CN102404903B - Lamp driving device - Google Patents

Abstract

The invention provides a lamp driving device, which is used for driving a plurality of lamps and comprises: a power conversion circuit for converting an input voltage into a first direct current voltage and outputting a first current of a substantially constant current value; the positive end and the negative end of each group of lamp connecting seats are electrically connected with the lamps corresponding to the lamps, and output voltage and output current to the lamps corresponding to the lamps; the plurality of groups of lamp connecting seats are electrically connected in series, the output voltage between the positive end and the negative end of each group of lamp connecting seats is obtained by dividing the voltage by the first direct current voltage, and the output currents output by each group of lamp connecting seats are substantially the same. The invention can improve the electricity utilization efficiency and ensure that the current and the brightness of each group of lamps are exactly the same. In addition, the invention can enable manufacturers of lamp driving devices for manufacturing different numbers of lamps to realize the lamp driving devices in a lower cost mode.

Description

Lamp driver

technical field

The invention relates to a lamp driving device, in particular to a lamp driving device for driving multiple sets of light-emitting diode (Light-Emitting Diode, LED) lamps.

Background technique

In recent years, the awareness of environmental protection has risen, and energy conservation and carbon reduction have become a national movement. The electronics industry is also committed to research and development of more environmentally friendly products, such as the use of solar energy and energy-saving products such as light-emitting diodes. In order to achieve the purpose of environmental protection and energy saving, light-emitting diodes are now widely used in general lighting equipment, such as household lighting devices, automotive lighting devices, hand-held lighting devices, and lighting applications such as signage.

Please refer to FIG. 1 , which is a known lamp driving device and its configuration diagram. As shown in FIG. 1 , each lamp 1A-1C is installed at different positions in the house according to the needs of users, and the lamp driving device 1 is used to simultaneously drive multiple sets of lamps 1A-1C. The lamp driving device 1 is implemented in the form of a two-stage power conversion circuit, which includes a first-stage circuit 11 and a second-stage circuit 12, wherein the first-stage circuit 11 is an AC-DC conversion circuit, which is used to convert the input The power supply V _in is converted into a bus voltage V _bus with a fixed voltage value and output to the second stage circuit 12 . The second stage circuit 12 includes a first DC-DC conversion circuit 121, a second DC-DC conversion circuit 122 and a third DC-DC conversion circuit 123, and the first to third DC-DC conversion circuits 121, 122, 123 The output ends of the lamps are respectively connected to the first group of lamp connectors 131A, 131B, the second group of lamp connectors 132A, 132B and the third group of lamp connectors 133A, 133B. Wherein, the first to third groups of lamp connectors (131A, 131B), (132A, 132B), (133A, 133B) are electrically connected to a lamp respectively, so as to respectively transmit the first to third output voltages V _o1 , V _o2 and V _o3 to the corresponding lamps 1A-1C.

When the lamp switch 10 is turned on, the input voltage V _in will be transmitted to the input terminal of the first-stage circuit 11 through the lamp switch 10, and converted by the first-stage circuit 11 to a bus voltage V _bus with a constant voltage value of about 52V, It is provided to the input end of each DC-DC conversion circuit 121, 122, 123 of the second stage circuit 12, and then the first to third DC-DC conversion circuits 121, 122, 123 are respectively stepped down to output the first output The voltage V _o1 , the second output voltage V _o2 and the third output voltage V _o3 . In this embodiment, the lamp driving device 1 is used to drive LED lamps of the same specification. Since LEDs are components whose brightness is proportional to current, in order to make each LED lamp have the same brightness, the first to third DC- The specifications of the DC conversion circuits 121, 122, and 123 must be the same, so the output voltages V _o1 , V _o2 , and V _o3 are all about 50V, and the first to third DC-DC conversion circuits 121, 122, and 123 must provide about the same current The first to third output currents I _o1 , I _o2 , I _o3 , however, the DC-DC conversion circuits 121, 122, 123 have different performances due to different production processes and errors between components. Therefore, the first to third output currents I _o1 , I _o2 , and I o3 provided by the first to third DC-DC conversion circuits 121 , 122 , and ₁₂₃ cannot be the same.

In addition, because each level of circuit has power loss, after the input power is converted by the first level circuit 11 and the second level circuit 12, the power transmitted to the lamp will be reduced, in addition to causing a decrease in efficiency and waste of excess power. , so that the operating efficiency of the lamp driving device 1 cannot be effectively improved, so the purpose of energy saving and carbon reduction cannot be achieved. Furthermore, each DC-DC conversion circuit 121, 122, 123 has a control circuit for controlling the operation of the DC-DC conversion circuit, so the complexity of the circuit is relatively high and the cost of modularization of the DC-DC conversion circuit is too high. If the number of lamps to be driven is different (for example: driving three lamps instead of driving six lamps), it is not possible to use the modular method to only adjust or replace the number of modular DC-DC conversion circuits, but it needs to be adjusted according to different users. Redesigning the circuit according to the requirement will result in a waste of development time and an increase in cost.

Therefore, how to develop a device that can solve the problems of high loss and high cost of the known lamp driving device, and can accurately provide the same current to the lamp is an urgent problem to be solved at present.

Contents of the invention

A main purpose of the present invention is to provide a lamp driving device, which solves the problem that the lighting brightness of each lamp driven by the known lamp driving device is different, and it cannot be applied to the lamp driving device with different numbers of lamps in a modular way, resulting in power consumption. Defects such as low performance or low overall operating efficiency of the lamp driving device.

To achieve the above purpose, a broad implementation of the present invention provides a lamp driving device, including: a power conversion circuit, which is used to convert the input voltage into a first DC voltage, and output a first DC voltage with a substantially constant current value. current; and multiple sets of lamp connectors, the positive and negative ends of each lamp connector are electrically connected to the lamps corresponding to the plurality of lamps, and an output voltage and an output current are output to the corresponding electric lamps of the plurality of lamps. lamps that are electrically connected; wherein, the multiple groups of lamp connectors are electrically connected in series, and the output voltage between the positive and negative ends of each group of lamp connectors is obtained by dividing the first DC voltage, and each The output currents output by a group of lamp connectors are substantially the same.

The lamp driving device for driving multiple groups of light-emitting diode lamps of the present invention is realized in the form of a single-stage circuit, which can improve its power consumption efficiency, and the lamps and lamps are electrically connected in series, so that the current and Brightness is exactly the same. In addition, the lamp driving device of the present invention can be applied to lamp driving devices with different numbers of lamps in a low-cost modular manner, which enables manufacturers of lamp driving devices with different numbers of lamps to implement at a lower cost.

Description of drawings

Fig. 1 is a known lamp driving device and its configuration diagram.

Fig. 2 is a schematic diagram of a lamp driving device according to a preferred embodiment of the present invention.

Fig. 3 is a schematic diagram of a lamp driving device according to another preferred embodiment of the present invention.

FIG. 4A is a schematic diagram of a lamp driving device according to another preferred embodiment of the present invention.

FIG. 4B is a partial detailed circuit diagram of FIG. 4A.

The reference numerals in the above-mentioned accompanying drawings are explained as follows:

Lamp driver: 2, 3, 4 Input voltage: V _in

Power conversion circuit: 21 The first DC voltage: V ₁

First output terminal: 21a First current: I ₁

Second output terminal: 21b First output voltage: V _o1

Lamp connector: 22, 23, 24 First output current: I _o1

Positive terminal of the first lamp connector: 22a Second output voltage: V _o2

Negative terminal of the first lamp connector: 22b Second output current: I _o2

Positive terminal of the second lamp connector: 23a The third output voltage: V _o3

Positive terminal of the second lamp connector: 23b The third output current: I _o3

Positive terminal of the third lamp connector: 24a The first resistor: R ₁

Positive terminal of the third lamp connector: 24b Second resistor: R ₂

Lamps: 221, 231, 241 Third resistor: R ₃

Overcurrent protection circuit: 31 Fourth resistor: R ₄

Current detection circuit: 311 Fifth resistor: R ₅

First node: K1 Second node: K ₂

Output protection circuit: 36a, 36b, 36c

First switching element: S ₁

The control terminal of the first switching element: S _1a

Current conducting terminals of the first switching element: S _1b , S _1c

Second switching element: _S2

The control terminal of the second switching element: S _2a

Current conducting terminals of the second switching element: S _2b , S _2c

Third switching element: S ₃ Body diode: D _b

First control voltage: V _k1 First Zener diode: D _z1

Second control voltage: V _k2 Second Zener diode: D _z2

First bypass current: I _a1 Second bypass current: I _a2

The third bypass current: I _a3

Detailed ways

Some typical embodiments embodying the features and advantages of the present invention will be described in detail in the description in the following paragraphs. It should be understood that the present invention is capable of various changes in different ways without departing from the scope of the present invention, and that the description and drawings therein are illustrative in nature rather than limiting the present invention.

The lamp driving device of the present invention is applicable to a plurality of lamps. The operation principle of the lamp driving device of the present invention will be illustrated below by applying it to three lamps, but not limited thereto. Please refer to FIG. 2 , which is a schematic diagram of a lamp driving device according to a preferred embodiment of the present invention. As shown in Figure 2, the lamp driving device 2 of the present invention includes a power conversion circuit 21, a first group of lamp connectors 22, a second group of lamp connectors 23, and a third group of lamp connectors 24, wherein the power conversion circuit 21 uses a single Stage circuit implementation, such as single-stage flyback conversion circuit, active-clamp flyback conversion circuit or resonant conversion circuit, used to convert an input voltage V _in is converted into a first direct current voltage V ₁ , and a first current I ₁ with a substantially constant current value is output. The first group of lamp connectors 22, the second group of lamp connectors 23, and the third group of lamp connectors 24 are electrically connected in series between the first output end 21a and the second output end 21b of the power conversion circuit 21, It is used to respectively provide corresponding connections to the first lamp 221, the second lamp 231, and the third lamp 241, and transmit the first ~The third output voltages V _o1 , V _o2 , V _o3 are sent to the first lamp 221 , the second lamp 231 , and the third lamp 241 .

In this embodiment, the first lamp 221 , the second lamp 231 , and the third lamp 241 are LED lamps, but not limited thereto. The first group of lamp connectors 22 includes a positive terminal 22a and a negative terminal 22b. Similarly, the second to third groups of lamp connectors 23, 24 include positive terminals 23a, 24a and negative terminals 23b, 24b. Among them, the positive terminal 22a of the first group of lamp connectors 22 is electrically connected to the first output terminal 21a (positive terminal) of the power conversion circuit 21, and the negative terminal of the last group of lamp connectors (that is, the third group of lamp connectors 24 The negative terminal 24b) of the power conversion circuit 21 is electrically connected to the second output terminal 21b (negative terminal) of the power conversion circuit 21, and the electrical connection relationship between the first group of lamp connectors 22 and the last group of lamp connectors is that of the previous group of lamps The negative end of the connecting seat is electrically connected to the positive end of the next group of lamp connecting seats, for example, the negative end 22b of the first group of lamp connecting seats 22 is electrically connected to the positive end 23a of the second group of lamp connecting seats 23, or the second group The negative terminal 23b of the group lamp connecting socket 23 is electrically connected with the positive terminal 24a of the third group lamp connecting socket 24 . In addition, each group of lamp connection sockets 22, 23, 24 respectively provides the first output current I _o1 , the second output current I _o2 , and the third output current I _o3 to the first to third lamps 221, 231, 241. In this embodiment, the lamp driving device 2 of the present invention is used to drive a plurality of LED lamps. When the lamp switch (not shown) is turned on and the input voltage V _in is transmitted to the input terminal of the power conversion circuit 21, the power conversion circuit 21 will convert the input voltage V _in into a first DC voltage V ₁ and output a substantial The first current I ₁ with a constant current value. Since the power conversion circuit 21 operates in a constant current mode, and the first to third groups of lamp connectors 22, 23, and 24 are electrically connected in series, the first to third output currents I _o1 , I _o2 , and I _o3 The current values are equal to the first current I ₁ , even if the first to third lamps 221, 231, 241 are composed of light-emitting diodes of different manufacturers, the first to third output currents I _o1 and I _o2 of the same current value , I _o3 can make the light emitting diodes in the first to third lamps 221, 231, 241 have similar brightness.

In this embodiment, the first DC voltage V ₁ is equal to the sum of the first to third output voltages V _o1 , V _o2 , and V _o3 (V ₁ =V _o1 +V _o2 +V _o3 ) The first to third output voltages V _o1 , V _o2 , and V _o3 of the three lamps 221, 231, and 241 change, because the voltage value of each output voltage V _o1 , V _o2 , and V _o3 will vary with the corresponding electrical connection Therefore, the voltage value of the first DC voltage V ₁ will correspondingly increase with the increase of the number of connecting sockets of the lamps and the rated operating voltage value of each lamp. In order to prevent the user from getting an electric shock if the user touches the lamp or the lamp driving device 2 when the lamp is in operation, the current rated operating voltage of the lamp is designed to be lower than the minimum voltage required by safety regulations for human body conduction, for example, about 60V the following.

The voltage value of the first DC voltage _V1 will increase correspondingly with the increase of the number of lamp connectors and the rated operating voltage of each lamp, and the first to third groups of lamp connectors 22 that users will touch , 23, 24 output voltage V _o1 , V _o2 , V _o3 voltage value is the rated operating voltage value of the lamp, which is generally lower than the minimum voltage value required by safety regulations for human body conduction, for example, below about 60V, and will not As the number of the connecting sockets of the lamp increases, the number increases correspondingly. Therefore, if the user accidentally touches the lamp or the lamp driving device 2, it will not cause the user to receive an electric shock.

The lamp driving device 2 of the present invention is implemented in a single-stage circuit, so the power consumption efficiency is improved, and the overall loss of electric energy when the lamp driving device 2 is converted is small, and the first to third groups of lamp connecting seats 22, 23 , 24 are electrically connected in series, so the current values of the output currents I _o1 , I _o2 , and I _o3 output to each lamp 221, 231, 241 are substantially the same, so that the brightness of each LED lamp is substantially the same . Please refer to FIG. 3 together with FIG. 2 , wherein FIG. 3 is a schematic diagram of a lamp driving device according to another preferred embodiment of the present invention. As shown in FIG. 3 , besides the power converter 21 , the first group of lamp connectors 22 , the second group of lamp connectors 23 , and the third group of lamp connectors 24 , the lamp driving device 3 of the present invention further includes a The current protection circuit 31 is electrically connected in series between the power conversion circuit 21 and the plurality of lamp connecting sockets 22 , 23 , 24 to prevent the first current I ₁ output by the power conversion circuit 21 from overcurrent. In some abnormal situations, the first current I ₁ will increase instantaneously. In order to prevent the excessive first current I ₁ from being directly fed back to the power conversion circuit 21 and causing damage to the lamp driving device 3, when the first current I ₁ is increased to a rated value , the overcurrent protection circuit 31 will start to act, and disconnect the entire current transfer loop of the first current _I1 between the power conversion circuit 21 and the plurality of sets of lamp connectors 22, 23, 24.

Please refer to FIG. 3 again, the overcurrent protection circuit 31 includes a current detection circuit 311 and a switch circuit, wherein the current detection circuit 311 is electrically connected to the output side of the power conversion circuit 21 and the switch circuit, and is used to detect the current according to the current The first current _I1 of the detection circuit 311 correspondingly generates a first control voltage V _k1 to the control terminal of the switch circuit, and controls the switch circuit to be turned on or off by the magnitude of the first control voltage V _k1 . In this embodiment, the switch circuit is electrically connected to the current loop of the lamp driving device 2 outputting the first current _I1 , and includes a first switch element _S1 and an integral diode Db (body diode). The current detection The circuit 311 includes a first resistor R ₁ , a second resistor R ₂ , a second switch element S ₂ and a first Zener diode D _Z1 (zener diode). In this embodiment, the first switch element _S1 is a Metal Oxide Semiconductor Field Effect Transistor (MOSFET), and the control terminal _S1a of the first switch element _S1 corresponds to the two current conduction terminals _S1b and _S1c respectively as The gate (Gate), the drain (Drain) and the source (Source) of the metal oxide semiconductor field effect transistor; the second switching element _S2 is a bipolar junction transistor (BTJ), and the second switching element _S2 The control terminal S _2a and the two current conducting terminals S _2b and S _2c correspond to a base, a collector and an emitter, respectively.

In the switch circuit, the control end S _1a of the first switch element S ₁ is electrically connected to the first node K ₁ , and a current conducting end S _1b of the first switch element S ₁ is electrically connected to the third set of lamp connecting sockets 24 negative terminal 24b, the other current conducting terminal S _1c of the first switching element S ₁ is electrically connected to a second node K ₂ , and the cathode (Cathode) of the body diode D _b is connected to the first switching element S ₁ The current conducting terminal S _1b is electrically connected, and the anode (Anode) of the body diode D _b is electrically connected to the other current conducting terminal S _1c of the first switching element S ₁ .

In the current detection circuit 311, one end of the first resistor _R1 is electrically connected to the first output end 21a of the power conversion circuit 21 and the positive end 22a of the first set of lamp connectors 22, and the other end is electrically connected to the first Node K ₁ (node); the cathode of the first Zener diode D _Z1 is electrically connected to the first node K ₁ , and the anode of the first Zener diode D _Z1 is electrically connected to the second node K ₂ for clamping the second node K 2 . The magnitude of the first control voltage V _k1 between the first node K ₁ and the second node K ₂ ; the control terminal S _2a of the second switching element S ₂ is electrically connected to the second node K ₂ , and a current of the second switching element S ₂ The conduction end S _2b is electrically connected to the first node K ₁ , and the other current conduction end S _2c of the second switch element S ₂ is electrically connected to the second output end 21b of the power conversion circuit 21 . One end of the second resistor R ₂ is connected to the second node K ₂ , and the other end of the second resistor R ₂ is connected to the second output end 21b of the power conversion circuit 21, so that the second resistor R ₂ and the first switching element of the switching circuit S ₁ is electrically connected in series. The first control voltage V _k1 is across the first node K ₁ and the second node K ₂ , and varies with the first DC voltage V ₁ , and when the first current I ₁ flows through the second resistor R ₂ , the second A second control voltage V _k2 is across the node K ₂ and the second output terminal 21 b of the power conversion circuit 21 , and varies with the first current I ₁ .

When the lamp driving device 3 operates under normal conditions, the actions of the lamp connectors 22, 23, 24 and the lamps 221, 231, 241 are the same as those described in the previous embodiment, so no further description is given. At this time, the first current The current value of I ₁ is within the rated value range, and the voltage value of the first control voltage V _k1 is greater than or equal to the conduction voltage V _th of the switch circuit, so the first switch element S ₁ of the switch circuit will be turned on, so that the first The current I ₁ flows through the current transfer loop of the first switching element S ₁ to the plurality of sets of lamp connectors 22, 23, 24; and the voltage drop of the second electric set R ₂ , that is, the voltage value of the second control voltage V _k2 , will be less than The turn-on voltage V _tb of the second switching element _S2 , for example 0.6V, turns off the second switching element S2, and the first current _I1 returns to the power supply after passing through the first switching element _S1 and the second resistor _R2 of the switching circuit. conversion circuit 21.

Conversely, when the current value of the first current _I1 is instantly increased and exceeds the range of the rated value of the first current _I1 , for example, it exceeds 10% of the rated current value of the first current _I1 , exceeding the rated value of the first current _I1 . The value range of the second control voltage V _k2 generated by flowing through the second resistor R ₂ will be greater than the turn-on voltage V _tb of the second switch element S ₂ , for example, greater than 0.6V, so that the second switch element S ₂ is turned on, As a result, the voltage value of the first control voltage V _k1 is zero or lower than the conduction voltage V _th of the first switching element S ₁ , so the first switching element S ₁ is turned off, and the excessive first current I ₁ is prevented from directly flowing back The power conversion circuit 21 is damaged to achieve the function of protecting the power conversion circuit 21 .

Please refer to FIG. 4A and FIG. 4B together with FIG. 2 and FIG. 3 , wherein FIG. 4A is a schematic diagram of a lamp driving device according to another preferred embodiment of the present invention, and FIG. 4B is a partial detailed circuit diagram of FIG. 4A . As shown in FIG. 4A and FIG. 4B , in addition to the power converter 21, the overcurrent protection circuit 31, and multiple sets of lamp connectors 22, 23, 24, the lamp driving device of the present invention further includes a plurality of output protection circuits 36a-36c. For example, but not limited to, the first output protection circuit 36a, the second output protection circuit 36b, and the third output protection circuit 36c are electrically connected in parallel with each group of lamp connection sockets 22-24, that is, the first output protection circuit 36a One end is electrically connected to the positive end 22a of the first group of lamp connectors 22, the other end is electrically connected to the negative end 22b of the first group of lamp connectors 22, and so on. The multiple output protection circuits 36a-36c are used to provide users with the ability to selectively drive only some of the lamps 221-241 without using all of them, or when any light-emitting diode of any lamp 221-241 is damaged, the The connection bases 22-24 are electrically connected in series so that all the lamps 221-241 stop being driven.

Taking the first group of lamp connectors 22 as an example, when the light emitting diode in the lamp 221 is damaged so that the lamp 221 is in an open state or the user does not electrically connect the lamp 221 to the first group of lamp connector 22 and other abnormal conditions occur, the first The voltage value of the output voltage V _o1 will instantly increase to exceed the rated operating voltage range of the first output voltage V _o1 . In this embodiment, when it is higher than about 55V, the third switching element _S3 will be triggered and turned on. The first output protection circuit 36a operates to bypass the first group of lamp connectors 22 to stop the output current of the first group of lamp connectors 22 . At this time, the current value of the first bypass current I _a1 flowing into the first output protection circuit 36a is equal to the first current I1, the current value of the first output current I o1 is zero, and the current value of the first bypass current I _a1 flowing into the first output protection circuit 36a The first bypass current I _a1 flows through the second group of lamp connecting sockets 23 to drive the remaining lamps 231 , 241 . In other words, when the lamps 221, 231, 241 are operating normally, the first to third groups of lamp connectors 22 to 24 will output electric energy to the corresponding lamps, and the first to third output protection circuits 36a to 36c will not operate and flow The current values of the currents I _a1 to I _a3 to the first to third output protection circuits 36 a to 36 c are all zero.

Please refer to FIG. 4A and FIG. 4B again, the circuits of the plurality of output protection circuits 36 a - 36 c are the same, but not limited thereto. For the convenience of description, the detailed circuit of the first output protection circuit 36a will be taken as an example to illustrate its circuit and its operating principle. The first output protection circuit 36a includes a third switch element _S3 and a trigger circuit, wherein the third switch element _S3 is electrically connected between the positive and negative terminals 22a and 22b of the first group of lamp connectors 22, and the trigger circuit It is electrically connected to the positive and negative terminals 22a, 22b of the first group of lamp connectors 22 and the control terminal of the third switch element _S3 , and is used to control the first to output voltage V _o1 of the first group of lamp connectors 22. Whether the three switching elements _S3 are turned on.

In this embodiment, the third switch element _S3 may be but not limited to a silicon-controlled rectifier (SCR); the trigger circuit includes: a third resistor _R3 , a fourth resistor _R4 and a first Two zener diodes D _Z2 , and the trigger circuit may optionally further include: a delay circuit formed by a fifth resistor R ₅ and a capacitor C, and electrically connected to the trigger circuit and the control terminal of the third switch element S ₃ between. The second zener diode D _Z2 , the third resistor R ₃ , and the fourth resistor R ₄ form a series electrical connection relationship between the positive and negative terminals 22a and 22b of the first group of lamp connectors 22, as a current limiting and voltage dividing for. When the voltage value of the first output voltage V _o1 instantly increases and exceeds the rated operating voltage range of the first output voltage V _o1 , for example, when it is higher than 10% of the rated operating voltage, the trigger circuit will send a trigger signal to the third The control terminal of the switch element _S3 controls the third switch element _S3 to conduct, so that the first output protection circuit 36a operates to bypass the first group of lamp connectors 22 to stop the output current of the first group of lamp connectors 22 .

In this embodiment, the capacitor C is electrically connected to the control terminal of the third switch element S3, and the fifth resistor _R5 is electrically connected between the third resistor _R3 and the capacitor C to protect the first output. The trigger circuit of the circuit 36a controls the third switch element _S3 to generate a delay time when it is turned on, so as to increase the judgment time of the trigger circuit and reduce the chance of malfunctioning of the first output protection circuit 36a.

Since the first to third groups of lamp connecting sockets 22 to 24 and the first to third output protection circuits 36a to 36c do not include complex control circuits, they can be easily modularized into an output module 32 at low cost, and It is designed as an output module 32 with different numbers of lamp connectors. When users need to drive more or different numbers of lamps, they only need to replace the output module 32. For example, replace the output module that drives three lamps with six lamps. output module.

To sum up, the lamp driving device of the present invention for driving multiple sets of LED lamps is implemented in the form of a single-stage circuit, which can improve its power consumption efficiency, and the lamps and lamps are electrically connected in series, so that each The current and brightness of the group lamps are exactly the same. In addition, the lamp driving device of the present invention can be applied to lamp driving devices with different numbers of lamps in a low-cost modular manner, which enables manufacturers of lamp driving devices with different numbers of lamps to implement at a lower cost.

The present invention can be modified in various ways by those skilled in the art without departing from the protection scope of the appended claims.

Claims (13)

1. A lamp driving device, used to drive multiple lamps, comprising: A power conversion circuit for converting an input voltage into a first DC voltage and outputting a first current with a substantially constant current value; and There are multiple sets of lamp connectors, one positive terminal and one negative terminal of each lamp connector are electrically connected to the lamps corresponding to the plurality of lamps, and an output voltage and an output current are output to the corresponding electrical terminals of the plurality of lamps. Connected luminaires; Wherein, the plurality of groups of lamp connectors are electrically connected in series, the output voltage between the positive and negative terminals of each group of lamp connectors is obtained by dividing the first DC voltage, and each group of lamp connectors The output currents of the outputs are substantially the same; and Wherein, the positive end of the first group of lamp connectors of the plurality of groups of lamp connectors is electrically connected to a first output end of the power conversion circuit, and the negative end of the last group of lamp connectors of the plurality of groups of lamp connectors is electrically connected to a first output end of the power conversion circuit. The terminal is electrically connected to a second output end of the power conversion circuit, and the electrical connection relationship between the first group of lamp connectors and the last group of lamp connectors of the multiple sets of lamp connectors is the last group of lamp connectors. The negative end of the socket is electrically connected with the positive end of the next group of lamp connecting sockets. 2. The lamp driving device according to claim 1, wherein the power conversion circuit is a single-stage flyback conversion circuit, an active clamp flyback conversion circuit or a resonant conversion circuit. 3. The lamp driving device as claimed in claim 1, wherein the power conversion circuit is a constant current type, outputs the first current with a substantially constant current value, and the outputted first DC voltage is equal to the plurality of lamps The sum of this output voltage of the connector. 4. The lamp driving device according to claim 1, further comprising an overcurrent protection circuit electrically connected between the power conversion circuit and the plurality of sets of lamp connection sockets to prevent the output of the power conversion circuit from The first current overcurrent occurs. 5. The lamp driving device as claimed in claim 4, wherein the overcurrent protection circuit comprises: a switch circuit electrically connected to the current loop of the lamp driving device outputting the first current; and a current detection circuit, electrically connected to the output side of the power conversion circuit and the switch circuit, for correspondingly generating a first control voltage to the control terminal of the switch circuit according to the first current flowing through the current detection circuit, And the switching circuit is controlled to be turned on or off by the first control voltage. 6. The lamp driving device as claimed in claim 5, wherein the switching circuit comprises: a first switch element, electrically connected to the current loop of the lamp driving device outputting the first current; and An integral diode is electrically connected between the two current conducting ends of the first switch element. 7. The lamp driving device as claimed in claim 6, wherein the current detection circuit comprises: A first resistor, one end of the first resistor is electrically connected to a first output end of the power conversion circuit, and the other end of the first resistor is electrically connected to a first node electrically connected to the switch circuit; A second resistor is electrically connected in series with the switch circuit, so that a second control voltage is generated when the first current flows through the second resistor; A second switch element, the control end of the second switch element is electrically connected to a second node, a current conduction end of the second switch element is electrically connected to the first node, the other of the second switch element the current conducting end is electrically connected to a second output end of the power conversion circuit; and a first zener diode element, the first zener diode is electrically connected between the first node and the second node, and is used for clamping the first control voltage between the first node and the second node . 8. The lamp driving device according to claim 1, further comprising a plurality of output protection circuits, which are electrically connected in parallel with each group of lamp connectors, and when one of the plurality of lamps is damaged, the lamp is open state or the user has not electrically connected the lamp to one of the plurality of lamp connectors, so that the voltage value of the output voltage corresponding to the lamp connector exceeds a rated operating voltage range, the multiple The corresponding output protection circuit of each output protection circuit acts, bypassing the corresponding lamp connection socket to stop the output current corresponding to the lamp connection socket. 9. The lamp driving device as claimed in claim 8, wherein one of the output protection circuits of the plurality of output protection circuits comprises: a third switch element, electrically connected between the positive and negative terminals of the corresponding set of lamp connectors of the multiple groups of lamp connectors; and A trigger circuit, electrically connected to the positive and negative terminals of the corresponding group of lamp connectors of the plurality of groups of lamp connectors and the control terminal of the third switch element, for The output voltage controls whether the third switching element is turned on; Wherein, when the output voltage of the corresponding group of lamp connectors exceeds the rated operating voltage range, the trigger circuit sends a trigger signal to the control terminal of the third switch element to control the conduction of the third switch element, so that the corresponding The output protection circuit operates to bypass the corresponding group of lamp connectors to stop the output current. 10. The lamp driving device as claimed in claim 9, wherein the trigger circuit comprises: a third resistor, a fourth resistor and a second Zener diode, and are connected to the positive and negative ends of the corresponding set of lamp connectors Form a series electrical connection relationship between them, as a current limiting and voltage dividing function. 11. The lamp driving device as claimed in claim 10, wherein the trigger circuit further comprises: a delay circuit formed by a fifth resistor and a capacitor, and is electrically connected to the trigger circuit and the control terminal of the third switch element between. 12 . The lamp driving device according to claim 8 , implemented by including an output module, wherein the output module includes: the plurality of lamp connectors, or optionally further includes the plurality of output protection circuits. 13. The lamp driving device according to claim 1, wherein the rated operating voltage of the plurality of lamp connectors is lower than the minimum voltage for human body to conduct electricity.

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