Wide input voltage range surge suppressor

Abstract

A wide input voltage range surge suppressor includes an inductor connected between an alternating current (AC) power input and the load to be protected, and a surge absorption circuit. The surge absorption circuit includes a capacitor, a resistor connected in parallel with the capacitor, and at least one crowbar or clamp element connected in series with the capacitor.

Description

[[Technical Field]]

[0001] The present application claims priority from U.S. Provisional Patent Application No. 63 / 537.038, filed on September 7, 2023, and entitled "Wide Input Voltage Range Surge Suppressor", the entire contents of which are incorporated herein by reference. The present disclosure relates to an imaging environment adjustment apparatus and a computer-readable storage medium. [[Background Art]]

[0002] The present disclosure relates generally to power line surge suppressors, and more specifically to surge suppressors compatible with a wide input voltage range, for example ranging from less than 100 volts to more than 2.5 kilovolts. [[Summary of Invention]] [[Problem to be Solved by Invention]]

[0003] Electrical and electronic loads that receive power from an external power grid are sometimes exposed to high-voltage surges. Such surges are caused by inductive loads, lightning strikes, or other phenomena, and may damage or even destroy electrical and electronic equipment and devices. The highest transient spike voltage has a short duration, which is usually tens of microseconds.

[0004] These high-voltage surges may involve voltages in the range of thousands of volts (e.g., from 1.5 kV to 20 kV) and currents of thousands of amperes. Such high voltages tend to impose excessive loads on electronic devices, components, motors, etc., and cause undesirable dangerous conditions. High voltages and large current flows can cause severe loads that result in permanent damage or destruction.

[0005] To address these issues, isolation transformers for commercial power frequency are sometimes used in DC power supplies. This is to supply energy from an AC power source while isolating the load from the commercial power voltage for surge protection. However, these devices are expensive, large, and heavy. To reduce cost, weight, and size, switching-mode voltage regulators may be used under certain circumstances, but these regulators are not entirely reliable and can be damaged by high-voltage surges.

[0006] Line surge suppressors are sometimes used, but their reliability may be reduced in the event of a lightning strike. In the field of surge protection systems, there is a constant demand for technological advancements to improve performance, reliability, cost, and ease of operation. [Means for solving the problem]

[0007] Below is a simplified overview of the present invention to provide a basic understanding of some embodiments of the invention. This overview is not a comprehensive overview of the invention. Furthermore, this overview is not intended to identify any important elements of the invention or to limit its scope. The purpose of this overview is simply to present some concepts in a simplified form as an introduction to the more detailed description that follows.

[0008] According to one aspect of the present invention, a wide input voltage range surge suppressor includes an inductor connected between an alternating current (AC) power input and a load to be protected, and a surge absorption circuit. The surge absorption circuit includes a capacitor, a resistor connected in parallel with the capacitor, and at least one crowbar element or clamp element connected in series with the capacitor.

[0009] In the wide input voltage range surge suppressor according to the above-described embodiment, the AC power input has a line connection and a neutral wire connection, and the surge absorption circuit is connected either between the line connection and the neutral wire connection, or between the line connection and ground. In the wide input voltage range surge suppressor according to the above-described embodiment, the surge absorption circuit is connected to the upstream side of the inductor.

[0010] In the wide input voltage range surge suppressor according to the above-described embodiment, the inductor is provided with a tap connected to a surge absorption circuit. The wide input voltage range surge protection system described herein relies on a line inductor connected upstream and in series with the load to be protected, and a surge trigger and absorption circuit located upstream of the line inductor. The surge trigger and absorption circuit includes a capacitor, a resistor connected in parallel with the capacitor, and at least one crowbar element or clamp element connected in series with the capacitor. This surge protection system diverts and interrupts most of the surge current so that it does not reach the protected load.

[0011] The aforementioned and other points of this disclosure will become apparent to those skilled in the art by reading the following description with reference to the accompanying drawings. [Brief explanation of the drawing]

[0012] [Figure 1A] This is a block diagram of the entire system of a wide input voltage range surge suppressor according to one embodiment. [Figure 1B] This is a circuit diagram of a wide input voltage range surge suppressor according to one embodiment. [Figure 2] Figure 1B is a circuit diagram of the surge protection circuit portion of the wide input voltage range surge suppressor according to one embodiment. [Figure 3] Figure 1B is a circuit diagram of the surge protection circuit portion of the wide input voltage range surge suppressor according to another embodiment. [Figure 4] Figure 1B is a circuit diagram of another embodiment of the wide input voltage range surge suppressor. [Figure 5] Figure 1B is a circuit diagram of a wide input voltage range surge suppressor according to one embodiment. [Figure 6A-6C]Figure 5 shows a graph of the output voltage deviation in the simulation circuit of the wide input voltage range surge suppressor. [Figures 7A-7B] Figure 5 shows a graph of surge current in the simulation circuit of a wide input voltage range surge suppressor. [Figure 8] Figure 1B shows experimental results based on a simulation circuit of a wide input voltage range surge suppressor. [Figure 9] Figure 1B shows the shunt capacitor voltage based on the simulation circuit of the wide input voltage range surge suppressor. [Figure 10] Figure 3 is a schematic diagram of the surge protection circuit portion of a wide input voltage range surge suppressor, including a monitoring circuit, according to another embodiment.

[0013] In the drawings and detailed description of the invention, unless otherwise specified, the same drawing reference number is understood to refer to the same element, feature, and structure. The relative sizes and depictions of these elements may be exaggerated for clarity, explanation, and convenience. [Modes for carrying out the invention]

[0014] The present invention will be described with reference to examples and modifications thereof. Although the present invention is illustrated and described with reference to specific examples, the illustrated examples are not limited to those described herein. Rather, various modifications can be made to the details within the claims and their equivalents without departing from the spirit of the invention. For example, one or more aspects of the disclosed embodiments can be used in other embodiments, and even in other types of devices and / or input voltage ranges. Furthermore, the use of certain terms herein is for convenience only and should not be construed as limiting.

[0015] According to the industry standard ANSI C62.41, power line surges within buildings can reach 6,000 volts, 3,000 amperes, and last for 50 microseconds. Underwriters Laboratories (UL) adopts 6,000 volts and 3,000 amperes for the UL 1449 safety duty factor (durability) test and the formulation of the suppressed voltage rating (SVR) in the safety standards for surge protection devices.

[0016] A power line surge suppressor should function to reduce such electrical surges to a harmless level in terms of voltage, current and duration (energy). Most electronic devices are powered by "switching mode" power supplies, which generally draw power from the peak of the power waveform. During the peak period of the waveform, these devices exhibit very low impedance to the power waveform, making them particularly susceptible to surges exceeding the peak voltage of the power waveform.

[0017] When a transient occurs, a surge protection device (SPD) can provide a bypass path around the protected load. For example, metal oxide varistors (MOV), gas discharge tubes (GDT), transient voltage suppressor (TVS) diodes, or a combination of these components can be used. Some SPDs can further limit the surge current flowing to the load by using a line inductor (also known as a choke) to provide large in-line impedance at high frequencies.

[0018] Regardless of the circuit configuration, all circuits adopting MOV or TVS consume a considerable amount of power. Furthermore, MOVs tend to degrade over time, and TVS diodes are limited in the amount of energy they can handle, so both may lead to catastrophic failure of the protected equipment.

[0019] There still exists a need for an improved surge protection system that achieves highly reliable surge protection without relying on active elements (transistors, diodes, etc.) and without using "consumable components" (components that "wear out" with use) such as MOVs or TVS diodes.

[0020] The waveform of a lightning surge can be modeled as an open-circuit voltage of 1.2 × 50 ps and a short-circuit current of 8 × 20 μs, as defined in IEEE 62.41.2 and IEC 61000-4-5. A similar surge waveform can be classified as a 100 kHz "ring wave" as defined in IEC 61000-4-12.

[0021] The wide input voltage range surge suppressor described here is particularly effective for protecting switching power supplies because it allows only extremely small amounts of surge energy to pass through to the protected equipment. In particular, the wide input voltage range surge suppressor described here does not use any "consumable parts" that "wear out" with use, and has the advantage of a long lifespan even in harsh electrical environments.

[0022] The block diagram in Figure 1 shows typical components of an exemplary wide-input voltage range surge suppressor 100. This surge suppressor operates in the range of 85V RMS to 265V RMS and has the unique feature of providing effective dynamic surge energy suppression across the entire operating voltage range.

[0023] The wide input voltage range surge suppressor 100 includes an AC power supply and surge source 102, a surge absorption circuit 104, a line inductor 106, an EMI filter 108, and a load to be protected 110. The AC power supply and surge source 102 are provided with line connections and neutral wire connections, for example, via appropriate connectors and wiring. The EMI filter 108 is an industry-standard low-impedance design, and its details are not covered in this application.

[0024] The left-hand portion of the wide input voltage range surge suppressor 100, including the surge absorption circuit 104 and the line inductor 106, is collectively referred to herein as the “surge protection circuit” 120. For example, referring to Figure 2, one embodiment of the surge protection circuit 120 is disclosed. Specifically, the surge protection circuit 120 may include inductors L1 and L2 (each connected between the AC power input (e.g., the AC power supply and surge source 102 in Figure 1) and the load to be protected (e.g., the load to be protected 110 in Figure 1)) and a surge absorption circuit 204.

[0025] Inductors L1 and L2 are line inductors (e.g., chokes) placed in series (e.g., on the line) with the conductor connecting the AC power supply and surge source 102 to the load 110 to be protected. Because inductors have the property of resisting changes in current, line inductors L1 and L2 can function as an open circuit for incoming surges. In other words, inductors L1 and L2 block or suppress changes in current, acting as a low-pass filter.

[0026] The surge absorption circuit 204 is connected upstream of inductors L1 and L2 and is positioned in series with the load 110 to be protected. The surge absorption circuit 204 is connected between the line connection and the neutral wire connection of the AC power supply and surge source 102 (Figure 1). Alternatively, the surge absorption circuit 204 can be connected to the line connection between the AC power supply and the surge source 102 (Figure 1) and ground.

[0027] Figure 2 shows two line inductors L1 and L2, but the embodiments are not limited to these, and other configurations can be used. For example, in a specific embodiment as shown in Figure 3, the surge protection circuit 320 may include only one line inductor L12 and a surge absorption circuit 304. In the embodiment of Figure 3, the surge absorption circuit 304 is connected upstream of the inductor L12 and on the same line as the load 110 to be protected.

[0028] A tap may be provided on the line inductor L1. For example, in a particular embodiment as shown in Figure 4, the surge protection circuit 420 may include only one line inductor L1 (including sub-inductors L11 and L12) and a surge absorption circuit 404. A tap from inductor L1 (for example, a point between sub-inductors L11 and L12) can be connected to the surge absorption circuit 404. Alternatively, if the inductor L1 does not have a tap, the surge absorption circuit 420 can be connected to the upstream side of the line inductor L1, for example, as shown in Figure 3.

[0029] Referring to Figure 3, the surge absorption circuit 304 includes a capacitor C14. Capacitor C14 is a shunt capacitor connected in parallel with the power supply 102 and the load 110 to be protected. Capacitor C14 can be, for example, a large capacitor bank with a total capacitance in the range of 150 μF to 200 μF.

[0030] For example, as shown in Figure 2, the surge absorption circuit 204 may include a capacitor bank containing capacitors C6, C7, C8, C9, and C10, each having a capacitance value of 40 μF. In this particular embodiment, the capacitor bank, including capacitors C6, C7, C8, C9, and C10, may have a total capacitance of 200 μF.

[0031] Alternatively, the surge absorption circuit 204 may include a single capacitor C14 (Figure 3) instead of a capacitor bank. Capacitor C14 may be, for example, a large-capacity capacitor with a total capacitance in the range of 150 μF to 200 μF. However, the embodiments are not limited thereto, and other configurations may be used. For example, in certain embodiments, the surge absorption circuit 204 (304, 404) may include a full-bridge rectifier to allow the use of physically small polarized electrolytic capacitors.

[0032] Because capacitors resist changes in voltage and inductors resist changes in current, the shunt capacitor C14 functions almost as a short circuit to incoming surges, and the series inductor L1 functions almost as an open circuit. The energy absorbed by capacitor C14 (or the capacitor bank including capacitors C6, C7, C8, C9, and C10) when a surge occurs is slowly discharged through the parallel resistor R1 (Figure 2) or R9 (Figures 3 and 4). For example, these resistors are connected in parallel to the capacitor bank including capacitors C6, C7, C8, C9, and C10, or in parallel to capacitor C14.

[0033] At commercial frequencies (e.g., 50 / 60Hz), shunt capacitor banks, such as capacitor C14 and capacitor banks containing capacitors C6, C7, C8, C9, and C10, can generate undesirable large currents.

[0034] This problem can be solved by connecting at least one crowbar element or clamp element, such as a gas discharge tube (GDT) or MOV, in series with a capacitor bank including capacitor C14 or capacitors C6, C7, C8, C9, and C10. In addition to GDTs, crowbar elements include thyristor-integrated surge protectors (TISPs), plasma surge arresters, spark gap elements, and thyristors (SCRs). Crowbar elements can limit the flow of current to a protection circuit by abruptly switching from a high-impedance state (e.g., open circuit) to a low-impedance state (e.g., short circuit) in response to the circuit voltage exceeding a set impedance switching threshold level.

[0035] During the high-impedance state, no current flows through the crowbar element, and therefore no power is consumed. When it switches to the low-impedance state, the voltage across the crowbar element becomes relatively low, and the element does not consume most of the power supplied during an overvoltage event; rather, it channels that power from the line connection to ground. For example, when the voltage across the GDT exceeds the characteristic gas breakdown voltage (e.g., the threshold voltage of the GDT), the GDT switches to the low-impedance state, and the voltage across the GDT becomes less than 15 volts. These characteristics make the crowbar element suitable for operating in high-current conduction mode for relatively long periods, and it can protect the circuit even during relatively long surges.

[0036] Clamping elements include, for example, MOV, TVS diodes, and Zener (avalanche) diodes. In contrast to crowbar elements, clamping elements can limit voltage transients to a predetermined voltage level by changing the internal resistance of the clamping element in response to the applied voltage.

[0037] In MOV elements, the internal resistance of the clamp element changes in response to the applied voltage, so the MOV functions as a voltage-sensitive nonlinear resistive element connected in parallel with the protection circuit. Because the clamp element must absorb surge energy with the clamp voltage, it cannot withstand surge currents as high as those in gas discharge tubes. Furthermore, MOVs also suffer from cumulative degradation and performance changes due to high-current surges.

[0038] Due to the aforementioned drawbacks associated with the use of MOVs (e.g., power loss, degradation over time), GDTs can be a superior solution to MOVs in blocking unwanted currents generated from shunt capacitor C14 (or the capacitor bank including capacitors C6, C7, C8, C9, and C10). Furthermore, MOVs can generate large clamping voltages (e.g., over 200V), while GDTs generate much smaller voltages (e.g., less than 50V), which is another advantage of using GDTs.

[0039] Returning to Figure 2, the GDT2 (for example, a crowbar element) can be connected in series with the capacitor bank containing capacitors C6, C7, C8, C9, and C10. The GDT2 only allows current to flow when a surge occurs, and under normal operating conditions, it blocks unwanted currents from the capacitor bank, including capacitors C6, C7, C8, C9, and C10. Because the capacitor bank, including capacitors C6, C7, C8, C9, and C10, is connected via the GDT2, under normal operating conditions (for example, when there are no significant surges or "voltage drop" events, or when a power company lowers the voltage on the transmission lines to conserve available power), the voltage across the capacitor bank, including capacitors C6, C7, C8, C9, and C10, is approximately 0 volts.

[0040] When a surge occurs, GDT2 "breaks over" and begins conducting. Only at that point does the capacitor bank, including capacitors C6, C7, C8, C9, and C10, begin charging.

[0041] Initially, the capacitor voltage is close to 0 volts, but because the surge current is almost unipolar, the capacitor bank, including capacitors C6, C7, C8, C9, and C10, begins to charge. Similarly, even after the surge occurs, the arc persists inside the device, so the GDT2 continues to carry a "follow-through current". After the surge event, the power supply frequency becomes dominant, and the capacitor bank, including capacitors C6, C7, C8, C9, and C10, can provide sufficient impedance to limit the follow-through current to a level where the arc can extinguish naturally.

[0042] Similarly, in the embodiments shown in Figures 3 and 4, the GDT 306 (or 406) can be connected in series with the capacitor bank C14. The GDT 306 (or 406) conducts current only during surge events and, under normal operating conditions, blocks the draw of unwanted current from the shunt capacitor C14.

[0043] Similarly, after a surge event, the arc persists within the device, causing the GDT 306 (or 406) to continue carrying a "follow-through current." After a surge event, the power supply frequency becomes dominant, and capacitor C14 can provide sufficient impedance to limit the follow-through current to a level where the arc can extinguish naturally.

[0044] Another drawback when using a large capacitor bank, such as capacitor C14 in a capacitor bank that includes capacitors C6, C7, C8, C9, and C10, is the large current spike that occurs when the GDT 2 (306, 406) starts to conduct current. This problem can be mitigated or solved, for example, by using a small series inductor that limits the rate of change of current flowing through the capacitor bank, which includes capacitor C14 and capacitors C6, C7, C8, C9, and C10.

[0045] For example, returning to Figures 3 and 4, a second inductor L13 can be connected in series with capacitor C14, or with a capacitor bank containing capacitors C6, C7, C8, C9, and C10. The second inductor L13 has a relatively small inductance value (e.g., 10 nH) and can serve to limit the rate of change of the current flowing through capacitor C14, or with the capacitor bank containing capacitors C6, C7, C8, C9, and C10.

[0046] However, the use of the second inductor L13 is optional, and in certain embodiments, such as the surge absorption circuit 204 shown in Figure 2, the second inductor L13 is not included, which is connected in series with the capacitor bank including capacitors C6, C7, C8, C9, and C10.

[0047] As an option, in certain embodiments of the surge protection circuit, MOV, TVS diodes, etc. (e.g., clamping elements) can be used instead of GDTs. In yet other embodiments, parallel crowbar elements, or clamping elements such as MOV, GDT, thyristor, or TVS diodes can be used instead of GDTs.

[0048] In other embodiments, for example, both the crowbar element and the clamp element, such as GDT and MOV, can be used by connecting them in series with each other and in series with a capacitor bank including capacitor C14 or capacitors C6, C7, C8, C9, C10.

[0049] A particular embodiment of the surge protection circuit may include at least two surge absorption circuits. For example, a first surge absorption circuit connected upstream of the inductor L1 (e.g., between the AC power supply and surge source 102 and a first end of the inductor L1 that is closer to the AC power supply and surge source 102 than to the load 110 to be protected) and a second surge absorption circuit connected downstream of the inductor L1 (e.g., between the load 110 to be protected and a second end of the inductor L1 that is closer to the load 110 than to the AC power supply and surge source 102).

[0050] Other embodiments of the surge protection circuit may include three or more surge absorption circuits. For example, the first and second surge absorption circuits may be connected upstream of the inductor L1 in a common-mode configuration between the line connection and ground, or between the line connection and the neutral wire connection, respectively, and a third surge absorption circuit may be connected downstream of the inductor L1 (for example, between the load to be protected 110 and the second end of the inductor L1 that is closer to the load to be protected 110 than the AC power supply and surge source 102).

[0051] Other embodiments of the surge protection circuit include a shunt capacitor and a GDT branch connected downstream of line inductors L1 and L2. Further embodiments of the surge protection circuit may include other parallel shunt branches, including crowbar elements and / or clamp elements, upstream or downstream of the line inductor L1.

[0052] Figure 5 is a schematic diagram of a simulation circuit 500 for an example wide input voltage range surge suppressor. A typical EMI filter 108 placed between the surge protection circuit 120 and the protected load 110 can further divert most of the remaining surge current away from the protected load 110.

[0053] Using the wide input voltage range surge suppressor shown in Figure 5 above, a surge current of 2.8 kA was applied, and simulations and experimental tests were conducted across various voltage ranges to demonstrate the effectiveness of the wide input voltage range surge suppressor.

[0054] Based on the simulation circuit, a prototype was created, and prototype values ​​for various components were obtained by referring to the datasheet and running a model of a wide input voltage range surge suppressor using the LTspice software module. The experimental results are in good agreement with the simulation results.

[0055] Any discrepancies can be attributed to the simplification of the GDT model, as well as the fact that parasitic resistances and inductances (such as ground resistance and lead inductance) in the modeled components are not considered. Since the GDT model is an approximation, experimental results may vary. The actual results are shown below. Figures 6A-6C and 9 show the results. In each figure, the applied surge voltage and the transmitted voltage are plotted against time.

[0056] The simulation implements a discrete model of a 1.2×50μs / 8×20μs composite waveform generator compliant with IEC61000-4-5. This generator uses an energy storage capacitor, and an initial condition of 6615V was given to obtain the required 6kV open-circuit (OC) voltage.

[0057] The generator was capacitively coupled between the line connection and the neutral wire connection, and the surge was applied with a 90° phase difference to a 120V AC waveform. Simulation data shows that the surge is suppressed within the first 100μs by using a typical downstream EMI filter.

[0058] Figures 6A to 6C show the deviation of the output voltage, with Figure 6A showing the surge current, Figure 6B showing the capacitor voltage, and Figure 6C showing the output voltage. Figures 7A and 7B show that almost all of the surge current is absorbed by capacitor C14. Figures 7A and 7B show the surge current, with Figure 7A showing the unabsorbed surge current and Figure 7B showing the surge current and capacitor current.

[0059] The simulation results described above (shown in Figures 2 and 3) assume the absence of dissipative elements. Optimal values ​​for resistance, capacitance, and inductance can be determined by testing and experimentation.

[0060] Figure 8 shows the experimental results based on the simulation circuit shown in Figure 1B. The EMI filter 108 was integrated onto a PCB to form a single board. The transmitted voltage was measured with no load connected (in accordance with UL1449) by connecting a differential probe between the line connection and the neutral wire connection of the power outlet. A Keytech 587 surge generator was used and configured as follows: • Combined waveform of 1.2×50μs / 8×20μs (Bi-wave), charging up to 6kV • Normal mode (from line connection to neutral wire connection) • Applied at 90° of AC waveform • Positive polarity

[0061] The surge protection circuit 120 for simulation shown in Figure 1B (most clearly shown as the surge absorption circuit 204 in Figure 2) includes five capacitors C6, C7, C8, C9, and C10, each with a capacitance of 40 μF, for a total capacitance of 200 μF, and these are connected in parallel. It also includes two line inductors L1 and L2 (each with an inductance of 40 μH), a GDT2 of AC 120 L (e.g., 285 V 5000 A (5 kA), 10 GΩ), and a resistor R1 with a resistance of 10 kΩ and 3 W.

[0062] Returning to Figure 8, the surge was applied at 90°, and the output voltage closely matches the results obtained from the simulation. The discrepancy in the results can be explained by parasitic elements (resistance, inductance, etc.) that were not included in the simulation, in addition to the GDT model used in the simulation. Figure 9 shows the voltage across the shunt capacitor. From Figure 9, it can be seen that almost all of the surge current is absorbed by capacitor C14.

[0063] Surge protection devices such as GDTs experience cumulative discharge over time, and the discharge is destroyed by surge overvoltage. See, for example, "Experimental Study on the Short-Circuit Failure Mechanism of Cumulative Discharge in Gas Discharge Tubes" by Lingyun Cheng et al. (published in IEEE Transactions on Plasma Science (Vol. 49, No. 9, September 2021)). Cumulative discharge in GDTs is rare in most cases, but there is a risk of short-circuit failure due to the decrease in insulation resistance after a certain number of discharges, which can be caused by cumulative discharge. In particular, the insulation resistance of a GDT decreases significantly during the last 10% of its lifespan, which can lead to GDT failure, potentially occurring at commercial frequencies (e.g., 50 / 60Hz) through capacitor banks including capacitors C14 (Figure 3) and capacitors C6, C7, C8, C9, C10 (Figure 2). In this surge suppressor circuit, the GDT is connected to a series inductance to increase the rise time and to a series capacitor or capacitor bank to store most of the surge energy. This configuration minimizes the impact on the GDT and results in a robust design.

[0064] Figure 10 is a schematic diagram showing an example of the surge protection circuit 320 portion, including a monitoring circuit 1002, of the wide input voltage range surge suppressor shown in Figure 3. The monitoring circuit 1002 is connected in parallel with the surge absorption circuit 304 between the line connection side of the surge absorption circuit 304 (and the GDT 306) and the neutral wire connection point of the AC power supply and surge source 102 (Figure 1). The monitoring circuit 1002 can be used to monitor the voltage across the surge absorption circuit 304, which correlates with the state of the GDT 306, and to transmit the detected voltage value to the controller, processor, or control circuit 1004. The monitoring circuit 1002 may include, for example, a fuse 1006, a diode D1, a filter capacitor C3 connected in series with a current limiting resistor R2, and an optocoupler U1. For example, if the fuse 1006 blows due to long-term use or cumulative discharge of the GDT, the current flowing through the monitoring circuit 1002 will be interrupted, and it will no longer be able to pass through the fuse 1006 and drive the optocoupler U1. This generates an open signal (for example, to a connector), which may be detected by the controller, processor, or control circuit 1004. However, the embodiment is not limited to the circuit configuration of the monitoring circuit 1002 shown in Figure 10, and other circuit configurations of the monitoring circuit 1002 can also be used.

[0065] The circuit design of the wide input voltage range surge suppressor shown in the drawings and described above functions optimally, substantially independent of the supply voltage, exhibits excellent transient-resistant performance, and enables optimal protection for wide input voltage range equipment using switching power supplies. For example, the wide input voltage range surge suppressor described herein is suitable for circuits operating in both the 110V to 120V and 220V to 240V voltage ranges.

[0066] This surge protection system diverts and interrupts most of the surge current, preventing it from reaching the protected load. The surge protection systems described herein provide reliable surge protection without using "consumable parts" (parts that "wear out" with use) such as MOV or TVS diodes.

[0067] Although the present invention is illustrated and described with reference to specific embodiments, the present invention is not limited to the details shown. Rather, various modifications can be made to the details within the scope of the claims and their equivalents without departing from the spirit of the invention.

Claims

1. A wide input voltage range surge suppressor, An inductor connected between the AC power input and the load to be protected, Equipped with a surge absorption circuit, The surge absorption circuit described above is Capacitors and, A resistor connected in parallel to the capacitor, At least one crowbar element or clamp element connected in series with the capacitor, A wide input voltage range surge suppressor, including one.

2. The wide input voltage range surge suppressor according to claim 1, wherein the AC power input has a line connection and a neutral wire connection, and the surge absorption circuit is connected between the line connection and the neutral wire connection, or between the line connection and ground.

3. The wide input voltage range surge suppressor according to claim 1, wherein the inductor is a line inductor.

4. The wide input voltage range surge suppressor according to claim 1, wherein the inductor is provided with a tap connected to the surge absorption circuit.

5. The wide input voltage range surge suppressor according to claim 1, wherein the capacitor is a shunt capacitor.

6. The wide input voltage range surge suppressor according to claim 1, wherein the capacitor is upstream of the inductor and connected in series with the load to be protected.

7. The wide input voltage range surge suppressor according to claim 1, wherein the capacitor is a capacitor bank having a capacitance between 150 μF and 200 μF.

8. The wide input voltage range surge suppressor according to claim 1, wherein the at least one crowbar element or clamp element is a gas discharge tube (GDT).

9. The wide input voltage range surge suppressor according to claim 8, wherein the gas discharge tube is connected between the AC power input and the inductor.

10. The wide input voltage range surge suppressor according to claim 1, wherein the at least one crowbar element or clamp element is at least one of a metal oxide varistor (MOV) or a transient voltage suppressor (TVS) diode.

11. The wide input voltage range surge suppressor according to claim 1, wherein the at least one crowbar element or clamp element is at least one of a metal oxide varistor (MOV) or a transient voltage suppressor (TVS) diode connected in parallel between the AC power input and the load to be protected.

12. The wide input voltage range surge suppressor according to claim 1, further comprising two inductors connected between the AC power input and the load to be protected.

13. The wide input voltage range surge suppressor according to claim 12, wherein the surge absorption circuit is connected to the first ends of the two inductors, and the first ends are closer to the AC power input side than to the load side to be protected.

14. The wide input voltage range surge suppressor according to claim 1, wherein the surge absorption circuit is connected to the upstream side of the inductor.

15. The wide input voltage range surge suppressor according to claim 1, further comprising a second surge absorption circuit connected downstream of the inductor.

16. The wide input voltage range surge suppressor according to claim 1, further comprising a second inductor connected in series with the capacitor.

17. The wide input voltage range surge suppressor according to claim 16, wherein the second inductor has an inductance value of 10 nH.

18. The wide input voltage range surge suppressor according to claim 1, wherein the capacitor is an electrolytic capacitor.

19. The wide input voltage range surge suppressor according to claim 18, further comprising a full-bridge rectifier.

20. The wide input voltage range surge suppressor according to claim 1, further comprising a monitoring circuit connected in parallel to the surge absorption circuit between the line connection of the AC power input and the neutral wire connection of the AC power input.

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