WO2021203649A1 - 一种液晶光阀的驱动电路、液晶光阀以及led灯 - Google Patents

一种液晶光阀的驱动电路、液晶光阀以及led灯 Download PDF

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Publication number
WO2021203649A1
WO2021203649A1 PCT/CN2020/120150 CN2020120150W WO2021203649A1 WO 2021203649 A1 WO2021203649 A1 WO 2021203649A1 CN 2020120150 W CN2020120150 W CN 2020120150W WO 2021203649 A1 WO2021203649 A1 WO 2021203649A1
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Prior art keywords
resistor
circuit
diode
chip
pin
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PCT/CN2020/120150
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English (en)
French (fr)
Inventor
刘阳
谢奕
周向军
童鹍
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深圳市爱图仕影像器材有限公司
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Publication of WO2021203649A1 publication Critical patent/WO2021203649A1/zh

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/13306—Circuit arrangements or driving methods for the control of single liquid crystal cells
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V14/00—Controlling the distribution of the light emitted by adjustment of elements
    • F21V14/003—Controlling the distribution of the light emitted by adjustment of elements by interposition of elements with electrically controlled variable light transmissivity, e.g. liquid crystal elements or electrochromic devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]

Definitions

  • This application relates to the technical field of electronic circuits, and in particular to a driving circuit of a liquid crystal light valve, a liquid crystal light valve and an LED lamp.
  • Traditional liquid crystal light valve drives are basically unidirectional low-voltage PWM (Pulse Width Modulation) drive. In this drive mode, if you want to change the light transmittance of the liquid crystal light valve, you generally adjust the PWM duty cycle. However, this adjustment method can only meet certain specific low-voltage unidirectional application scenarios with low precision requirements, and cannot meet high-precision application scenarios.
  • the traditional liquid crystal light valve drive circuit is used to drive the liquid crystal light valve with larger power, and an external drive circuit is needed. When the power supply adopts a switch circuit, this will bring about greater ripple and noise, not only It will shorten the life of the liquid crystal light valve, increase the instability of the liquid crystal light valve, and even damage the liquid crystal light valve.
  • the existing liquid crystal light valve drive circuit has the problems of low adjustment accuracy and low stability, which need to be solved.
  • the present invention provides a driving circuit of a liquid crystal light valve, a liquid crystal light valve and an LED lamp, so as to improve the problems of low adjustment accuracy and low stability of the existing liquid crystal light valve driving circuit.
  • the present invention provides a driving circuit for a liquid crystal light valve, which includes an LDO (Low Drop Output, low dropout linear regulator) step-down circuit (110) and a full-bridge drive circuit (120).
  • the LDO step-down circuit (110) Is connected to the power supply (130), the output of the LDO step-down circuit (110) is connected to the input of the full-bridge drive circuit (120), and the full-bridge drive circuit (120) is connected to the liquid crystal light
  • the valve (140) is connected; the LDO step-down circuit (110) includes:
  • the linear step-down circuit (111) includes a linear step-down chip (U1), the input end of the linear step-down chip (U1) is connected to the power supply (130), and the linear step-down chip (U1) is used to connect the power supply The voltage is subjected to linear step-down processing;
  • the step-down adjustment circuit (112) includes at least one digital potentiometer, the stroke pin (W) of the digital potentiometer is connected to the voltage adjustment pin (ADJ) of the linear step-down chip (U1), and the The digital potentiometer is used to adjust the voltage output by the voltage output pin (Vout) of the linear step-down chip (U1);
  • a step-down processing circuit (113), the input end of the step-down processing circuit (113) is connected to the voltage output pin (Vout) of the linear step-down chip (U1), and the step-down processing circuit (113) The output terminal is connected to the input terminal of the full-bridge drive circuit (120), and the step-down processing circuit (113) is used to filter and step-down the voltage output by the linear step-down circuit (111);
  • the output feedback circuit (114) is connected to the output terminal of the step-down processing circuit (113), and is used to feed back the voltage output by the LDO step-down circuit (110), so as to adjust the step-down regulator circuit, and then The output voltage of the linear step-down circuit (111) is adjusted.
  • the step-down regulator circuit (112) includes a resistor (R1), a diode (D2), a capacitor (C3), and a digital potentiometer (U2); the resistor (R1) and the The digital potentiometer (U2) is connected in series, one end of the resistor (R1) and the cathode of the diode (D2) are connected to the voltage output pin (Vout) of the linear step-down chip (U1), and the resistor ( The other end of R1), the anode of the diode (D2), the first electrode of the capacitor (C3), the arm pin (W) of the digital potentiometer (U2) and the linear step-down chip ( The voltage adjustment pin (ADJ) of U1) is connected, and the second electrode of the capacitor (C3) and the pin (L) of the digital potentiometer (U2) are grounded.
  • the step-down regulator circuit (112) includes a resistor (R1), a diode (D2), a capacitor (C3), and a digital potentiometer (U2) and a digital potentiometer (U3);
  • the resistor (R1), the digital potentiometer (U2), and the digital potentiometer (U3) are connected in series, one end of the resistor (R1), the cathode of the diode (D2) and the linear step-down chip (
  • the voltage output pin (Vout) of U1) is connected, the other end of the resistor (R1), the anode of the diode (D2), the first electrode of the capacitor (C3), and the digital potentiometer (U2)
  • the arm stroke pin (W) is connected to the voltage adjustment pin (ADJ) of the linear step-down chip (U1), and the pin (L) of the digital potentiometer (U2) and the digital potentiometer (U3)
  • the stroke arm pin (W) of) is connected,
  • the step-down regulator circuit (112) includes at least three digital potentiometers, and the digital potentiometers are connected in series.
  • the step-down processing circuit includes a filter unit and a step-down processing unit
  • the filter unit includes a capacitor (EC1), a capacitor (C6), and a resistor (R2).
  • the unit includes a diode (D3), a diode (D4), a diode (D5), a diode (D6), and a resistor (R3), a resistor (R4); the capacitor (EC1), the capacitor (C6), and the The resistor (R2) is connected in parallel, and the first electrode of the capacitor (EC1), the first electrode of the capacitor (C6), and one end of the resistor (R2) are connected to the voltage output of the linear step-down chip (U1).
  • the pin (Vout) is connected, the second electrode of the capacitor (EC1), the second electrode of the capacitor (C6), and the other end of the resistor (R2) are grounded; the diode (D3) and the diode ( D4) in series, the diode (D5) and the diode (D6) are in series, the resistor (R3) and the resistor (R4) are in series, the anode of the diode (D3), the diode (D5)
  • the anode and one end of the resistor (R3) are connected to the voltage output pin (Vout) of the linear step-down chip (U1), the cathode of the diode (D4), the cathode of the diode (D6), the The other end of the resistor (R4) is connected to the output end of the LDO step-down circuit.
  • the output feedback circuit (114) includes a feedback resistor (R5) and a feedback resistor (R6); the feedback resistor (R5) and the feedback resistor (R6) are connected in series, and the feedback One end of the resistor (R5) is connected to the output end of the LDO step-down circuit, the other end of the feedback resistor (R5) and one end of the feedback resistor (R6) are connected to the feedback signal end (ADC), and the feedback The other end of the resistor (R6) is grounded.
  • the linear step-down circuit further includes an amplifying circuit unit, and the amplifying circuit unit includes a sampling resistor (R13), a triode (Q5), a triode (Q6), and a bias resistor (R14) , A bias resistor (R15), one end of the sampling resistor (R13) is connected to the emitter of the transistor (Q5) and the emitter of the transistor (Q6), and the other end of the sampling resistor (R13) is connected to One end of the bias resistor (R14) is connected to the voltage input pin (Vin) of the linear step-down chip (U1), and the other end of the bias resistor (R14) is connected to the base of the transistor (Q5).
  • the amplifying circuit unit includes a sampling resistor (R13), a triode (Q5), a triode (Q6), and a bias resistor (R14) , A bias resistor (R15), one end of the sampling resistor (R13) is connected to the emitter of the transistor (Q5) and
  • the collector of the transistor (Q5) is connected to the base of the transistor (Q6) and one end of the bias resistor (R15), the collector of the transistor (Q6), the bias resistor The other end of (R15) is connected to the voltage output pin (Vout) of the linear step-down chip (U1).
  • the full bridge drive circuit (120) includes a drive control circuit, a switch control circuit, and a drive adjustment circuit; the drive control circuit includes a first drive control circuit and a second drive control circuit,
  • the first drive control circuit includes a drive chip (U4), a capacitor (C7), a capacitor (C8), a resistor (R7), and a diode (D7)
  • the second drive control circuit includes a drive chip (U5), a capacitor ( C9), capacitor (C10), resistor (R10), diode (D10), the power supply pin (VDD) of the driver chip (U4), the other end of the resistor (R7), the capacitor (C8)
  • the first electrode plate is connected to the voltage signal, the common pin (VSS) of the driving chip (U4), the second electrode plate of the capacitor (C8) are grounded, and the pin (HB) of the driving chip (U4) Connected to the first electrode plate of the capacitor (C7) and the cathode of the diode (D7)
  • the circuit includes four switch control devices. The input terminal of the first switch control device and the input terminal of the second switch control device are connected to the output terminal of the LDO step-down circuit.
  • the output terminal of the first switch control device, the third The input terminal of the switch control device, the pin (HS) of the driving chip (U4), the second electrode plate of the capacitor (C7) are connected to the first connection terminal of the liquid crystal light valve (140), and
  • the output terminal of the second switch control device, the input terminal of the fourth switch control device, the pin (HS) of the drive chip (U5), the second electrode plate of the capacitor (C9) and the liquid crystal light valve ( 140) is connected to the second connection terminal, the output terminal of the third switch control device and the output terminal of the fourth switch control device are grounded;
  • the drive regulation circuit includes a first drive regulation circuit, a second drive regulation circuit, A third drive adjustment circuit and a fourth drive adjustment circuit.
  • the first drive adjustment circuit includes a diode (D8) and a resistor (R8).
  • the cathode of the diode (D8), one end of the resistor (R8) and the The pin (HO) of the driver chip (U4) is connected, the anode of the diode (D8) and the other end of the resistor (R8) are connected to the control terminal of the first switch control device, and the second driver
  • the adjustment circuit includes two poles Tube (D9) and resistor (R9), the cathode of the diode (D9) and one end of the resistor (R9) are connected to the pin (LO) of the drive chip (U4), and the diode (D9) The anode and the other end of the resistor (R9) are connected to the control end of the third switch control device.
  • the third drive adjustment circuit includes a diode (D11) and a resistor (R11).
  • the cathode of the diode (D11) One end of the resistor (R11) is connected to the pin (HO) of the drive chip (U5), the anode of the diode (D11) and the other end of the resistor (R11) are connected to the second switch control
  • the control terminal of the device is connected;
  • the fourth drive adjustment circuit includes a diode (D12) and a resistor (R12), the cathode of the diode (D12), one end of the resistor (R12) and the drive chip (U5)
  • the pin (LO) is connected, and the anode of the diode (D12) and the other end of the resistor (R12) are connected to the control terminal of the fourth switch control device.
  • the present invention also provides a liquid crystal light valve, which includes any one of the liquid crystal light valve driving circuits provided by the present invention.
  • the present invention also provides an LED lamp, which includes the liquid crystal light valve provided by the present invention.
  • the present invention provides a driving circuit for a liquid crystal light valve, a liquid crystal light valve and an LED lamp.
  • the driving circuit includes an LDO step-down circuit and a full-bridge drive circuit.
  • the LDO step-down circuit is connected to the full-bridge drive circuit.
  • the LDO step-down circuit is connected to a power supply, the full-bridge drive circuit is connected to the liquid crystal light valve;
  • the LDO step-down circuit includes: a linear step-down circuit, including a linear step-down chip, the input end of the linear step-down chip is connected to the power supply, The linear step-down chip is used to perform linear step-down processing on the power supply voltage;
  • the step-down adjustment circuit includes at least one digital potentiometer, the arm pin of the digital potentiometer is connected to the voltage adjustment pin of the linear step-down chip, and the digital potentiometer is used To adjust the voltage output by the voltage output pin of the linear step-down chip;
  • step-down processing circuit the input end of the step-down processing circuit is connected to the voltage output pin of the linear step-down chip, and the output end of the step-down processing circuit is connected to the full bridge
  • the input end of the drive circuit is connected, the step-down processing circuit is used to filter and step-down the voltage output by the linear step-down circuit; the output
  • the linear step-down processing of the power supply voltage through the LDO step-down circuit improves the adjustment accuracy of the drive circuit, reduces the noise and ripple ratio, and improves the stability of the liquid crystal light valve; realizes the driving of the liquid crystal light valve through the full bridge drive circuit , It realizes AC PWM voltage and unidirectional PWM voltage to drive the liquid crystal light valve, which improves the driving capability of the entire driving circuit.
  • FIG. 1 is a structural block diagram of a driving circuit of a liquid crystal light valve provided by an embodiment of the present invention.
  • FIG. 2 is a schematic diagram of a first circuit of a driving circuit for a liquid crystal light valve provided by an embodiment of the present invention.
  • FIG. 3 is a schematic diagram of a second circuit of a driving circuit for a liquid crystal light valve provided by an embodiment of the present invention.
  • the present invention provides a liquid crystal light valve drive circuit, which solves the problems of adjustment accuracy and stability, and has a wide input voltage range and peripheral devices. Few, simple structure and low cost.
  • the driving circuit of the liquid crystal light valve provided by the present invention includes an LDO step-down circuit 110 and a full-bridge drive circuit 120.
  • the input end of the LDO step-down circuit 110 is connected to the power supply 130, and the LDO The output end of the step-down circuit 110 is connected to the input end of the full-bridge drive circuit 120, and the full-bridge drive circuit 120 is connected to the liquid crystal light valve 140;
  • the LDO step-down circuit 110 includes:
  • the linear step-down circuit 111 includes a linear step-down chip U1, the input end of the linear step-down chip U1 is connected to the power supply 130, and the linear step-down chip U1 is used to perform linear step-down processing on the power supply voltage;
  • the step-down adjustment circuit 112 includes at least one digital potentiometer.
  • the arm pin W of the digital potentiometer is connected to the voltage adjustment pin ADJ of the linear step-down chip U1.
  • the digital potentiometer is used to output the voltage of the linear step-down chip U1. Adjust the output voltage of Vout;
  • the step-down processing circuit 113 the input end of the step-down processing circuit 113 is connected to the voltage output pin Vout of the linear step-down chip U1, the output end of the step-down processing circuit 113 is connected to the input end of the full-bridge drive circuit 120, and the step-down processing
  • the circuit 113 is used for filtering and stepping down the voltage output by the linear step-down circuit 111;
  • the output feedback circuit 114 is connected to the output terminal of the step-down processing circuit 113, and is used to feed back the voltage output by the LDO step-down circuit 110, so as to adjust the step-down regulator circuit, and then adjust the output voltage of the linear step-down circuit.
  • the embodiment of the present invention provides a drive circuit for a liquid crystal light valve.
  • the linear step-down circuit of the drive circuit uses a linear step-down chip to perform linear step-down processing on the power supply voltage. Since the linear step-down chip has a very low noise and ripple ratio, Therefore, it can reduce noise and ripple and improve the stability of the liquid crystal light valve; the output voltage of the linear step-down circuit can be adjusted by a step-down regulator circuit composed of a digital potentiometer, and the digital potentiometer can accurately adjust the linear drop. The output voltage of the voltage circuit improves the adjustment accuracy of the drive circuit.
  • the power supply 130 outputs the power supply voltage signal to the linear step-down circuit 111, the capacitor C1 and the capacitor C2 are connected in parallel, the first electrode plate of the capacitor C1 and the first electrode plate of the capacitor C2 Connected to the output terminal of the power supply, the second electrode plate of the capacitor C1 and the second electrode plate of the capacitor C2 are grounded.
  • the capacitor C1 and the capacitor C2 are used to filter the clutter in the DC voltage output by the power supply 130.
  • the linear step-down circuit 111 includes a linear step-down chip U1 and a diode D1; the voltage input pin Vin of the linear step-down chip U1 and the cathode of the diode D1 are connected to the output terminal of the power supply, and the linear step-down circuit 111
  • the voltage output pin Vout of the chip U1 is connected to the anode of the diode D1.
  • the linear step-down chip U1 may be an LM317HV chip, the highest input voltage of the LM317HV chip is 60V, and the output voltage is 1.25-57V.
  • the voltage output by the voltage output pin Vout under normal circumstances is less than the input voltage of the voltage input pin Vin; but when the anode voltage of the diode D1 is greater than the cathode voltage, the diode D1 is turned on, linear The voltage output pin Vout and the voltage input pin Vin of the step-down chip U1 are short-circuited by the diode D1, thereby avoiding the risk of burning the linear step-down chip U1.
  • the linear step-down circuit 111 includes a linear step-down chip U1 and an amplifying circuit unit.
  • the amplifying circuit unit includes a sampling resistor R13, a transistor Q5, a transistor Q6, and a bias resistor R14. Resistor R15, one end of the sampling resistor R13 is connected to the emitter of the transistor Q5 and the emitter of the transistor Q6, and the other end of the sampling resistor R13 is connected to one end of the bias resistor R14 and the voltage input pin Vin of the linear buck chip U1.
  • the other end of the resistor R14 is connected to the base of the transistor Q5, the collector of the transistor Q5 is connected to the base of the transistor Q6, and one end of the bias resistor R15.
  • the linear step-down chip U1 may be an LM317HV chip, the highest input voltage of the LM317HV chip is 60V, and the output voltage is 1.25-57V.
  • the current required by the liquid crystal light valve is small, the current provided by the power supply is small, the current flowing through the sampling resistor R13 is small, and the voltage difference between the two ends of the sampling resistor R13 is relatively small, which does not meet the conduction condition of the transistor Q5, and the transistor Q5 is off.
  • the transistor Q6 is off; the current provided by the power supply is only outputted to the liquid crystal light valve through the linear step-down chip U1 to meet the power demand of the liquid crystal light valve.
  • the transistor Q6 When the voltage difference between the emitter and collector of the amplified transistor Q5 meets the conduction condition of the transistor Q6, the transistor Q6 is turned on, and the transistor Q6 turns on the emitter of the transistor Q5
  • the voltage difference between the collector and the collector is amplified again; the current provided by the power supply outputs voltage to the liquid crystal light valve 140 through the linear step-down chip U1, and the other path is amplified by the amplifier circuit unit to output current to the liquid crystal light valve 140, the linear step-down chip U1 and the amplifying circuit unit together provide the required current for the liquid crystal light valve 140.
  • the linear step-down circuit uses the linear step-down chip U1 to perform linear step-down processing on the power supply voltage. Since the linear step-down chip U1 has a very low noise and ripple ratio, it can reduce Noise and ripples improve the stability of the liquid crystal light valve 140.
  • the linear step-down chip U1 can be the LM317HV chip. The maximum input voltage of the LM317HV chip is 60V and the output voltage is 1.25-57V. It has the advantages of wide output voltage range, few peripheral components, simple structure and low cost. Of course, the linear step-down chip U1 can also use other chips with the same function type or model, which is not specifically limited here.
  • the step-down regulator circuit 112 includes a resistor R1, a diode D2, a digital potentiometer U2, and a capacitor C3; the resistor R1 is connected in series with the digital potentiometer U2, and one end of the resistor R1 and the diode D2
  • the cathode and the voltage output pin Vout of the linear buck chip U1 are connected to the first node, the other end of the resistor R1, the anode of the diode D2, the first electrode of the capacitor C3, the arm pin W of the digital potentiometer U2 and the linear
  • the voltage adjustment pin ADJ of the step-down chip U1 is connected to the second node, and the second electrode of the capacitor C3 and the pin L of the digital potentiometer U2 are grounded.
  • the voltage of the first node is the voltage output by the voltage output pin Vout of the linear step-down chip U1.
  • the voltage difference between the two ends of the digital potentiometer U2 The linear buck chip U1 is fed back through the voltage adjustment pin ADJ, and the voltage fed back to the linear buck chip U1 is compared with the reference voltage inside the linear buck chip U1, and the voltage output by the voltage output pin Vout is adjusted by the comparison result.
  • Digital potentiometer also known as numerical control potentiometer, is a device that uses digital signals to control its resistance change. It has the characteristics of programmable resistance change, flexible use and high adjustment accuracy.
  • the resistance value of the digital potentiometer U2 is adjusted to adjust the voltage of the voltage adjustment pin ADJ of the linear step-down chip U1, and then the output voltage of the linear step-down circuit is accurately regulated. Improve the adjustment accuracy of the drive circuit.
  • the digital potentiometer U2 can be a digital potentiometer such as MAX5483, MAX5432, or X9315.
  • the output voltage of the linear step-down circuit is adjusted by a step-down adjustment circuit composed of a digital potentiometer, which can accurately adjust the output voltage of the linear step-down circuit, which greatly improves the driving The adjustment accuracy of the circuit.
  • the voltage of the first node is higher than the voltage of the second node, and the voltage of the second node is higher than the ground voltage.
  • the diode D2 is turned on, and the voltage output pin Vout of the linear step-down chip U1 and the voltage adjustment pin ADJ are short-circuited by the diode D2, which prevents the linear step-down chip U1 from burning risks of.
  • the step-down regulator circuit 112 includes a resistor R1, a diode D2, a digital potentiometer U2, a digital potentiometer U3, and a capacitor C3; a resistor R1, a digital potentiometer U2, and a digital potential
  • the resistor U3 is connected in series, one end of the resistor R1, the cathode of the diode D2 and the voltage output pin Vout of the linear step-down chip U1 are connected, the other end of the resistor R1, the anode of the diode D2, the first electrode of the capacitor C3, and the digital potentiometer U2
  • the arm stroke pin W is connected to the voltage regulation pin ADJ of the linear step-down chip U1, the pin L of the digital potentiometer U2 is connected to the arm stroke pin W of the digital potentiometer U3, the second electrode of the capacitor C3, the digital potentiometer Pin L of U3 is grounded.
  • the step-down regulator circuit 112 includes at least three digital potentiometers, and the digital potentiometers are connected in series.
  • V (ADJ) V (Vout) ⁇ R of the voltage regulation pin ADJ of the linear step-down chip U1 in the above embodiment (U2) ⁇ (R (U2) + R (R1) )
  • V (ADJ) V (Vout) ⁇ R of the voltage regulation pin ADJ of the linear step-down chip U1 in the above embodiment (U2) ⁇ (R (U2) + R (R1) )
  • the step-down processing circuit 113 includes a filter unit and a step-down processing unit.
  • the filter unit includes a capacitor EC1, a capacitor C6, and a resistor R2; the capacitor EC1, a capacitor C6, and a resistor R2 are connected in parallel, the first electrode of the capacitor EC1, the first electrode of the capacitor C6, one end of the resistor R2 and the voltage of the linear step-down chip U1
  • the output pin Vout is connected, and the second electrode of the capacitor EC1, the second electrode of the capacitor C6, and the other end of the resistor R2 are grounded.
  • the filter unit adopts the capacitor EC1 and the capacitor C6 to filter the clutter in the output voltage of the voltage output pin Vout of the linear step-down chip U1, thereby ensuring the stability of the output voltage of the LDO step-down circuit .
  • the resistor R2 is used to discharge the capacitor EC1 and the capacitor C6 when the filter unit stops working.
  • the step-down processing unit includes a diode D3, a diode D4, a diode D5, a diode D6, and a resistor R3 and a resistor R4; the diode D3 and the diode D4 are connected in series, the diode D5 and the diode D6 are connected in series, the resistor R3 and the resistor R4 are connected in series, and the anode of the diode D3, The anode of the diode D5 and one end of the resistor R3 are connected to the voltage output pin Vout of the linear step-down chip U1, and the cathode of the diode D4, the cathode of the diode D6, and the other end of the resistor R4 are connected to the output end of the LDO step-down circuit.
  • the step-down processing unit is used to reduce the voltage output by the voltage output pin Vout of the linear step-down chip U1.
  • the conduction conditions of the diode D3, the diode D4, the diode D5, and the diode D6 are not met.
  • the diode D3, the diode D4, the diode D5, and the diode D6 are closed, and the resistance R3 and resistor R4 are turned on.
  • Resistor R3 and resistor R4 are used to reduce the voltage output by the voltage output pin Vout of the linear step-down chip U1; when the voltage output pin Vout of the linear step-down chip U1 outputs a large current, it satisfies
  • the conduction conditions of diode D3, diode D4, diode D5, and diode D6, diode D3, diode D4, diode D5, and diode D6 are turned on, and the voltage output by the voltage output pin Vout of the linear buck chip U1 is output by diode D3 and diode D4 , Diode D5, diode D6 divides the voltage; after the step-down processing of the step-down processing unit, the LDO step-down circuit can meet the voltage output of the 0-55V liquid crystal light valve 140.
  • the output feedback circuit 114 includes a feedback resistor R5 and a feedback resistor R6; the feedback resistor R5 and the feedback resistor R6 are connected in series, and one end of the feedback resistor R5 is connected to the output terminal of the LDO step-down circuit. The other end, one end of the feedback resistor R6 is connected to the feedback signal end ADC, and the other end of the feedback resistor R6 is grounded.
  • the voltage difference between the two ends of the feedback resistor R6 is fed back to the single-chip microcomputer through the feedback signal terminal ADC, and the single-chip uses the feedback voltage signal to adjust the step-down regulator circuit 112
  • the resistance value of the digital potentiometer increases/decreases the input signal of the control pin DIN, thereby adjusting the output signal of the arm pin W of the digital potentiometer, adjusting the resistance value of the digital potentiometer, and then adjusting the voltage of the linear step-down chip U1 Adjust the voltage of the pin ADJ, adjust the voltage output by the voltage output pin Vout of the linear step-down chip U1.
  • the LDO step-down circuit performs linear step-down processing on the power supply voltage through the linear step-down circuit, and the linear step-down chip has the characteristics of very low noise and ripple ratio, which improves the liquid crystal light.
  • the full bridge driving circuit 120 includes a driving control circuit, a switch control circuit, and a driving adjustment circuit.
  • the drive control circuit includes a first drive control circuit and a second drive control circuit.
  • the first drive control circuit includes a drive chip U4, a capacitor C7, a capacitor C8, a resistor R7, and a diode D7.
  • the second drive control circuit includes a drive chip U5 and a capacitor C9.
  • the two electrode plates are grounded, the pin HB of the drive chip U4 is connected to the first electrode plate of the capacitor C7 and the cathode of the diode D7, and the output pin LO of the drive chip U4 is connected to one end of the resistor R9 and the cathode of the diode D9; the drive chip U5
  • the power supply pin VDD, the other end of the resistor R10, the first electrode plate of the capacitor C10 are connected to the voltage signal, the common pin VSS of the driving chip U5, the second electrode plate of the capacitor C10 are grounded, and the pin HB of the driving chip U5 is connected to The first electrode plate of the capacitor C10 is connected to the cathode
  • the switch control circuit includes four switch control devices.
  • the input terminal of the first switch control device and the input terminal of the second switch control device are connected to the output terminal of the LDO step-down circuit.
  • the output terminal of the first switch control device and the third switch control device The input terminal of the device, the pin HS of the driving chip U4, the second electrode plate of the capacitor C7 are connected to the first connection terminal of the liquid crystal light valve 140, the output terminal of the second switch control device, the input terminal of the fourth switch control device,
  • the pin HS of the driving chip U5 and the second electrode plate of the capacitor C9 are connected to the second connection end of the liquid crystal light valve 140, and the output end of the third switch control device and the output end of the fourth switch control device are grounded.
  • the drive regulation circuit includes a first drive regulation circuit, a second drive regulation circuit, a third drive regulation circuit, and a fourth drive regulation circuit;
  • the first drive regulation circuit includes a diode D8 and a resistor R8, the cathode of the diode D8, and one end of the resistor R8 Connected to the pin HO of the driver chip U4, the anode of the diode D8 and the other end of the resistor R8 are connected to the control terminal of the first switch control device;
  • the second drive regulation circuit includes a diode D9 and a resistor R9, and the cathode of the diode D9 and a resistor R9 One end of the D9 is connected to the pin LO of the driver chip U4, the anode of the diode D9 and the other end of the resistor R9 are connected to the control end of the third switch control device;
  • the third drive adjustment circuit includes a diode D11 and a resistor R11, the cathode of the diode
  • the switching control device is a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, metal-oxide semiconductor field-effect transistor) tube, which may be, for example, an N-channel type MOS tube or P-channel type MOS tube, etc.
  • the first switching control device is a P-channel type MOSFET tube Q1
  • the second switching control device is a P-channel type MOSFET tube Q2
  • the third switching control device is a P-channel type MOSFET tube Q2.
  • the device is a P-channel type MOSFET tube Q3, and the fourth switching control device is a P-channel type MOSFET tube Q4.
  • the control terminal of the switch control device is the gate of the MOSFET tube.
  • the switching control device may be a triode (such as an NPN or PNP type transistor) or other electronic devices that can control the conduction of the full-bridge drive circuit circuit, a combination thereof, etc., of course, it can also be The combination of triode and MOS tube, etc., is not specifically limited here.
  • the driver chip U4 outputs a signal to the gate of the MOSFET Q1 through the output pin HO to control the on and off of the MOSFET Q1; the driver chip U4 outputs a signal to the gate of the MOSFET Q3 through the output pin LO to control the MOSFET.
  • the MOSFET tube Q1 When the MOSFET tube Q1 is turned on, the MOSFET tube Q3 is turned off; when the MOSFET tube Q3 is turned on, the MOSFET tube Q1 is turned off; that is, the MOSFET tube Q1 and the MOSFET tube Q3 are logically interlocked to avoid the drive chip U4 driving signal output error, As a result, the MOSFET tube Q1 and the MOSFET tube Q3 are turned on at the same time, thereby causing the risk of short circuit of the full-bridge driving circuit, and ensuring the safety of the full-bridge driving circuit.
  • the driver chip U5 outputs a signal to the gate of the MOSFET Q2 through the output pin HO to control the on and off of the MOSFET Q2; the driver chip U5 outputs a signal to the gate of the MOSFET Q4 through the output pin LO to control the MOSFET.
  • the MOSFET tube Q2 When the MOSFET tube Q2 is turned on, the MOSFET tube Q4 is turned off; when the MOSFET tube Q4 is turned on, the MOSFET tube Q2 is turned off; that is, the MOSFET tube Q2 and the MOSFET tube Q4 are logically interlocked to avoid the drive chip U5 driving signal output error, As a result, the MOSFET Q2 and the MOSFET Q4 are turned on at the same time, thereby causing the risk of short circuit of the full-bridge driving circuit, and ensuring the safety of the full-bridge driving circuit.
  • the connecting end flows out of the liquid crystal light valve 140 and is grounded by the MOSFET Q4 to form a complete path; when the MOSFET Q1 and MOSFET Q4 are turned off, and the MOSFET Q2 and MOSFET Q3 are turned on, the current flows from the MOSFET Q2 from the liquid crystal light
  • the second connection end of the valve 140 flows into the liquid crystal light valve 140, and flows out of the liquid crystal light valve 140 from the first connection end of the liquid crystal light valve 140, and is grounded by the MOSFET Q3 to form a complete path.
  • the full-bridge driving circuit outputs an AC PWM driving voltage to the liquid crystal light valve 140, so that the liquid crystal light valve 140 is fully transparent or fully shielded.
  • MOSFET Q1 and MOSFET Q4 are turned on, MOSFET Q2 and MOSFET Q3 are turned off, or MOSFET Q1 and MOSFET Q4 are turned off, MOSFET Q2 and MOSFET Q3 are turned on, and the full-bridge drive circuit lights to the liquid crystal.
  • the valve outputs a one-way PWM driving voltage to realize the semi-transmission of the liquid crystal light valve 140, and the light transmittance of the liquid crystal light valve 140 is realized by adjusting the output voltage of the LDO driving circuit.
  • drive MOSFET Q1, MOSFET Q2, MOSFET Q3 and MOSFET Q4 not only can achieve AC PWM voltage drive liquid crystal light valve 140, but also can achieve unidirectional PWM voltage The liquid crystal light valve 140 is driven.
  • the driver chip U4 and the driver chip U5 can be both LM5109B chips.
  • the LM5109B chip has a high MOSFET drive capability, which not only enables the full-bridge drive circuit to reach dozens or even hundreds of watts, but also It can improve the driving capability of the entire circuit and at the same time make the waveform of the PWM driving voltage more regular.
  • the diode D8 When the MOSFET Q1 changes from the off state to the on state, or is always in the on state, the diode D8 is turned off, and the voltage output by the output pin LO of the driving chip U4 is charged to the gate of the MOSFET Q1 through the resistor R8; When the MOSFET Q1 changes from the on state to the off state, the diode D8 is turned on, and the gate of the MOSFET Q1 is quickly discharged through the diode D8, which can accelerate the turn-off speed of the MOSFET Q1.
  • the diode D9, the diode D11, and the diode D12 act to speed up the MOSFET Q2, the MOSFET Q3, and the MOSFET Q4, respectively, so that the waveform of the PWM drive voltage output by the full-bridge drive circuit to the liquid crystal light valve is more regular.
  • the driving chip U4 outputs a driving voltage to the gate of the MOSFET Q1, and there is a risk of a spike in the output driving voltage.
  • One end of the resistor R8 is connected to the output pin HO of the drive chip U4, and the other end of the resistor R8 is connected to the gate of the MOSFET Q1; the drive voltage output by the output pin HO of the drive chip U4 is input to the MOSFET Q1 after passing through the resistor R8
  • the gate, resistor R8 can eliminate the spike signal in the driving voltage flowing through, making the waveform of the driving voltage input to the gate of the MOSFET Q1 more regular, thereby more effectively controlling the turning off and on of the MOSFET Q1, thereby making the whole
  • the PWM drive voltage output by the bridge drive circuit to the liquid crystal light valve is more stable.
  • the resistor R9 makes the waveform of the driving voltage input to the gate of the MOSFET Q3 more regular, which can more effectively control the turn-off and conduction of the MOSFET Q3; the resistor R11 makes the driving voltage input to the gate of the MOSFET Q2 more effective.
  • the waveform is more regular, which can more effectively control the turn-off and conduction of the MOSFET Q2; the resistor R12 makes the waveform of the driving voltage input to the gate of the MOSFET Q4 more regular, so that it can more effectively control the turn-off and conduction of the MOSFET Q4. Pass; Makes the PWM drive voltage output by the entire full-bridge drive circuit to the liquid crystal light valve more stable.
  • the four MOSFET tubes are driven by the driving chip U4 and the driving chip U5 to output specific driving signals, which can not only achieve AC PWM voltage driving the liquid crystal light valve 140, but also
  • the one-way PWM voltage drives the liquid crystal light valve 140
  • the driver chip U4 and the driver chip U5 have high MOSFET drive capability, which can not only improve the drive capability of the entire drive circuit, but also make the PWM drive waveform more regular
  • the drive chips U4 and U5 The logic interlocking feature of the driving chip U5 avoids the risk of short circuit of the full-bridge driving circuit due to the wrong driving signal output of the driving chip U4 and the driving chip U5, and ensures the safety of the full-bridge driving circuit.
  • the embodiment of the present invention also provides a liquid crystal light valve, which includes any one of the driving circuits of the liquid crystal light valve provided in the embodiment of the present invention.
  • the driving circuit includes an LDO step-down circuit 110 and a full-bridge drive circuit 120.
  • the input end of the LDO step-down circuit 110 is connected to the power supply 130, and the output end of the LDO step-down circuit 110 is connected to the full-bridge drive circuit 120.
  • the input end is connected, and the full-bridge driving circuit 120 is connected to the liquid crystal light valve 140;
  • the LDO step-down circuit 110 includes:
  • the linear step-down circuit 111 is connected to the power supply 130 and is used to perform linear step-down processing on the power supply voltage.
  • the linear step-down circuit 111 includes a linear step-down chip U1;
  • the step-down regulator circuit 112 is connected to the linear step-down circuit 111 and is used to adjust the output voltage of the linear step-down circuit 111.
  • the step-down regulator circuit 112 includes at least one digital potentiometer;
  • the step-down processing circuit 113 is connected to the linear step-down circuit 111, and is used to filter and step-down the voltage output by the linear step-down circuit 111;
  • the output feedback circuit 114 is connected to the step-down processing circuit 113, and is used to feed back the voltage output by the LDO step-down circuit 110, so as to adjust the step-down regulator circuit, and then to the linear step-down circuit 111 The output voltage is adjusted.
  • the liquid crystal light valve provided by the embodiment of the present invention includes any liquid crystal light valve drive circuit provided in the embodiment of the present invention, and has the beneficial effects that can be achieved by any liquid crystal light valve drive circuit provided by the embodiment of the present invention
  • any liquid crystal light valve drive circuit provided by the embodiment of the present invention For the specific implementation, please refer to the previous embodiment, which will not be repeated here.
  • the embodiment of the present invention further provides an LED (Light Emitting Diode, light-emitting diode) lamp.
  • the LED lamp includes an LED and any liquid crystal light valve provided in the embodiment of the present invention.
  • the liquid crystal light valve is located on the light-emitting surface of the LED for adjusting the LED. The light from the lamp.
  • the liquid crystal light valve includes any one of the driving circuits of the liquid crystal light valve provided by the embodiments of the present invention.
  • the driving circuit includes an LDO step-down circuit 110 and a full-bridge drive circuit 120.
  • the input terminal of the LDO step-down circuit 110 is connected to the power supply 130. Connected, the output terminal of the LDO step-down circuit 110 is connected to the input terminal of the full-bridge drive circuit 120, and the full-bridge drive circuit 120 is connected to the liquid crystal light valve 140;
  • the LDO step-down circuit 110 includes:
  • the linear step-down circuit 111 is connected to the power supply 130 and is used to perform linear step-down processing on the power supply voltage.
  • the linear step-down circuit 111 includes a linear step-down chip U1;
  • the step-down regulator circuit 112 is connected to the linear step-down circuit 111 and is used to adjust the output voltage of the linear step-down circuit 111.
  • the step-down regulator circuit 112 includes at least one digital potentiometer;
  • the step-down processing circuit 113 is connected to the linear step-down circuit 111, and is used to filter and step-down the voltage output by the linear step-down circuit 111;
  • the output feedback circuit 114 is connected to the step-down processing circuit 113, and is used to feed back the voltage output by the LDO step-down circuit 110, so as to adjust the step-down regulator circuit, and then to the linear step-down circuit 111 The output voltage is adjusted.
  • the LED lamp provided in the embodiment of the present invention includes any liquid crystal light valve provided in the embodiment of the present invention, and the liquid crystal light valve includes any liquid crystal light valve driving circuit provided in the embodiment of the present invention.
  • the driving circuit of the liquid crystal light valve includes any liquid crystal light valve driving circuit provided in the embodiment of the present invention.
  • Any of the beneficial effects that can be achieved by the driving circuit of the liquid crystal light valve is that the precise and stable adjustment of the liquid crystal light valve by the driving circuit realizes the soft light effect of the LED lamp. Please refer to the previous embodiment for the specific implementation method.
  • the embodiment of the present invention provides a driving circuit for a liquid crystal light valve, a liquid crystal light valve, and an LED lamp.
  • the driving circuit includes an LDO step-down circuit and a full-bridge drive circuit.
  • the LDO step-down circuit is connected to the full-bridge drive circuit.
  • the circuit is connected to the power supply, and the full bridge drive circuit is connected to the liquid crystal light valve;
  • the LDO step-down circuit includes: a linear step-down circuit, including a linear step-down chip, the input end of the linear step-down chip is connected to the power supply, and the linear step-down chip is used to connect the power supply
  • the voltage is subjected to linear step-down processing;
  • the step-down adjustment circuit includes at least one digital potentiometer, the arm pin of the digital potentiometer is connected to the voltage adjustment pin of the linear step-down chip, and the digital potentiometer is used to output the voltage of the linear step-down chip
  • the voltage output by the pin is adjusted;
  • the step-down processing circuit the input end of the step-down processing circuit is connected to the voltage output pin of the linear step-down chip, and the output end of the step-down processing circuit is connected to the input end of the full-bridge drive circuit.
  • the voltage processing circuit is used to filter and step down the voltage output by the linear step-down circuit;
  • the output feedback circuit is connected to the output terminal of the step-down processing circuit and is used to feedback the voltage output by the LDO step-down circuit to adjust the drop Voltage regulator circuit, and then adjust the output voltage of the linear step-down circuit.
  • the LDO step-down circuit uses a linear step-down circuit to perform linear step-down processing on the power supply voltage.
  • the linear step-down chip has the characteristics of very low noise and ripple ratio, which improves the stability of the liquid crystal light valve;
  • the output voltage of the linear step-down circuit can be adjusted, and the digital potentiometer can be used to programmatically change the resistance, flexible use, and high adjustment accuracy.
  • the output voltage of the linear step-down circuit can be accurately adjusted, which improves the adjustment accuracy of the drive circuit;
  • the voltage processing circuit performs filtering and step-down processing on the voltage output by the linear step-down circuit to ensure the stability of the output voltage of the LDO step-down circuit and meet the voltage output of the liquid crystal light valve;
  • the output feedback circuit is used to output the LDO step-down circuit.
  • the voltage is fed back to adjust the step-down regulator circuit to adjust the output voltage of the linear step-down circuit, which further ensures the accuracy of the output voltage of the LDO step-down circuit.
  • the full-bridge drive circuit drives the four MOSFET tubes through the drive chip, and realizes the AC PWM voltage and unidirectional PWM voltage to drive the liquid crystal light valve, which improves the drive capability of the entire drive circuit.

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Abstract

一种液晶光阀的驱动电路、液晶光阀以及LED灯，该驱动电路包括LDO降压电路(110)和全桥驱动电路(120)，LDO降压电路(110)包括：线性降压电路(111)，包括线性降压芯片(U1)，线性降压芯片(U1)的输入端连接电源(130)，线性降压芯片(U1)用于对电源电压进行线性降压处；降压调节电路(112)，包括至少一个数字电位器，数字电位器的划臂引脚(W)与线性降压芯片(U1)的电压调节引脚(ADJ)连接，数字电位器用于对线性降压芯片(U1)电压输出引脚(Vout)输出的电压进行调节；降压处理电路(113)，用于对线性降压电路(111)输出的电压进行滤波、降压处理；输出反馈电路(114)，用于对LDO降压电路(110)输出的电压进行反馈。提高了驱动电路的调节精度，降低了噪声和波纹比，提高了液晶光阀的稳定性。

Description

一种液晶光阀的驱动电路、液晶光阀以及LED灯 技术领域
本申请涉及电子电路技术领域，尤其涉及一种液晶光阀的驱动电路、液晶光阀以及LED灯。
背景技术
传统的液晶光阀驱动基本都是单向低压的PWM(Pulse Width Modulation，脉冲宽度调制)驱动，在这种驱动方式下，要想改变液晶光阀的透光度，一般是调节PWM的占空比，但这种调节方式只能够满足某些特定的低压单向，且精度要求不高的应用场景，无法满足高精度的应用场景。同时，传统的液晶光阀驱动电路用于驱动功率较大的液晶光阀，需要加外加驱动电路，在供电电源采用开关电路的情况下，这样就会带来较大的纹波和噪声，不但会缩短液晶光阀的寿命，还会增加液晶光阀的不稳定性，甚至损坏液晶光阀。
因此，现有液晶光阀驱动电路存在调节精度低和稳定性不高的问题，需要解决。
发明内容
本发明提供一种液晶光阀的驱动电路、液晶光阀以及LED灯，以改进现有液晶光阀驱动电路存在调节精度低和稳定性不高的问题。
为解决以上问题，本发明提供的技术方案如下：
本发明提供一种液晶光阀的驱动电路，其包括LDO(Low Drop Output，低压差线性稳压器)降压电路(110)和全桥驱动电路(120)，所述LDO降压电路(110)的输入端与电源(130)连接，所述LDO降压电路(110)的输出端与所述全桥驱动电路(120)的输入端连接，所述全桥驱动电路(120)与液晶光阀(140)连接；所述LDO降压电路(110)包括：
线性降压电路(111)，包括线性降压芯片(U1)，所述线性降压芯片(U1)的输入端连接所述电源(130)，所述线性降压芯片(U1)用于对电源电压进行线性降压处理；
降压调节电路(112)，包括至少一个数字电位器，所述数字电位器的划臂引 脚(W)与所述线性降压芯片(U1)的电压调节引脚(ADJ)连接，所述数字电位器用于对所述线性降压芯片(U1)电压输出引脚(Vout)输出的电压进行调节；
降压处理电路(113)，所述降压处理电路(113)的输入端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述降压处理电路(113)的输出端与所述全桥驱动电路(120)的输入端连接，所述降压处理电路(113)用于对所述线性降压电路(111)输出的电压进行滤波、降压处理；
输出反馈电路(114)，与所述降压处理电路(113)的输出端连接，用于对所述LDO降压电路(110)输出的电压进行反馈，从而调整所述降压调节电路，进而对所述线性降压电路(111)的输出电压进行调节。
在本发明提供的驱动电路中，所述降压调节电路(112)包括电阻(R1)、二极管(D2)、电容(C3)、以及数字电位器(U2)；所述电阻(R1)与所述数字电位器(U2)串联，所述电阻(R1)的一端、所述二极管(D2)的阴极与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述电阻(R1)的另一端、所述二极管(D2)的阳极、所述电容(C3)的第一电极、所述数字电位器(U2)的划臂引脚(W)与所述线性降压芯片(U1)的电压调节引脚(ADJ)连接，所述电容(C3)的第二电极、所述数字电位器(U2)的引脚(L)接地。
在本发明提供的驱动电路中，所述降压调节电路(112)包括电阻(R1)、二极管(D2)、电容(C3)、以及数字电位器(U2)、数字电位器(U3)；所述电阻(R1)、所述数字电位器(U2)、所述数字电位器(U3)串联，所述电阻(R1)的一端、所述二极管(D2)的阴极与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述电阻(R1)的另一端、所述二极管(D2)的阳极、所述电容(C3)的第一电极、所述数字电位器(U2)的划臂引脚(W)与所述线性降压芯片(U1)的电压调节引脚(ADJ)连接，所述数字电位器(U2)的引脚(L)和所述数字电位器(U3)的划臂引脚(W)连接，所述电容(C3)的第二电极、、所述数字电位器(U3)的引脚(L)接地。
在本发明提供的驱动电路中，所述降压调节电路(112)包括至少三个数字电位器，所述数字电位器串联。
在本发明提供的驱动电路中，所述降压处理电路包括滤波单元和降压处理单 元，所述滤波单元包括电容(EC1)、电容(C6)、以及电阻(R2)，所述降压处理单元包括二极管(D3)、二极管(D4)、二极管(D5)、二极管(D6)、以及电阻(R3)、电阻(R4)；所述电容(EC1)、所述电容(C6)、以及所述电阻(R2)并联，所述电容(EC1)的第一电极、所述电容(C6)的第一电极、所述电阻(R2)的一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述电容(EC1)的第二电极、所述电容(C6)的第二电极、所述电阻(R2)的另一端接地；所述二极管(D3)和所述二极管(D4)串联，所述二极管(D5)和所述二极管(D6)串联，所述电阻(R3)和所述电阻(R4)串联，所述二极管(D3)的阳极、所述二极管(D5)的阳极、所述电阻(R3)的一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述二极管(D4)的阴极、所述二极管(D6)的阴极、所述电阻(R4)的另一端与所述LDO降压电路的输出端连接。
在本发明提供的驱动电路中，所述输出反馈电路(114)包括反馈电阻(R5)和反馈电阻(R6)；所述反馈电阻(R5)和所述反馈电阻(R6)串联，所述反馈电阻(R5)的一端与所述LDO降压电路的输出端连接，所述反馈电阻(R5)的另一端、所述反馈电阻(R6)的一端与反馈信号端(ADC)连接，所述反馈电阻(R6)的另一端接地。
在本发明提供的驱动电路中，所述线性降压电路还包括放大电路单元，所述放大电路单元包括采样电阻(R13)、三极管(Q5)、三极管(Q6)、以及偏置电阻(R14)、偏置电阻(R15)，所述采样电阻(R13)的一端与所述三极管(Q5)的发射极、所述三极管(Q6)的发射极连接，所述采样电阻(R13)的另一端与所述偏置电阻(R14)的一端、所述线性降压芯片(U1)的电压输入引脚(Vin)连接，所述偏置电阻(R14)的另一端与所述三极管(Q5)的基极连接，所述三极管(Q5)的集电极与所述三极管(Q6)的基极、所述偏置电阻(R15)的一端连接，所述三极管(Q6)的集电极、所述偏置电阻(R15)的另一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接。
在本发明提供的驱动电路中，所述全桥驱动电路(120)包括驱动控制电路、开关控制电路、以及驱动调节电路；所述驱动控制电路包括第一驱动控制电路和第二驱动控制电路，所述第一驱动控制电路包括驱动芯片(U4)、电容(C7)、电容(C8)、电阻(R7)、二极管(D7)，所述第二驱动控制电路包括驱动芯片 (U5)、电容(C9)、电容(C10)、电阻(R10)、二极管(D10)，所述驱动芯片(U4)的电源引脚(VDD)、所述电阻(R7)的另一端、所述电容(C8)的第一电极板与电压信号连接，所述驱动芯片(U4)的公共引脚(VSS)、所述电容(C8)的第二电极板接地，所述驱动芯片(U4)的引脚(HB)与所述电容(C7)的第一电极板、所述二极管(D7)的阴极连接，所述驱动芯片(U4)的输出引脚(LO)与所述电阻(R9)的一端、所述二极管(D9)的阴极连接，所述驱动芯片(U5)的电源引脚(VDD)、所述电阻(R10)的另一端、所述电容(C10)的第一电极板与电压信号连接，所述驱动芯片(U5)的公共引脚(VSS)、所述电容(C10)的第二电极板接地，所述驱动芯片(U5)的引脚(HB)与所述电容(C10)的第一电极板、所述二极管(D10)的阴极连接，所述驱动芯片(U5)的输出引脚(LO)与所述电阻(R10)的一端、所述二极管(D10)的阴极连接；所述开关控制电路包括四个开关控制器件，第一开关控制器件的输入端、第二开关控制器件的输入端与所述LDO降压电路的输出端连接，所述第一开关控制器件的输出端、第三开关控制器件的输入端、所述驱动芯片(U4)的引脚(HS)、所述电容(C7)的第二电极板与所述液晶光阀(140)的第一连接端连接，所述第二开关控制器件的输出端、第四开关控制器件的输入端、所述驱动芯片(U5)的引脚(HS)、所述电容(C9)的第二电极板与所述液晶光阀(140)的第二连接端连接，所述第三开关控制器件的输出端、所述第四开关控制器件的输出端接地；所述驱动调节电路包括第一驱动调节电路、第二驱动调节电路、第三驱动调节电路、以及第四驱动调节电路，所述第一驱动调节电路包括二极管(D8)和电阻(R8)，所述二极管(D8)的阴极、所述电阻(R8)的一端与所述驱动芯片(U4)的引脚(HO)连接，所述二极管(D8)的阳极、所述电阻(R8)的另一端与所述第一开关控制器件的控制端连接，所述第二驱动调节电路包括二极管(D9)和电阻(R9)，所述二极管(D9)的阴极、所述电阻(R9)的一端与所述驱动芯片(U4)的引脚(LO)连接，所述二极管(D9)的阳极、所述电阻(R9)的另一端与所述第三开关控制器件的控制端连接，所述第三驱动调节电路包括二极管(D11)和电阻(R11)，所述二极管(D11)的阴极、所述电阻(R11)的一端与所述驱动芯片(U5)的引脚(HO)连接，所述二极管(D11)的阳极、所述电阻(R11)的另一端与所述第二开关控制器件的控制端连接；所述第四驱 动调节电路包括二极管(D12)和电阻(R12)，所述二极管(D12)的阴极、所述电阻(R12)的一端与所述驱动芯片(U5)的引脚(LO)连接，所述二极管(D12)的阳极、所述电阻(R12)的另一端与所述第四开关控制器件的控制端连接。
本发明还提供一种液晶光阀，其包括本发明提供的任意一种液晶光阀的驱动电路。
本发明还提供一种LED灯，其包括本发明提供的液晶光阀。
本发明提供了一种液晶光阀的驱动电路、液晶光阀以及LED灯，该驱动电路包括LDO降压电路和全桥驱动电路，所述LDO降压电路与所述全桥驱动电路连接，所述LDO降压电路与电源连接，所述全桥驱动电路与液晶光阀连接；所述LDO降压电路包括：线性降压电路，包括线性降压芯片，线性降压芯片的输入端连接电源，线性降压芯片用于对电源电压进行线性降压处理；降压调节电路，包括至少一个数字电位器，数字电位器的划臂引脚与线性降压芯片的电压调节引脚连接，数字电位器用于对线性降压芯片电压输出引脚输出的电压进行调节；降压处理电路，降压处理电路的输入端与线性降压芯片的电压输出引脚连接，降压处理电路的输出端与全桥驱动电路的输入端连接，降压处理电路用于对线性降压电路输出的电压进行滤波、降压处理；输出反馈电路，与降压处理电路的输出端连接，用于对LDO降压电路输出的电压进行反馈，从而调整降压调节电路，进而对线性降压电路的输出电压进行调节。通过LDO降压电路对电源电压进行线性降压处理，提高了驱动电路的调节精度，降低了噪声和波纹比，提高了液晶光阀的稳定性；通过全桥驱动电路实现对液晶光阀的驱动，实现了交流PWM电压、单向PWM电压驱动液晶光阀，提升了整个驱动电路的驱动能力。
附图说明
下面结合附图，通过对本申请的具体实施方式详细描述，将使本申请的技术方案及其它有益效果显而易见。
图1为本发明实施例提供的液晶光阀的驱动电路的结构框图。
图2为本发明实施例提供的液晶光阀的驱动电路的第一种电路示意图。
图3为本发明实施例提供的液晶光阀的驱动电路的第二种电路示意图。
具体实施方式
下面将结合本发明的具体实施方案，对本发明实施方案和/或实施例中的技术方案进行清楚、完整的描述，显而易见的，下面所描述的实施方案和/或实施例仅仅是本发明一部分实施方案和/或实施例，而不是全部的实施方案和/或实施例。基于本发明中的实施方案和/或实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施方案和/或实施例，都属于本发明保护范围。
针对现有液晶光阀驱动电路存在调节精度低和稳定性不高的问题，本发明提供一种液晶光阀的驱动电路，解决了调节精度和稳定性问题，同时具有输入电压范围宽、外围器件少、结构简洁以及成本低的特点。
在一种实施例中，如图1所示，本发明提供的液晶光阀的驱动电路包括LDO降压电路110和全桥驱动电路120，LDO降压电路110的输入端与电源130连接，LDO降压电路110的输出端与全桥驱动电路120的输入端连接，全桥驱动电路120与液晶光阀140连接；LDO降压电路110包括：
线性降压电路111，，包括线性降压芯片U1，线性降压芯片U1的输入端连接所述电源130，线性降压芯片U1用于对电源电压进行线性降压处理；
降压调节电路112，包括至少一个数字电位器，数字电位器的划臂引脚W与线性降压芯片U1的电压调节引脚ADJ连接，数字电位器用于对线性降压芯片U1电压输出引脚Vout输出的电压进行调节；
降压处理电路113，降压处理电路113的输入端与线性降压芯片U1的电压输出引脚Vout连接，降压处理电路113的输出端与全桥驱动电路120的输入端连接，降压处理电路113用于对线性降压电路111输出的电压进行滤波、降压处理；
输出反馈电路114，与降压处理电路113的输出端连接，用于对LDO降压电路110输出的电压进行反馈，从而调整降压调节电路，进而对线性降压电路的输出电压进行调节。
本发明实施例提供一种液晶光阀的驱动电路，该驱动电路的线性降压电路采用线性降压芯片对电源电压进行线性降压处理，由于线性降压芯片具有很低的噪 声和波纹比，因此能够起到降低噪声和波纹，提高液晶光阀的稳定性的作用；采用由数字电位器构成的降压调节电路对线性降压电路的输出电压进行调节，数字电位器可精准的调控线性降压电路的输出电压，提高了驱动电路的调节精度。
如图2和图3所示，开关K1导通时，电源130输出电源电压信号至线性降压电路111，电容C1和电容C2并联，电容C1的第一电极板、电容C2的第一电极板与电源输出端连接，电容C1的第二电极板、电容C2的第二电极板接地。电容C1和电容C2用于过滤电源130输出的直流电压中的杂波。
可选地，如图2所示，线性降压电路111包括线性降压芯片U1和二极管D1；线性降压芯片U1的电压输入引脚Vin、二极管D1的阴极与电源输出端连接，线性降压芯片U1的电压输出引脚Vout与二极管D1的阳极连接。在一种实施例中，线性降压芯片U1可为LM317HV芯片，LM317HV芯片的最高输入电压为60V，输出电压为1.25-57V。
由于线性降压芯片U1的降压作用，正常情况下电压输出引脚Vout输出的电压小于电压输入引脚Vin的输入电压；但当二极管D1的阳极电压大于阴极电压时，二极管D1导通，线性降压芯片U1的电压输出引脚Vout和电压输入引脚Vin被二极管D1短路，从而避免了线性降压芯片U1烧毁的风险。
在一些实施例中，如图3所示，线性降压电路111包括线性降压芯片U1和放大电路单元，放大电路单元包括采样电阻R13、三极管Q5、三极管Q6、以及偏置电阻R14、偏置电阻R15，采样电阻R13的一端与三极管Q5的发射极、三极管Q6的发射极连接，采样电阻R13的另一端与偏置电阻R14的一端、线性降压芯片U1的电压输入引脚Vin连接，偏置电阻R14的另一端与三极管Q5的基极连接，三极管Q5的集电极与三极管Q6的基极、偏置电阻R15的一端连接，三极管Q6的集电极、偏置电阻R15的另一端与线性降压芯片U1的电压输出引脚Vout连接。在一种实施例中，线性降压芯片U1可为LM317HV芯片，LM317HV芯片的最高输入电压为60V，输出电压为1.25-57V。
当液晶光阀所需的电流较小时，电源提供的电流较小，流经采样电阻R13的电流较小，采样电阻R13两端的电压差比较小，不满足三极管Q5的导通条件，三极管Q5关断，三极管Q6关断；电源提供的电流只通过线性降压芯片U1输出电压给液晶光阀，满足液晶光阀的用电需求。
当液晶光阀所需的电流较大时，电源提供的电流较大，流经采样电阻R13的电流较大，采样电阻R13两端的电压差满足三极管Q5的导通条件时，三极管Q5导通，三极管Q5将采样电阻R13两端的电压差进行放大，放大后的三极管Q5的发射极和集电极之间的电压差满足三极管Q6的导通条件时，三极管Q6导通，三极管Q6将三极管Q5发射极和集电极之间的电压差再次放大；电源提供的电流一路通过线性降压芯片U1输出电压给液晶光阀140，另一路通过放大电路单元放大后输出电流给液晶光阀140，线性降压芯片U1和放大电路单元共同为液晶光阀140提供所需的电流。
在本发明实施例提供的驱动电路中，线性降压电路采用线性降压芯片U1对电源电压进行线性降压处理，由于线性降压芯片U1具有很低的噪声和波纹比，因此能够起到降低噪声和波纹，提高液晶光阀140的稳定性的作用。线性降压芯片U1可为LM317HV芯片，LM317HV芯片的最高输入电压为60V，输出电压为1.25-57V，具有输出电压范围宽、外围器件少、结构简洁以及成本低的优点。当然该线性降压芯片U1也可以使用其它具有相同功能种类或者型号的芯片，在此不作具体限定。
在一种实施例中，如图2所示，降压调节电路112包括电阻R1、二极管D2、数字电位器U2、以及电容C3；电阻R1与数字电位器U2串联，电阻R1的一端、二极管D2的阴极与线性降压芯片U1的电压输出引脚Vout连接于第一节点，电阻R1的另一端、二极管D2的阳极、电容C3的第一电极、数字电位器U2的划臂引脚W与线性降压芯片U1的电压调节引脚ADJ连接于第二节点，电容C3的第二电极、数字电位器U2的引脚L接地。
第一节点的电压为线性降压芯片U1的电压输出引脚Vout输出的电压，电压输出引脚Vout输出的电压经过电阻R1和数字电位器U2分压后，数字电位器U2两端的电压差值通过电压调节引脚ADJ反馈回线性降压芯片U1，反馈回线性降压芯片U1的电压与线性降压芯片U1内部的基准电压进行比较，通过比较结果调整电压输出引脚Vout输出的电压。
线性降压芯片U1的电压调节引脚ADJ的电压V (ADJ)＝V (Vout)×R (U2)÷(R (U2)+R (R1))，因此数字电位器U2的电阻值决定了线性降压芯片U1的电压调节引脚ADJ的电压。
数字电位器也称为数控电位器，是一种用数字信号控制其阻值改变的器件，具有可程控改变阻值，使用灵活且调节精度高的特点。通过调节数字电位器U2的划臂引脚W，调节数字电位器U2的电阻值，从而调节线性降压芯片U1的电压调节引脚ADJ的电压，进而精准的调控线性降压电路的输出电压，提高了驱动电路的调节精度。在一种实施例中，数字电位器U2可为MAX5483或MAX5432或X9315等数字电位器。
在本发明实施例提供的驱动电路中，采用由数字电位器构成的降压调节电路对线性降压电路的输出电压进行调节，可精准的调控线性降压电路的输出电压，极大地提高了驱动电路的调节精度。
正常情况下，第一节点的电压高于第二节点的电压，第二节点的电压高于接地电压。当第二节点的电压高于第一节点的电压时，二极管D2导通，线性降压芯片U1的电压输出引脚Vout和电压调节引脚ADJ被二极管D2短路，避免了线性降压芯片U1烧毁的风险。
在另一种实施例中，如图3所示，降压调节电路112包括电阻R1、二极管D2、数字电位器U2、数字电位器U3、以及电容C3；电阻R1、数字电位器U2、数字电位器U3串联，电阻R1的一端、二极管D2的阴极与线性降压芯片U1的电压输出引脚Vout连接，电阻R1的另一端、二极管D2的阳极、电容C3的第一电极、数字电位器U2的划臂引脚W与线性降压芯片U1的电压调节引脚ADJ连接，数字电位器U2的引脚L和数字电位器U3的划臂引脚W连接，电容C3的第二电极、数字电位器U3的引脚L接地。
在又一种实施例中，降压调节电路112包括至少三个数字电位器，数字电位器之间串联。
数字电位器串联的个数越多，数字电位器的电阻值范围越大，由上述实施例中线性降压芯片U1的电压调节引脚ADJ的电压公式V (ADJ)＝V (Vout)×R (U2)÷(R (U2)+R (R1))可知，在R1电阻值、Vout电压值一定的条件下，数字电位器的电阻值范围越大，数字电位器对驱动电路的调节精度越高。可以通过选择合适的数字电位器，选择数字电位器串联的个数，从而调整整个驱动电路的调节精度。
如图2和图3所示，降压处理电路113包括滤波单元和降压处理单元。
滤波单元包括电容EC1、电容C6、以及电阻R2；电容EC1、电容C6、以及电阻R2并联，电容EC1的第一电极、电容C6的第一电极、电阻R2的一端与线性降压芯片U1的电压输出引脚Vout连接，电容EC1的第二电极、电容C6的第二电极、电阻R2的另一端接地。
在本发明实施例提供的驱动电路中，滤波单元采用电容EC1、电容C6，过滤线性降压芯片U1的电压输出引脚Vout输出电压中的杂波，保证了LDO降压电路输出电压的稳定性。电阻R2用于在滤波单元停止工作时，对电容EC1、电容C6进行放电。
降压处理单元包括二极管D3、二极管D4、二极管D5、二极管D6、以及电阻R3、电阻R4；二极管D3和二极管D4串联，二极管D5和二极管D6串联，电阻R3和电阻R4串联，二极管D3的阳极、二极管D5的阳极、电阻R3的一端与线性降压芯片U1的电压输出引脚Vout连接，二极管D4的阴极、二极管D6的阴极、电阻R4的另一端与LDO降压电路的输出端连接。
在本发明实施例提供的驱动电路中，降压处理单元用于降低线性降压芯片U1的电压输出引脚Vout输出的电压。当线性降压芯片U1的电压输出引脚Vout输出的电流较小时，不满足二极管D3、二极管D4、二极管D5、二极管D6的导通条件，二极管D3、二极管D4、二极管D5、二极管D6关闭，电阻R3和电阻R4导通，电阻R3和电阻R4用于降低线性降压芯片U1的电压输出引脚Vout输出的电压；当线性降压芯片U1的电压输出引脚Vout输出的电流较大时，满足二极管D3、二极管D4、二极管D5、二极管D6的导通条件，二极管D3、二极管D4、二极管D5、二极管D6导通，线性降压芯片U1的电压输出引脚Vout输出的电压由二极管D3、二极管D4、二极管D5、二极管D6分压；经过降压处理单元的降压处理，LDO降压电路可以满足0-55V液晶光阀140的电压输出。
如图2和图3所示，输出反馈电路114包括反馈电阻R5和反馈电阻R6；反馈电阻R5和反馈电阻R6串联，反馈电阻R5的一端与LDO降压电路的输出端连接，反馈电阻R5的另一端、反馈电阻R6的一端与反馈信号端ADC连接，反馈电阻R6的另一端接地。
LDO降压电路110输出的电压经过反馈电阻R5和反馈电阻R6分压后，反馈电阻R6两端的电压差值通过反馈信号端ADC反馈给单片机，单片机通过反 馈的电压信号，调节降压调节电路112中数字电位器的阻值升/降控制引脚DIN的输入信号，从而调节数字电位器的划臂引脚W的输出信号，调整数字电位器的电阻值，进而调整线性降压芯片U1的电压调节引脚ADJ的电压，调整线性降压芯片U1的电压输出引脚Vout输出的电压。
在本发明实施例提供的驱动电路中，LDO降压电路通过线性降压电路，对电源电压进行线性降压处理，利用线性降压芯片具有很低的噪声和波纹比的特性，提高了液晶光阀的稳定性；通过降压调节电路对线性降压电路的输出电压进行调节，利用数字电位器可程控改变阻值、使用灵活、调节精度高的特性，精准的调控线性降压电路的输出电压，提高了驱动电路的调节精度；通过降压处理电路对线性降压电路输出的电压进行滤波、降压处理，保证了LDO降压电路输出电压的稳定性，满足了液晶光阀的电压输出；通过输出反馈电路对LDO降压电路输出的电压进行反馈，从而调整降压调节电路对线性降压电路的输出电压进行调节，进一步保证了LDO降压电路输出电压的准确性。
如图2和图3所示，全桥驱动电路120包括驱动控制电路、开关控制电路、以及驱动调节电路。
驱动控制电路包括第一驱动控制电路和第二驱动控制电路，第一驱动控制电路包括驱动芯片U4、电容C7、电容C8、电阻R7、二极管D7，第二驱动控制电路包括驱动芯片U5、电容C9、电容C10、电阻R10、二极管D10；驱动芯片U4的电源引脚VDD、电阻R7的另一端、电容C8的第一电极板与电压信号连接，驱动芯片U4的公共引脚VSS、电容C8的第二电极板接地，驱动芯片U4的引脚HB与电容C7的第一电极板、二极管D7的阴极连接，驱动芯片U4的输出引脚LO与电阻R9的一端、二极管D9的阴极连接；驱动芯片U5的电源引脚VDD、电阻R10的另一端、电容C10的第一电极板与电压信号连接，驱动芯片U5的公共引脚VSS、电容C10的第二电极板接地，驱动芯片U5的引脚HB与电容C10的第一电极板、二极管D10的阴极连接，驱动芯片U5的输出引脚LO与电阻R10的一端、二极管D10的阴极连接。
开关控制电路包括四个开关控制器件，第一开关控制器件的输入端、第二开关控制器件的输入端与LDO降压电路的输出端连接，第一开关控制器件的输出端、第三开关控制器件的输入端、驱动芯片U4的引脚HS、电容C7的第二电极 板与液晶光阀140的第一连接端连接，第二开关控制器件的输出端、第四开关控制器件的输入端、驱动芯片U5的引脚HS、电容C9的第二电极板与液晶光阀140的第二连接端连接，第三开关控制器件的输出端、第四开关控制器件的输出端接地。
驱动调节电路包括第一驱动调节电路、第二驱动调节电路、第三驱动调节电路、以及第四驱动调节电路；第一驱动调节电路包括二极管D8和电阻R8，二极管D8的阴极、电阻R8的一端与驱动芯片U4的引脚HO连接，二极管D8的阳极、电阻R8的另一端与第一开关控制器件的控制端连接；第二驱动调节电路包括二极管D9和电阻R9，二极管D9的阴极、电阻R9的一端与驱动芯片U4的引脚LO连接，二极管D9的阳极、电阻R9的另一端与第三开关控制器件的控制端连接；第三驱动调节电路包括二极管D11和电阻R11，二极管D11的阴极、电阻R11的一端与驱动芯片U5的引脚HO连接，二极管D11的阳极、电阻R11的另一端与第二开关控制器件的控制端连接；第四驱动调节电路包括二极管D12和电阻R12，二极管D12的阴极、电阻R12的一端与驱动芯片U5的引脚LO连接，二极管D12的阳极、电阻R12的另一端与第四开关控制器件的控制端连接。
在一种实施例中，如图2和图3所示，开关控制器件为MOSFET(Metal-Oxide-Semiconductor Field-Effect Transistor，金属-氧化物半导体场效应晶体管)管，例如可以为N沟道型MOS管或者P沟道型MOS管等，在本实施例中第一开关控制器件为P沟道型的MOSFET管Q1，第二开关控制器件为P沟道型的MOSFET管Q2，第三开关控制器件为P沟道型的MOSFET管Q3，第四开关控制器件为P沟道型的MOSFET管Q4。开关控制器件的控制端为MOSFET管的栅极。
在其他实施例中，开关控制器件可为三极管(例如NPN型或PNP型的三极管)或其他可以起到控制全桥驱动电路线路导通作用的电子器件及其组合等等，当然，也可以是三极管和MOS管的组合等等，具体再此不做限定。
驱动芯片U4通过输出引脚HO输出信号至MOSFET管Q1的栅极，控制MOSFET管Q1的导通与关断；驱动芯片U4通过输出引脚LO输出信号至MOSFET管Q3的栅极，控制MOSFET管Q3的导通与关断。当MOSFET管 Q1导通时，MOSFET管Q3关断；当MOSFET管Q3导通时，MOSFET管Q1关断；即MOSFET管Q1和MOSFET管Q3逻辑互锁，避免了驱动芯片U4驱动信号输出错误，导致MOSFET管Q1和MOSFET管Q3同时导通，从而造成全桥驱动电路短路的风险，保证了全桥驱动电路工作的安全性。
驱动芯片U5通过输出引脚HO输出信号至MOSFET管Q2的栅极，控制MOSFET管Q2的导通与关断；驱动芯片U5通过输出引脚LO输出信号至MOSFET管Q4的栅极，控制MOSFET管Q4的导通与关断。当MOSFET管Q2导通时，MOSFET管Q4关断；当MOSFET管Q4导通时，MOSFET管Q2关断；即MOSFET管Q2和MOSFET管Q4逻辑互锁，避免了驱动芯片U5驱动信号输出错误，导致MOSFET管Q2和MOSFET管Q4同时导通，从而造成全桥驱动电路短路的风险，保证了全桥驱动电路工作的安全性。
当MOSFET管Q1、MOSFET管Q4导通，MOSFET管Q2、MOSFET管Q3关断时，电流由MOSFET管Q1从液晶光阀的第一连接端流入液晶光阀140，从液晶光阀140的第二连接端流出液晶光阀140，并由MOSFET管Q4接地，形成完整的通路；当MOSFET管Q1、MOSFET管Q4关断，MOSFET管Q2、MOSFET管Q3导通时，电流由MOSFET管Q2从液晶光阀140的第二连接端流入液晶光阀140，从液晶光阀140的第一连接端流出液晶光阀140，并由MOSFET管Q3接地，形成完整的通路。
通过MOSFET管Q1和MOSFET管Q4、MOSFET管Q2和MOSFET管Q3交替导通，全桥驱动电路向液晶光阀140输出交流PWM的驱动电压，实现液晶光阀140全透光或全遮光。
通过MOSFET管Q1和MOSFET管Q4导通，MOSFET管Q2和MOSFET管Q3关断，或是MOSFET管Q1和MOSFET管Q4关断，MOSFET管Q2和MOSFET管Q3导通，全桥驱动电路向液晶光阀输出单向PWM的驱动电压，实现液晶光阀140半透光，通过调节LDO驱动电路的输出电压实现液晶光阀140的透光度。
通过驱动芯片U4和驱动芯片U5输出特定的驱动信号，驱动MOSFET管Q1、MOSFET管Q2、MOSFET管Q3和MOSFET管Q4，不但可以实现交流PWM电压驱动液晶光阀140，也能实现单向PWM电压驱动液晶光阀140。
在一种实施例中，驱动芯片U4、驱动芯片U5可均为LM5109B芯片，LM5109B芯片具有较高的MOSFET管驱动能力，不但能使全桥驱动电路的驱动功率达到几十甚至上百瓦，不但能够提升整个电路的驱动能力，同时能使PWM驱动电压的波形更加规整。
当MOSFET管Q1由关断状态到导通状态，或一直处于导通状态时，二极管D8关断，驱动芯片U4的输出引脚LO输出的电压，经由电阻R8给MOSFET管Q1的栅极充电；当MOSFET管Q1由导通状态到关断状态时，二极管D8导通，MOSFET管Q1的栅极经由二极管D8快速放电，能够加快MOSFET管Q1的关断速度。同样的，二极管D9、二极管D11、二极管D12分别起到加快MOSFET管Q2、MOSFET管Q3、MOSFET管Q4的作用，使全桥驱动电路向液晶光阀输出的PWM驱动电压的波形更加规整。
驱动芯片U4向MOSFET管Q1的栅极输出驱动电压，输出的驱动电压会存在出现尖峰信号的风险。电阻R8的一端连接驱动芯片U4的输出引脚HO，电阻R8的另一端连接MOSFET管Q1的栅极；驱动芯片U4的输出引脚HO输出的驱动电压，经过电阻R8后输入到MOSFET管Q1的栅极，电阻R8能够消除流经的驱动电压中的尖峰信号，使得输入到MOSFET管Q1栅极的驱动电压的波形更加规整，从而更加有效的控制MOSFET管Q1地关闭和导通，进而使得全桥驱动电路向液晶光阀输出的PWM驱动电压更加稳定。
同样的，电阻R9使得输入到MOSFET管Q3栅极的驱动电压的波形更加规整，从而能够更加有效的控制MOSFET管Q3地关闭和导通；电阻R11使得输入到MOSFET管Q2栅极的驱动电压的波形更加规整，从而能够更加有效的控制MOSFET管Q2地关闭和导通；电阻R12使得输入到MOSFET管Q4栅极的驱动电压的波形更加规整，从而能够更加有效的控制MOSFET管Q4地关闭和导通；使得整个全桥驱动电路向液晶光阀输出的PWM驱动电压更加稳定。
在本发明实施例提供的全桥驱动电路中，通过驱动芯片U4和驱动芯片U5输出特定的驱动信号，对四个MOSFET管进行驱动，不但可以实现交流PWM电压驱动液晶光阀140，也能实现单向PWM电压驱动液晶光阀140；驱动芯片U4和驱动芯片U5具有较高的MOSFET管驱动能力，不但能够提升整个驱动电路的驱动能力，同时能使PWM的驱动波形更加规整；驱动芯片U4和驱动芯片 U5的逻辑互锁特性，避免了驱动芯片U4和驱动芯片U5驱动信号输出错误，而造成全桥驱动电路短路的风险，保证了全桥驱动电路工作的安全性。
本发明实施例还提供一种液晶光阀，其包括本发明实施例提供的任意一种液晶光阀的驱动电路。该驱动电路包括LDO降压电路110和全桥驱动电路120，所述LDO降压电路110的输入端与电源130连接，所述LDO降压电路110的输出端与所述全桥驱动电路120的输入端连接，所述全桥驱动电路120与液晶光阀140连接；所述LDO降压电路110包括：
线性降压电路111，连接所述电源130，用于对电源电压进行线性降压处理，所述线性降压电路111包括线性降压芯片U1；
降压调节电路112，与所述线性降压电路111连接，用于对所述线性降压电路111的输出电压进行调节，所述降压调节电路112包括至少一个数字电位器；
降压处理电路113，与所述线性降压电路111连接，用于对所述线性降压电路111输出的电压进行滤波、降压处理；
输出反馈电路114，与所述降压处理电路113连接，用于对所述LDO降压电路110输出的电压进行反馈，从而调整所述降压调节电路，进而对所述线性降压电路111的输出电压进行调节。
液晶光阀的驱动电路的具体电路结构请参照上述实施例。
本发明实施例提供的液晶光阀，包括本发明实施例提供的任意一种液晶光阀的驱动电路，具备了本发明实施例提供的任意一种液晶光阀的驱动电路所能实现的有益效果，具体实现方式请参照前面的实施例，在此不再赘述。
本发明实施例进一步提供一种LED(Light Emitting Diode，发光二极管)灯，该LED灯包括LED和本发明实施例提供的任意一种液晶光阀，液晶光阀位于LED的出光面用于调节LED灯发出的光。该液晶光阀包括本发明实施例提供的任意一种液晶光阀的驱动电路，该驱动电路包括LDO降压电路110和全桥驱动电路120，所述LDO降压电路110的输入端与电源130连接，所述LDO降压电路110的输出端与所述全桥驱动电路120的输入端连接，所述全桥驱动电路120与液晶光阀140连接；所述LDO降压电路110包括：
线性降压电路111，连接所述电源130，用于对电源电压进行线性降压处理，所述线性降压电路111包括线性降压芯片U1；
降压调节电路112，与所述线性降压电路111连接，用于对所述线性降压电路111的输出电压进行调节，所述降压调节电路112包括至少一个数字电位器；
降压处理电路113，与所述线性降压电路111连接，用于对所述线性降压电路111输出的电压进行滤波、降压处理；
输出反馈电路114，与所述降压处理电路113连接，用于对所述LDO降压电路110输出的电压进行反馈，从而调整所述降压调节电路，进而对所述线性降压电路111的输出电压进行调节。
液晶光阀的驱动电路的具体电路结构请参照上述实施例。
本发明实施例提供的LED灯包括本发明实施例提供的任意一种液晶光阀，该液晶光阀包括本发明实施例提供的任意一种液晶光阀的驱动电路，具备了本发明实施例提供的任意一种液晶光阀的驱动电路所能实现的有益效果，通过该驱动电路对液晶光阀精确、稳定的调节，实现了LED灯的柔光效果，具体实现方式请参照前面的实施例。
根据上述实施例可知：
本发明实施例提供了一种液晶光阀的驱动电路、液晶光阀以及LED灯，该驱动电路包括LDO降压电路和全桥驱动电路，LDO降压电路与全桥驱动电路连接，LDO降压电路与电源连接，全桥驱动电路与液晶光阀连接；LDO降压电路包括：线性降压电路，包括线性降压芯片，线性降压芯片的输入端连接电源，线性降压芯片用于对电源电压进行线性降压处理；降压调节电路，包括至少一个数字电位器，数字电位器的划臂引脚与线性降压芯片的电压调节引脚连接，数字电位器用于对线性降压芯片电压输出引脚输出的电压进行调节；降压处理电路，降压处理电路的输入端与线性降压芯片的电压输出引脚连接，降压处理电路的输出端与全桥驱动电路的输入端连接，降压处理电路用于对线性降压电路输出的电压进行滤波、降压处理；输出反馈电路，与降压处理电路的输出端连接，用于对LDO降压电路输出的电压进行反馈，从而调整降压调节电路，进而对线性降压电路的输出电压进行调节。LDO降压电路通过线性降压电路，对电源电压进行线性降 压处理，利用线性降压芯片具有很低的噪声和波纹比的特性，提高了液晶光阀的稳定性；通过降压调节电路对线性降压电路的输出电压进行调节，利用数字电位器可程控改变阻值、使用灵活、调节精度高的特性，精准的调控线性降压电路的输出电压，提高了驱动电路的调节精度；通过降压处理电路对线性降压电路输出的电压进行滤波、降压处理，保证了LDO降压电路输出电压的稳定性，满足了液晶光阀的电压输出；通过输出反馈电路对LDO降压电路输出的电压进行反馈，从而调整降压调节电路对线性降压电路的输出电压进行调节，进一步保证了LDO降压电路输出电压的准确性。全桥驱动电路通过驱动芯片对四个MOSFET管进行驱动，实现了交流PWM电压、单向PWM电压驱动液晶光阀，提升了整个驱动电路的驱动能力。
综上所述，虽然本发明已以优选实施例揭露如上，但上述优选实施例并非用以限制本发明，本领域的普通技术人员，在不脱离本发明的精神和范围内，均可作各种更动与润饰，因此本发明的保护范围以权利要求界定的范围为准。

Claims (20)

  1. 一种液晶光阀的驱动电路，其中，包括LDO降压电路(110)和全桥驱动电路(120)，所述LDO降压电路(110)的输入端与电源(130)连接，所述LDO降压电路(110)的输出端与所述全桥驱动电路(120)的输入端连接，所述全桥驱动电路(120)与液晶光阀(140)连接；所述LDO降压电路(110)包括：
    线性降压电路(111)，包括线性降压芯片(U1)，所述线性降压芯片(U1)的输入端连接所述电源(130)，所述线性降压芯片(U1)用于对电源电压进行线性降压处理；
    降压调节电路(112)，包括至少一个数字电位器，所述数字电位器的划臂引脚(W)与所述线性降压芯片(U1)的电压调节引脚(ADJ)连接，所述数字电位器用于对所述线性降压芯片(U1)电压输出引脚(Vout)输出的电压进行调节；
    降压处理电路(113)，所述降压处理电路(113)的输入端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述降压处理电路(113)的输出端与所述全桥驱动电路(120)的输入端连接，所述降压处理电路(113)用于对所述线性降压电路(111)输出的电压进行滤波、降压处理；
    输出反馈电路(114)，与所述降压处理电路(113)的输出端连接，用于对所述LDO降压电路(110)输出的电压进行反馈，从而调整所述降压调节电路，进而对所述线性降压电路(111)的输出电压进行调节。
  2. 如权利要求1所述的驱动电路，其中，所述降压调节电路(112)包括电阻(R1)、二极管(D2)、电容(C3)、以及数字电位器(U2)；所述电阻(R1)与所述数字电位器(U2)串联，所述电阻(R1)的一端、所述二极管(D2)的阴极与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述电阻(R1)的另一端、所述二极管(D2)的阳极、所述电容(C3)的第一电极、所述数字电位器(U2)的划臂引脚(W)与所述线性降压芯片(U1)的电压调节引脚(ADJ)连接，所述电容(C3)的第二电极、所述数字电位器(U2)的引脚(L)接地。
  3. 如权利要求1所述的驱动电路，其中，所述降压调节电路(112)包括 电阻(R1)、二极管(D2)、电容(C3)、以及数字电位器(U2)、数字电位器(U3)；所述电阻(R1)、所述数字电位器(U2)、所述数字电位器(U3)串联，所述电阻(R1)的一端、所述二极管(D2)的阴极与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述电阻(R1)的另一端、所述二极管(D2)的阳极、所述电容(C3)的第一电极、所述数字电位器(U2)的划臂引脚(W)与所述线性降压芯片(U1)的电压调节引脚(ADJ)连接，所述数字电位器(U2)的引脚(L)和所述数字电位器(U3)的划臂引脚(W)连接，所述电容(C3)的第二电极、所述数字电位器(U3)的引脚(L)接地。
  4. 如权利要求1所述的驱动电路，其中，所述降压调节电路(112)包括至少三个数字电位器，所述数字电位器之间串联。
  5. 如权利要求1所述的驱动电路，其中，所述降压处理电路(113)包括滤波单元和降压处理单元，所述滤波单元包括电容(EC1)、电容(C6)、以及电阻(R2)，所述降压处理单元包括二极管(D3)、二极管(D4)、二极管(D5)、二极管(D6)、以及电阻(R3)、电阻(R4)；所述电容(EC1)、所述电容(C6)、以及所述电阻(R2)并联，所述电容(EC1)的第一电极、所述电容(C6)的第一电极、所述电阻(R2)的一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述电容(EC1)的第二电极、所述电容(C6)的第二电极、所述电阻(R2)的另一端接地；所述二极管(D3)和所述二极管(D4)串联，所述二极管(D5)和所述二极管(D6)串联，所述电阻(R3)和所述电阻(R4)串联，所述二极管(D3)的阳极、所述二极管(D5)的阳极、所述电阻(R3)的一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述二极管(D4)的阴极、所述二极管(D6)的阴极、所述电阻(R4)的另一端与所述LDO降压电路的输出端连接。
  6. 如权利要求1所述的驱动电路，其中，所述输出反馈电路(114)包括反馈电阻(R5)和反馈电阻(R6)；所述反馈电阻(R5)和所述反馈电阻(R6)串联，所述反馈电阻(R5)的一端与所述LDO降压电路的输出端连接，所述反馈电阻(R5)的另一端、所述反馈电阻(R6)的一端与反馈信号端(ADC)连接，所述反馈电阻(R6)的另一端接地。
  7. 如权利要求1所述的驱动电路，其中，所述线性降压电路(111)还包 括放大电路单元，所述放大电路单元包括采样电阻(R13)、三极管(Q5)、三极管(Q6)、以及偏置电阻(R14)、偏置电阻(R15)，所述采样电阻(R13)的一端与所述三极管(Q5)的发射极、所述三极管(Q6)的发射极连接，所述采样电阻(R13)的另一端与所述偏置电阻(R14)的一端、所述线性降压芯片(U1)的电压输入引脚(Vin)连接，所述偏置电阻(R14)的另一端与所述三极管(Q5)的基极连接，所述三极管(Q5)的集电极与所述三极管(Q6)的基极、所述偏置电阻(R15)的一端连接，所述三极管(Q6)的集电极、所述偏置电阻(R15)的另一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接。
  8. 如权利要求1所述的驱动电路，其中，所述全桥驱动电路(120)包括驱动控制电路、开关控制电路、以及驱动调节电路；所述驱动控制电路包括第一驱动控制电路和第二驱动控制电路，所述第一驱动控制电路包括驱动芯片(U4)、电容(C7)、电容(C8)、电阻(R7)、二极管(D7)，所述第二驱动控制电路包括驱动芯片(U5)、电容(C9)、电容(C10)、电阻(R10)、二极管(D10)，所述驱动芯片(U4)的电源引脚(VDD)、所述电阻(R7)的另一端、所述电容(C8)的第一电极板与电压信号连接，所述驱动芯片(U4)的公共引脚(VSS)、所述电容(C8)的第二电极板接地，所述驱动芯片(U4)的引脚(HB)与所述电容(C7)的第一电极板、所述二极管(D7)的阴极连接，所述驱动芯片(U4)的输出引脚(LO)与所述电阻(R9)的一端、所述二极管(D9)的阴极连接，所述驱动芯片(U5)的电源引脚(VDD)、所述电阻(R10)的另一端、所述电容(C10)的第一电极板与电压信号连接，所述驱动芯片(U5)的公共引脚(VSS)、所述电容(C10)的第二电极板接地，所述驱动芯片(U5)的引脚(HB)与所述电容(C10)的第一电极板、所述二极管(D10)的阴极连接，所述驱动芯片(U5)的输出引脚(LO)与所述电阻(R10)的一端、所述二极管(D10)的阴极连接；所述开关控制电路包括四个开关控制器件，第一开关控制器件的输入端、第二开关控制器件的输入端与所述LDO降压电路的输出端连接，所述第一开关控制器件的输出端、第三开关控制器件的输入端、所述驱动芯片(U4)的引脚(HS)、所述电容(C7)的第二电极板与所述液晶光阀(140)的第一连接端连接，所述第二开关控制器件的输出端、第四开关控制器件的输入端、所述驱动芯片(U5)的引脚(HS)、所述电容(C9)的第二电极板与所述液晶光阀(140) 的第二连接端连接，所述第三开关控制器件的输出端、所述第四开关控制器件的输出端接地；所述驱动调节电路包括第一驱动调节电路、第二驱动调节电路、第三驱动调节电路、以及第四驱动调节电路，所述第一驱动调节电路包括二极管(D8)和电阻(R8)，所述二极管(D8)的阴极、所述电阻(R8)的一端与所述驱动芯片(U4)的引脚(HO)连接，所述二极管(D8)的阳极、所述电阻(R8)的另一端与所述第一开关控制器件的控制端连接，所述第二驱动调节电路包括二极管(D9)和电阻(R9)，所述二极管(D9)的阴极、所述电阻(R9)的一端与所述驱动芯片(U4)的引脚(LO)连接，所述二极管(D9)的阳极、所述电阻(R9)的另一端与所述第三开关控制器件的控制端连接，所述第三驱动调节电路包括二极管(D11)和电阻(R11)，所述二极管(D11)的阴极、所述电阻(R11)的一端与所述驱动芯片(U5)的引脚(HO)连接，所述二极管(D11)的阳极、所述电阻(R11)的另一端与所述第二开关控制器件的控制端连接；所述第四驱动调节电路包括二极管(D12)和电阻(R12)，所述二极管(D12)的阴极、所述电阻(R12)的一端与所述驱动芯片(U5)的引脚(LO)连接，所述二极管(D12)的阳极、所述电阻(R12)的另一端与所述第四开关控制器件的控制端连接。
  9. 一种液晶光阀，其中，包括LDO降压电路(110)和全桥驱动电路(120)，所述LDO降压电路(110)的输入端与电源(130)连接，所述LDO降压电路(110)的输出端与所述全桥驱动电路(120)的输入端连接，所述全桥驱动电路(120)与液晶光阀(140)连接；所述LDO降压电路(110)包括：
    线性降压电路(111)，包括线性降压芯片(U1)，所述线性降压芯片(U1)的输入端连接所述电源(130)，所述线性降压芯片(U1)用于对电源电压进行线性降压处理；
    降压调节电路(112)，包括至少一个数字电位器，所述数字电位器的划臂引脚(W)与所述线性降压芯片(U1)的电压调节引脚(ADJ)连接，所述数字电位器用于对所述线性降压芯片(U1)电压输出引脚(Vout)输出的电压进行调节；
    降压处理电路(113)，所述降压处理电路(113)的输入端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述降压处理电路(113)的输出 端与所述全桥驱动电路(120)的输入端连接，所述降压处理电路(113)用于对所述线性降压电路(111)输出的电压进行滤波、降压处理；
    输出反馈电路(114)，与所述降压处理电路(113)的输出端连接，用于对所述LDO降压电路(110)输出的电压进行反馈，从而调整所述降压调节电路，进而对所述线性降压电路(111)的输出电压进行调节。
  10. 如权利要求9所述的液晶光阀，其中，所述降压调节电路(112)包括电阻(R1)、二极管(D2)、电容(C3)、以及数字电位器(U2)；所述电阻(R1)与所述数字电位器(U2)串联，所述电阻(R1)的一端、所述二极管(D2)的阴极与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述电阻(R1)的另一端、所述二极管(D2)的阳极、所述电容(C3)的第一电极、所述数字电位器(U2)的划臂引脚(W)与所述线性降压芯片(U1)的电压调节引脚(ADJ)连接，所述电容(C3)的第二电极、所述数字电位器(U2)的引脚(L)接地。
  11. 如权利要求9所述的液晶光阀，其中，所述降压处理电路(113)包括滤波单元和降压处理单元，所述滤波单元包括电容(EC1)、电容(C6)、以及电阻(R2)，所述降压处理单元包括二极管(D3)、二极管(D4)、二极管(D5)、二极管(D6)、以及电阻(R3)、电阻(R4)；所述电容(EC1)、所述电容(C6)、以及所述电阻(R2)并联，所述电容(EC1)的第一电极、所述电容(C6)的第一电极、所述电阻(R2)的一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述电容(EC1)的第二电极、所述电容(C6)的第二电极、所述电阻(R2)的另一端接地；所述二极管(D3)和所述二极管(D4)串联，所述二极管(D5)和所述二极管(D6)串联，所述电阻(R3)和所述电阻(R4)串联，所述二极管(D3)的阳极、所述二极管(D5)的阳极、所述电阻(R3)的一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述二极管(D4)的阴极、所述二极管(D6)的阴极、所述电阻(R4)的另一端与所述LDO降压电路的输出端连接。
  12. 如权利要求9所述的液晶光阀，其中，所述输出反馈电路(114)包括反馈电阻(R5)和反馈电阻(R6)；所述反馈电阻(R5)和所述反馈电阻(R6)串联，所述反馈电阻(R5)的一端与所述LDO降压电路的输出端连接，所述反馈电阻(R5)的另一端、所述反馈电阻(R6)的一端与反馈信号端(ADC)连 接，所述反馈电阻(R6)的另一端接地。
  13. 如权利要求9所述的液晶光阀，其中，所述线性降压电路(111)还包括放大电路单元，所述放大电路单元包括采样电阻(R13)、三极管(Q5)、三极管(Q6)、以及偏置电阻(R14)、偏置电阻(R15)，所述采样电阻(R13)的一端与所述三极管(Q5)的发射极、所述三极管(Q6)的发射极连接，所述采样电阻(R13)的另一端与所述偏置电阻(R14)的一端、所述线性降压芯片(U1)的电压输入引脚(Vin)连接，所述偏置电阻(R14)的另一端与所述三极管(Q5)的基极连接，所述三极管(Q5)的集电极与所述三极管(Q6)的基极、所述偏置电阻(R15)的一端连接，所述三极管(Q6)的集电极、所述偏置电阻(R15)的另一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接。
  14. 如权利要求9所述的液晶光阀，其中，所述全桥驱动电路(120)包括驱动控制电路、开关控制电路、以及驱动调节电路；所述驱动控制电路包括第一驱动控制电路和第二驱动控制电路，所述第一驱动控制电路包括驱动芯片(U4)、电容(C7)、电容(C8)、电阻(R7)、二极管(D7)，所述第二驱动控制电路包括驱动芯片(U5)、电容(C9)、电容(C10)、电阻(R10)、二极管(D10)，所述驱动芯片(U4)的电源引脚(VDD)、所述电阻(R7)的另一端、所述电容(C8)的第一电极板与电压信号连接，所述驱动芯片(U4)的公共引脚(VSS)、所述电容(C8)的第二电极板接地，所述驱动芯片(U4)的引脚(HB)与所述电容(C7)的第一电极板、所述二极管(D7)的阴极连接，所述驱动芯片(U4)的输出引脚(LO)与所述电阻(R9)的一端、所述二极管(D9)的阴极连接，所述驱动芯片(U5)的电源引脚(VDD)、所述电阻(R10)的另一端、所述电容(C10)的第一电极板与电压信号连接，所述驱动芯片(U5)的公共引脚(VSS)、所述电容(C10)的第二电极板接地，所述驱动芯片(U5)的引脚(HB)与所述电容(C10)的第一电极板、所述二极管(D10)的阴极连接，所述驱动芯片(U5)的输出引脚(LO)与所述电阻(R10)的一端、所述二极管(D10)的阴极连接；所述开关控制电路包括四个开关控制器件，第一开关控制器件的输入端、第二开关控制器件的输入端与所述LDO降压电路的输出端连接，所述第一开关控制器件的输出端、第三开关控制器件的输入端、所述驱动芯片(U4)的引脚(HS)、所述电容(C7)的第二电极板与所述液晶光阀(140)的第一连接 端连接，所述第二开关控制器件的输出端、第四开关控制器件的输入端、所述驱动芯片(U5)的引脚(HS)、所述电容(C9)的第二电极板与所述液晶光阀(140)的第二连接端连接，所述第三开关控制器件的输出端、所述第四开关控制器件的输出端接地；所述驱动调节电路包括第一驱动调节电路、第二驱动调节电路、第三驱动调节电路、以及第四驱动调节电路，所述第一驱动调节电路包括二极管(D8)和电阻(R8)，所述二极管(D8)的阴极、所述电阻(R8)的一端与所述驱动芯片(U4)的引脚(HO)连接，所述二极管(D8)的阳极、所述电阻(R8)的另一端与所述第一开关控制器件的控制端连接，所述第二驱动调节电路包括二极管(D9)和电阻(R9)，所述二极管(D9)的阴极、所述电阻(R9)的一端与所述驱动芯片(U4)的引脚(LO)连接，所述二极管(D9)的阳极、所述电阻(R9)的另一端与所述第三开关控制器件的控制端连接，所述第三驱动调节电路包括二极管(D11)和电阻(R11)，所述二极管(D11)的阴极、所述电阻(R11)的一端与所述驱动芯片(U5)的引脚(HO)连接，所述二极管(D11)的阳极、所述电阻(R11)的另一端与所述第二开关控制器件的控制端连接；所述第四驱动调节电路包括二极管(D12)和电阻(R12)，所述二极管(D12)的阴极、所述电阻(R12)的一端与所述驱动芯片(U5)的引脚(LO)连接，所述二极管(D12)的阳极、所述电阻(R12)的另一端与所述第四开关控制器件的控制端连接。
  15. 一种LED灯，其中，包括LED和液晶光阀，其中所述液晶光阀包括DO降压电路(110)和全桥驱动电路(120)，所述LDO降压电路(110)的输入端与电源(130)连接，所述LDO降压电路(110)的输出端与所述全桥驱动电路(120)的输入端连接，所述全桥驱动电路(120)与液晶光阀(140)连接；所述LDO降压电路(110)包括：
    线性降压电路(111)，包括线性降压芯片(U1)，所述线性降压芯片(U1)的输入端连接所述电源(130)，所述线性降压芯片(U1)用于对电源电压进行线性降压处理；
    降压调节电路(112)，包括至少一个数字电位器，所述数字电位器的划臂引脚(W)与所述线性降压芯片(U1)的电压调节引脚(ADJ)连接，所述数字电位器用于对所述线性降压芯片(U1)电压输出引脚(Vout)输出的电压进行调 节；
    降压处理电路(113)，所述降压处理电路(113)的输入端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述降压处理电路(113)的输出端与所述全桥驱动电路(120)的输入端连接，所述降压处理电路(113)用于对所述线性降压电路(111)输出的电压进行滤波、降压处理；
    输出反馈电路(114)，与所述降压处理电路(113)的输出端连接，用于对所述LDO降压电路(110)输出的电压进行反馈，从而调整所述降压调节电路，进而对所述线性降压电路(111)的输出电压进行调节。
  16. 如权利要求15所述的LED灯，其中，所述降压调节电路(112)包括电阻(R1)、二极管(D2)、电容(C3)、以及数字电位器(U2)；所述电阻(R1)与所述数字电位器(U2)串联，所述电阻(R1)的一端、所述二极管(D2)的阴极与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述电阻(R1)的另一端、所述二极管(D2)的阳极、所述电容(C3)的第一电极、所述数字电位器(U2)的划臂引脚(W)与所述线性降压芯片(U1)的电压调节引脚(ADJ)连接，所述电容(C3)的第二电极、所述数字电位器(U2)的引脚(L)接地。
  17. 如权利要求15所述的LED灯，其中，所述降压处理电路(113)包括滤波单元和降压处理单元，所述滤波单元包括电容(EC1)、电容(C6)、以及电阻(R2)，所述降压处理单元包括二极管(D3)、二极管(D4)、二极管(D5)、二极管(D6)、以及电阻(R3)、电阻(R4)；所述电容(EC1)、所述电容(C6)、以及所述电阻(R2)并联，所述电容(EC1)的第一电极、所述电容(C6)的第一电极、所述电阻(R2)的一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述电容(EC1)的第二电极、所述电容(C6)的第二电极、所述电阻(R2)的另一端接地；所述二极管(D3)和所述二极管(D4)串联，所述二极管(D5)和所述二极管(D6)串联，所述电阻(R3)和所述电阻(R4)串联，所述二极管(D3)的阳极、所述二极管(D5)的阳极、所述电阻(R3)的一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接，所述二极管(D4)的阴极、所述二极管(D6)的阴极、所述电阻(R4)的另一端与所述LDO降压电路的输出端连接。
  18. 如权利要求15所述的LED灯，其中，所述输出反馈电路(114)包括 反馈电阻(R5)和反馈电阻(R6)；所述反馈电阻(R5)和所述反馈电阻(R6)串联，所述反馈电阻(R5)的一端与所述LDO降压电路的输出端连接，所述反馈电阻(R5)的另一端、所述反馈电阻(R6)的一端与反馈信号端(ADC)连接，所述反馈电阻(R6)的另一端接地。
  19. 如权利要求15所述的LED灯，其中，所述线性降压电路(111)还包括放大电路单元，所述放大电路单元包括采样电阻(R13)、三极管(Q5)、三极管(Q6)、以及偏置电阻(R14)、偏置电阻(R15)，所述采样电阻(R13)的一端与所述三极管(Q5)的发射极、所述三极管(Q6)的发射极连接，所述采样电阻(R13)的另一端与所述偏置电阻(R14)的一端、所述线性降压芯片(U1)的电压输入引脚(Vin)连接，所述偏置电阻(R14)的另一端与所述三极管(Q5)的基极连接，所述三极管(Q5)的集电极与所述三极管(Q6)的基极、所述偏置电阻(R15)的一端连接，所述三极管(Q6)的集电极、所述偏置电阻(R15)的另一端与所述线性降压芯片(U1)的电压输出引脚(Vout)连接。
  20. 如权利要求15所述的LED灯，其中，所述全桥驱动电路(120)包括驱动控制电路、开关控制电路、以及驱动调节电路；所述驱动控制电路包括第一驱动控制电路和第二驱动控制电路，所述第一驱动控制电路包括驱动芯片(U4)、电容(C7)、电容(C8)、电阻(R7)、二极管(D7)，所述第二驱动控制电路包括驱动芯片(U5)、电容(C9)、电容(C10)、电阻(R10)、二极管(D10)，所述驱动芯片(U4)的电源引脚(VDD)、所述电阻(R7)的另一端、所述电容(C8)的第一电极板与电压信号连接，所述驱动芯片(U4)的公共引脚(VSS)、所述电容(C8)的第二电极板接地，所述驱动芯片(U4)的引脚(HB)与所述电容(C7)的第一电极板、所述二极管(D7)的阴极连接，所述驱动芯片(U4)的输出引脚(LO)与所述电阻(R9)的一端、所述二极管(D9)的阴极连接，所述驱动芯片(U5)的电源引脚(VDD)、所述电阻(R10)的另一端、所述电容(C10)的第一电极板与电压信号连接，所述驱动芯片(U5)的公共引脚(VSS)、所述电容(C10)的第二电极板接地，所述驱动芯片(U5)的引脚(HB)与所述电容(C10)的第一电极板、所述二极管(D10)的阴极连接，所述驱动芯片(U5)的输出引脚(LO)与所述电阻(R10)的一端、所述二极管(D10)的阴极连接；所述开关控制电路包括四个开关控制器件，第一开关控制器件的输入 端、第二开关控制器件的输入端与所述LDO降压电路的输出端连接，所述第一开关控制器件的输出端、第三开关控制器件的输入端、所述驱动芯片(U4)的引脚(HS)、所述电容(C7)的第二电极板与所述液晶光阀(140)的第一连接端连接，所述第二开关控制器件的输出端、第四开关控制器件的输入端、所述驱动芯片(U5)的引脚(HS)、所述电容(C9)的第二电极板与所述液晶光阀(140)的第二连接端连接，所述第三开关控制器件的输出端、所述第四开关控制器件的输出端接地；所述驱动调节电路包括第一驱动调节电路、第二驱动调节电路、第三驱动调节电路、以及第四驱动调节电路，所述第一驱动调节电路包括二极管(D8)和电阻(R8)，所述二极管(D8)的阴极、所述电阻(R8)的一端与所述驱动芯片(U4)的引脚(HO)连接，所述二极管(D8)的阳极、所述电阻(R8)的另一端与所述第一开关控制器件的控制端连接，所述第二驱动调节电路包括二极管(D9)和电阻(R9)，所述二极管(D9)的阴极、所述电阻(R9)的一端与所述驱动芯片(U4)的引脚(LO)连接，所述二极管(D9)的阳极、所述电阻(R9)的另一端与所述第三开关控制器件的控制端连接，所述第三驱动调节电路包括二极管(D11)和电阻(R11)，所述二极管(D11)的阴极、所述电阻(R11)的一端与所述驱动芯片(U5)的引脚(HO)连接，所述二极管(D11)的阳极、所述电阻(R11)的另一端与所述第二开关控制器件的控制端连接；所述第四驱动调节电路包括二极管(D12)和电阻(R12)，所述二极管(D12)的阴极、所述电阻(R12)的一端与所述驱动芯片(U5)的引脚(LO)连接，所述二极管(D12)的阳极、所述电阻(R12)的另一端与所述第四开关控制器件的控制端连接。
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