LED drive circuit with night lamp function

Abstract

The utility model provides an LED drive circuit with a night lamp function. The LED drive circuit comprises a compatible dimming chip, a constant current chip, a switching module, a main light source module and an auxiliary light source module. The power supply input end of the compatible dimming chip is used for being connected with an external power supply; the high-voltage end of the compatible dimming chip is connected with the high-voltage end of the constant-current chip and the power input end of the switching module. The compatible dimming chip is used for compensating the bleeder current according to the type of the accessed dimmer; the first output end of the switching module is connected with the main light source module; the second output end of the switching module is connected with the auxiliary light source module. The signal input end of the switching module is connected with an external power supply, generates a switching signal based on the switching state of the external power supply, and switches the main light source module or the auxiliary light source module according to the switching signal; therefore, the loss of a single chip is reduced, and the chip is effectively prevented from heating due to excessive loss.

Description

Technical Field

[0001] The utility model relates to the technical field of LED circuits, in particular to an LED driving circuit with a night light function. Background Art

[0002] At present, the existing linear dimming solution for night lights based on thyristor dimming has the following disadvantages: when the dimmer is connected, the discharge current of the chip will be turned on, resulting in increased chip loss, excessive chip temperature, and reduced product performance.

[0003] At the same time, there are two main implementation modes for the existing night light switching function: one is to realize the switching of the night light and the main power supply based on the PWM (pulse width modulation) signal of the main chip controlled by the MCU (Microcontroller Unit). However, the method circuit is relatively complicated, and the current thyristor dimming-based chips usually do not have PWM function pins, making this solution difficult to implement.

[0004] The second is to use a two-stage adjustable current LED linear constant current chip to switch between the night light and the main power supply. However, since the LED linear constant current chip is used, it cannot withstand a large current and can usually only withstand a current of less than 100mA. Therefore, this solution has limitations when there is a demand for relatively large power. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide an LED driving circuit with a night light function, so as to solve the problem that the existing product performance is reduced due to the discharge current.

[0006] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0007] A LED driving circuit with a night light function, characterized in that it includes a compatible dimming chip, a constant current chip, a switching module, a main light source module and a secondary light source module; the power input end of the compatible dimming chip is used to connect to an external power supply; the high voltage end of the compatible dimming chip is respectively connected to the high voltage end of the constant current chip and the power input end of the switching module; the compatible dimming chip is used to compensate for the discharge current according to the type of connected dimmer; the first output end of the switching module is connected to the main light source module; the second output end of the switching module is connected to the secondary light source module; the signal input end of the switching module is used to connect to an external power supply, and generate a switching signal based on the switching state of the external power supply, and switch the main light source module or the secondary light source module according to the switching signal.

[0008] Furthermore, the main light source module includes a first LED light source and a dial color temperature control unit; the input end of the dial color temperature control unit is connected to the first output end of the switching module; the output end of the dial color temperature control unit is connected to the input end of the first LED light source; and the output end of the first LED light source is grounded.

[0009] Furthermore, the first LED light source includes at least two groups of sub-light sources with different color temperatures; input ends of different sub-light sources are respectively connected to different output ends of the dial color temperature control unit, and the dial color temperature control unit is used to dial and select different sub-light sources.

[0010] Furthermore, the auxiliary light source module includes a second LED light source and a current limiting unit; the input end of the current limiting unit is connected to the second output end of the switching module; the output end of the current limiting unit is connected to the input end of the second LED light source; and the output end of the second LED light source is grounded.

[0011] Furthermore, the current limiting unit includes a current limiting chip and a first resistor; one end of the first resistor is connected to the second output end of the switching module, and the other end of the first resistor is connected to the input end of the current limiting chip; the output end of the current limiting chip is connected to the input end of the second LED light source.

[0012] Furthermore, the switching module includes a wall-cut two-speed control chip and a second resistor; the power input end of the wall-cut two-speed control chip is connected to the high-voltage end of the constant current chip; the clock input end of the wall-cut two-speed control chip is connected to one end of the second resistor, and the clock input end is used to connect to an external power supply; the ground end of the wall-cut two-speed control chip is connected to the other end of the second resistor.

[0013] Furthermore, the switching module also includes a first diode and a third resistor; the positive electrode of the first diode is connected to the high voltage end of the constant current chip; the negative electrode of the first diode is connected to one end of the third resistor; the other end of the third resistor is connected to the power input end of the wall cutting two-speed control chip.

[0014] Furthermore, it also includes a varistor; the varistor is arranged at the power input end of the compatible dimming chip.

[0015] The beneficial effect of the utility model is that the traditional MCU control scheme is replaced by a compatible dimming chip and a constant current chip, making the circuit periphery simpler and the cost lower; at the same time, the compatible dimming chip can compensate for the discharge current according to the type of connected dimmer, so that the discharge current loss is on the compatible dimming chip, while the constant current output current loss is on the constant current chip. Compared with the existing constant current output current loss and discharge current loss on the same chip, the loss of a single chip is reduced by allocating the loss to different chips, and the problem of chip heating due to excessive loss is effectively avoided, so that it can be applied to high-power demand scenarios and solve the problem of reduced product performance due to discharge current. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a circuit connection diagram of an LED driving circuit with a night light function in an embodiment of the utility model;

[0017] Figure 2 This is a schematic diagram of the connection between a compatible dimming chip and a constant current chip in an LED driving circuit with a night light function in an embodiment of the utility model;

[0018] Figure 3 This is a schematic diagram of the connection of a main light source module in an LED driving circuit with a night light function in an embodiment of the utility model;

[0019] Figure 4 This is a schematic diagram of the connection of an auxiliary light source module in an LED driving circuit with a night light function in an embodiment of the utility model;

[0020] Description of labels:

[0021] 1. Switching module; 2. Main light source module; 21. First LED light source; 22. DIP color temperature control unit; 3. Auxiliary light source module; 31. Second LED light source; 32. Current limiting unit;

[0022] IC1, compatible dimming chip; IC2, constant current chip; IC3, two-speed wall-cut control chip; IC4, current limiting chip; RS4, first resistor; R17, second resistor; D2, first diode; R3, third resistor; RV1, varistor. DETAILED DESCRIPTION

[0023] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0024] Please refer to Figure 1, an LED driving circuit with a night light function, characterized in that it includes a compatible dimming chip, a constant current chip, a switching module, a main light source module and a secondary light source module; the power input end of the compatible dimming chip is used to connect to an external power supply; the high voltage end of the compatible dimming chip is respectively connected to the high voltage end of the constant current chip and the power input end of the switching module; the compatible dimming chip is used to compensate for the discharge current according to the type of connected dimmer; the first output end of the switching module is connected to the main light source module; the second output end of the switching module is connected to the secondary light source module; the signal input end of the switching module is used to connect to an external power supply, and generate a switching signal based on the switching state of the external power supply, and switch the main light source module or the secondary light source module according to the switching signal.

[0025] From the above description, it can be seen that the beneficial effects of the utility model are: by replacing the traditional MCU control scheme with a compatible dimming chip and a constant current chip, the circuit periphery is simpler and the cost is lower; at the same time, the compatible dimming chip can compensate for the discharge current according to the type of connected dimmer, so that the discharge current loss is on the compatible dimming chip, while the constant current output current loss is on the constant current chip. Compared with the existing constant current output current loss and discharge current loss on the same chip, by distributing the loss to different chips, the loss of a single chip is reduced, and the problem of chip heating due to excessive loss is effectively avoided, so that it can be applied to high-power demand scenarios and solve the problem of reduced product performance due to discharge current.

[0026] Furthermore, the main light source module includes a first LED light source and a dial color temperature control unit; the input end of the dial color temperature control unit is connected to the first output end of the switching module; the output end of the dial color temperature control unit is connected to the input end of the first LED light source; and the output end of the first LED light source is grounded.

[0027] It can be seen from the above description that by providing a dial color temperature control unit and a first LED light source, the first LED light source can be controlled by the dial color temperature control unit to achieve the effect of color temperature change.

[0028] Furthermore, the first LED light source includes at least two groups of sub-light sources with different color temperatures; input ends of different sub-light sources are respectively connected to different output ends of the dial color temperature control unit, and the dial color temperature control unit is used to dial and select different sub-light sources.

[0029] It can be seen from the above description that more different color temperature changes can be achieved by forming the first LED light source with multiple groups of sub-light sources with different color temperatures and switching the sub-light sources with different color temperatures through a dial color temperature control unit.

[0030] Furthermore, the auxiliary light source module includes a second LED light source and a current limiting unit; the input end of the current limiting unit is connected to the second output end of the switching module; the output end of the current limiting unit is connected to the input end of the second LED light source; and the output end of the second LED light source is grounded.

[0031] It can be seen from the above description that by providing a current limiting chip, the power output by the switching module can be converted into the power required by the second LED light source, so that the second LED light source can work stably.

[0032] Furthermore, the current limiting unit includes a current limiting chip and a first resistor; one end of the first resistor is connected to the second output end of the switching module, and the other end of the first resistor is connected to the input end of the current limiting chip; the output end of the current limiting chip is connected to the input end of the second LED light source.

[0033] It can be seen from the above description that by providing the first resistor between the switching module and the current limiting chip, the current limiting chip can stably output the current required by the second LED light source.

[0034] Furthermore, the switching module includes a wall-cut two-speed control chip and a second resistor; the power input end of the wall-cut two-speed control chip is connected to the high-voltage end of the constant current chip; the clock input end of the wall-cut two-speed control chip is connected to one end of the second resistor, and the clock input end is used to connect to an external power supply; the ground end of the wall-cut two-speed control chip is connected to the other end of the second resistor.

[0035] From the above description, it can be seen that a two-speed wall-cut control chip is used as a switching module, and a second resistor is set at the clock input end of the two-speed wall-cut control chip, so that the two-speed wall-cut control chip can effectively receive the switching signal of the external power supply and switch the main light source and the auxiliary light source according to the switch.

[0036] Furthermore, the switching module also includes a first diode and a third resistor; the positive electrode of the first diode is connected to the high voltage end of the constant current chip; the negative electrode of the first diode is connected to one end of the third resistor; the other end of the third resistor is connected to the power input end of the wall cutting two-speed control chip.

[0037] It can be seen from the above description that by connecting the first diode and the third resistor in series before the power input terminal of the wall-cut two-speed control chip, a stable power supply can be provided for the wall-cut two-speed control chip.

[0038] Furthermore, it also includes a varistor; the varistor is arranged at the power input end of the compatible dimming chip.

[0039] It can be seen from the above description that by setting a varistor at the power input end of the compatible dimming chip, the circuit can be protected from surges.

[0040] The LED driving circuit with night light function provided by the utility model can be applied to home lighting scenes, and is described below through specific implementation methods:

[0041] Embodiment 1

[0042] Please refer to Figure 1-Figure 4 , an LED driving circuit with a night light function, comprising a compatible dimming chip IC1, a constant current chip IC2, a switching module 1, a main light source module 2 and an auxiliary light source module 3; in an optional embodiment, the chip model used by the compatible dimming chip IC1 is BP5176GB, which is a high-performance, high-integration, high-voltage input compatible thyristor dimmer linear constant current chip; the chip model used by the constant current chip IC2 is BP5176GC, which is a linear constant current chip; wherein, the compatible dimming chip IC1 integrates a rectifier bridge stack and an integrated high-voltage dimmer detection circuit, when the chip detects the dimmer, the slope of the voltage of the 4th pin of the compatible dimming chip IC1 changes (after the dimmer is input through the 6th and 7th pins (N / L) of the compatible dimming chip IC1, the 4th pin can detect the voltage change), at this time the system determines that the compatible dimming chip IC1 is connected to the dimmer; at the same time, the compatible dimming chip IC1 can distinguish the type of dimmer, and according to the different dimmers connected, the compensation of its discharge current is also different, so as to reduce the heat generation of the chip through line compensation. When the chip detects that a dimmer is connected, the chip will automatically turn on the discharge current to improve the compatibility of the dimmer. When the chip detects that the dimmer is not connected, the chip will turn off the discharge current to reduce losses and improve system efficiency. Therefore, when the dimmer is connected, the chip loss distribution is as follows: the discharge current loss is on the compatible dimming chip IC1, and the constant current output current loss is on the constant current chip IC2. The temperature of the chip when the dimmer is connected is reduced by separating and distributing different current losses. That is, the compatible dimming chip IC1 and the constant current chip IC2 are combined to form a thyristor linear constant current main circuit to solve the problem of excessive chip temperature when the chip is connected to the dimmer. In contrast, in the existing linear thyristor dimming solution, the linear constant current and the discharge current of the compatible dimmer are on the same chip. When the dimmer is connected, the chip loss is the sum of the discharge current loss and the output current loss, which makes the chip heat up more seriously. The specific connection method of the circuit is as follows:

[0043] The power input terminal (L&N) of the compatible dimming chip IC1 is used to connect to an external power supply; the high voltage terminal (HV) of the compatible dimming chip IC1 is respectively connected to the high voltage terminal (HV) of the constant current chip IC2 and the power input terminal of the switching module 1; the dimming signal terminal (VIN) of the compatible dimming chip IC1 is connected to the dimming signal terminal (VIN) of the constant current chip IC2; the first output terminal of the switching module 1 is connected to the main light source module 2; the second output terminal of the switching module 1 is connected to the auxiliary light source module 3; the signal input terminal of the switching module 1 is used to connect to an external power supply, and generate a switching signal based on the switching state of the external power supply, and switch the main light source module 2 or the auxiliary light source module 3 according to the switching signal; at the same time, the power input terminal of the compatible dimming chip IC1 is also provided with a varistor RV1; the number and size of the varistor RV1 can be set according to actual needs, such as Figure 1 As shown, a varistor RV2 is also provided.

[0044] Among them, the switching module 1 includes a wall-cut two-speed control chip IC3, a second resistor R17, a first diode D2 and a third resistor R3; the chip model used by the wall-cut two-speed control chip IC3 is S4225MTB. Compared with the LED linear constant current chip with two adjustable currents on the market, the chip has an output current of up to 300mA, and has greater design selectivity for those with higher power requirements; the clock input end (CLK) of the wall-cut two-speed control chip IC3 is connected to one end of the second resistor R17, and the clock input end is used to connect to an external power supply (ACL1); the ground end of the wall-cut two-speed control core is connected to the other end of the second resistor R17; the positive electrode of the first diode D2 is connected to the high voltage end (HV) of the constant current chip IC2; the negative electrode of the first diode D2 is connected to one end of the third resistor R3; the other end of the third resistor R3 is connected to the power input end (VCC) of the wall-cut two-speed control chip IC3; wherein the third resistor R3 can be composed of multiple resistors, such as Figure 1 As shown, a resistor R4 and a resistor R5 are also included.

[0045] The main light source module 2 includes a first LED light source 21 and a dial color temperature control unit 22; the input end of the dial color temperature control unit 22 is connected to the first output end (D1) of the switching module 1; the output end of the dial color temperature control unit 22 is connected to the input end of the first LED light source 21; the output end of the first LED light source 21 is grounded; in an optional embodiment, the first LED light source 21 includes at least two groups of sub-light sources with different color temperatures; the input ends of different sub-light sources are respectively connected to different output ends of the dial color temperature control unit 22, and different sub-light sources are selected by dialing the dial color temperature control unit 22; Figure 3As shown, LEDW1-LEDW15 form a first group of sub-light sources; LEDDA1-LEDAD15 form a second group of sub-light sources, and the first group of sub-light sources and / or the second group of sub-light sources are switched on by switching the color temperature control unit 22 .

[0046] The auxiliary light source module 3 includes a second LED light source 31 and a current limiting unit 32, wherein the current limiting unit 32 includes a current limiting chip IC4 and a first resistor RS4; Figure 4 As shown, the second LED light source 31 includes LEDCL1-LEDCL14; the output end of the second LED light source 31 is grounded; one end of the first resistor RS4 is connected to the second output end (D2) of the switching module 1, and the other end of the first resistor RS4 is connected to the input end (REXT) of the current limiting chip IC4; the output end of the current limiting chip IC4 is connected to the input end of the second LED light source 31.

[0047] The specific working principle of the switching module 1 is as follows:

[0048] The two-speed wall-cut control chip IC3 detects the pulse signal waveform of the input power supply through the clock input terminal (CLK) to determine the power-on state; wherein, a pulse signal will be generated when the external switch is closed, and the pulse signal disappears when the switch is closed.

[0049] When the external switch is closed, the wall-cut two-speed control chip IC3 detects the pulse signal input, and the first output terminal (D1) of the wall-cut two-speed control chip IC3 is turned on, and the second output terminal (D2) is turned off, that is, the main light source module 2 is lit. When the external switch is turned off, the circuit is powered off.

[0050] If the power is restored within the preset time after the power is off, for example, within 6 seconds after the switch is powered off, that is, the wall-cut two-speed control chip IC3 detects the pulse signal again within 6 seconds after the switch is powered off, the wall-cut two-speed control chip IC3 will control the first output end (D1) to be closed, the second output end (D2) to be opened, and a small current is output through the current limiting chip IC4 to light up the auxiliary light source module 3.

[0051] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. An LED driving circuit with night light function, characterized in that: Including compatible dimming chip, constant current chip, switching module, main light source module and auxiliary light source module; The power input terminal of the compatible dimming chip is used for connecting to an external power source; The high voltage end of the compatible dimming chip is respectively connected to the high voltage end of the constant current chip and the power input end of the switching module; The compatible dimming chip is used to compensate the discharge current according to the type of the connected dimmer; The first output end of the switching module is connected to the main light source module; The second output end of the switching module is connected to the auxiliary light source module; The signal input end of the switching module is used to connect to an external power source, and generate a switching signal based on the switching state of the external power source, and switch the main light source module or the auxiliary light source module according to the switching signal.

2. The LED driving circuit with night light function according to claim 1, characterized in that: The main light source module includes a first LED light source and a dial color temperature control unit; The input end of the dial color temperature control unit is connected to the first output end of the switching module; The output end of the dial color temperature control unit is connected to the input end of the first LED light source; The output end of the first LED light source is grounded.

3. The LED driving circuit with night light function according to claim 2, characterized in that: The first LED light source includes at least two groups of sub-light sources with different color temperatures; The input ends of different sub-light sources are respectively connected to different output ends of the dial color temperature control unit, and the dial color temperature control unit is used to dial and select different sub-light sources.

4. The LED driving circuit with night light function according to claim 1, characterized in that: The auxiliary light source module includes a second LED light source and a current limiting unit; The input end of the current limiting unit is connected to the second output end of the switching module; The output end of the current limiting unit is connected to the input end of the second LED light source; The output end of the second LED light source is grounded.

5. The LED driving circuit with night light function according to claim 4, characterized in that: The current limiting unit includes a current limiting chip and a first resistor; One end of the first resistor is connected to the second output end of the switching module, and the other end of the first resistor is connected to the input end of the current limiting chip; The output end of the current limiting chip is connected to the input end of the second LED light source.

6. The LED driving circuit with night light function according to claim 1, characterized in that: The switching module includes a two-speed wall cutting control chip and a second resistor; The power input terminal of the wall cutting two-speed control chip is connected to the high voltage terminal of the constant current chip; The clock input end of the wall cutting two-speed control chip is connected to one end of the second resistor, and the clock input end is used to connect to an external power supply; The grounding end of the wall-cut two-speed control core is connected to the other end of the second resistor.

7. The LED driving circuit with night light function according to claim 6, characterized in that: The switching module also includes a first diode and a third resistor; The anode of the first diode is connected to the high voltage end of the constant current chip; The cathode of the first diode is connected to one end of the third resistor; The other end of the third resistor is connected to the power input end of the wall cutting two-speed control chip.

8. The LED driving circuit with night light function according to claim 1, characterized in that: Also includes varistors; The varistor is arranged at the power input terminal of the compatible dimming chip.

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