LED backlight source drive circuit, LED backlight source and liquid crystal display device

1. A light emitting diode (LED) backlight source drive circuit, comprising:

a voltage input terminal;

a coupling module connected to the voltage input terminal for receiving a current complying with a total working voltage of two power consumption modules from the voltage input terminal, and converting the current into a current complying with a working voltage of one power consumption module; and

a rectifier module connected to the coupling module for inputting the current complying with the working voltage of one power consumption module into two serially-connected power consumption modules, thereby supplying power to the power consumption modules;

wherein the rectifier module comprises a first current input terminal, a current output terminal and a second current input terminal;

wherein the first current input terminal of the rectifier module is connected to the coupling module for inputting the current complying with the working voltage of one power consumption module into two serially-connected power consumption modules, the current output terminal of the rectifier module is connected to a current input terminal of the two serially-connected power consumption modules, and the second current input terminal of the rectifier module is connected to a current output terminal of the two serially-connected power consumption modules;

wherein the LED backlight source ddrive circuit further comprising a voltage conversion module, a control.module and a protecting module;

wherein the voltage conversion module is configured for receiving the current from a current output terminal of an external power source, and converting the current into the current complying with the total working voltage of two power consumption modules to be inputted into the coupling module;

wherein the protecting module is connected to the control module, wherein if the power consumption module is in an open-circuit state, an over-current state or a short-circuit state, the protecting module issues a high or low voltage-level fault signal to the control module; and

wherein after the fault signal is received by the control module, the voltage conversion module is disabled by the control module.

2. The LED backlight source drive circuit according to claim 1 , wherein the coupling module comprises at least one capacitor or at least two serially-connected or parallel-connected capacitors;

and/or the two power consumption modules have the same power;

and/or each of the two power consumption modules comprises one LED light strip or at least two serially-connected LED light strips;

and/or the rectifier module comprises a rectifying unit and an energy storage unit;

wherein the rectifying unit is configured for inputting the current complying with the working voltage of one power consumption module into the energy storage unit; and

wherein the energy storage unit is configured for receiving and storing the current from the rectifying unit, and inputting the current into the two power consumption modules.

3. The LED backlight source drive circuit according to claim 2 , wherein the capacitor of the coupling module is an electrodeless capacitor; and/or the rectifying unit comprises a first diode and a second diode, the energy storage unit comprises a first capacitor and a second capacitor, and the two power consumption modules comprises a first power consumption module and a second power consumption module;

wherein an anode of the first diode is connected to the coupling module, a cathode of the first diode is connected to a current input terminal of the first power consumption module, and a current output terminal of the first power consumption module is connected to a current input terminal of the second power consumption module and a ground terminal;

wherein a cathode of the second diode is connected to the coupling module, and an anode of the second diode is connected to a current output terminal of the second power consumption module;

wherein two ends of the first capacitor are connected between the current input terminal and the current output terminal of the first power consumption module; and

wherein two ends of the second capacitor are connected between the current input terminal and the current output terminal of the second power consumption module.

4. The LED backlight source drive circuit according to claim 3 , wherein the coupling module, the first capacitor and/or the second capacitor are polypropylene capacitors.

5. The LED backlight source drive circuit according to claim 1 , further comprising a current sampling module;

wherein the voltage conversion module is connected to the control module and the coupling module, and the current sampling module is connected to the control module and a current output terminal of the first power consumption module;

and

wherein the control module is configured for sensing a magnitude of the current from the current output terminal of the first power consumption module through the current sampling module, and allowing the current outputted from the voltage conversion module to be used as a working current of the power consumption modules.

6. The LED backlight source drive circuit according to claim 5 , wherein the voltage conversion module is a boost circuit; and/or the control module is a control chip; and/or the current sampling module comprises a first bipolar junction transistor, a first resistor and a second resistor;

wherein the first resistor is connected between the current output terminal of the first power consumption module and a ground terminal;

wherein a base of the first bipolar junction transistor is connected to a node between the current output terminal of the first power consumption module and the first resistor through the second resistor;

wherein an emitter of the first bipolar junction transistor is connected to the ground terminal, and a collector of the first bipolar junction transistor is connected to the control module; and

wherein a magnitude of the current and/or the voltage from the current output terminal of the first power consumption module is sensed by the control module through the collector of the first bipolar junction transistor.

7. The LED backlight source drive circuit according to claim 1 , wherein the voltage conversion module comprises a boost inductor, a metal-oxide-semiconductor MOS transistor and a fourth resistor, the protecting module comprises a NPN bipolar junction transistor, a PNP bipolar junction transistor, an energy storage capacitor, a fifth resistor, a sixth resistor and a regulator diode;

wherein a current input terminal of the boost inductor is connected to the current output terminal of the external power source, and a current output terminal of the boost inductor is connected to a drain terminal of the MOS transistor and the voltage input terminal;

wherein a source terminal of the MOS transistor is connected to the ground terminal through the fourth resistor, and a terminal of the MOS transistor is connected to the control module;

wherein an anode of the regulator diode is connected to the voltage input terminal, and a cathode of the regulator diode is connected to the ground terminal through the energy storage capacitor;

wherein the fifth resistor and the sixth resistor are connected to each other in series, and the energy storage capacitor is connected to the serially-connected fifth resistor and sixth resistor in parallel;

wherein the cathode of the regulator diode is connected to a node between the fifth resistor and the sixth resistor;

wherein the anode of the regulator diode is connected to the source terminal of the MOS transistor the control module, a base of the NPN bipolar junction transistor and an emitter of the PNP bipolar junction transistor;

wherein an emitter of the NPN bipolar junction transistor is connected to the ground terminal, and a collector of the NPN bipolar junction transistor is connected to a base of the PNP bipolar junction transistor; and

wherein a collector of the PNP bipolar junction transistor is connected to the control module, an emitter of the PNP bipolar junction transistor is connected to a constant voltage source, and the fault signal is a voltage signal that is outputted from the constant voltage source.

8. The LED backlight source drive circuit according to claim 1 , wherein the control module comprises a controlling unit, a feedback pin, a start pin, a protection pin, a drive pin and a supply voltage pin;

wherein the feedback pin is connected to the collector of the first bipolar junction transistor;

wherein the start pin is connected to a start signal input terminal and a light-adjusting signal input terminal of an external circuit board;

wherein the protection pin is connected to the source terminal of the MOS transistor, the anode of the regulator diode and the collector of the PNP bipolar junction transistor;

wherein the drive pin is connected to a gate terminal of the MOS transistor;

wherein the supply voltage pin is connected to the current output terminal of the external power source for receiving the current from the external power source;

wherein according to a start signal received by the start signal input terminal, the controlling unit issues a high or low voltage-level control signal to the voltage conversion module through the drive pin, thereby enabling or disabling the voltage conversion module;

wherein according to a light-adjusting signal received by the light-adjusting signal input terminal, the controlling unit changes a duty cycle of the high or low voltage-level control signal that is issued through the drive pin, so that a frequency of enabling or disabling the voltage conversion module is controlled by the controlling unit; and

wherein after the fault signal is received by the protection pin, the voltage conversion module is disabled by the controlling unit.

9. A liquid crystal display device, comprising:

two power consumption modules; and

the LED backlight source drive circuit according to claim 1 for supplying power to the power consumption modules, wherein each of the power consumption modules comprises one LED light strip or at least two serially-connected LED light strips.

10. A light emitting diode (LED) backlight source drive circuit, comprising:

a voltage input terminal;

a coupling module connected to the voltage input terminal for receiving a current complying with a total working voltage of two power consumption modules from the voltage input terminal, and converting the current into a current complying with a working voltage of one power consumption module; and

a rectifier module connected to the coupling module for inputting the current complying with the working voltage of one power consumption module into two serially-connected power consumption modules, thereby supplying power to the power consumption modules;

wherein the rectifier module comprises a rectifying unit, and the rectifying unit is configured for directly inputting the current into one of the two serially-connected power consumption modules;

wherein the LED backlight source drive circuit further comprising a voltage conversion module a control module and a protecting module;

wherein the voltage conversion module is configured for receiving the current from a current output terminal of an external power source and converting the current into the current complying with the total working voltage of two power consumption modules to be inputted into the coupling module;

wherein the protecting module is connected to the control module wherein if the power consumption module is in an open-circuit state an over-current state or a short-circuit state the protecting module issues a high or low voltage-level fault signal to the control module; and

wherein after fault signal is received by the control module, the voltage conversion module is disabled by the control module.

11. The LED backlight source drive circuit according to claim 10 , wherein the coupling module comprises at least one capacitor or at least two serially-connected or parallel-connected capacitors;

and/or the two power consumption modules have the same power;

and/or each of the two power consumption modules comprises one LED light strip or at least two serially-connected LED light strips;

and/or the rectifier module comprises an energy storage unit;

wherein the rectifying unit is configured for inputting the current complying with the working voltage of one power consumption module into the energy storage unit; and

wherein the energy storage unit is configured for receiving and storing the current from the rectifying unit, and inputting the current into the two power consumption modules.

12. The LED backlight source drive circuit according to claim 11 , wherein the capacitor of the coupling module is an electrodeless capacitor; and/or the rectifying unit comprises a first diode and a second diode, the energy storage unit comprises a first capacitor and a second capacitor, and the two power consumption modules comprises a first power consumption module and a second power consumption module;

wherein an anode of the first diode is connected to the coupling module, a cathode of the first diode is connected to a current input terminal of the first power consumption module, and a current output terminal of the first power consumption module is connected to a current input terminal of the second power consumption module and a ground terminal;

wherein a cathode of the second diode is connected to the coupling module, and an anode of the second diode is connected to a current output terminal of the second power consumption module;

wherein two ends of the first capacitor are connected between the current input terminal and the current output terminal of the first power consumption module; and

wherein two ends of the second capacitor are connected between the current input terminal and the current output terminal of the second power consumption module.

13. The LED backlight source drive circuit according to claim 12 , wherein the coupling module, the first capacitor and/or the second capacitor are polypropylene capacitors.

14. The LED backlight source drive circuit according to claim 10 , further comprising a current sampling module;

wherein the voltage conversion module is connected to the control module and the coupling module, and the current sampling module is connected to the control module and a current output terminal of the first power consumption module;

and

wherein the control module is configured for sensing a magnitude of the current from the current output terminal of the first power consumption module through the current sampling module, and allowing the current outputted from the voltage conversion module to be used as a working current of the power consumption modules.

15. The LED backlight source drive circuit according to claim 14 , wherein the voltage conversion module is a boost circuit; and/or the control module is a control chip; and/or the current sampling module comprises a first bipolar junction transistor, a first resistor and a second resistor;

wherein the first resistor is connected between the current output terminal of the first power consumption module and a ground terminal;

wherein a base of the first bipolar junction transistor is connected to a node between the current output terminal of the first power consumption module and the first resistor through the second resistor;

wherein an emitter of the first bipolar junction transistor is connected to the ground terminal, and a collector of the first bipolar junction transistor is connected to the control module; and

wherein a magnitude of the current and/or the voltage from the current output terminal of the first power consumption module is sensed by the control module through the collector of the first bipolar junction transistor.

16. The LED backlight source drive circuit according to claim 10 , wherein the voltage conversion module comprises a boost inductor, a metal-oxide-semiconductor (MOS) transistor and a fourth resistor, the protecting module comprises a NPN bipolar junction transistor, a PNP bipolar junction transistor, an energy storage capacitor, a fifth resistor, a sixth resistor and a regulator diode;

wherein a current input terminal of the boost inductor is connected to the current output terminal of the external power source, and a current output terminal of the boost inductor is connected to a drain terminal of the MOS transistor and the voltage input terminal;

wherein a source terminal of the MOS transistor is connected to the ground terminal through the fourth resistor, and a terminal of the MOS transistor is connected to the control module;

wherein an anode of the regulator diode is connected to the voltage input terminal, and a cathode of the regulator diode is connected to the ground terminal through the energy storage capacitor;

wherein the fifth resistor and the sixth resistor are connected to each other in series, and the energy storage capacitor is connected to the serially-connected fifth resistor and sixth resistor in parallel;

wherein the cathode of the regulator diode is connected to a node between the fifth resistor and the sixth resistor;

wherein the anode of the regulator diode is connected to the source terminal of the MOS transistor, the control module, a base of the NPN bipolar junction transistor and an emitter of the PNP bipolar junction transistor;

wherein an emitter of the NPN bipolar junction transistor is connected to the ground terminal, and a collector of the NPN bipolar junction transistor is connected to a base of the PNP bipolar junction transistor; and

wherein a collector of the PNP bipolar junction transistor is connected to the control module, an emitter of the PNP bipolar junction transistor is connected to a constant voltage source, and the fault signal is a voltage signal that is outputted from the constant voltage source.

17. The LED backlight source drive circuit according to claim 10 , wherein the control module comprises a controlling unit, a feedback pin, a start pin, a protection pin, a drive pin and a supply voltage pin;

wherein the feedback pin is connected to the collector of the first bipolar junction transistor;

wherein the start pin is connected to a start signal input terminal and a light-adjusting signal input terminal of an external circuit board;

wherein the protection pin is connected to the source terminal of the MOS transistor, the anode of the regulator diode and the collector of the PNP bipolar junction transistor;

wherein the drive pin is connected to a gate terminal of the MOS transistor;

wherein the supply voltage pin is connected to the current output terminal of the external power source for receiving the current from the external power source;

wherein according to a start signal received by the start signal input terminal, the controlling unit issues a high or low voltage-level control signal to the voltage conversion module through the drive pin, thereby enabling or disabling the voltage conversion module;

wherein according to a light-adjusting signal received by the light-adjusting signal input terminal, the controlling unit changes a duty cycle of the high or low voltage-level control signal that is issued through the drive pin, so that a frequency of enabling or disabling the voltage conversion module is controlled by the controlling unit; and

wherein after the fault signal is received by the protection pin, the voltage conversion module is disabled by the controlling unit.