Non-isolation switch circuit

Abstract

The utility model provides a non-isolation switch circuit. The circuit comprises a rectification filtering module, a boost module, a switch module, a voltage reduction module and an LED load. When one input end of the non-isolation switch circuit stops inputting alternating current voltage, disconnection between the voltage boosting module and the voltage reducing module is achieved through the switch module, so that disconnection of a power supply loop of a non-isolation LED is achieved, and then complete closing of the non-isolation LED is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of power supply circuits, and in particular to a non-isolated switch circuit. Background Art

[0002] At present, non-isolated light-emitting diode (LED) lighting power supplies have the advantages of low cost, simple structure, and small size compared to isolated LED lighting power supplies, so they are widely used in LED lighting applications. Although non-isolated LED lighting power supplies have many advantages, when non-isolated LEDs are turned off, there will be afterglow, which makes it impossible to completely turn off. Therefore, how to completely turn off non-isolated LEDs is a technical problem that needs to be solved in this field. Utility Model Content

[0003] The present application provides a non-isolated switch circuit. When a non-isolated LED is turned off, a power supply circuit of the non-isolated LED is disconnected through a switch module, thereby completely turning off the non-isolated LED.

[0004] The present application provides a non-isolated switch circuit, which includes: a rectifier and filter module, a boost module, a switch module, a buck module, and an LED load;

[0005] The first input end and the second input end of the rectifier and filter module are respectively input with an AC voltage, the first output end and the second output end of the rectifier and filter module are respectively connected with the first input end and the second input end of the boost module, and the second input end of the boost module is connected with a ground wire, the first output end and the second output end of the boost module are respectively connected with the first input end and the second input end of the switch module, the first output end and the second output end of the switch module are respectively connected with the first input end and the second input end of the buck module, the first output end and the second output end of the buck module are respectively connected with the first input end and the second input end of the LED load, and the output end of the LED load is connected with a ground wire;

[0006] A rectifier and filter module, used for rectifying and filtering the input AC voltage;

[0007] A boost module is used to increase the output voltage of the rectifier and filter module;

[0008] A switch module, used for controlling the voltage boost module and the voltage buck module to be disconnected when the AC voltage is stopped from being input to the second input end of the rectifier and filter module;

[0009] The step-down module is used to reduce the output voltage of the step-up module.

[0010] In a feasible example, the switch module includes a switch K3 and a diode D3; wherein the first port of the diode D3 is connected to the first output end of the boost module, the second port of the diode D3 is connected to the first input end of the buck module, the first port of the switch K3 is connected to the second output end of the boost module, and the second port of the switch K3 is connected to the second input end of the buck module.

[0011] In a feasible example, the switch module includes a switch K3 and a diode D3; wherein the first port of the switch K3 is connected to the first output end of the boost module, the second port of the switch K3 is connected to the first input end of the buck module, the second port of the diode D3 is connected to the second output end of the boost module, and the first port of the diode D3 is connected to the second input end of the buck module.

[0012] In a feasible example, the boost module includes an inductor L1, a switch K1, a diode D2 and a capacitor C1; wherein the first port of the inductor L1 is connected to the first output end of the rectifier and filter module, the second port of the inductor L1 is connected to the first port of the switch K1 and the first port of the diode D1, the second port of the diode D1 is connected to the first input end of the switch module and the first port of the capacitor C1, and the second port of the capacitor C1 is connected to the second input end of the switch module, the second port of the switch K1 and the second output end of the rectifier and filter module.

[0013] In a feasible example, the buck module includes a switch K2, a diode D2, an inductor L2 and a capacitor C2; wherein the first port of the switch K2 is connected to the first output end of the switch module, the second port of the switch K2 is connected to the second port of the diode D2 and the first port of the inductor L2, the second port of the inductor L2 is connected to the first input end of the LED load and the first port of the capacitor C2, and the second port of the capacitor C2 is connected to the second input end of the LED load, the first port of the diode D2 and the second output end of the switch module.

[0014] In a feasible example, the rectifier and filter module includes a capacitor C3 and four diodes; wherein the four diodes form a rectifier bridge, the first input end of the rectifier bridge inputs a first AC voltage, the second input end of the rectifier bridge inputs a second AC voltage, the first output end of the rectifier bridge is connected to the first port of the capacitor C3 and the first input end of the boost module, and the second output end of the rectifier bridge is connected to the second port of the capacitor C3 and the second input end of the boost module.

[0015] In a feasible example, the circuit further includes a switch K0 , a first port of the switch K0 inputs an AC voltage, and a second port of the switch K0 is connected to a second input end of the rectifying and filtering module.

[0016] In a feasible example, when the switch K0 is turned off, the switch module controls the voltage-boosting module and the voltage-buckling module to be disconnected.

[0017] In a feasible example, the rectifying and filtering module further includes a fuse F1 , a first port of the fuse F1 inputs a first AC voltage, and a second port of the fuse F1 is connected to a first input end of the rectifier bridge.

[0018] In a feasible example, the LED load includes at least one light-emitting module, and the light-emitting module includes a light-emitting diode and two parasitic capacitors.

[0019] It can be seen that when one input end of the non-isolated switch circuit stops inputting AC voltage, the switch module is used to disconnect the boost module and the buck module, thereby disconnecting the power supply circuit of the non-isolated LED, and further completely shutting down the non-isolated LED. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the structure of a non-isolated switch circuit provided in an embodiment of the present application;

[0022] Figure 2 A non-isolated switch circuit topology diagram provided in an embodiment of the present application;

[0023] Figure 3 Another non-isolated switch circuit topology diagram provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0025] The terms "first", "second", etc. in the specification and claims of this application and the above drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions.

[0026] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0027] See also Figure 1 , Figure 1 A schematic diagram of a non-isolated switch circuit provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, it includes a rectifier and filter module 101 , a boost module 102 , a switch module 103 , a buck module 104 and an LED load 105 .

[0028] The first input terminal and the second input terminal of the rectifier and filter module 101 respectively input AC voltage, and the first input terminal and the second input terminal of the rectifier and filter module 101 can be connected to the live wire and the neutral wire respectively, or the first input terminal and the second input terminal of the rectifier and filter module 101 can be connected to two live wires respectively.

[0029] The first output end and the second output end of the rectifier and filter module 101 are respectively connected to the first input end and the second input end of the boost module 102, and the second input end of the boost module 102 is connected to the ground wire. The first output end and the second output end of the boost module 102 are respectively connected to the first input end and the second input end of the switch module 103, and the first output end and the second output end of the switch module 103 are respectively connected to the first input end and the second input end of the buck module 104, and the first output end and the second output end of the buck module 104 are respectively connected to the first input end and the second input end of the LED load 105, and the output end of the LED load 105 is connected to the ground wire.

[0030] The rectification and filtering module 101 is used to rectify and filter the input AC voltage.

[0031] The boost module 102 is used to increase the voltage output by the rectifier and filter module 101. The boost module 102 can be implemented by a BOOST circuit.

[0032] The switch module 103 is used to control the voltage boost module 102 and the voltage drop module 104 to be disconnected when the AC voltage is stopped being input to the second input terminal of the rectifier and filter module 101 .

[0033] The voltage reduction module 104 is used to reduce the voltage output by the voltage boost module 102. The voltage reduction module 104 can be implemented by a BUCK circuit.

[0034] It can be seen that when one input end of the non-isolated switch circuit stops inputting AC voltage, the switch module 103 is used to disconnect the boost module 102 and the buck module 104, thereby disconnecting the power supply circuit of the non-isolated LED, and further completely shutting down the non-isolated LED.

[0035] The following is a detailed description of the non-isolated switch circuit:

[0036] See also Figure 2 , Figure 2 A non-isolated switch circuit topology diagram provided in an embodiment of the present application, such as Figure 2 As shown, the non-isolated switch circuit includes a switch K0, a rectifier and filter module 101, a boost module 102, a switch module 103, a buck module 104 and an LED load 105, wherein the rectifier and filter module includes a fuse F1, a diode D4, a diode D5, a diode D6, a diode D7 and a capacitor C3; the boost module 102 includes an inductor L1, a switch K1, a diode D1 and a capacitor C2; the switch module 103 includes a diode D3 and a switch K3, and the buck module 104 includes a switch K2, a diode D2, an inductor L2 and a capacitor C2; the LED load 105 includes n light-emitting modules, each of which includes a light-emitting diode and two parasitic capacitors, for example, the first light-emitting module includes a light-emitting diode DL1, a parasitic capacitor Cs1 and a parasitic capacitor Cr1.

[0037] Among them, the first port of the fuse F1 is connected to the live wire (AC_L), the second port of the fuse F1 is connected to the second port of the diode D4 and the first port of the diode D5, the second port of the diode D5 is connected to the second port of the diode D6, the first port of the capacitor C3 and the first port of the inductor L1, the first port of the diode D6 is connected to the second port of the diode D7 and the second port of the switch K0, the first port of the diode D7 is connected to the first port of the diode D4, the second port of the capacitor C3, the second port of the switch K1, the second port of the capacitor C2 and the first port of the switch K3; the first port of the switch K0 is connected to the neutral line (AC_N), the second port of the capacitor C3 is also connected to the ground line (PE), and the ground line is grounded.

[0038] The second port of the inductor L1 is connected to the first port of the switch K1 and the first port of the diode D1, the second port of the diode D1 is connected to the first port of the diode D3 and the first port of the capacitor C2, the second port of the diode D3 is connected to the first port of the switch K2, the second port of the switch K2 is connected to the second port of the diode D2 and the first port of the inductor L2, the second port of the inductor L2 is connected to the first port of the capacitor C2, the first port of the light-emitting diode DL1, the first port of the parasitic capacitor Cs1 and the first port of the parasitic capacitor Cr1, the second port of the switch K3 is connected to the first port of the diode D2, the second port of the capacitor C2, the second port of the light-emitting diode DLn and the second port of the parasitic capacitor Csn; the n light-emitting modules are connected in series. For example, when n is equal to 2, the second port of the light-emitting diode DL1 is connected to the second port of the parasitic capacitor Cs1, the first port of the light-emitting diode DLn, the first port of the parasitic capacitor Csn and the first port of the parasitic capacitor Crn, and the second port of the parasitic capacitor Cr1 and the second port of the parasitic capacitor Crn are simultaneously connected to the ground line.

[0039] The rectifier and filter module 101 rectifies the input AC voltage through a rectifier bridge composed of diodes D4 , D5 , D6 and D7 , filters the voltage output by the rectifier bridge through capacitor C3 , and outputs a stable DC voltage.

[0040] The boost module 102 controls the on and off of the switch K1 to control the output voltage of the boost module 102 to be greater than the input voltage of the boost module 102 .

[0041] The switch module 103 controls the conduction and disconnection between the boost module 102 and the buck module 104 by controlling the conduction and disconnection of the switch K3. Specifically, when the switch K0 is disconnected, the switch K3 is controlled to be disconnected, so that the switch K3 and the diode D3 unidirectionally block the loop between the positive terminal of the LED load 105 or the negative terminal of the LED load 105 and the ground line, so that the voltage cannot pass through the light-emitting diode DL and its own parasitic capacitance Cs to complete the charge and discharge to the parasitic capacitance Cr, thereby achieving complete shutdown of the LED and achieving no afterglow.

[0042] The step-down module 104 controls the switch K2 to be turned on and off, thereby controlling the output voltage of the step-down module 104 to be lower than the input voltage of the step-down module 104 .

[0043] The aforementioned switches K1, K2 and K3 can all be controllable switch devices such as metal-oxide-semiconductor field-effect transistors (MOSFET), thyristors, relays, etc. When the aforementioned switches are MOS tubes, the MOS tubes can be but are not limited to ordinary silicon-based power field effect transistors (Si MOSFET), silicon carbide high electron mobility transistors (SiC HEMT), gallium nitride high electron mobility transistors (GaN HEMT), etc. Among them, the switch K0 is an ordinary mechanical switch, and the path between the external power grid and the rectifier and filter module is turned on or off by turning K0 on or off.

[0044] The aforementioned switches K1 , K2 and K3 should have corresponding control chips, and the conduction and disconnection of the aforementioned switches K1 , K2 and K3 should be controlled by the corresponding control chips.

[0045] For example, since it is necessary to control the disconnection of switch K3 when switch K0 is disconnected, the control power supply of the control chip corresponding to switch K3 can be provided by the input voltage corresponding to the second port of switch K0. When switch K0 is disconnected, there is no input voltage at the second port of switch K0, and thus the operating voltage cannot be provided to the control chip of switch K3, causing switch K3 to be disconnected.

[0046] Also, see Figure 3 , Figure 3 Another non-isolated switch circuit topology diagram provided in the embodiment of the present application is as follows: Figure 3 As shown, including Figure 2 All components of the non-isolated switch circuit shown in FIG. 1 are shown in FIG. 1 , but the connection positions of the switch K3 and the diode D3 in the switch module 103 are shown in FIG. 1 . Figure 3 There is a difference in.

[0047] The first port of switch K3 is connected to the second port of diode D1 and the first port of capacitor C2, the second port of switch K3 is connected to the first port of switch K2, the second port of diode D3 is connected to the second port of capacitor C2, and the first port of diode D3 is connected to the first port of diode D2.

[0048] Similarly, the switch module 103 controls the conduction and disconnection between the boost module 102 and the buck module 104 by still controlling the conduction and disconnection of the switch K3 .

[0049] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0050] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A non-isolated switch circuit, characterized in that: The circuit includes a rectifier and filter module, a boost module, a switch module, a buck module and an LED load; The first input end and the second input end of the rectifier and filter module are respectively input with an AC voltage, the first output end and the second output end of the rectifier and filter module are respectively connected with the first input end and the second input end of the boost module, and the second input end of the boost module is connected with a ground wire, the first output end and the second output end of the boost module are respectively connected with the first input end and the second input end of the switch module, the first output end and the second output end of the switch module are respectively connected with the first input end and the second input end of the buck module, the first output end and the second output end of the buck module are respectively connected with the first input end and the second input end of the LED load, and the output end of the LED load is connected with the ground wire; The rectification and filtering module is used to rectify and filter the input AC voltage; The boost module is used to increase the voltage output by the rectifier and filter module; The switch module is used to control the voltage boost module to be disconnected from the voltage buck module when the second input end of the rectifier and filter module stops inputting the AC voltage; The step-down module is used to reduce the voltage output by the step-up module.

2. The circuit according to claim 1, characterized in that The switch module includes a switch K3 and a diode D3; Among them, the first port of the diode D3 is connected to the first output end of the boost module, the second port of the diode D3 is connected to the first input end of the buck module, the first port of the switch K3 is connected to the second output end of the boost module, and the second port of the switch K3 is connected to the second input end of the buck module.

3. The circuit according to claim 1, characterized in that The switch module includes a switch K3 and a diode D3; Among them, the first port of the switch K3 is connected to the first output end of the boost module, the second port of the switch K3 is connected to the first input end of the buck module, the second port of the diode D3 is connected to the second output end of the boost module, and the first port of the diode D3 is connected to the second input end of the buck module.

4. The circuit according to any one of claims 1 to 3, characterized in that: The boost module includes an inductor L1, a switch K1, a diode D2 and a capacitor C1; Among them, the first port of the inductor L1 is connected to the first output end of the rectifier and filter module, the second port of the inductor L1 is connected to the first port of the switch K1 and the first port of the diode D1, the second port of the diode D1 is connected to the first input end of the switch module and the first port of the capacitor C1, and the second port of the capacitor C1 is connected to the second input end of the switch module, the second port of the switch K1 and the second output end of the rectifier and filter module.

5. The circuit according to claim 1, characterized in that The step-down module includes a switch K2, a diode D2, an inductor L2 and a capacitor C2; The first port of the switch K2 is connected to the first output end of the switch module, the second port of the switch K2 is connected to the second port of the diode D2 and the first port of the inductor L2, the second port of the inductor L2 is connected to the first input end of the LED load and the first port of the capacitor C2, and the second port of the capacitor C2 is connected to the second input end of the LED load, the first port of the diode D2, and the second output end of the switch module.

6. The circuit according to claim 1, characterized in that The rectification and filtering module includes a capacitor C3 and four diodes; Among them, the four diodes form a rectifier bridge, the first input end of the rectifier bridge inputs a first AC voltage, the second input end of the rectifier bridge inputs a second AC voltage, the first output end of the rectifier bridge is connected to the first port of the capacitor C3 and the first input end of the boost module, and the second output end of the rectifier bridge is connected to the second port of the capacitor C3 and the second input end of the boost module.

7. The circuit according to claim 1, characterized in that The circuit further comprises a switch K0 , a first port of the switch K0 inputs an AC voltage, and a second port of the switch K0 is connected to a second input end of the rectifying and filtering module.

8. The circuit according to claim 7, characterized in that When the switch K0 is disconnected, the switch module controls the voltage boost module and the voltage drop module to be disconnected.

9. The circuit according to claim 6, characterized in that The rectification and filtering module further includes a fuse F1 , a first port of the fuse F1 inputs the first AC voltage, and a second port of the fuse F1 is connected to a first input end of the rectifier bridge.

10. The circuit according to claim 1, characterized in that The LED load includes at least one light emitting module, and the light emitting module includes a light emitting diode and two parasitic capacitors.

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