitor C7 is fully charged, it is equivalent to a power supply. Therefore, under ideal conditions, the sum of the voltages of the resistor group and the capacitor group can be considered to be 110V. It should be noted here that R is the sum of the resistance of the resistor group, and C is the sum of the capacitance of the capacitor group. Therefore, substituting R = 47kohm * 2 and C = 4.7uF * 2 into the calculation formula, we can solve for the time it takes for capacitors C173 and C174 to charge to 11.2V t = 0.1074 * RC = 0.1074 * 883.6ms = 94.9ms. It should be noted that since capacitor C173 is connected in parallel with diode D33, the voltage of capacitor C173 is 11.2 at this time, and the voltage regulation parameter of diode D33 is 18V, which does not exceed the rated voltage of diode D33. Therefore, capacitor C175 has not started charging at this time.

[0048] When the 110V supply voltage is limited by the resistor R165 and the resistor R167, the first capacitor C175 is charged through the first diode D34. Since the voltage regulation parameter of the diode D33 is 18V and the voltage regulation parameter of the diode D34 is 6.2V, the voltage across the first capacitor C175 is 18V-6.2V=11.8V after it is fully charged. The voltage Vt across the first capacitor C175 satisfies the formula, V t =V u *[1–exp(-t / RC)], ideally, at V u =11.8V, it is necessary to calculate when V t =3V charging time t, V u =11.8V, V t =3V into the calculation formula, we can solve for the charging time t = 0.293 * RC. Here, R is the resistance of the resistor group, and C is the capacitance of the first capacitor C175. Substituting R = 47kohm * 2 and C = 0.1uF into the calculation formula, we can solve for the charging time t = 0.293 * RC = 0.293 * 9.4ms = 2.75ms when the voltage across the first capacitor C175 is 3V. Therefore, in the above design analysis, the control time for limiting the power-on transient surge current is: 16.5ms + 94.9ms + 2.75ms = 114.15ms. Subsequently, when the first capacitor C175 is charged to above 3V, MOS transistor Q11 is fully turned on, bypassing the current-limiting resistor R169 and completing the system power-on control.

[0049] It should be noted that although the power supply power-on transient current control circuit is described above using this application as an example, those skilled in the art will understand that this application should not be limited to this. In fact, users can flexibly set parameters based on personal preferences and / or actual application scenarios, as long as they are reasonable.

[0050] The embodiments of the present application have been described above. The above description is illustrative and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A power supply transient current control circuit, characterized in that: include: MOS tube, current limiting resistor, electrolytic capacitor and first capacitor; The first end of the MOS tube is suitable for being electrically connected to the input end of the power supply; One end of the current limiting resistor is electrically connected to the first end of the MOS transistor, and the other end of the current limiting resistor is electrically connected to the second end of the MOS transistor, so as to reduce the transient impact current of the power supply system; The negative electrode of the electrolytic capacitor is electrically connected to the other end of the current limiting resistor, the positive electrode of the electrolytic capacitor is suitable for being electrically connected to the output end of the power supply, and both ends of the electrolytic capacitor are suitable for being electrically connected to a load; One end of the first capacitor is electrically connected to the positive electrode of the electrolytic capacitor, and one end of the first capacitor is electrically connected to the third end of the MOS tube, and the other end of the first capacitor is electrically connected to the first end of the MOS tube to control the opening of the MOS tube.

2. The power supply power-on transient current control circuit according to claim 1, characterized in that: Also includes: A first diode, wherein a cathode of the first diode is electrically connected to the anode of the electrolytic capacitor, and an anode of the first diode is electrically connected to one end of the first capacitor.

3. The power supply power-on transient current control circuit according to claim 2, characterized in that: Also includes: a first resistor, one end of the first resistor being electrically connected to one end of the first capacitor, and the other end of the first resistor being electrically connected to the other end of the first capacitor.

4. The power supply power-on transient current control circuit according to claim 1, characterized in that: The MOS transistor is an N-channel MOS field effect transistor, the gate of the MOS transistor is electrically connected to one end of the first capacitor, the source of the MOS transistor is electrically connected to the other end of the first capacitor, and the drain of the MOS transistor is electrically connected to one end of the electrolytic capacitor.

5. The power supply power-on transient current control circuit according to claim 3, characterized in that: Also includes: A second capacitor, one end of the second capacitor is electrically connected to one end of the electrolytic capacitor, and the other end of the second capacitor is electrically connected to the other end of the electrolytic capacitor.

6. The power supply power-on transient current control circuit according to claim 5, characterized in that: The capacitance of the second capacitor is 0.1 uF.

7. The power supply power-on transient current control circuit according to any one of claims 1 to 6, characterized in that: The model of the MOS tube is FQB34N20.

8. The power supply power-on transient current control circuit according to any one of claims 1 to 6, characterized in that: The resistance of the current-limiting resistor is 10Ω, the capacitance of the electrolytic capacitor is 330uF; and the capacitance of the first capacitor is 0.1uF.

9. The power supply power-on transient current control circuit according to claim 3, characterized in that: The first diode is a voltage stabilizing diode, and a voltage stabilizing parameter of the first diode is 6.2V.

10. The power supply power-on transient current control circuit according to claim 3, characterized in that: The resistance of the first resistor is 100K.

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