Protection circuit for suppressing AC power-on surge impact

Abstract

The utility model relates to the field of stage lamp protection circuits, and particularly discloses a protection circuit for inhibiting AC power-on surge impact, which comprises an AC input end electrically connected with a mains supply and an AC output end for providing a power supply for a stage lamp, and a voltage clamping mechanism protection circuit is arranged between a live wire and a zero wire of the AC input end. A current limiting circuit for limiting instant surge impact current and a switching circuit which is in an off state when AC is powered on are arranged on a live wire at the output end of the voltage clamping mechanism protection circuit, the current limiting circuit is connected with the switching circuit in parallel, the input ends of the current limiting circuit and the switching circuit are electrically connected with the voltage clamping mechanism protection circuit, and the output ends are electrically connected with the AC output end. The AC output end is further electrically connected with a control circuit which controls the switching circuit to close the switching circuit to enable the current limiting circuit to be short-circuited after the AC is powered on, the input end of the control circuit is electrically connected with the AC output end, and the output end of the control circuit is electrically connected with the switching circuit.

Description

Technical Field

[0001] This utility model relates to the field of stage light protection circuits, and in particular to a protection circuit for suppressing AC power surge impact. Background Technology

[0002] With the continuous development of the stage lighting industry and the expanding application of LED stage lights, when multiple LED stage lights are powered on simultaneously in the circuit breaker of the power supply system protection device, the peak current flowing into the power supply equipment is much greater than the steady-state input current due to the rapid charging of the input filter capacitor. This results in excessively high surge current, causing the circuit breaker to activate overcurrent protection, leading to problems such as component damage, equipment failure, power grid interference, and safety accidents. Utility Model Content

[0003] The purpose of this invention is to provide a protection circuit for suppressing AC power surges, thereby improving the safety of stage lighting equipment.

[0004] The AC surge protection circuit described in this utility model includes an AC input terminal connected to the mains power supply and an AC output terminal providing power to the stage lights. A voltage clamping mechanism protection circuit is provided between the live wire and the neutral wire of the AC input terminal. A current limiting circuit that limits the instantaneous surge current and a switching circuit that is in an open state when the AC is powered on are provided on the live wire of the output terminal of the voltage clamping mechanism protection circuit. The current limiting circuit and the switching circuit are connected in parallel. The input terminals of the current limiting circuit and the switching circuit are electrically connected to the voltage clamping mechanism protection circuit, and their output terminals are electrically connected to the AC output terminal. The AC output terminal is also electrically connected to a control circuit that controls the switching circuit to close the switching circuit and short-circuit the current limiting circuit after the AC is powered on. The input terminal of the control circuit is electrically connected to the AC output terminal, and its output terminal is electrically connected to the switching circuit.

[0005] The AC surge protection circuit described in this invention uses a voltage clamping mechanism between the live and neutral wires at the AC input terminal. The output wire of this voltage clamping mechanism has a current-limiting circuit to limit instantaneous surge current and a switching circuit that is disconnected when the AC is powered on. The current-limiting circuit and the switching circuit are connected in parallel. When one or more AC units connected in parallel are powered on, the AC input voltage passes through the voltage clamping mechanism, which limits the instantaneous surge current, thus preventing damage to the stage lights from transient voltages or surge currents. When the current reaches the current-limiting circuit after passing through the voltage clamping mechanism, the switching circuit is disconnected. The live wire, just after power-on, passes through the current-limiting circuit, utilizing its current-limiting characteristics to use the maximum voltage instantaneous input to limit the current surge, and then outputs power to the stage lights from the AC output terminal, thereby suppressing AC surge impact. After power-on, the control circuit closes the switch circuit to short-circuit the current limiting circuit. At this time, the switch circuit can supply power to the stage lights by overload rated current. Since there has been a delay since the AC power-on, it can effectively delay and suppress the surge current impact of the stage lights power supply, thus improving the safety of the stage lights equipment.

[0006] As a preferred embodiment of this utility model, an overcurrent protection circuit is provided on the live wire between the AC input terminal and the voltage clamping mechanism protection circuit. The input terminal of the overcurrent protection circuit is electrically connected to the AC input terminal, and the output terminal is electrically connected to the voltage clamping mechanism protection circuit.

[0007] As a preferred embodiment of this utility model, a common-mode circuit is provided between the current limiting circuit and the voltage clamping mechanism protection circuit.

[0008] As a preferred embodiment of this utility model, the common-mode circuit includes a common-mode inductor, a first common-mode capacitor, and a second common-mode capacitor;

[0009] The input terminal of the common mode inductor is electrically connected to the live wire and neutral wire of the output terminal of the voltage clamping mechanism protection circuit, the live wire terminal of the output terminal is electrically connected to the current limiting circuit, and the neutral wire terminal of the output terminal is electrically connected to the neutral wire of the AC output terminal.

[0010] One end of the first common-mode capacitor is electrically connected to the ground wire, and the other end is electrically connected to the neutral wire of the common-mode inductor output terminal;

[0011] One end of the second common-mode capacitor is electrically connected to the ground wire, and the other end is electrically connected to the live wire of the common-mode inductor output terminal.

[0012] As a preferred embodiment of this utility model, a differential mode capacitor is provided between the current limiting circuit and the AC output terminal. One end of the differential mode capacitor is connected to the neutral wire, and the other end is connected to the live wire.

[0013] As a preferred embodiment of this utility model, the current limiting circuit is a surge impulse current limiting resistor.

[0014] In a preferred embodiment of this utility model, the switching circuit is a relay switch.

[0015] As a preferred embodiment of this utility model, the control circuit includes a rectifier bridge chip that rectifies AC power to output DC power, a power supply chip that reduces high voltage to low voltage, and a transistor.

[0016] The input terminal of the rectifier bridge chip is electrically connected to the AC output terminal, and the output terminal is electrically connected to the power supply chip.

[0017] The output terminal of the power chip is electrically connected to one end of the coil of the relay switch and the base of the transistor, respectively.

[0018] The collector of the transistor is electrically connected to the other end of the relay switch coil, and the emitter is electrically connected to ground.

[0019] As a preferred embodiment of this utility model, a voltage regulator circuit is provided at the output terminal of the power chip.

[0020] In a preferred embodiment of this utility model, a first current-limiting resistor is provided between the output terminal of the voltage regulator circuit and one end of the coil of the relay switch; a second current-limiting resistor and a third current-limiting resistor are provided between the output terminal of the voltage regulator circuit and the base of the transistor. One end of the second current-limiting resistor is electrically connected to the output terminal of the voltage regulator circuit, and the other end is electrically connected to one end of the third current-limiting resistor. The other end of the third current-limiting resistor is electrically connected to the base of the transistor. A grounding capacitor is provided between the second and third current-limiting resistors. One end of the grounding capacitor is electrically connected to the connection point between the second and third current-limiting resistors, and the other end is grounded. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the AC surge protection circuit of this utility model.

[0022] Figure 2 This is a circuit diagram of the AC surge protection circuit of this utility model. Detailed Implementation

[0023] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] This embodiment provides a surge protection circuit for suppressing AC power surges, such as... Figure 1 As shown, it includes an AC input terminal connected to the mains power supply and an AC output terminal providing power to the stage lights. A voltage clamping mechanism protection circuit is set between the live wire and the neutral wire of the AC input terminal. A current limiting circuit that limits the instantaneous surge current and a switching circuit that is in the open state when the AC is powered on are set on the live wire of the output terminal of the voltage clamping mechanism protection circuit. The current limiting circuit and the switching circuit are connected in parallel. The input terminals of the current limiting circuit and the switching circuit are electrically connected to the voltage clamping mechanism protection circuit, and their output terminals are electrically connected to the AC output terminal. The AC output terminal is also electrically connected to a control circuit that controls the switching circuit to close the switching circuit and short-circuit the current limiting circuit after the AC is powered on. The input terminal of the control circuit is electrically connected to the AC output terminal, and its output terminal is electrically connected to the switching circuit.

[0025] like Figure 2 As shown, CN1 is the AC input terminal. A socket can be used as the AC input terminal. Connect pin 1 of the socket to the live wire L, pin 3 to the neutral wire N, and pin 5 to the ground wire FG. The input voltage AC is 100V-240V 50Hz / 60Hz. CN2 is the AC output terminal. A socket can be used as the AC output terminal. Connect pin 1 of the socket to the live wire L, pin 3 to the neutral wire N, and pin 5 to the ground wire FG. The output voltage AC is 100V-240V 50Hz / 60Hz.

[0026] The voltage clamping protection circuit can use a 560V withstand voltage varistor RV1 to protect the circuit from damage caused by transient voltages or surge currents through the voltage clamping mechanism of the varistor. The current limiting circuit can use a surge current limiting resistor PTC with a resistance of 10 ohms to limit instantaneous surge current using Ohm's law. The switching circuit can use a relay switch KG1, a 16A / 250VAC relay capable of overloading large AC currents.

[0027] An overcurrent protection circuit F1 is installed on the live wire between the AC input terminal and the voltage clamping mechanism protection circuit. The input terminal of the overcurrent protection circuit is electrically connected to the AC input terminal, and the output terminal is electrically connected to the voltage clamping mechanism protection circuit. The overcurrent protection circuit F1 can be a T10A fuse F1, used for short-circuit overcurrent protection at the live wire input.

[0028] A common-mode circuit is installed between the current-limiting circuit and the voltage clamping mechanism protection circuit. The common-mode circuit includes a common-mode inductor L1, a first common-mode capacitor CY1, and a second common-mode capacitor CY2. The input terminal of the common-mode inductor is electrically connected to the live and neutral wires of the output terminal of the voltage clamping mechanism protection circuit. The live wire of the output terminal is electrically connected to the current-limiting circuit, and the neutral wire of the output terminal is electrically connected to the neutral wire of the AC output terminal. One end of the first common-mode capacitor is electrically connected to ground, and the other end is electrically connected to the neutral wire of the common-mode inductor's output terminal. One end of the second common-mode capacitor is electrically connected to ground, and the other end is electrically connected to the live wire of the common-mode inductor's output terminal. The common-mode inductor L1 is a 10uH common-mode inductor. The live and neutral wires pass through the 10uH common-mode inductor, and the high permeability material provided by the common-mode inductor suppresses common-mode noise interference. The first common-mode capacitor CY1 and the second common-mode capacitor CY2 are 1nF 1.2KV Y capacitors, which can filter out common-mode noise interference in the circuit.

[0029] A differential-mode capacitor CX1 is placed between the current-limiting circuit and the AC output terminal. One end of the differential-mode capacitor is connected to the neutral wire, and the other end is connected to the live wire. The differential-mode capacitor CX1 is a 0.01uF 2.5KV X capacitor, which can filter out differential-mode noise interference in the circuit.

[0030] The control circuit includes a rectifier bridge chip U2 that rectifies AC power to DC power, a power supply chip U1 that reduces high voltage to low voltage, and a transistor Q1. The input terminal of the rectifier bridge chip is electrically connected to the AC output terminal, and the output terminal is electrically connected to the power supply chip. The output terminal of the power supply chip is electrically connected to one end of the relay switch coil and the base of the transistor. The collector of the transistor is electrically connected to the other end of the relay switch coil, and the emitter is electrically connected to ground. The rectifier bridge chip U2 is an ABS210 model, which converts AC voltage to DC voltage. The power supply chip U1 is a Viper22A surface-mount power supply chip, a high-voltage offline switching power supply chip with an input AC voltage of 85-265V and an output DC voltage of 12V. The transistor Q1 is an NPN transistor. A pull-down resistor R5 is installed at the base of transistor Q1, with one end of R5 electrically connected to the base of transistor Q1 and the other end grounded. The emitter of transistor Q1 is equipped with a pull-down resistor R6. One end of the pull-down resistor R6 is electrically connected to the emitter of transistor Q1, and the other end is grounded.

[0031] A voltage regulator circuit is provided at the output terminal of the power chip. The voltage regulator circuit consists of diodes D1, D2, D3, Zener diode DZ1, capacitors C1, C2, C3, C4, and inductor L3.

[0032] A first current-limiting resistor R2 is provided between the output terminal of the voltage regulator circuit and one end of the coil of the relay switch; a second current-limiting resistor R3 and a third current-limiting resistor R4 are provided between the output terminal of the voltage regulator circuit and the base of the transistor. One end of the second current-limiting resistor is electrically connected to the output terminal of the voltage regulator circuit, and the other end is electrically connected to one end of the third current-limiting resistor. The other end of the third current-limiting resistor is electrically connected to the base of the transistor. A grounding capacitor C5 is provided between the second and third current-limiting resistors. One end of the grounding capacitor is electrically connected to the connection point between the second and third current-limiting resistors, and the other end is grounded.

[0033] The stage lights are LED stage lights. Because the AC input terminal of the switching power supply in the LED stage lights has large-capacity filter capacitors and energy storage capacitors, a surge current is generated during the instantaneous charging of the capacitors within 10ms of power-on. When one or more LED stage lights are powered on in parallel with AC input, the AC voltage is connected to the live wire (L) at pin 1 of CN1, the neutral wire (N) at pin 3, and the ground wire (FG) at pin 5. The input voltage is AC: 100V-240V 50Hz / 60Hz. The live wire is protected from overcurrent by the T10A fuse F1, passes through the 560V withstand voltage varistor RV1, and reaches the 10uH common-mode inductor L1. The varistor RV1 protects the circuit from damage by transient voltage or surge current through a voltage clamping mechanism. The live and neutral wires, through the 10uH common-mode inductor, are suppressed by the high permeability material provided by the common-mode inductor to suppress common-mode noise interference. Y capacitors CY1 and CY2 are connected to the output terminal of the common-mode inductor L1 and then to ground FG to suppress common-mode noise interference in the circuit. Capacitor X (CX1) is connected between the live and neutral wires to suppress differential-mode noise interference in the circuit. Capacitors Y and X are safety-certified capacitors, used to filter out high-frequency noise interference. Common-mode capacitor CY1, common-mode capacitor CY2, differential-mode capacitor CX1, and common-mode inductor L1 form the core components for EMC, and their combined use satisfies electromagnetic compatibility (EMI). At this time, relay KG1 is in the off state. Upon power-up, the live wire experiences a surge impact through the 10Ω surge current-limiting resistor PTC input. Utilizing the current-limiting characteristic of the resistor, the maximum voltage is instantaneously input to limit the sudden current change, which is then output from the CN2 socket to power the stage lights, thus suppressing the AC power-up surge impact.

[0034] After the LED stage light is powered on, the AC voltage is input at pins 3 and 4 of the rectifier bridge chip U2, and the DC voltage is output at pins 1 and 2. After being filtered by capacitor CE1, inductor L2, and capacitor CE2, a clean DC voltage is obtained to power the power supply chip U1. The voltage is regulated by diodes D1, D2, D3, Zener diode DZ1, capacitors C1, C2, C3, C4, and inductor L3. After being filtered by capacitor CE3 and resistor R1, a clean DC 12V voltage is obtained. The DC 12V voltage is connected to pin 3 of the relay through the first current-limiting resistor R2. The 12V voltage is then used to charge the grounding capacitor C5 (delay capacitor) through the second current-limiting resistor R3. After a 10ms delay, the grounding capacitor C5 is fully charged and then provides voltage to the base of transistor Q1 through the third current-limiting resistor R4. At this time, the transistor conducts, pin 2 of the relay is grounded, and the relay operates. Pins 4 and 5 of the relay conduct, which short-circuits the surge current-limiting resistor PTC. At this time, the switching circuit can supply power to the stage lights with overload rated current. Since there is a delay between the AC power-on and the stage lights, the surge current impact of the stage lights power supply can be effectively suppressed, improving the safety of the stage lights equipment.

[0035] The above embodiments are only used to illustrate the detailed solution of this utility model. This utility model is not limited to the above detailed solution, that is, it does not mean that this utility model must rely on the above detailed solution to be implemented. Those skilled in the art should understand that any improvement to this utility model, equivalent substitution of the raw materials of this utility model product, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this utility model.

Claims

1. A protection circuit for suppressing AC power-on surge impact, comprising an AC input end electrically connected with commercial power and an AC output end for providing power supply for a stage lamp, characterized in that, A voltage clamping mechanism protection circuit is installed between the live wire and the neutral wire at the AC input terminal. A current limiting circuit that limits the instantaneous surge current and a switching circuit that is in the open state when the AC is powered on are installed on the live wire at the output terminal of the voltage clamping mechanism protection circuit. The current limiting circuit and the switching circuit are connected in parallel. The input terminals of the current limiting circuit and the switching circuit are electrically connected to the voltage clamping mechanism protection circuit, and the output terminals are electrically connected to the AC output terminal. The AC output terminal is also electrically connected to a control circuit that controls the switching circuit to close the switching circuit and short-circuit the current limiting circuit after the AC is powered on. The input terminal of the control circuit is electrically connected to the AC output terminal, and the output terminal is electrically connected to the switching circuit.

2. The AC power-on surge suppression protection circuit of claim 1, wherein, An overcurrent protection circuit (F1) is installed on the live wire between the AC input terminal and the voltage clamping mechanism protection circuit. The input terminal of the overcurrent protection circuit is electrically connected to the AC input terminal, and the output terminal is electrically connected to the voltage clamping mechanism protection circuit.

3. The AC power-on surge suppression protection circuit of claim 1, wherein, A common-mode circuit is provided between the current-limiting circuit and the voltage clamping mechanism protection circuit.

4. The AC power-on surge suppression protection circuit according to claim 3, wherein, The common-mode circuit includes a common-mode inductor (L1), a first common-mode capacitor (CY1), and a second common-mode capacitor (CY2). The input terminal of the common mode inductor is electrically connected to the live wire and neutral wire of the output terminal of the voltage clamping mechanism protection circuit, the live wire terminal of the output terminal is electrically connected to the current limiting circuit, and the neutral wire terminal of the output terminal is electrically connected to the neutral wire of the AC output terminal. One end of the first common-mode capacitor is electrically connected to the ground wire, and the other end is electrically connected to the neutral wire of the common-mode inductor output terminal; One end of the second common-mode capacitor is electrically connected to the ground wire, and the other end is electrically connected to the live wire of the common-mode inductor output terminal.

5. The AC power-on surge suppression protection circuit of claim 1, wherein, A differential capacitor (CX1) is provided between the current limiting circuit and the AC output terminal. One end of the differential capacitor is connected to the neutral wire, and the other end is connected to the live wire.

6. The AC power surge suppression circuit of any one of claims 1-5, wherein, The current limiting circuit is a surge current limiting resistor (PTC).

7. The AC power-on surge suppression protection circuit according to claim 6, wherein, The switching circuit is a relay switch (KG1).

8. The AC power-on surge suppression protection circuit according to claim 7, wherein, The control circuit includes a rectifier bridge chip (U2) that rectifies AC power to output DC power, a power supply chip (U1) that reduces high voltage to low voltage, and a transistor (Q1). The input terminal of the rectifier bridge chip is electrically connected to the AC output terminal, and the output terminal is electrically connected to the power supply chip. The output terminal of the power chip is electrically connected to one end of the coil of the relay switch and the base of the transistor, respectively. The collector of the transistor is electrically connected to the other end of the relay switch coil, and the emitter is electrically connected to ground.

9. The AC power-on surge suppression protection circuit according to claim 8, wherein, A voltage regulator circuit is provided at the output of the power chip.

10. The AC power-on surge suppression protection circuit according to claim 9, wherein, A first current-limiting resistor (R2) is provided between the output terminal of the voltage regulator circuit and one end of the coil of the relay switch; a second current-limiting resistor (R3) and a third current-limiting resistor (R4) are provided between the output terminal of the voltage regulator circuit and the base of the transistor. One end of the second current-limiting resistor is electrically connected to the output terminal of the voltage regulator circuit, and the other end is electrically connected to one end of the third current-limiting resistor. The other end of the third current-limiting resistor is electrically connected to the base of the transistor. A grounding capacitor (C5) is provided between the second and third current-limiting resistors. One end of the grounding capacitor is electrically connected to the connection point between the second and third current-limiting resistors, and the other end is grounded.

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