LED switching system and control method thereof

Abstract

The application provides an LED switching system and a control method thereof. The LED switching system is electrically connected to a three-phase power supply device including first, second and third phase terminals. The LED switching system includes a control unit and a light emitting module. The control unit is electrically connected to the first phase terminal and includes N control switches, where N is a positive integer. The light emitting unit of the light emitting module includes a power supply circuit, (N+1) LED strings and a switching circuit electrically connected to each other. The power supply circuit is electrically connected to any two phase terminals and supplies power to the LED strings. The switching circuit is electrically connected to the second or third phase terminal and the control unit to switch according to the switching state of the control switches to turn on the corresponding LED string.

Description

TECHNICAL FIELD

[0001] The present application relates to a switching system and a control method thereof, in particular to a LED switching system and a control method thereof. BACKGROUND

[0002] In the application of traditional fishing lamps, in order to emit corresponding light colors for various fish habits to lure the fish, various light bulbs of different colors must be installed to change the light color according to actual needs. In terms of light switching control, a control switch must be set up for each light bulb, resulting in complex wiring and complicated control. The control switch actually needs to flow through the current driving the light bulb, so a larger rated current specification switch must be selected, thus occupying a larger space.

[0003] Therefore, how to develop a LED switching system and a control method thereof to improve the problems of the prior art is an urgent need at present. SUMMARY

[0004] The purpose of the present application is to provide a LED switching system and a control method thereof, which realizes the switching conduction of multiple LED strings with a small number of switches, is simple in wiring and easy to control, and the switch is only used for signal driving, so a smaller rated current specification switch can be selected, the occupied space is small, and the cost is also lower.

[0005] To achieve the above purpose, the present application provides a LED switching system electrically connected to a three-phase power supply device, wherein the three-phase power supply device includes a first phase terminal, a second phase terminal and a third phase terminal for providing three phase voltages respectively. The LED switching system includes a control unit and a light emitting module. The control unit is electrically connected to the first phase terminal of the three-phase power supply device and includes N control switches, where N is a positive integer. The light emitting module includes a light emitting unit, which includes a power supply circuit, (N+1) LED strings and a switching circuit electrically connected to each other. The power supply circuit is also electrically connected to any two of the three phase terminals of the three-phase power supply device and provides a power supply voltage to the (N+1) LED strings. The switching circuit is also electrically connected to the second phase terminal or the third phase terminal of the three-phase power supply device, and the switching circuit is also electrically connected to the control unit to switch according to the switching state of the control switch to make the corresponding LED string conductive.

[0006] To achieve the above object, the present application provides a control method of an LED switching system. The LED switching system is electrically connected to a three-phase power supply device, wherein the three-phase power supply device comprises a first phase terminal, a second phase terminal and a third phase terminal for providing three phase voltages respectively. The LED switching system comprises a control unit and a light emitting module. The control unit is electrically connected to the first phase terminal of the three-phase power supply device, and comprises N control switches, wherein N is a positive integer. The light emitting module comprises a light emitting unit, and the light emitting unit comprises a power supply circuit, (N+1) LED strings and a switching circuit which are electrically connected to each other. The power supply circuit is further electrically connected to any two of the three phase terminals of the three-phase power supply device, and provides a power supply voltage to the (N+1) LED strings. The switching circuit is further electrically connected to the second phase terminal or the third phase terminal of the three-phase power supply device, and the switching circuit is further electrically connected to the control unit. The control method comprises: (a) controlling the N control switches to be all off, so that the first LED string is turned on; and (b) controlling the nth control switch to be turned on, so that the switching circuit is further electrically connected to the first phase terminal through the nth control switch, and the switching circuit is controlled to switch so that the (n+1)th LED string is turned on, wherein n is a positive integer less than or equal to N. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 The circuit structure schematic diagram of the LED switching system of the first embodiment of the present application;

[0008] Figure 2 The circuit structure schematic diagram of the LED switching system of the first embodiment of the present application when N=1; Figure 1 The circuit structure schematic diagram of the LED switching system of the first embodiment of the present application when N=1;

[0009] Figure 3 The circuit structure schematic diagram of the LED switching system of the second embodiment of the present application;

[0010] Figure 4 The circuit structure schematic diagram of the LED switching system of the second embodiment of the present application when N=1; Figure 3 The circuit structure schematic diagram of the LED switching system of the second embodiment of the present application when N=1;

[0011] Figure 5 The circuit structure schematic diagram of the LED switching system of the third embodiment of the present application;

[0012] Figure 6 The circuit structure schematic diagram of the LED switching system of the third embodiment of the present application when N=1; Figure 5 The circuit structure schematic diagram of the LED switching system of the third embodiment of the present application when N=1;

[0013] Figure 7 The circuit structure schematic diagram of the LED switching system of the fourth embodiment of the present application;

[0014] Figure 8 The circuit structure schematic diagram of the LED switching system of the fourth embodiment of the present application when N=1; Figure 7 The circuit structure schematic diagram of the LED switching system of the fourth embodiment of the present application when N=1;

[0015] Figure 9 Circuit structure schematic diagram of LED switching system of the fifth embodiment of the present application;

[0016] Figure 10 Circuit structure schematic diagram of LED switching system of the fifth embodiment of the present application; Figure 9 Circuit structure schematic diagram of LED switching system of the fifth embodiment of the present application;

[0017] Figure 11 Circuit structure schematic diagram of LED switching system of the sixth embodiment of the present application;

[0018] Figure 12 Circuit structure schematic diagram of LED switching system of the sixth embodiment of the present application; Figure 11 Circuit structure schematic diagram of LED switching system of the sixth embodiment of the present application;

[0019] Figure 13A , 13B , 13C and 13D illustrate various possible implementation manners of the internal control circuit in the LED switching system. Figure 10

[0020]

Symbol explanation

[0021] 1: LED switching system

[0022] 2: Three-phase power supply device

[0023] L1, L2, L3: Phase terminal

[0024] 11: Control unit

[0025] 12: Light emitting module

[0026] SW1, SW2, SWN: Control switch

[0027] 13: Light emitting unit

[0028] 14: Power supply circuit

[0029] LED1, LED2, LED3, LED(N+1): LED string

[0030] 15: Switching circuit

[0031] AC1, AC2: AC terminal

[0032] DC+: First DC terminal

[0033] DC-: Second DC terminal

[0034] RY1, RY2, RYN: Relay

[0035] 151: Coil

[0036] 152: Switching switch

[0037] P1: First contact​

[0038] P2: Second contact point

[0039] P3: Third junction

[0040] VCC1: First power supply terminal

[0041] VCC2: Second power supply terminal

[0042] OC1, OC2, OCN: Isolators

[0043] 153: Internal Controller

[0044] Q1, Q2, Q3, Q(N+1): Drive switches

[0045] 154: Coil

[0046] 155: Switch

[0047] 156: Launcher

[0048] 157: Receiver

[0049] 158: Internal control circuit

[0050] 159: Driver Detailed Implementation

[0051] Some typical embodiments embodying the features and advantages of this application will be described in detail in the following description. It should be understood that this application can have various variations in different forms, all of which do not depart from the scope of this application, and the descriptions and illustrations therein are for illustrative purposes only and not intended to limit this application.

[0052] Figure 1 This is a schematic diagram of the circuit structure of the LED switching system according to the first embodiment of this application. Figure 1 As shown, the LED switching system 1 is electrically connected to the three-phase power supply device 2, which includes three phase terminals L1, L2, and L3. These three phase terminals L1, L2, and L3 provide three phase voltages with a phase difference of 120 degrees. In this embodiment, phase terminals L1, L2, and L3 are respectively used as the first phase terminal, the second phase terminal, and the third phase terminal (i.e., the first phase terminal L1, the second phase terminal L2, and the third phase terminal L3). However, this is not a limitation; in other embodiments, phase terminals L1, L3, and L2 can also be used as the first, second, and third phase terminals, or vice versa.

[0053] The LED switching system 1 comprises a control unit 11 and a light emitting module 12. The control unit 11 is electrically connected to a first phase terminal LI of a three-phase power supply device 2, and comprises N control switches SW1, SW2, …, SWN, where N is a positive integer. The light emitting module 12 comprises a light emitting unit 13, where the light emitting unit 13 comprises a power supply circuit 14, (N+1) LED strings LED1, LED2, …, LED(N+1), and a switching circuit 15 electrically connected to each other. The power supply circuit 14 is further electrically connected to any two of three phase terminals LI, L2, and L3 of the three-phase power supply device 2, and provides a power supply voltage to the LED strings LED1, LED2, …, LED(N+1). Each of the LED strings LED1, LED2, …, LED(N+1) may, for example but not limited to, comprise a plurality of LEDs connected in series, where the plurality of LEDs of the same LED string preferably but not limited to have the same light color. The switching circuit 15 is further electrically connected to a second phase terminal L2 or a third phase terminal L3 of the three-phase power supply device 2 (the subsequent drawings and descriptions take the third phase terminal L3 as an example), and the switching circuit 15 is further electrically connected to the control unit 11 to switch the corresponding LED string to be turned on according to the switching state of the control switches SW1, SW2, …, SWN. Specifically, when all the control switches SW1, SW2, …, SWN are turned off, the first LED string LED1 is turned on; and when the nth control switch SWn is turned on, the switching circuit 15 is further electrically connected to the first phase terminal LI via the nth control switch SWn, and switches the (n+1)th LED string LED(n+1) to be turned on, where n is a positive integer less than or equal to N.

[0054] Therefore, a smaller number of control switches than the conventional fishing light frame can be used to switch and turn on the plurality of LED strings, the wiring is relatively simple, and it is relatively easy to control. The control switches are only used for signal driving, and switches with a smaller rated current specification can be selected, thereby occupying a smaller space and having a lower cost.

[0055] In practice, the number of control switches in the on state at the same time is not limited. For example, in some embodiments, at most only one control switch is in the on state at any time; in other embodiments, a plurality of control switches can be in the on state at the same time.

[0056] In addition, in the LED switching system 1 of the present application, the number of light emitting units 13 is not limited, for example, in some embodiments, there is only one light emitting unit 13; in other embodiments, there are a plurality of light emitting units 13. Figure 1In the shown embodiment, each light emitting module 12 comprises three light emitting units 13, wherein each light emitting unit 13 is electrically connected to the control unit 11 and the three-phase power supply device 2. The (N+1) LED strings LED1, LED2, …, LED(N+1) in each light emitting unit 13 are preferably arranged in the same light color order, but are not limited thereto. In addition, in the LED switching system 1 of the present application, the number of control units 11 and the number of light emitting modules 12 are the same and are not limited, for example, the LED switching system 1 can comprise a plurality of control units 11 and a plurality of light emitting modules 12 corresponding to each other one by one, and the LED strings in each light emitting module 12 can be arranged in the same or different light color order. Therefore, when the LED switching system 1 of the present application is applied to a fishing lamp, all control units 11 can be centrally arranged in the same space, and light emitting modules 12 can be arranged in different areas on the fishing boat, so that the user can centrally control the light color of the LEDs in each area.

[0057] In addition, each LED string has opposite first and second ends. In the case where the LED string comprises a plurality of LEDs connected in series, the first end of the LED string is connected to the anode of the first LED, and the cathode of each LED is sequentially connected to the anode of the next LED, and the cathode of the last LED is connected to the second end of the LED string.

[0058] In some embodiments, the power supply circuit 14 comprises two alternating current terminals AC1 and AC2, a first direct current terminal DC+, and a second direct current terminal DC-. The two alternating current terminals AC1 and AC2 are electrically connected to any two phase terminals of the three-phase power supply device 2, and in the shown embodiment, the two alternating current terminals AC1 and AC2 of the power supply circuit 14 in the first light emitting unit 13 are electrically connected to the first and second phase terminals L1 and L2, respectively, the two alternating current terminals AC1 and AC2 of the power supply circuit 14 in the second light emitting unit 13 are electrically connected to the second and third phase terminals L2 and L3, respectively, and the two alternating current terminals AC1 and AC2 of the power supply circuit 14 in the third light emitting unit 13 are electrically connected to the first and third phase terminals L1 and L3, respectively, but are not limited thereto, and in actual application, the phase terminals to which the power supply circuit 14 in each light emitting unit 13 is connected can be adjusted as needed. Figure 1

[0059] The switching circuit 15 of the LED switching system 1 of the present application has various possible implementation forms, which will be specifically exemplified and described below.

[0060] In the first embodiment of the present application, as shown in FIG. 1, the switching circuit 15 comprises a plurality of switching units 151, 152, and 153 corresponding to the plurality of light emitting units 13, respectively. Figure 1 ​As shown, the switching circuit 15 includes N relays RY1, RY2, ..., RYN, each electrically connected to N control switches SW1, SW2, ..., SWN. Each relay (RY1, RY2, ..., RYN) includes a coil 151 and a switching switch 152. The two ends of the coil 151 are electrically connected to the corresponding control switch (SW1, SW2, ..., SWN) and the third phase terminal L3, respectively. The switching switch 152 includes a first contact P1, a second contact P2, and a third contact P3. The third contact P3 is electrically connected to the second contact P2 and the first contact P1 when the coil 151 is energized and de-energized, respectively.

[0061] The first terminals of all (N+1) LED strings LED1 to LED(N+1) are electrically connected to the first DC terminal DC+. The second terminal of the first LED string LED1 is electrically connected to the first contact P1 of the first relay RY1. The second terminals of the second to (N+1)th LED strings LED2 to LED(N+1) are electrically connected to the second contacts P2 of the first to Nth relays RY1 to RYN, respectively. The first contacts P1 of the second to Nth relays RY2 to RYN are electrically connected to the third contacts P3 of the first to (N-1)th relays RY1 to RY(N-1), respectively. The third contact P3 of the Nth relay RYN is grounded.

[0062] When all control switches SW1 to SWN are off, the third contact P3 of all relays RY1 to RYN is electrically connected to the first contact P1, turning on the first LED string LED1. When the nth control switch SWn is on, the third contact P3 of the nth relay RYn is electrically connected to the second contact P2, turning on the (n+1)th LED string LED(n+1).

[0063] Figure 2 for Figure 1 The circuit diagram of the LED switching system when N=1 is shown. Figure 2 As shown, when N=1, the number of control switches and relays in each light-emitting unit 13 is equal to 1. The first contact P1, the second contact P2, and the third contact P3 of relay RY1 are electrically connected to the second terminal of the first LED string LED1, the second terminal of the second LED string LED2, and the ground terminal, respectively. The first terminals of both LED strings LED1 and LED2 are electrically connected to the first DC terminal DC+.

[0064] In the second embodiment of this application, as Figure 3As shown, the switching circuit 15 includes N relays RY1, RY2, ..., RYN, each electrically connected to N control switches SW1, SW2, ..., SWN. Each relay (RY1, RY2, ..., RYN) includes a coil 151 and a switching switch 152. The two ends of each coil 151 are electrically connected to the control switch (SW1, SW2, ..., SWN) and the third phase terminal L3 corresponding to each relay (RY1, RY2, ..., RYN). The switching switch 152 includes a first contact P1, a second contact P2, and a third contact P3. The third contact P3 is electrically connected to the second contact P2 and the first contact P1 when the coil 151 is energized and de-energized, respectively.

[0065] The third contact P3 of the first relay RY1 is electrically connected to the first DC terminal DC+. The third contacts P3 of the second to Nth relays RY2 to RYN are respectively electrically connected to the first contacts P1 of the first to (N-1)th relays RY1 to RY(N-1). The first contact P1 of the Nth relay RYN is electrically connected to the first terminal of the first LED string LED1. The first terminals of the second to (N+1)th LED strings LED2 to LED(N+1) are respectively electrically connected to the second contacts P2 of the first to Nth relays RY1 to RYN. The second terminals of all (N+1)th LED strings LED1 to LED(N+1) are grounded.

[0066] When all control switches SW1 to SWN are off, the third contact P3 of all relays RY1 to RYN is electrically connected to the first contact P1, turning on the first LED string LED1. When the nth control switch SWn is on, the third contact P3 of the nth relay RYn is electrically connected to the second contact P2, turning on the (n+1)th LED string LED(n+1).

[0067] Figure 4 for Figure 3 The circuit diagram of the LED switching system when N=1 is shown. Figure 4 As shown, when N=1, the number of control switches and relays in each light-emitting unit 13 is equal to 1. The first contact P1, the second contact P2, and the third contact P3 of relay RY1 are electrically connected to the second terminal of the first LED string LED1, the second terminal of the second LED string LED2, and the first DC terminal DC+, respectively. The second terminals of both LED strings LED1 and LED2 are grounded.

[0068] In the third embodiment of this application, as Figure 5As shown, the power supply circuit 14 further comprises a first supply terminal VCC1 and a second supply terminal VCC2, wherein the first supply terminal VCC1 and the second supply terminal VCC2 are configured to provide a first voltage and a second voltage, respectively. The switching circuit 15 comprises N relays RY1, RY2, …, RYN, N isolators OC1, OC2, …, OCN, an internal controller 153, and (N+1) driving switches Q1, Q2, …, Q(N+1). The N relays RY1-RYN are electrically connected to the N control switches SW1-SWN, respectively, and the N isolators OC1-OCN are electrically connected to the N relays RY1-RYN, respectively. Each relay (RY1-RYN) comprises a coil 154 and a switching switch 155, wherein two ends of each coil 154 are electrically connected to the control switch (SW1-SWN) corresponding to the relay (RY1-RYN) and a third phase terminal L3, respectively, and two ends of each switching switch 155 are electrically connected to the first supply terminal VCC1 and the transmitter 156 of the isolator (OC1-OCN) corresponding to the relay (RY1-RYN), respectively. The switching switch 155 is turned on when the coil 154 is energized, and is turned off when the coil 154 is not energized. Two ends of the receiver 157 of each isolator (OC1-OCN) are electrically connected to the second supply terminal VCC2 and the internal controller 153, respectively, and when the transmitter 156 corresponding to the receiver 157 receives the first voltage through the turn-on of the switching switch 155, the receiver 157 transmits the second voltage to the internal controller 153. The internal controller 153 is electrically connected to all the (N+1) driving switches Q1-Q(N+1), and is configured to control the switching state of all the (N+1) driving switches Q1-Q(N+1). The first ends of all the (N+1) LED strings LED1-LED(N+1) are electrically connected to the first DC terminal DC+, and the second ends of all the (N+1) LED strings LED1-LED(N+1) are electrically connected to all the (N+1) driving switches Q1-Q(N+1), respectively. The isolators (OC1-OCN) of the present application can be, for example but not limited to, optocoupler elements or digital isolators. For example, when the isolators (OC1-OCN) are optocoupler elements, the transmitter 156 and the receiver 157 are light transmitters and light receivers, respectively, wherein the light transmitter and the light receiver can be a light source and a light sensor, respectively, such as an LED and a phototransistor, but are not limited thereto, as long as the light receiver can be triggered to turn on when the light transmitter receives the first voltage.

[0069] When all control switches SW1 to SWN are off, the switching switches 155 of all relays RY1 to RYN are off. The internal controller 153 does not receive the second voltage transmitted by any isolator (OC1 to OCN), so it controls the first drive switch Q1 to turn on, making the first LED string LED1 turn on. When the nth control switch SWn turns on, the switching switch 155 of the nth relay RYn turns on and transmits the first voltage to the transmitter 156 of the nth isolator OCn. The receiver 157 of the nth isolator OCn is triggered and transmits the second voltage to the internal controller 153. The internal controller 153 then controls the (n+1)th drive switch Q(n+1) to turn on, making the (n+1)th LED string LED(n+1) turn on.

[0070] Figure 6 for Figure 5 The circuit diagram of the LED switching system when N=1 is shown. Figure 6 As shown, when N=1, the number of control switches, relays in each light-emitting unit 13, and isolators is equal to 1, and the number of drive switches is equal to 2. The two ends of the switching switch 155 of relay RY1 are electrically connected to the first power supply terminal VCC1 and the transmitter 156 of isolator OC1, respectively. The two ends of the receiver 157 of isolator OC1 are electrically connected to the second power supply terminal VCC2 and the internal controller 153, respectively. The internal controller 153 is connected to drive switches Q1 and Q2. The first ends of LED strings LED1 and LED2 are both electrically connected to the first DC terminal DC+, and the second ends of LED strings LED1 and LED2 are electrically connected to drive switches Q1 and Q2, respectively.

[0071] In the fourth embodiment of this application, as Figure 7 As shown, where with Figure 5 In the third embodiment shown, components with similar structures and functions are represented by the same reference numerals, and their control method for the LED string is the same as... Figure 5 The third embodiment shown is the same. However, compared to... Figure 5 The third embodiment shown is in Figure 7 In the fourth embodiment shown, the first ends of all (N+1) LED strings LED1 to LED(N+1) are electrically connected to the first DC terminal DC+ via all (N+1) drive switches Q1 to Q(N+1), and the second ends of all (N+1) LED strings LED1 to LED(N+1) are grounded.

[0072] Figure 8 for Figure 7 The circuit diagram of the LED switching system when N=1 is shown. Figure 8As shown, when N = 1, the number of control switches, the number of relays and the number of isolators in each light emitting unit 13 are all equal to 1, and the number of driving switches is equal to 2. The two ends of the switching switch 155 of the relay RYl are electrically connected to the first power supply terminal VCCl and the transmitter 156 of the isolator OC1, respectively. The two ends of the receiver 157 of the isolator OC1 are electrically connected to the second power supply terminal VCC2 and the internal controller 153, respectively. The internal controller 153 is connected to the driving switches Ql and Q2. The first ends of the LED strings LEDl and LED2 are electrically connected to the first DC terminal DC+ via the driving switches Ql and Q2, respectively, and the second ends of the LED strings LEDl and LED2 are both grounded.

[0073] In the fifth embodiment of the present application, as shown in Figure 9 the power supply circuit 14 further comprises a first power supply terminal VCCl and a second power supply terminal VCC2, wherein the first power supply terminal VCCl and the second power supply terminal VCC2 are used to provide a first voltage and a second voltage, respectively. The switching circuit 15 comprises an internal control circuit 158 and (N+l) driving switches Ql, Q2,..., Q(N+l). The internal control circuit 158 is electrically connected to all the N control switches SWl-SWN, the third phase terminal L3 and all the (N+l) driving switches Ql-Q(N+l). The first ends of all the (N+l) LED strings LEDl-LED(N+l) are electrically connected to the first DC terminal DC+, and the second ends of all the (N+l) LED strings LEDl-LED(N+l) are electrically connected to all the (N+l) driving switches Ql-Q(N+l), respectively.

[0074] When all the control switches SWl-SWN are turned off, the internal control circuit 158 controls the first driving switch Ql to be turned on, so that the first LED string LEDl is turned on. When the nth control switch SWn is turned on, the AC power provided by the first phase terminal LI and the third phase terminal L3 is input to the internal control circuit 158, and the internal control circuit 158 controls the (n+l)th driving switch Q(n+l) to be turned on, so that the (n+l)th LED string LED(n+l) is turned on.

[0075] Figure 10 For Figure 9 the circuit structure of the LED switching system when N = 1. As shown in Figure 10 when N = 1, the number of control switches is equal to 1, and the number of driving switches in each light emitting unit 13 is equal to 2. The internal control circuit 158 is electrically connected to the control switch SWl, the third phase terminal L3 and the two driving switches Ql and Q2. The first ends of the two LED strings LEDl and LED2 are both electrically connected to the first DC terminal DC+, and the second ends of the two LED strings LEDl and LED2 are electrically connected to the two driving switches Ql and Q2, respectively.

[0076] In the sixth embodiment of the present application, as shown in Figure 11 the elements having similar structures and functions as those in the fifth embodiment shown in Figure 9 are denoted by the same reference numerals, and the control mode of the LED strings is the same as that of the fifth embodiment shown in Figure 9 However, compared with the fifth embodiment shown in Figure 9 in the sixth embodiment shown in Figure 11 , the first ends of all the (N+1) LED strings LED1-LED(N+1) are electrically connected to the first DC terminal DC+ via all the (N+1) driving switches Q1-Q(N+1), and the second ends of all the (N+1) LED strings LED1-LED(N+1) are grounded.

[0077] Figure 12 The circuit structure schematic diagram of the LED switching system of N=1 is shown in Figure 11 As shown in Figure 10 when N=1, the number of control switches is equal to 1, and the number of driving switches in each light emitting unit 13 is equal to 2. The internal control circuit 158 is electrically connected to the control switch SW1, the third phase terminal L3, and the two driving switches Q1 and Q2. The first ends of the two LED strings LED1 and LED2 are electrically connected to the first DC terminal DC+ via the driving switches Q1 and Q2, respectively, and the second ends of the two LED strings LED1 and LED2 are grounded.

[0078] In the embodiments shown in Figures 5 to 12 , the driving switches can be, for example but not limited to, metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0079] In practical applications, appropriate switching circuit implementation can be selected according to requirements. For example, when applied to super-high power LED lamps above kilowatts, if the switching circuit in the first or second embodiment is used, a high-voltage relay must be selected, which will result in a substantial increase in cost, so it is better to use the switching circuit in the third to sixth embodiments in this case.

[0080] In addition, Figures 9 to 12 the internal control circuit 158 in the embodiments shown in Figure 10 includes various possible implementations, which are exemplarily illustrated below with the internal control circuit 158 in , and for the sake of simplicity of the drawing, only the internal control circuit 158 and the driving switches Q1 and Q2 are shown in the drawing.

[0081] Figure 13AAs shown, in some embodiments, the internal control circuit 158 ​​includes a relay RY1, an isolator OC1, and an internal controller 153. The relay RY1 includes a coil 154 and a switch 155, wherein the two ends 154a and 154b of the coil 154 are electrically connected to a control switch SW1 and a third phase terminal L3, respectively, and the two ends of the switch 155 are electrically connected to a first power supply terminal VCC1 and a transmitter 156 of the isolator OC1, respectively. The switch 155 is turned on when the coil 154 is energized and turned off when the coil 154 is not energized. The two ends of the receiver 157 of the isolator OC1 are electrically connected to a second power supply terminal VCC2 and the internal controller 153, respectively. When the transmitter 156 corresponding to the receiver 157 receives a first voltage through the conduction of the switch 155, the receiver 157 transmits a second voltage to the internal controller 153. The internal controller 153 is electrically connected to drive switches Q1 and Q2 and is used to control the switching states of drive switches Q1 and Q2.

[0082] like Figure 13B As shown, in some embodiments, it can be Figure 13A The relay RY1 is replaced by driver 159. The two ends 159a and 159b of driver 159 are electrically connected to control switch SW1 and third phase terminal L3, respectively, and driver 159 is also electrically connected to first power supply terminal VCC1 and transmitter 156 of isolator OC1. Driver 159 is mounted on control isolator OC1.

[0083] like Figure 13C As shown, in some embodiments, the internal control circuit 158 ​​includes a relay RY1 and an internal controller 153. The relay RY1 includes a coil 154 and a switch 155, wherein the two ends 154a and 154b of the coil 154 are electrically connected to a control switch SW1 and a third phase terminal L3, respectively. One end of the switch 155 is electrically connected to a first power supply terminal VCC1 and one end of the internal controller 153, and the other end of the switch 155 is electrically connected to the other end of the internal controller 153. The switch 155 is turned on when the coil 154 is energized and turned off when the coil 154 is not energized. The internal controller 153 is also electrically connected to drive switches Q1 and Q2 and is used to control the switching states of drive switches Q1 and Q2.

[0084] like Figure 13D As shown, in some embodiments, the internal control circuit 158 ​​includes an internal controller 153. The first terminal 153a, the second terminal 153b, the third terminal 153c, and the fourth terminal 153d of the internal controller 153 are electrically connected to the control switch SW1, the third phase terminal L3, the drive switch Q1, and the drive switch Q2, respectively, and the fifth terminal 153e of the internal controller 153 is grounded. The internal controller 153 is configured to control the switching states of the drive switches Q1 and Q2.

[0085] It can be understood that the various possible implementation manners of the internal control circuit 158 exemplified in Figures 13A to 13D are also applicable to the internal control circuit 158 in Figure 10 , Figure 9 , 11 and 12. In the case where the number of control switches is N, the number of driving switches and LED strings is N+1, and in the case of using the implementation manner shown in Figure 13A , the number of relays and isolators is N, and the number of internal controllers is 1; in the case of using the implementation manner shown in Figure 13B , the number of drivers and isolators is N, and the number of internal controllers is 1; in the case of using the implementation manner shown in Figure 13C , the number of relays is N, and the number of internal controllers is 1; in the case of using the implementation manner shown in Figure 13D , the number of internal controllers is 1.

[0086] In summary, the present application provides an LED switching system and a control method thereof, which realizes switching conduction of multiple LED strings with a small number of switches, is relatively simple in wiring, is relatively easy to control, and has a small occupied space and a low cost. In addition, appropriate switching circuit implementation manners can be used according to actual needs, so that the applicability of the LED switching system is improved.

[0087] It should be noted that the above is only a preferred embodiment proposed for the purpose of illustrating the present application, and the scope of the present application is determined by the appended claims. The present application can be modified in various ways by those skilled in the art, but all modifications shall not deviate from the scope of protection desired by the appended claims.

Claims

1. An LED switching system, characterized in that, Electrically connected to a three-phase power supply unit, wherein the three-phase power supply unit includes a first phase terminal, a second phase terminal, and a third phase terminal respectively providing three phase voltages, the LED switching system includes: A control unit, electrically connected to the first phase terminal of the three-phase power supply, and comprising N control switches, where N is a positive integer; and A light-emitting module includes a light-emitting unit, wherein the light-emitting unit includes a power supply circuit, (N+1) LED strings and a switching circuit that are electrically connected to each other; the power supply circuit is also electrically connected to any two of the three phase terminals of the three-phase power supply device and provides a power supply voltage to the (N+1) LED strings; the switching circuit is also electrically connected to the second phase terminal or the third phase terminal of the three-phase power supply device, and the switching circuit is also electrically connected to the control unit to switch according to the switching state of the N control switches to turn on the LED string corresponding to the control switch.

2. The LED switching system as described in claim 1, characterized in that, The power supply circuit includes two AC terminals, a first DC terminal and a second DC terminal, wherein the two AC terminals are electrically connected to any two phase terminals of the three-phase power supply device, the first DC terminal is used to provide the power supply voltage, and the second DC terminal is grounded.

3. The LED switching system as described in claim 2, characterized in that, The switching circuit includes N relays electrically connected to the N control switches. Each relay includes a coil and a switching switch. The two ends of the coil are electrically connected to the control switch corresponding to the relay and the second phase terminal or the third phase terminal, respectively. The switching switch includes a first contact, a second contact, and a third contact. The third contact is electrically connected to the second contact and the first contact when the coil is energized and de-energized, respectively. The first ends of the (N+1) LED strings are all electrically connected to the first DC terminal. The second end of the first LED string is electrically connected to the first contact of the first relay. The second ends of the second to (N+1) LED strings are electrically connected to the second contacts of the first to Nth relays, respectively. The first contacts of the second to Nth relays are electrically connected to the third contacts of the first to (N-1)th relays, respectively. The third contact of the Nth relay is grounded.

4. The LED switching system as described in claim 2, characterized in that, The switching circuit includes N relays electrically connected to the N control switches. Each relay includes a coil and a switching switch. The two ends of the coil are electrically connected to the control switch corresponding to the relay and the second phase terminal or the third phase terminal, respectively. The switching switch includes a first contact, a second contact, and a third contact. The third contact is electrically connected to the second contact and the first contact when the coil is energized and de-energized, respectively. The third contact of the first relay is electrically connected to the first DC terminal. The third contacts of the second to Nth relays are electrically connected to the first contacts of the first to (N-1)th relays, respectively. The first contact of the Nth relay is electrically connected to the first terminal of the first LED string. The first terminals of the second to (N+1)th LED strings are electrically connected to the second contacts of the first to Nth relays, respectively. The second terminals of the (N+1)th LED strings are all grounded.

5. The LED switching system as described in claim 2, characterized in that, The power supply circuit also includes a first power supply terminal and a second power supply terminal, which are used to provide a first voltage and a second voltage, respectively. The switching circuit includes an internal control circuit and (N+1) drive switches. The internal control circuit is electrically connected to the N control switches, the second phase terminal or the third phase terminal, and the (N+1) drive switches. The first terminals of the (N+1) LED strings are all electrically connected to the first DC terminal, and the second terminals of the (N+1) LED strings are respectively electrically connected to the (N+1) drive switches. When all N control switches are off, the internal control circuit controls the first drive switch to turn on, so that the first LED string is turned on. When the nth control switch is turned on, the internal control circuit controls the (n+1)th drive switch to turn on, so that the (n+1)th LED string is turned on, where n is a positive integer less than or equal to N.

6. The LED switching system as described in claim 2, characterized in that, The power supply circuit also includes a first power supply terminal and a second power supply terminal, which are used to provide a first voltage and a second voltage, respectively. The switching circuit includes an internal control circuit and (N+1) drive switches. The internal control circuit is electrically connected to the N control switches, the second phase terminal or the third phase terminal, and the (N+1) drive switches. The first terminals of the (N+1) LED strings are respectively electrically connected to the first DC terminal via the (N+1) drive switches, and the second terminals of the (N+1) LED strings are all grounded. When all N control switches are off, the internal control circuit controls the first drive switch to turn on, so that the first LED string is turned on. When the nth control switch is turned on, the internal control circuit controls the (n+1)th drive switch to turn on, so that the (n+1)th LED string is turned on, where n is a positive integer less than or equal to N.

7. The LED switching system as described in claim 5 or 6, characterized in that, The internal control circuit includes N relays, N isolators, and an internal controller. The N relays are electrically connected to the N control switches, and the N isolators are electrically connected to the N relays. Each relay includes a coil and a switching switch. The two ends of the coil are electrically connected to the control switch corresponding to the relay and to either the second phase terminal or the third phase terminal. The two ends of the switching switch are electrically connected to the first power supply terminal and the transmitter of the corresponding isolator. The switching switch is turned on when the coil is energized and turned off when the coil is not energized. The two ends of the receiver of each isolator are electrically connected to the second power supply terminal and the internal controller. The internal controller is electrically connected to the (N+1) drive switches and is used to control the switching state of the (N+1) drive switches.

8. The LED switching system as described in claim 5 or 6, characterized in that, The internal control circuit includes N drivers, N isolators, and an internal controller. Each driver is electrically connected to the second phase terminal or the third phase terminal and the corresponding control switch. The N isolators are electrically connected to the N drivers. Each driver is also electrically connected to the first power supply terminal and the transmitter of the corresponding isolator. The two ends of the receiver of each isolator are electrically connected to the second power supply terminal and the internal controller. The internal controller is electrically connected to the (N+1) drive switches and is used to control the switching state of the (N+1) drive switches.

9. The LED switching system as described in claim 5 or 6, characterized in that, The internal control circuit includes N relays and an internal controller. The N relays are electrically connected to the N control switches. Each relay includes a coil and a switching switch. The two ends of the coil are electrically connected to the control switch corresponding to the relay and the second phase terminal or the third phase terminal, respectively. One end of the switching switch is electrically connected to the second power supply terminal and one end of the internal controller, and the other end of the switching switch is electrically connected to the other end of the internal controller. The switching switch is turned on when the coil is energized and turned off when the coil is not energized. The internal controller is electrically connected to the (N+1) drive switches and is used to control the switching state of the (N+1) drive switches.

10. The LED switching system as described in claim 5 or 6, characterized in that, The internal control circuit includes an internal controller electrically connected to the N control switches, the second phase terminal or the third phase terminal, and the (N+1) drive switches, and is used to control the switching state of the (N+1) drive switches.

11. The LED switching system as described in claim 1, characterized in that, The light-emitting module includes multiple light-emitting units, which are electrically connected to the control unit and the three-phase power supply device, respectively.

12. The LED switching system as described in claim 1, characterized in that, The LED switching system includes multiple control units and multiple light-emitting modules that correspond to each other.

13. The LED switching system as described in claim 1, characterized in that, Each LED string contains multiple LEDs connected in series.

14. The LED switching system as described in claim 1, characterized in that, The phase difference between the two phase voltages provided by the first phase terminal and the third phase terminal is 120 degrees.

15. A control method for an LED switching system, characterized in that, The LED switching system is electrically connected to a three-phase power supply device, wherein the three-phase power supply device includes a first phase terminal, a second phase terminal, and a third phase terminal that respectively provide three phase voltages. The LED switching system includes a control unit and a light-emitting module, wherein the control unit is electrically connected to the first phase terminal of the three-phase power supply device and includes N control switches, where N is a positive integer. The light-emitting module includes a light-emitting unit, which includes a power supply circuit, (N+1) LED strings, and a switching circuit that are electrically connected to each other. The power supply circuit is also electrically connected to any two of the three phase terminals of the three-phase power supply device and provides a power supply voltage to the (N+1) LED strings. The switching circuit is also electrically connected to the second phase terminal or the third phase terminal of the three-phase power supply device, and the switching circuit is also electrically connected to the control unit. The control method includes: (a) Control all N control switches to turn off, so that the first LED string is turned on; and (b) Control the nth control switch to turn on, so that the switching circuit is also electrically connected to the first phase terminal via the nth control switch, and control the switching circuit to switch so that the (n+1)th LED string is turned on, where n is a positive integer less than or equal to N.

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