LED driving power supply circuit and LED lamp

Abstract

The utility model discloses an LED driving power supply circuit and an LED lamp, and relates to the technical field of LED lamps. The LED driving power supply circuit comprises a first constant current driving circuit, a second constant current driving circuit, a switching circuit and a control circuit. When the control circuit detects that the voltage value of the first driving voltage is within a preset range value, the first constant current driving circuit outputs the first driving voltage to provide a driving power supply. When the control circuit detects that the voltage value of the first driving voltage is out of a preset voltage range, the control circuit controls the switching circuit to switch off the path between the first constant current driving circuit and the power output end and switch on the path between the second constant current driving circuit and the power output end. And the second constant-current driving circuit outputs a second driving voltage to provide a driving power supply. Therefore, when the output of the first constant current driving circuit is abnormal, the driving power supply can be switched to the second constant current driving circuit to output the driving power supply, and the driving power supply circuit is suitable for application scenes with higher requirements on the driving power supply.

Description

Technical Field

[0001] The utility model relates to the technical field of LED lamps, and in particular to an LED driving power supply circuit and an LED lamp. Background Art

[0002] Light Emitting Diode (LED) has been widely used due to its advantages of environmental protection, energy saving, shock resistance, and long service life. LED is a low-voltage DC device driven by a constant current, so it is impossible to directly connect the power grid to the LED to power the LED. It is necessary to convert the power grid electricity through a driving power circuit to power the LED.

[0003] However, during the use of LED lamps, the LED driver power circuit is most likely to be damaged, which can easily cause a dead light. In some LED driver power application scenarios that have high requirements for the driver power, such as emergency lighting scenarios, the existing LED driver power can no longer meet the requirements. Utility Model Content

[0004] The main purpose of the utility model is to provide an LED driving power supply circuit, aiming to achieve the purpose of dual-path driving output driving power supply, and solve the problem that the existing LED driving power supply circuit is prone to cause dead light.

[0005] To achieve the above purpose, the LED driving power supply circuit proposed by the utility model includes:

[0006] Power input terminal, used for inputting AC voltage;

[0007] Power supply output terminal;

[0008] A first constant current driving circuit, wherein an input end of the first constant current driving circuit is connected to the power input end, and the first constant current driving circuit is used to convert the AC voltage into a first driving voltage output;

[0009] A second constant current driving circuit, wherein an input end of the second constant current driving circuit is connected to the power input end, and the second constant current driving circuit is used to convert the AC voltage into a second driving voltage output;

[0010] A switch circuit, wherein a first input end of the switch circuit is connected to an output end of the first constant current drive circuit, a second input end of the switch circuit is connected to an output end of the second constant current drive circuit, an output end of the switch circuit is connected to the power supply output end, and the switch circuit is used to control the on / off of a path between the first constant current drive circuit and the power supply output end, and to control the on / off of a path between the second constant current drive circuit and the power supply output end;

[0011] A control circuit, wherein the power supply end of the control circuit is connected to the power supply input end, the detection end of the control circuit is connected to the output end of the first constant current drive circuit, the control end of the control circuit is connected to the controlled end of the switch circuit, and the control circuit is used to control the operation of the switch circuit according to the output state of the first constant current drive circuit.

[0012] In one embodiment, the second detection terminal of the control circuit is connected to the output terminal of the second constant current driving circuit;

[0013] The LED driving power supply circuit also includes a battery, and the battery is connected to the switch circuit; the switch circuit is also used to control the on / off of the path between the battery and the power output end;

[0014] The control circuit is further used to control the operation of the switch circuit according to the output state of the second constant current drive circuit.

[0015] In one embodiment, the first constant current driving circuit includes:

[0016] a first rectifier circuit, wherein an input end of the first rectifier circuit is connected to an input end of the first constant current drive circuit, and the first rectifier circuit is used to convert the AC voltage into a first DC voltage;

[0017] a first power factor correction circuit, wherein an input end of the first power factor correction circuit is connected to an output end of the first rectifier circuit;

[0018] a first voltage conversion circuit, wherein an input end of the first voltage conversion circuit is connected to an output end of the first power factor correction circuit, an output end of the first voltage conversion circuit is connected to a first input end of the switch circuit, and the first voltage conversion circuit is used to convert the first DC voltage into the first driving voltage and then output it;

[0019] a first detection circuit, wherein an input end of the first detection circuit is connected to an output end of the first voltage conversion circuit, an output end of the first detection circuit is connected to a detection end of the control circuit, and the first detection circuit is used to output a detection signal according to the first driving voltage;

[0020] The control circuit is also used to control the operation of the switch circuit according to the detection signal.

[0021] In one embodiment, the second constant current driving circuit includes:

[0022] a second rectifier circuit, wherein an input end of the second rectifier circuit is connected to an input end of the second constant current drive circuit, and the second rectifier circuit is used for converting the AC voltage into a second DC voltage;

[0023] a second power factor correction circuit, wherein an input end of the second power factor correction circuit is connected to an output end of the second rectifier circuit;

[0024] A second voltage conversion circuit, wherein the input end of the second voltage conversion circuit is connected to the output end of the second power factor correction circuit, the output end of the second voltage conversion circuit is connected to the second input end of the switching circuit, and the second voltage conversion circuit is used to convert the second DC voltage into the second drive voltage and then output it.

[0025] In one embodiment, the first power factor correction circuit includes a first control chip, a first switch tube, a first inductor, a first resistor, a first diode and a first capacitor;

[0026] Among them, the IN1 pin of the first control chip is connected to the first end of the main winding of the first inductor, the IN2 pin of the first control chip and one end of the first resistor are connected to the negative electrode of the first capacitor, the ZCD pin of the first control chip is connected to the first end of the secondary winding of the first inductor, and the OUT pin of the first control chip is connected to the controlled end of the first switch tube; the second end of the main winding of the first inductor and the first end of the first switch tube are connected to the positive electrode of the first diode, and the second end of the secondary winding of the first inductor is grounded; the second end of the first switch tube is connected to the other end of the first resistor; the negative electrode of the first diode is connected to the positive electrode of the first capacitor.

[0027] In one embodiment, the second power factor correction circuit includes a second control chip, a second switch tube, a second inductor, a second resistor, a second diode and a second capacitor;

[0028] Among them, the IN1 pin of the second control chip is connected to the first end of the main winding of the second inductor, the IN2 pin of the second control chip and one end of the second resistor are connected to the negative electrode of the second capacitor, the ZCD pin of the second control chip is connected to the first end of the secondary winding of the second inductor, and the OUT pin of the second control chip is connected to the controlled end of the second switch tube; the second end of the main winding of the second inductor and the first end of the second switch tube are connected to the positive electrode of the second diode, and the second end of the secondary winding of the second inductor is grounded; the second end of the second switch tube is connected to the other end of the second resistor; the negative electrode of the second diode is connected to the positive electrode of the second capacitor.

[0029] In one embodiment, the first rectifier circuit includes a third diode, a fourth diode, a fifth diode and a sixth diode; the anode of the third diode and the cathode of the fifth diode are connected to the first end of the power input terminal; the cathode of the fourth diode and the anode of the sixth diode are connected to the second end of the power input terminal; the cathode of the third diode and the cathode of the fourth diode are connected to the IN1 pin of the first control chip; the anode of the fifth diode and the anode of the sixth diode are connected to the IN2 pin of the first control chip.

[0030] In one embodiment, the second rectifier circuit includes a seventh diode, an eighth diode, a ninth diode and a tenth diode; the anode of the seventh diode and the cathode of the ninth diode are connected to the first end of the power input terminal; the cathode of the eighth diode and the anode of the tenth diode are connected to the second end of the power input terminal; the cathode of the seventh diode and the cathode of the eighth diode are connected to the IN1 pin of the second control chip; the anode of the ninth diode and the anode of the tenth diode are connected to the IN2 pin of the second control chip.

[0031] In one embodiment, the power output end includes a first power output end and a second power output end; the switching circuit includes a first output end and a second output end, the first output end of the switching circuit is connected to the first power output end, and the second output end of the switching circuit is connected to the second power output end; the switching circuit is used to control the conduction / offset of the path between the first constant current drive circuit and the first power output end, control the conduction / offset of the path between the second constant current drive circuit and the second power output end, and control the conduction / offset of the path between the second constant current drive circuit and the first power output end.

[0032] The utility model also provides an LED lamp, which comprises an LED lamp and the LED driving power supply circuit as described above.

[0033] The technical solution of the utility model adopts an LED driving power supply circuit, including a first constant current driving circuit, a second constant current driving circuit, a switch circuit and a control circuit. When the first constant current driving circuit works normally, the switch circuit controls the path between the first constant current driving circuit and the power output end to be in a conducting state. Among them, the path between the first constant current driving circuit and the power output end is in a conducting state as a permanent state. The first constant current driving circuit can convert an alternating voltage into a first driving voltage output, and the control circuit detects that the voltage value of the first driving voltage is within a preset range value, and the switch circuit controls the path between the second constant current driving circuit and the power output end to be in a shutoff state, and the power output end outputs the first driving voltage. When the first constant current driving circuit is damaged, the control circuit detects that the voltage value of the first driving voltage is outside the preset voltage range, then the switch circuit controls the path between the first constant current driving circuit and the power output end to be in a shutoff state, and controls the path between the second constant current driving circuit and the power output end to be in a conducting state, and the second constant current driving circuit can convert the alternating voltage into a second driving voltage output, and the power output end outputs the second driving voltage. Thus, compared with the prior art, when the output of the first constant current driving circuit is abnormal, the utility model can switch to the second constant current driving circuit to output the driving power supply, which is suitable for LED driving power supply application scenarios that have higher requirements on the driving power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0035] Figure 1 A schematic diagram of the structure of an embodiment of an LED driving power supply circuit provided by the utility model;

[0036] Figure 2 A structural schematic diagram of another embodiment of the LED driving power supply circuit provided by the utility model;

[0037] Figure 3 An electronic circuit diagram of an embodiment of an LED driving power supply circuit provided by the utility model;

[0038] Figure 4 A schematic diagram of the structure of another embodiment of the LED driving power supply circuit provided by the utility model;

[0039] Figure 5 This is a structural schematic diagram of an embodiment of an LED lamp provided by the utility model.

[0040] Description of Figure Numbers:

[0041]

[0042] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0044] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0045] In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0046] During the use of LED lamps, the LED driver power circuit is most likely to be damaged, which can easily cause dead lights. In some LED driver power application scenarios that have high requirements for the driver power, such as emergency lighting scenarios, the existing LED driver power can no longer meet the requirements.

[0047] The utility model provides an LED driving power supply circuit 100 .

[0048] See also Figure 1 In one embodiment of the present utility model, the LED driving power supply circuit 100 includes:

[0049] Power input terminal, used for inputting AC voltage;

[0050] Power supply output terminal;

[0051] A first constant current driving circuit 110, wherein an input end of the first constant current driving circuit 110 is connected to a power input end, and the first constant current driving circuit 110 is used to convert an AC voltage into a first driving voltage output;

[0052] A second constant current driving circuit 120, wherein the input end of the second constant current driving circuit is connected to the power input end, and the second constant current driving circuit is used to convert the AC voltage into a second driving voltage output;

[0053] A switch circuit 130, wherein a first input end of the switch circuit 130 is connected to an output end of the first constant current drive circuit 110, a second input end of the switch circuit 130 is connected to an output end of the second constant current drive circuit 120, and an output end of the switch circuit 130 is connected to a power supply output end. The switch circuit 130 is used to control the on / off of a path between the first constant current drive circuit 110 and the power supply output end, and to control the on / off of a path between the second constant current drive circuit 120 and the power supply output end;

[0054] The control circuit 140 has a power supply end connected to a power supply input end, a detection end connected to an output end of the first constant current drive circuit 110, and a control end of the control circuit 140 connected to a controlled end of the switch circuit 130. The control circuit 140 is used to control the operation of the switch circuit 130 according to the output state of the first constant current drive circuit 110.

[0055] It should be noted that, in the present embodiment, the control circuit 140 can detect the output state of the first constant current drive circuit 110 by detecting whether the voltage value of the first drive voltage is within a preset voltage range. When the voltage value of the first drive voltage is within the preset voltage range, it is considered that the first constant current drive circuit 110 is in a normal output state; otherwise, it is considered that the first constant current drive circuit 110 is in an abnormal output state.

[0056] It should be noted that, in this embodiment, the outputs of the first driving voltage and the second driving voltage are approximately equal, and both can provide driving power to the load connected to the power output terminal.

[0057] In the present embodiment, when the first constant current driving circuit 110 works normally, the switch circuit 130 controls the path between the first constant current driving circuit 110 and the power output terminal to be in a conducting state. Wherein, the path between the first constant current driving circuit 110 and the power output terminal is in a conducting state as a permanent state. The first constant current driving circuit 110 can convert the AC voltage into a first driving voltage output, and the control circuit 140 detects that the voltage value of the first driving voltage is within a preset range value, and the switch circuit 130 controls the path between the second constant current driving circuit 120 and the power output terminal to be in an off state, and the power output terminal outputs the first driving voltage. When the first constant current driving circuit 110 is damaged, the control circuit detects that the voltage value of the first driving voltage is outside the preset voltage range, then the switch circuit 130 controls the path between the first constant current driving circuit 110 and the power output terminal to be in an off state, and controls the path between the second constant current driving circuit 120 and the power output terminal to be in a conducting state, and the second constant current driving circuit can convert the AC voltage into a second driving voltage output, and the power output terminal outputs the second driving voltage. Thus, compared with the prior art, when the output of the first constant current driving circuit 110 is abnormal, this embodiment can switch to the second constant current driving circuit 120 to output the driving power, which is suitable for LED driving power application scenarios with higher requirements on the driving power.

[0058] In this embodiment, the control circuit 140 may further include a second detection end, and the second detection end of the control circuit 140 is connected to the output end of the second constant current drive circuit 120. The control circuit 140 is also used to control the operation of the switch circuit 130 according to the output state of the second constant current drive circuit 120. For example, when the output of the second constant current drive circuit 120 is abnormal, the path between the second constant current drive circuit 120 and the power supply output end is cut off, thereby protecting the subsequent circuit.

[0059] In this embodiment, the switching circuit 130 may include a first electronic switch and a second electronic switch to respectively realize the control of the on / off of the path between the first constant current driving circuit 110 and the power output end and the on / off of the path between the second constant current driving circuit 120 and the power output end.

[0060] In the utility model, when the first constant current drive circuit 110 works normally, the switch circuit 130 controls the path between the first constant current drive circuit 110 and the power output terminal to be in a conducting state. Wherein, the path between the first constant current drive circuit 110 and the power output terminal is in a conducting state as a permanent state. The first constant current drive circuit 110 can convert the AC voltage into a first drive voltage output, and the control circuit 140 detects that the voltage value of the first drive voltage is within a preset range value, and the switch circuit 130 controls the path between the second constant current drive circuit 120 and the power output terminal to be in an off state, and the power output terminal outputs the first drive voltage. When the first constant current drive circuit 110 is damaged, the control circuit detects that the voltage value of the first drive voltage is outside the preset voltage range, then the switch circuit 130 controls the path between the first constant current drive circuit 110 and the power output terminal to be in an off state, and controls the path between the second constant current drive circuit 120 and the power output terminal to be in a conducting state, and the second constant current drive circuit can convert the AC voltage into a second drive voltage output, and the power output terminal outputs the second drive voltage. Thus, compared with the prior art, when the output of the first constant current driving circuit 110 is abnormal, the utility model can switch to the second constant current driving circuit 120 to output the driving power, which is suitable for LED driving power application scenarios with higher requirements on the driving power.

[0061] For further information, see Figure 2 In one embodiment of the utility model, the second detection end of the control circuit 140 is connected to the output end of the second constant current driving circuit 120;

[0062] The LED driving power supply circuit 100 further includes a battery 150, which is connected to a switch circuit 130; the switch circuit 130 is also used to control the on / off of a path between the battery 150 and the power output terminal;

[0063] The control circuit 140 is further configured to control the operation of the switch circuit 130 according to the output state of the second constant current driving circuit 120 .

[0064] In this embodiment, when the first constant current drive circuit 110 or the second constant current drive circuit 120 can normally provide the driving power supply, the switch circuit 130 controls the path between the battery 150 and the power output terminal to be in an off state, which is a permanent state. When the first constant current drive circuit 110 and the second constant current drive circuit 120 output abnormalities, that is, when the control circuit 140 respectively detects that the voltage value of the first drive voltage and the voltage value of the second drive voltage are not within the preset range value, the switch circuit 130 controls the path between the battery 150 and the power output terminal to be in an on state, and the battery 150 provides the driving power supply. In this way, when the first constant current drive circuit 110 and the second constant current drive circuit 120 output abnormalities, this embodiment can switch to the battery 150 to output the driving power supply, which is suitable for LED driving power supply application scenarios with higher requirements for the driving power supply. Please refer to Figure 3 The battery 150 and the switch circuit 130 may be provided with a third resistor R3 for current limiting protection.

[0065] It should be noted that the battery 150 in this embodiment can be replaced with a charging capacitor, and the first constant current drive circuit 110 or the second constant current drive circuit 120 can be connected to the charging capacitor by the switch circuit 130, and the charging capacitor can be charged during normal operation. The charging capacitor can be connected to the power output end by the switch circuit 130, and the charging capacitor discharges when the output of the first constant current drive circuit 110 and the second constant current drive circuit 120 is abnormal, which can ensure that the driving power can be output in a short time when the output is abnormal.

[0066] For further information, see Figure 2 In one embodiment of the present utility model, the first constant current driving circuit 110 includes:

[0067] A first rectifier circuit 111, the first rectifier circuit 111 is used to convert an AC voltage into a first DC voltage;

[0068] A first power factor correction circuit 112, the first power factor correction circuit 112 is connected to the first rectifier circuit 111;

[0069] A first voltage conversion circuit 113, wherein an input end of the first voltage conversion circuit 113 is connected to an output end of the first power factor correction circuit 112, and an output end of the first voltage conversion circuit 113 is connected to a first input end of the switch circuit 130, and the first voltage conversion circuit 113 is used to convert the first DC voltage into a first driving voltage and then output it;

[0070] A first detection circuit 114, wherein an input end of the first detection circuit 114 is connected to an output end of the first voltage conversion circuit 113, an output end of the first detection circuit 114 is connected to a detection end of the control circuit 140, and the first detection circuit 114 is used to output a detection signal according to the first driving voltage;

[0071] The control circuit 140 is further configured to control the operation of the switch circuit 130 according to the detection signal.

[0072] It should be noted that the power factor (Power Factor Correction, PFC) refers to the relationship between active power and total power, that is, the ratio of effective power to total power. The power factor can measure the degree to which electricity is effectively used. The larger the power factor value, the higher the power utilization rate. Among them, the phase difference between current and voltage will cause an increase in reactive power and reduce the utilization rate of electric energy. In this embodiment, the output end of the power supply can be connected to an LED lamp. Since LED lamps are generally nonlinear loads, the input current waveform will be distorted, containing a large number of harmonic components, which reduces the power factor of the circuit. In this embodiment, the first power factor correction circuit 112 is used to improve the power factor of the circuit to reduce the influence of the input harmonic components on the first constant current drive circuit 110.

[0073] In this embodiment, the first rectifier circuit 111 can convert the AC voltage into a first DC voltage, and the first power factor correction circuit 112 can improve the power factor of the circuit so that the first DC voltage can be stably transmitted. The first voltage conversion circuit 113 can convert the first DC voltage into a first drive voltage and then output it. The control circuit 140 can determine whether the output of the first constant current drive circuit 110 is abnormal according to the detection signal output by the first detection circuit 114. When the output of the first constant current drive circuit 110 is abnormal, the switch circuit 130 controls the path between the first constant current drive circuit 110 and the power supply output terminal to be in an off state, and controls the path between the second constant current drive circuit 120 and the power supply output terminal to be in an on state. In this way, this embodiment can improve the power factor of the circuit, reduce the influence of the input harmonic component on the output of the first constant current drive circuit 110, and improve the stability of the first constant current drive circuit 110.

[0074] In this embodiment, the first voltage conversion circuit 113 may include a first voltage conversion chip U3, which is used to realize DC to DC voltage conversion and constant current output control. In this way, the AC voltage can be converted into the first driving voltage output through the first constant current driving circuit 110.

[0075] In this embodiment, the first detection circuit 114 can be detected by using a current detection IC, a current sensor, or by setting a sampling resistor and detecting the driving power supply through a comparator.

[0076] For further information, see Figure 2 In one embodiment of the present utility model, the second constant current driving circuit 120 includes:

[0077] A second rectifier circuit 121, wherein an input end of the second rectifier circuit 121 is connected to an input end of the second constant current drive circuit 120, and the second rectifier circuit 121 is used to convert an AC voltage into a second DC voltage;

[0078] A second power factor correction circuit 122, wherein an input end of the second power factor correction circuit 122 is connected to an output end of the second rectifier circuit 121;

[0079] The second voltage conversion circuit 123, the input end of the second voltage conversion circuit 123 is connected to the output end of the second power factor correction circuit 122, the output end of the second voltage conversion circuit 123 is connected to the second input end of the switching circuit 130, and the second voltage conversion circuit 123 is used to convert the second DC voltage into a second driving voltage and then output it.

[0080] In the present embodiment, the second rectifier circuit 121 can convert the AC voltage into a second DC voltage, and the second power factor correction circuit 122 can improve the power factor of the circuit so that the second DC voltage can be stably transmitted. The second voltage conversion circuit 123 can convert the second DC voltage into a second drive voltage and then output it. In the present embodiment, the second voltage conversion circuit 113 can include a second voltage conversion chip U4, and the second voltage conversion chip U4 is used to realize DC to DC voltage conversion, and constant current output control. In this way, the AC voltage can be converted into the second drive voltage output through the second constant current drive circuit 110.

[0081] For further information, see Figure 3 In one embodiment of the present utility model, the first power factor correction circuit 112 includes a first control chip U1, a first switch tube Q1, a first inductor L1, a first resistor R1, a first diode D1 and a first capacitor C1;

[0082] Among them, the IN1 pin of the first control chip U1 is connected to the first end of the main winding of the first inductor L1, the IN2 pin of the first control chip U1 and one end of the first resistor R1 are connected to the negative electrode of the first capacitor C1, the ZCD pin of the first control chip U1 is connected to the first end of the secondary winding of the first inductor L1, and the OUT pin of the first control chip U1 is connected to the controlled end of the first switch tube Q1; the second end of the main winding of the first inductor L1 and the first end of the first switch tube Q1 are connected to the positive electrode of the first diode D1, and the second end of the secondary winding of the first inductor L1 is grounded; the second end of the first switch tube Q1 is connected to the other end of the first resistor R1; the negative electrode of the first diode D1 is connected to the positive electrode of the first capacitor C1.

[0083] In this embodiment, the first control chip U1 can be a PFC chip, wherein the PFC chip is used to measure the input current and the output voltage, and generate a control signal to adjust the conduction time of the switch tube to achieve power factor correction. For example, in the initial stage, the first switch tube Q1 is turned on, the circuit forms a closed loop, the current flows through the main winding of the first inductor L1, the main winding of the first inductor L1 begins to store energy, and the current gradually increases. When the inductor current reaches a peak value, the first control chip U1 can detect that the voltage of the secondary winding of the first inductor L1 reaches a peak value through the ZCD pin, and at this time, a control signal is sent to control the first switch tube Q1 to be disconnected, and the energy stored in the first inductor L1 is released to charge the first capacitor. When the first switch tube Q1 is turned off, the current in the first inductor L1 begins to decrease. Until the inductor current of the first inductor L1 drops to zero, the voltage detected by the ZCD pin also drops to zero, and the first switch tube Q1 is controlled to be turned on again, and the above process is repeated. It should be noted that the conduction time of the above switch tube can be adjusted according to the specific circuit, and the power factor correction process of this circuit is not limited thereto. In this way, this embodiment can control the conduction time of the first switch tube Q1 to make the current waveform close to a sine wave, thereby reducing the harmonic content and improving the power factor. When the current waveform is closer to a sine wave, the power factor is closer to 1, thereby achieving power factor correction.

[0084] For further information, see Figure 3 In one embodiment of the present utility model, the second power factor correction circuit 122 includes a second control chip U2, a second switch tube Q2, a second inductor L2, a second resistor R2, a second diode D2 and a second capacitor C2;

[0085] Among them, the IN1 pin of the second control chip U2 is connected to the first end of the main winding of the second inductor L2, the IN2 pin of the second control chip U2 and one end of the second resistor R2 are connected to the negative electrode of the second capacitor C2, the ZCD pin of the second control chip U2 is connected to the first end of the secondary winding of the second inductor L2, and the OUT pin of the second control chip U2 is connected to the controlled end of the second switch tube Q2; the second end of the main winding of the second inductor L2 and the first end of the second switch tube Q2 are connected to the positive electrode of the second diode D2, and the second end of the secondary winding of the second inductor L2 is grounded; the second end of the second switch tube Q2 is connected to the other end of the second resistor R2; the negative electrode of the second diode D2 is connected to the positive electrode of the second capacitor C2.

[0086] In this embodiment, the second control chip U2 can be a PFC chip, wherein the PFC chip is used to measure the input current and the output voltage, and generate a control signal to adjust the conduction time of the switch tube to achieve power factor correction. For example, in the initial stage, the second switch tube Q2 is turned on, the circuit forms a closed loop, the current flows through the main winding of the second inductor L2, the main winding of the second inductor L2 begins to store energy, and the current gradually increases. When the inductor current reaches a peak value, the second control chip U2 can detect that the voltage of the secondary winding of the second inductor L2 reaches a peak value through the ZCD pin, and at this time, a control signal is sent to control the second switch tube Q2 to be disconnected, and the energy stored in the second inductor L2 is released to charge the second capacitor. When the second switch tube Q2 is turned off, the current in the second inductor L2 begins to decrease. Until the inductor current of the second inductor L2 drops to zero, the voltage detected by the ZCD pin also drops to zero, and the second switch tube Q2 is controlled to be turned on again, and the above process is repeated. It should be noted that the conduction time of the above-mentioned switch tube can be adjusted according to the specific circuit, and the power factor correction process of this circuit is not limited thereto. In this way, this embodiment can control the conduction time of the second switch tube Q2 to make the current waveform close to a sine wave, thereby reducing the harmonic content and improving the power factor. When the current waveform is closer to a sine wave, the power factor is closer to 1, thereby achieving power factor correction.

[0087] For further information, see Figure 3 In one embodiment of the utility model, the first rectifier circuit 111 includes a third diode D3, a fourth diode D4, a fifth diode D5 and a sixth diode D6; the anode of the third diode D3 and the cathode of the fifth diode D5 are connected to the first end of the power input terminal; the cathode of the fourth diode D4 and the anode of the sixth diode D6 are connected to the second end of the power input terminal; the cathode of the third diode D3 and the cathode of the fourth diode D4 are connected to the IN1 pin of the first control chip U1; the anode of the fifth diode D5 and the anode of the sixth diode D6 are connected to the IN2 pin of the first control chip U1.

[0088] In this embodiment, the AC voltage can be converted into the first DC voltage through the third diode D3, the fourth diode D4, the fifth diode D5 and the sixth diode D6, with high conversion efficiency and small ripple.

[0089] For further information, see Figure 3In one embodiment of the utility model, the second rectifier circuit 121 includes a seventh diode D7, an eighth diode D8, a ninth diode D9 and a tenth diode D10; the anode of the seventh diode D7 and the cathode of the ninth diode D9 are connected to the first end of the power input terminal; the cathode of the eighth diode D8 and the anode of the tenth diode D10 are connected to the second end of the power input terminal; the cathode of the seventh diode D7 and the cathode of the eighth diode D8 are connected to the IN1 pin of the second control chip U2; the anode of the ninth diode D9 and the anode of the tenth diode D10 are connected to the IN2 pin of the second control chip U2.

[0090] In this embodiment, the AC voltage can be converted into a second DC voltage via the seventh diode D7, the eighth diode D8, the ninth diode D9 and the tenth diode D10, with high conversion efficiency and small ripple.

[0091] For further information, see Figure 4 In one embodiment of the utility model, the power output end includes a first power output end and a second power output end; the switch circuit 130 includes a first output end and a second output end, the first output end of the switch circuit 130 is connected to the first power output end, and the second output end of the switch circuit 130 is connected to the second power output end; the switch circuit 130 is used to control the conduction / offset of the path between the first constant current drive circuit 110 and the first power output end, control the conduction / offset of the path between the second constant current drive circuit 120 and the second power output end, and control the conduction / offset of the path between the second constant current drive circuit 120 and the first power output end 110.

[0092] In this embodiment, when two LED lamps need to be connected, the path between the second constant current drive circuit 120 and the first power supply output terminal 110 can be controlled to remain closed, the path between the first constant current drive circuit 110 and the first power supply output terminal can be controlled to be in a conductive state, and the path between the second constant current drive circuit 120 and the second power supply output terminal can be controlled to be in a conductive state. At this time, the first constant current drive circuit 110 can provide driving power to the first LED lamp, and the second constant current drive circuit 120 can provide driving power to the second LED lamp. In this way, this embodiment makes maximum use of the dual constant current drive circuit and enhances practicality.

[0093] See also Figure 5 The utility model also provides an LED lamp, which includes an LED lamp 200 and an LED driving power supply circuit 100. The specific structure of the LED driving power supply circuit 100 refers to the above embodiment. Since the LED lamp adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0094] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An LED driving power supply circuit, characterized in that: include: Power input terminal, used for inputting AC voltage; Power output terminal; A first constant current driving circuit, wherein an input end of the first constant current driving circuit is connected to the power input end, and the first constant current driving circuit is used to convert the AC voltage into a first driving voltage output; A second constant current driving circuit, wherein an input end of the second constant current driving circuit is connected to the power input end, and the second constant current driving circuit is used to convert the AC voltage into a second driving voltage output; A switch circuit, wherein a first input end of the switch circuit is connected to an output end of the first constant current drive circuit, a second input end of the switch circuit is connected to an output end of the second constant current drive circuit, an output end of the switch circuit is connected to the power supply output end, and the switch circuit is used to control the on / off of a path between the first constant current drive circuit and the power supply output end, and to control the on / off of a path between the second constant current drive circuit and the power supply output end; A control circuit, wherein the power supply end of the control circuit is connected to the power supply input end, the detection end of the control circuit is connected to the output end of the first constant current drive circuit, the control end of the control circuit is connected to the controlled end of the switch circuit, and the control circuit is used to control the operation of the switch circuit according to the output state of the first constant current drive circuit.

2. The LED driving power supply circuit according to claim 1, characterized in that: The second detection end of the control circuit is connected to the output end of the second constant current driving circuit; The LED driving power supply circuit also includes a battery, and the battery is connected to the switch circuit; the switch circuit is also used to control the on / off of the path between the battery and the power output end; The control circuit is further used to control the operation of the switch circuit according to the output state of the second constant current drive circuit.

3. The LED driving power supply circuit according to claim 1, characterized in that: The first constant current driving circuit comprises: a first rectifier circuit, wherein an input end of the first rectifier circuit is connected to an input end of the first constant current drive circuit, and the first rectifier circuit is used to convert the AC voltage into a first DC voltage; a first power factor correction circuit, wherein an input end of the first power factor correction circuit is connected to an output end of the first rectifier circuit; a first voltage conversion circuit, wherein an input end of the first voltage conversion circuit is connected to an output end of the first power factor correction circuit, an output end of the first voltage conversion circuit is connected to a first input end of the switch circuit, and the first voltage conversion circuit is used to convert the first DC voltage into the first driving voltage and then output it; a first detection circuit, wherein an input end of the first detection circuit is connected to an output end of the first voltage conversion circuit, an output end of the first detection circuit is connected to a detection end of the control circuit, and the first detection circuit is used to output a detection signal according to the first driving voltage; The control circuit is also used to control the operation of the switch circuit according to the detection signal.

4. The LED driving power supply circuit according to claim 1, characterized in that: The second constant current driving circuit comprises: a second rectifier circuit, wherein an input end of the second rectifier circuit is connected to an input end of the second constant current drive circuit, and the second rectifier circuit is used for converting the AC voltage into a second DC voltage; a second power factor correction circuit, wherein an input end of the second power factor correction circuit is connected to an output end of the second rectifier circuit; A second voltage conversion circuit, wherein the input end of the second voltage conversion circuit is connected to the output end of the second power factor correction circuit, the output end of the second voltage conversion circuit is connected to the second input end of the switching circuit, and the second voltage conversion circuit is used to convert the second DC voltage into the second drive voltage and then output it.

5. The LED driving power supply circuit according to claim 3, characterized in that: The first power factor correction circuit includes a first control chip, a first switch tube, a first inductor, a first resistor, a first diode and a first capacitor; Among them, the IN1 pin of the first control chip is connected to the first end of the main winding of the first inductor, the IN2 pin of the first control chip and one end of the first resistor are connected to the negative electrode of the first capacitor, the ZCD pin of the first control chip is connected to the first end of the secondary winding of the first inductor, and the OUT pin of the first control chip is connected to the controlled end of the first switch tube; the second end of the main winding of the first inductor and the first end of the first switch tube are connected to the positive electrode of the first diode, and the second end of the secondary winding of the first inductor is grounded; the second end of the first switch tube is connected to the other end of the first resistor; the negative electrode of the first diode is connected to the positive electrode of the first capacitor.

6. The LED driving power supply circuit according to claim 4, characterized in that: The second power factor correction circuit includes a second control chip, a second switch tube, a second inductor, a second resistor, a second diode and a second capacitor; Among them, the IN1 pin of the second control chip is connected to the first end of the main winding of the second inductor, the IN2 pin of the second control chip and one end of the second resistor are connected to the negative electrode of the second capacitor, the ZCD pin of the second control chip is connected to the first end of the secondary winding of the second inductor, and the OUT pin of the second control chip is connected to the controlled end of the second switch tube; the second end of the main winding of the second inductor and the first end of the second switch tube are connected to the positive electrode of the second diode, and the second end of the secondary winding of the second inductor is grounded; the second end of the second switch tube is connected to the other end of the second resistor; the negative electrode of the second diode is connected to the positive electrode of the second capacitor.

7. The LED driving power supply circuit according to claim 5, characterized in that: The first rectifier circuit includes a third diode, a fourth diode, a fifth diode and a sixth diode; the anode of the third diode and the cathode of the fifth diode are connected to the first end of the power input terminal; the cathode of the fourth diode and the anode of the sixth diode are connected to the second end of the power input terminal; the cathode of the third diode and the cathode of the fourth diode are connected to the IN1 pin of the first control chip; the anode of the fifth diode and the anode of the sixth diode are connected to the IN2 pin of the first control chip.

8. The LED driving power supply circuit according to claim 6, characterized in that: The second rectifier circuit includes a seventh diode, an eighth diode, a ninth diode and a tenth diode; the anode of the seventh diode and the cathode of the ninth diode are connected to the first end of the power input terminal; the cathode of the eighth diode and the anode of the tenth diode are connected to the second end of the power input terminal; the cathode of the seventh diode and the cathode of the eighth diode are connected to the IN1 pin of the second control chip; the anode of the ninth diode and the anode of the tenth diode are connected to the IN2 pin of the second control chip.

9. The LED driving power supply circuit according to claim 1, characterized in that: The power output end includes a first power output end and a second power output end; the switching circuit includes a first output end and a second output end, the first output end of the switching circuit is connected to the first power output end, and the second output end of the switching circuit is connected to the second power output end; the switching circuit is used to control the on / off of the path between the first constant current drive circuit and the first power output end, control the on / off of the path between the second constant current drive circuit and the second power output end, and control the on / off of the path between the second constant current drive circuit and the first power output end.

10. An LED lamp, characterized in that: The LED lamp comprises an LED lamp and an LED driving power supply circuit as claimed in any one of claims 1 to 9.

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