LED drive circuit and lamp

Abstract

The invention provides an LED drive circuit and a lamp, and relates to the technical field of LED lamps. The LED driving circuit comprises a DCDC module, an isolation constant current driving module and a main control module, the input end of the DCDC module is connected with the battery, and the output end of the DCDC module is connected with the LED; the input end of the isolation constant-current driving module is connected with an external alternating-current power supply, and the output end of the isolation constant-current driving module is connected with the LED; the control end of the DCDC module and the control end of the isolation constant current driving module are connected with the main control module. And the main control module is used for controlling the DCDC module or the isolation constant current driving module to supply power to the LED. Isolation constant current driving and DCDC are combined, the electric energy efficiency is high, and the power supply cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of LED lamps, and in particular to an LED driving circuit and a lamp. Background Art

[0002] As the use of clean energy becomes more and more widespread, solar energy, as a clean energy, is increasingly being applied to various fields. For outdoor lamps, in order to save energy, batteries and AC power are usually used.

[0003] In the prior art, dual-powered lamps usually use one constant voltage power supply from the mains and one DC conversion power supply from batteries. This solution has low mains efficiency, causes energy waste, and increases electricity costs. Summary of the invention

[0004] The embodiments of the present invention provide an LED driving circuit and a lamp to solve the problem of low power efficiency and waste of resources in the prior art of dual-channel shared lamps.

[0005] In a first aspect, an embodiment of the present invention provides an LED driving circuit, comprising: a DCDC module, an isolated constant current driving module and a main control module;

[0006] The input end of the DCDC module is connected to the battery, and the output end of the DCDC module is connected to the LED;

[0007] The input end of the isolation constant current driving module is connected to the external AC power supply, and the output end of the isolation constant current driving module is connected to the LED;

[0008] The control end of the DCDC module and the control end of the isolated constant current drive module are both connected to the main control module; the main control module is used to control the DCDC module or the isolated constant current drive module to power the LED.

[0009] Optionally, the LED driving circuit further includes: a main control power supply module;

[0010] The first input end of the main control power supply module is connected to the DCDC module, the second input end of the main control power supply module is connected to the isolation constant current drive module, and the output end of the main control power supply module is connected to the power supply end of the main control module for powering the main control module.

[0011] Optionally, the first input terminal of the main control power supply module is connected to the input terminal of the DCDC module; the DCDC module includes: a battery switch unit and a DCDC unit;

[0012] The input end of the battery switch unit is connected to the input end of the DCDC module, the output end of the battery switch unit is connected to the input end of the DCDC unit, and the control end of the battery switch unit is connected to the main control module; the battery switch unit is used to receive the first switch signal sent by the main control module, and control the battery switch unit to be turned on when the first switch signal is received;

[0013] The output end of the DCDC unit is connected to the output end of the DCDC module, and the control end of the DCDC unit is connected to the main control module; the control end of the DCDC unit is used to receive the DC dimming signal sent by the main control module, and adjust the output voltage of the DCDC unit according to the DC dimming signal;

[0014] The input end of the DCDC unit is also connected to the first control end of the main control power supply module;

[0015] The main control power supply module is used to detect the input voltage of the DCDC unit, and when it is detected that the input voltage of the DCDC unit is not less than a preset voltage, the main control power supply module is controlled to be powered by a battery.

[0016] Optionally, the main control power supply module further includes a second control end; the second control end of the main control power supply module is connected to the main control module; the main control power supply module includes: an AC switch unit, a voltage conversion unit, a first diode and a second diode;

[0017] The input end of the AC switch unit is connected to the second input end of the main control power supply module, the output end of the AC switch unit is connected to the anode of the first diode, the first control end of the AC switch unit is connected to the first control end of the main control power supply module, and the second control end of the AC switch unit is connected to the second control end of the main control power supply module; the AC switch unit is used to receive the second switch signal sent by the main control module and detect the input voltage of the DCDC unit, and control the AC switch unit to turn on when the second switch signal is received and it is detected that the input voltage of the DCDC unit is less than the preset voltage;

[0018] The anode of the second diode is connected to the first input end of the main control power supply module, and the cathode of the second diode is respectively connected to the cathode of the first diode and the input end of the voltage conversion unit; the output end of the voltage conversion unit is connected to the output end of the main control power supply module.

[0019] Optionally, the battery switch unit includes: a first switch tube, a second switch tube, a third switch tube, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor;

[0020] A first switch tube, wherein a first end is respectively connected to the first end of the third resistor, the first end of the fourth resistor and the control end of the second switch tube, a second end is connected to the DC ground end, and a control end is connected to the first end of the second resistor;

[0021] A second switch tube, a first end of which is respectively connected to the first end of the fifth resistor and the control end of the third switch tube, a second end of which is connected to the second end of the third resistor, and a second end of which is also connected to the DC grounding end;

[0022] A third switch tube, a first end of which is respectively connected to the second end of the fifth resistor, the second end of the fourth resistor and the input end of the battery switch unit, and a second end of which is connected to the output end of the battery switch unit;

[0023] The second end of the second resistor is connected to the control end of the battery switch unit, and the second end of the second resistor is also connected to the first DC power supply through the first resistor.

[0024] Optionally, the AC switch unit includes: a fourth switch tube, a fifth switch tube, a sixth switch tube, a seventh switch tube, a third diode, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor and an eleventh resistor;

[0025] a fourth switch tube, wherein a first end is respectively connected to the first end of the seventh resistor, the first end of the eighth resistor and the control end of the fifth switch tube, a second end is connected to the DC ground end, and a control end is connected to the second control end of the AC switch unit through a sixth resistor;

[0026] a fifth switch tube, a first end of which is respectively connected to the first end of the ninth resistor and the control end of the sixth switch tube, and a second end of which is respectively connected to the second end of the seventh resistor and the DC ground end;

[0027] a sixth switch tube, wherein a first end is respectively connected to the second end of the eighth resistor, the second end of the ninth resistor, the first end of the eleventh resistor and the input end of the AC switch unit, and a second end is connected to the first end of the seventh switch tube;

[0028] A seventh switch tube, a second end of which is respectively connected to the cathode of the third diode and the output end of the AC switch unit, and a control end of which is respectively connected to the anode of the third diode, the first end of the tenth resistor and the first control end of the AC switch unit;

[0029] The second end of the tenth resistor and the second end of the eleventh resistor are both connected to the DC ground terminal.

[0030] Optionally, the DCDC unit includes: an eighth switch tube, a fourth diode, a first inductor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a twelfth resistor, a thirteenth resistor and a fourteenth resistor;

[0031] an eighth switch tube, wherein a first end is respectively connected to the anode of the fourth diode, the first end of the third capacitor and the first end of the first inductor, a second end is connected to the DC ground terminal, and a control end is connected to the control end of the DCDC unit;

[0032] The second end of the first inductor is connected to the first end of the first capacitor and the input end of the DCDC unit respectively;

[0033] The first end of the twelfth resistor is connected to the second end of the third capacitor, and the second end of the twelfth resistor is respectively connected to the cathode of the fourth diode, the first end of the second capacitor, and the output end of the DCDC unit;

[0034] The first end of the fourteenth resistor is respectively connected to the first end of the thirteenth resistor and the virtual ground end, and the second end of the fourteenth resistor is connected to the first end of the fourth capacitor; the second end of the fourteenth resistor is also connected to the main control module, and is used to send a current sampling signal to the main control module; the main control module is used to generate a DC dimming signal according to the current sampling signal;

[0035] The second end of the thirteenth resistor, the second end of the first capacitor, the second end of the second capacitor and the second end of the fourth capacitor are all connected to the DC ground terminal;

[0036] The output end of the DCDC unit is used to be connected to the positive electrode of the LED, and the negative electrode of the LED is connected to the virtual ground end.

[0037] Optionally, the current sampling signal is a discrete voltage value; generating a DC dimming signal according to the current sampling signal includes:

[0038] Continuously acquiring a first preset number of groups of current sampling signals, wherein each group includes a second number of current sampling signals;

[0039] For any group of current sampling signals, filter the group of current sampling signals to obtain filtered current sampling signals corresponding to the group of current sampling signals; calculate the mean value of each filtered current sampling signal to obtain the target value corresponding to the group of current sampling signals;

[0040] Remove the maximum and minimum values ​​from each target value, calculate the average value, and obtain the target sampling current;

[0041] A DC dimming signal is determined according to the target sampling current.

[0042] Optionally, the isolated constant current driving module includes: an isolated constant current driving unit and a fifth diode;

[0043] The input end of the isolated constant current driving unit is connected to the input end of the isolated constant current driving module, the first output end of the isolated constant current driving unit is connected to the anode of the fifth diode, and the second output end of the isolated constant current driving unit is connected to the DC grounding end;

[0044] The first output terminal of the isolated constant current driving unit is also connected to the second input terminal of the main control power supply module;

[0045] The cathode of the fifth diode is used to be connected to the anode of the LED.

[0046] In a second aspect, an embodiment of the present invention provides a lamp, comprising an LED driving circuit as provided in the first aspect of the above embodiment.

[0047] The embodiment of the present invention provides an LED driving circuit and lamp. The above-mentioned LED driving circuit includes: a DCDC module, an isolated constant current driving module and a main control module; the input end of the DCDC module is connected to the battery, and the output end of the DCDC module is connected to the LED; the input end of the isolated constant current driving module is connected to the external AC power supply, and the output end of the isolated constant current driving module is connected to the LED; the control end of the DCDC module and the control end of the isolated constant current driving module are both connected to the main control module; the main control module is used to control the DCDC module or the isolated constant current driving module to power the LED. In the embodiment of the present invention, the main power part adopts isolated constant current drive, and the battery part adopts DCDC, which combines the isolated constant current drive with DCDC, effectively improves the power efficiency, reduces the power supply cost, and has a simple circuit structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 1 is a schematic diagram of a circuit structure of an LED driving circuit provided by an embodiment of the present invention;

[0049] Figure 2 is a circuit structure schematic diagram of another LED driving circuit provided by an embodiment of the present invention;

[0050] Figure 3 1 is a circuit structure diagram of another LED driving circuit provided by an embodiment of the present invention;

[0051] Figure 4 It is a schematic diagram of the circuit structure of a main control power supply module provided by an embodiment of the present invention;

[0052] Figure 5 is a circuit schematic diagram of a battery switch unit provided by an embodiment of the present invention;

[0053] Figure 6 is a circuit schematic diagram of an AC switch unit provided by an embodiment of the present invention;

[0054] Figure 7 is a circuit schematic diagram of a DCDC unit provided by an embodiment of the present invention;

[0055] Figure 8 It is a circuit schematic diagram of an isolated constant current driving module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to enable people in the technical field to better understand the present solution, the technical solution in the embodiment of the present solution will be clearly described below in conjunction with the drawings in the embodiment of the present solution. Obviously, the described embodiment is an embodiment of a part of the present solution, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0057] The term "including" and any other variations in the specification and claims of this solution and the above drawings mean "including but not limited to", and is intended to cover non-exclusive inclusions and is not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0058] The following is a detailed description of the implementation of the present invention in conjunction with the specific drawings:

[0059] Figure 1 This is a schematic diagram of the structure of an LED driving circuit provided by an embodiment of the present invention. Figure 1 , the LED driving circuit includes: a DCDC module 1, an isolated constant current driving module 2 and a main control module 3;

[0060] The input end of the DCDC module 1 is connected to the battery, and the output end of the DCDC module 1 is connected to the LED;

[0061] The input end of the isolation constant current driving module 2 is connected to the external alternating current power supply AC, and the output end of the isolation constant current driving module 2 is connected to the LED;

[0062] The control end of the DCDC module 1 and the control end of the isolated constant current driving module 2 are both connected to the main control module 3; the main control module 3 is used to control the DCDC module 1 or the isolated constant current driving module 2 to power the LED.

[0063] In the embodiment of the present invention, the mains power supplies the LED through the isolated constant current drive module 2, and the battery supplies the LED through the DCDC module 1, thereby realizing dual-circuit power supply for the LED. At the same time, the mains power adopts isolated constant current drive, which has high power efficiency and reduces the power supply cost. In addition, the circuit structure is simple and the circuit cost is low.

[0064] In one possible implementation, reference Figure 2 , the LED driving circuit may further include: a main control power supply module 4;

[0065] The first input end of the main control power supply module 4 is connected to the DCDC module 1, the second input end of the main control power supply module 4 is connected to the isolated constant current drive module 2, and the output end of the main control power supply module 4 is connected to the power supply end of the main control module 3, for powering the main control module 3.

[0066] In order to ensure that the main control module 3 can operate stably and reliably, the LED driving circuit may further include a crucial component, namely, the main control power supply module 4. In the embodiment of the present invention, the main control module 3 is powered by the DCDC module 1 and the isolated constant current driving module 2.

[0067] Based on the above embodiment, in a possible implementation manner, refer to Figure 3 , the first input end of the main control power supply module 4 is connected to the input end of the DCDC module 1; the DCDC module 1 includes: a battery switch unit 11 and a DCDC unit 12;

[0068] The input end of the battery switch unit 11 is connected to the input end of the DCDC module 1, the output end of the battery switch unit 11 is connected to the input end of the DCDC unit 12, and the control end of the battery switch unit 11 is connected to the main control module 3; the battery switch unit 11 is used to receive the first switch signal BAT_EN sent by the main control module 3, and control the battery switch unit 11 to be turned on when the first switch signal BAT_EN is received;

[0069] The output end of the DCDC unit 12 is connected to the output end of the DCDC module 1, and the control end of the DCDC unit 12 is connected to the main control module 3; the control end of the DCDC unit 12 is used to receive the DC dimming signal sent by the main control module 3, and adjust the output voltage of the DCDC unit 12 according to the DC dimming signal;

[0070] The input end of the DCDC unit 12 is also connected to the first control end of the main control power supply module 4;

[0071] The main control power supply module 4 is used to detect the input voltage of the DCDC unit 12, and when it is detected that the input voltage of the DCDC unit 12 is not less than a preset voltage, the main control power supply module 4 is controlled to be powered by a battery.

[0072] In the embodiment of the present invention, a battery switch unit 11 is provided, and the battery supplies power to the DCDC unit 12 through the battery switch unit 11. The main control module 3 sends a first switch signal BAT_EN to the battery switch unit 11 to control the battery switch unit 11 to be turned on. For example, a user can send an energy-saving control signal to the main control module 3 through a wireless device. After receiving the energy-saving control signal, the main control module 3 sends a first switch signal BAT_EN to the battery switch unit 11 to control the battery switch unit 11 to be turned on, and the battery supplies power to the back end. For solar lamps, solar energy charges the battery, and battery power can be used preferentially. Based on this, the main control module 3 can also detect the battery voltage. When it is detected that the battery voltage is normal, the first switch signal BAT_EN is sent to the battery switch unit 11 to control the battery switch unit 11 to be turned on, and the battery supplies power to the back end.

[0073] The DC dimming signal is a dimming signal of the DCDC unit 12 and may be a PWM wave. The duty cycle of the DC dimming signal is adjusted to adjust the output voltage of the DCDC unit 12 to dim the LED.

[0074] In the embodiment of the present invention, the main control module 3 also detects the input voltage of the DCDC unit 12. When the input voltage of the DCDC unit 12 is not less than the preset voltage, it indicates that the battery has sufficient power, and the main control power supply module 4 is controlled to be powered by the battery. That is, when the battery voltage is normal, the battery supplies power to the main control module 3 and the LED at the same time.

[0075] In one possible implementation, reference Figure 4 , the main control power supply module 4 also includes a second control end; the second control end of the main control power supply module 4 is connected to the main control module 3; the main control power supply module 4 may include: an AC switch unit 41, a voltage conversion unit 42, a first diode D1 and a second diode D2;

[0076] The input end of the AC switch unit 41 is connected to the second input end of the main control power supply module 4, the output end of the AC switch unit 41 is connected to the anode of the first diode D1, the first control end of the AC switch unit 41 is connected to the first control end of the main control power supply module 4, and the second control end of the AC switch unit 41 is connected to the second control end of the main control power supply module 4; the AC switch unit 41 is used to receive the second switch signal AC_EN sent by the main control module 3 and detect the input voltage of the DCDC unit 12, and when the second switch signal AC_EN is received and it is detected that the input voltage of the DCDC unit 12 is less than the preset voltage, the AC switch unit 41 is controlled to be turned on;

[0077] The anode of the second diode D2 is connected to the first input end of the main control power supply module 4, and the cathode of the second diode D2 is respectively connected to the cathode of the first diode D1 and the input end of the voltage conversion unit 42; the output end of the voltage conversion unit 42 is connected to the output end of the main control power supply module 4.

[0078] refer to Figure 4 When the battery voltage is normal, the battery voltage supplies power to the voltage conversion unit 42 through the second diode D2, and the voltage conversion unit 42 supplies power to the main control module 3 after voltage conversion, giving priority to the use of battery power to achieve energy saving. When the battery voltage is abnormal (the input voltage of the DCDC unit 12 is less than the preset voltage), the battery cannot supply power normally, the main control module 3 sends a second switch signal AC_EN, the AC switch unit 41 is turned on, and the AC power supply supplies power to the main control module 3. Based on the above, the battery is given priority to power supply, and it automatically switches to AC power supply when the battery voltage is abnormal.

[0079] Specifically, the main control module 3 can also detect the battery voltage and the AC voltage. When the battery voltage is abnormal and the AC voltage is normal, the second switch signal AC_EN can be sent to the AC switch unit 41. The control logic of the second switch signal AC_EN includes but is not limited to the above, and can be set according to actual application requirements.

[0080] In one possible implementation, reference Figure 5 The battery switch unit 11 may include: a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5;

[0081] A first switch tube Q1, a first end of which is respectively connected to the first end of the third resistor R3, the first end of the fourth resistor R4 and the control end of the second switch tube Q2, a second end of which is connected to the DC ground terminal (GND), and a control end of which is connected to the first end of the second resistor R2;

[0082] A second switch tube Q2, a first end of which is respectively connected to the first end of the fifth resistor R5 and the control end of the third switch tube Q3, a second end of which is connected to the second end of the third resistor R3, and a second end of which is also connected to the DC ground end;

[0083] The third switch tube Q3 has a first end connected to the second end of the fifth resistor R5, the second end of the fourth resistor R4 and the input end of the battery switch unit 11, and a second end connected to the output end of the battery switch unit 11;

[0084] The second end of the second resistor R2 is connected to the control end of the battery switch unit 11 , and the second end of the second resistor R2 is also connected to the first DC power supply through the first resistor R1 .

[0085] Specific reference Figure 5 For example, the first switch tube Q1 and the second switch tube Q2 may be NPN transistors, and the third switch tube Q3 may be a P-type MOS tube.

[0086] Specifically, the first switch signal BAT_EN can be low level. When the first switch signal BAT_EN is received, the first switch tube Q1 is turned off at low level, the second switch tube Q2 is turned on, and then the third switch tube Q3 is turned on, the battery switch unit 11 is turned on, and the battery supplies power to the DCDC unit 12.

[0087] When the first switch signal BAT_EN is not received, the first switch tube Q1 is turned on at a high level, the second switch tube Q2 is turned off, the third switch tube Q3 is turned off, the battery switch unit 11 is turned off, and the battery cannot supply power to the back end.

[0088] Based on the above circuit, the battery switch unit 11 has a simple circuit structure, fewer components, and low cost, and can realize the control of DC power supply.

[0089] In one possible implementation, reference Figure 6 The AC switch unit 41 may include: a fourth switch tube Q4, a fifth switch tube Q5, a sixth switch tube Q6, a seventh switch tube Q7, a third diode D3, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and an eleventh resistor R11;

[0090] The fourth switch tube Q4 has a first end connected to the first end of the seventh resistor R7, the first end of the eighth resistor R8 and the control end of the fifth switch tube Q5, a second end connected to the DC ground end, and a control end connected to the second control end of the AC switch unit 41 through the sixth resistor R6;

[0091] A fifth switch tube Q5, a first end of which is respectively connected to the first end of the ninth resistor R9 and the control end of the sixth switch tube Q6, and a second end of which is respectively connected to the second end of the seventh resistor R7 and the DC ground end;

[0092] a sixth switch tube Q6, a first end of which is respectively connected to the second end of the eighth resistor R8, the second end of the ninth resistor R9, the first end of the eleventh resistor R11 and the input end of the AC switch unit 41, and a second end of which is connected to the first end of the seventh switch tube Q7;

[0093] The seventh switch tube Q7 has a second end connected to the cathode of the third diode D3 and the output end of the AC switch unit 41, and a control end connected to the anode of the third diode D3, the first end of the tenth resistor R10 and the first control end of the AC switch unit 41;

[0094] The second end of the tenth resistor R10 and the second end of the eleventh resistor R11 are both connected to the DC ground terminal.

[0095] refer to Figure 6 The AC switch unit 41 is controlled by the second switch signal AC_EN and the input voltage of the DCDC unit 12. Specifically, the second switch signal AC_EN may be at a low level.

[0096] When the battery cannot supply power and the AC is normal, the main control module 3 sends a second switch signal AC_EN. When the second switch signal AC_EN is received, the fourth switch tube Q4 is turned off, the fifth switch tube Q5 is turned on, and the sixth switch tube Q6 is turned on; at the same time, due to the abnormal battery power supply, the input voltage of the DCDC unit 12 is low, the seventh switch tube Q7 is also turned on, and the AC switch unit 41 is turned on, corresponding to Figure 5 , the main control module 3 is powered by AC through the first diode D1.

[0097] When the battery is powered normally, the second switch signal AC_EN is not received and the input voltage of the DCDC unit 12 is at a high level, the fourth switch tube Q4 is turned on, the fifth switch tube Q5 is turned off, the sixth switch tube Q6 is turned off, the input voltage of the DCDC unit 12 is at a high level, and the seventh switch tube Q7 is also turned off. At this time, even if the second switch signal AC_EN is received, since the input voltage of the DCDC unit 12 is at a high level, the seventh switch tube Q7 is still turned off, the AC cannot be powered, and the main control module 3 is still powered by the battery.

[0098] When the battery power supply is abnormal and the AC power is just turned on, the main control module 3 is not powered on yet and cannot send the second switch signal AC_EN. One end of the sixth resistor R6 enters a suspended or low level state, the AC switch unit 41 is turned on, and the AC power is used for the main control module 3.

[0099] based on Figures 4 to 6 It can be seen that the battery and the AC can be switched in for power supply independently. As long as one of the battery and the AC has power, the main control module 3 and the LED can be powered, ensuring the stable power supply of the main control module 3.

[0100] In one possible implementation, reference Figure 7 , the DCDC unit 12 may include: an eighth switch tube Q8, a fourth diode D4, a first inductor L1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a twelfth resistor R12, a thirteenth resistor R13 and a fourteenth resistor R14;

[0101] An eighth switch tube Q8, a first end of which is respectively connected to the anode of the fourth diode D4, the first end of the third capacitor C3 and the first end of the first inductor L1, a second end of which is connected to the DC ground terminal, and a control end of which is connected to the control end of the DCDC unit 12;

[0102] The second end of the first inductor L1 is connected to the first end of the first capacitor C1 and the input end of the DCDC unit 12 respectively;

[0103] A first end of the twelfth resistor R12 is connected to the second end of the third capacitor C3, and a second end of the twelfth resistor R12 is respectively connected to the cathode of the fourth diode D4, the first end of the second capacitor C2, and the output end of the DCDC unit 12;

[0104] The first end of the fourteenth resistor R14 is respectively connected to the first end of the thirteenth resistor R13 and the virtual ground end (GND1), and the second end of the fourteenth resistor R14 is connected to the first end of the fourth capacitor C4; the second end of the fourteenth resistor R14 is also connected to the main control module 3, and is used to send a current sampling signal to the main control module 3; the main control module 3 is used to generate a DC dimming signal according to the current sampling signal;

[0105] The second end of the thirteenth resistor R13, the second end of the first capacitor C1, the second end of the second capacitor C2 and the second end of the fourth capacitor C4 are all connected to the DC ground terminal;

[0106] The output end of the DCDC unit 12 is used to be connected to the positive electrode (LED+) of the LED, and the negative electrode (LED-) of the LED is connected to the virtual ground terminal (GND1).

[0107] refer to Figure 7 The DCDC unit 12 adjusts the output voltage according to the DC dimming signal to achieve dimming. At the same time, the main control module 3 also samples the current through the thirteenth resistor R13 and the fourteenth resistor R14, and then adjusts the duty cycle of the DC dimming signal.

[0108] In a possible implementation, the current sampling signal is a discrete voltage value; and generating a DC dimming signal according to the current sampling signal includes:

[0109] 1. Continuously acquiring a first preset number of groups of current sampling signals, wherein each group includes a second number of current sampling signals;

[0110] 2. For any group of current sampling signals, filter the group of current sampling signals to obtain filtered current sampling signals corresponding to the group of current sampling signals; calculate the mean value of each filtered current sampling signal to obtain the target value corresponding to the group of current sampling signals;

[0111] 3. Remove the maximum and minimum values ​​from each target value and calculate the average to obtain the target sampling current;

[0112] 4. Determine the DC dimming signal based on the target sampling current.

[0113] In the embodiment of the present invention, multiple groups of current sampling signals are continuously sampled (a single signal is collected at the 50μs level), each group of signals is filtered and then the mean is calculated, and then the mean of each target value is calculated after the maximum and minimum values ​​are removed, which further improves the accuracy of the calculation and the accuracy of the dimming. Specifically, the median filtering method can be used to filter each group of current sampling signals.

[0114] For example, the first set of sampling values ​​is 20, 25, 10, 25, 60. After removing the abnormal data using the median filter method, 20, 25, 25 are retained, and the target value is calculated to be 23.3. The same method is used to calculate 10 sets of target values, remove the maximum and minimum values, calculate the mean, and obtain the target sampling current.

[0115] In one possible implementation, reference Figure 8 , the isolation constant current driving module 2 may include: an isolation constant current driving unit 21 and a fifth diode D5;

[0116] The input end of the isolation constant current driving unit 21 is connected to the input end of the isolation constant current driving module 2, the first output end of the isolation constant current driving unit 21 is connected to the anode of the fifth diode D5, and the second output end of the isolation constant current driving unit 21 is connected to the DC grounding end;

[0117] The first output terminal of the isolated constant current driving unit 21 is also connected to the second input terminal of the main control power supply module 4;

[0118] The cathode of the fifth diode D5 is used to be connected to the anode of the LED.

[0119] In the embodiment of the present invention, the first output end of the isolated constant current driving unit 21 is connected to the positive electrode of the LED through a diode to avoid backflow.

[0120] The specific principle of the isolated constant current drive unit 21 can be referred to Figure 8 , the details will not be repeated here.

[0121] Corresponding to the above embodiments, an embodiment of the present invention provides a lamp, comprising the LED driving circuit provided by any of the above embodiments.

[0122] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An LED driving circuit, characterized in that: include: DCDC module, isolated constant current drive module and main control module; The input end of the DCDC module is connected to the battery, and the output end of the DCDC module is connected to the LED; The input end of the isolated constant current driving module is connected to the external AC power supply, and the output end of the isolated constant current driving module is connected to the LED; The control end of the DCDC module and the control end of the isolated constant current driving module are both connected to the main control module; the main control module is used to control the DCDC module or the isolated constant current driving module to power the LED.

2. The LED driving circuit according to claim 1, characterized in that: The LED driving circuit also includes: a main control power supply module; The first input end of the main control power supply module is connected to the DCDC module, the second input end of the main control power supply module is connected to the isolated constant current drive module, and the output end of the main control power supply module is connected to the power supply end of the main control module, for powering the main control module.

3. The LED driving circuit according to claim 2, characterized in that: The first input end of the main control power supply module is connected to the input end of the DCDC module; the DCDC module includes: a battery switch unit and a DCDC unit; The input end of the battery switch unit is connected to the input end of the DCDC module, the output end of the battery switch unit is connected to the input end of the DCDC unit, and the control end of the battery switch unit is connected to the main control module; the battery switch unit is used to receive a first switch signal sent by the main control module, and control the battery switch unit to be turned on when receiving the first switch signal; The output end of the DCDC unit is connected to the output end of the DCDC module, and the control end of the DCDC unit is connected to the main control module; the control end of the DCDC unit is used to receive the DC dimming signal sent by the main control module, and adjust the output voltage of the DCDC unit according to the DC dimming signal; The input end of the DCDC unit is also connected to the first control end of the main control power supply module; The main control power supply module is used to detect the input voltage of the DCDC unit, and when it is detected that the input voltage of the DCDC unit is not less than a preset voltage, control the main control power supply module to be powered by the battery.

4. The LED driving circuit according to claim 3, characterized in that: The main control power supply module also includes a second control end; the second control end of the main control power supply module is connected to the main control module; the main control power supply module includes: an AC switch unit, a voltage conversion unit, a first diode and a second diode; The input end of the AC switch unit is connected to the second input end of the main control power supply module, the output end of the AC switch unit is connected to the anode of the first diode, the first control end of the AC switch unit is connected to the first control end of the main control power supply module, and the second control end of the AC switch unit is connected to the second control end of the main control power supply module; the AC switch unit is used to receive the second switch signal sent by the main control module and detect the input voltage of the DCDC unit, and control the AC switch unit to be turned on when the second switch signal is received and it is detected that the input voltage of the DCDC unit is less than the preset voltage; The anode of the second diode is connected to the first input end of the main control power supply module, and the cathode of the second diode is respectively connected to the cathode of the first diode and the input end of the voltage conversion unit; the output end of the voltage conversion unit is connected to the output end of the main control power supply module.

5. The LED driving circuit according to claim 3, characterized in that: The battery switch unit includes: a first switch tube, a second switch tube, a third switch tube, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor; The first switch tube has a first end connected to the first end of the third resistor, the first end of the fourth resistor and the control end of the second switch tube respectively, a second end connected to the DC grounding end, and a control end connected to the first end of the second resistor; The second switch tube has a first end connected to the first end of the fifth resistor and the control end of the third switch tube respectively, a second end connected to the second end of the third resistor, and a second end further connected to the DC grounding end; The third switch tube has a first end connected to the second end of the fifth resistor, the second end of the fourth resistor and the input end of the battery switch unit, and a second end connected to the output end of the battery switch unit; The second end of the second resistor is connected to the control end of the battery switch unit, and the second end of the second resistor is also connected to the first DC power supply through the first resistor.

6. The LED driving circuit according to claim 4, characterized in that: The AC switch unit includes: a fourth switch tube, a fifth switch tube, a sixth switch tube, a seventh switch tube, a third diode, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor and an eleventh resistor; The fourth switch tube has a first end connected to the first end of the seventh resistor, the first end of the eighth resistor and the control end of the fifth switch tube respectively, a second end connected to the DC grounding end, and a control end connected to the second control end of the AC switch unit through the sixth resistor; The fifth switch tube has a first end connected to the first end of the ninth resistor and the control end of the sixth switch tube, and a second end connected to the second end of the seventh resistor and the DC grounding end; The sixth switch tube has a first end connected to the second end of the eighth resistor, the second end of the ninth resistor, the first end of the eleventh resistor and the input end of the AC switch unit, and a second end connected to the first end of the seventh switch tube; The seventh switch tube has a second end connected to the cathode of the third diode and the output end of the AC switch unit, and a control end connected to the anode of the third diode, the first end of the tenth resistor and the first control end of the AC switch unit; The second end of the tenth resistor and the second end of the eleventh resistor are both connected to the DC ground terminal.

7. The LED driving circuit according to claim 3, characterized in that: The DCDC unit includes: an eighth switch tube, a fourth diode, a first inductor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a twelfth resistor, a thirteenth resistor and a fourteenth resistor; The eighth switch tube has a first end connected to the anode of the fourth diode, the first end of the third capacitor and the first end of the first inductor respectively, a second end connected to the DC ground terminal, and a control end connected to the control end of the DCDC unit; The second end of the first inductor is connected to the first end of the first capacitor and the input end of the DCDC unit respectively; The first end of the twelfth resistor is connected to the second end of the third capacitor, and the second end of the twelfth resistor is respectively connected to the cathode of the fourth diode, the first end of the second capacitor and the output end of the DCDC unit; The first end of the fourteenth resistor is respectively connected to the first end of the thirteenth resistor and the virtual ground end, and the second end of the fourteenth resistor is connected to the first end of the fourth capacitor; the second end of the fourteenth resistor is also connected to the main control module, for sending a current sampling signal to the main control module; the main control module is used to generate the DC dimming signal according to the current sampling signal; The second end of the thirteenth resistor, the second end of the first capacitor, the second end of the second capacitor and the second end of the fourth capacitor are all connected to the DC ground terminal; The output end of the DCDC unit is used to be connected to the positive electrode of the LED, and the negative electrode of the LED is connected to the virtual ground end.

8. The LED driving circuit according to claim 7, characterized in that: The current sampling signal is a discrete voltage value; and generating the DC dimming signal according to the current sampling signal includes: Continuously acquiring a first preset number of groups of current sampling signals, wherein each group includes a second number of current sampling signals; For any group of current sampling signals, filter the group of current sampling signals to obtain filtered current sampling signals corresponding to the group of current sampling signals; calculate the mean value of each filtered current sampling signal to obtain the target value corresponding to the group of current sampling signals; Remove the maximum and minimum values ​​from each target value, calculate the average value, and obtain the target sampling current; The DC dimming signal is determined according to the target sampling current.

9. The LED driving circuit according to claim 7, characterized in that: The isolated constant current driving module comprises: an isolated constant current driving unit and a fifth diode; The input end of the isolated constant current driving unit is connected to the input end of the isolated constant current driving module, the first output end of the isolated constant current driving unit is connected to the anode of the fifth diode, and the second output end of the isolated constant current driving unit is connected to the DC grounding end; The first output end of the isolated constant current driving unit is also connected to the second input end of the main control power supply module; The cathode of the fifth diode is used to be connected to the anode of the LED.

10. A lamp, characterized in that: The LED driving circuit comprises the LED driving circuit as claimed in any one of claims 1 to 9.

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