阅读说明：本技术 一种降低显示器待机和关机功率的电路和方法 (Circuit and method for reducing standby and shutdown power of display ) 是由 潘小红 黎旭 吴俊恺 于 2020-12-31 设计创作，主要内容包括：本发明公开了一种降低显示器待机和关机功率的电路和方法,显示器进入关机或者待机时,显示器MCU模块通过控制直流电压输出控制模块使AC-DC电源模块输出的直流电压的变低,DC-DC开关模块,AC-DC电源模块输出直流电压的变低时DC-DC开关模块断开AC-DC电源模块和DC-DC电源模块之间的连接,使DC-DC电源模块不能给储能模块充电；显示器MCU模块控制关机和待机下的供电模块工作其接收AC-DC电源模块输出的低直流电压后给储能模块充电；当显示器进入关机或者待机时,将由DC-DC电源模块给储能模块充电切换为关机和待机下的供电模块给储能模块充电,储能模块供电给显示器MCU模块,DC-DC电源模块停止工作后就进一步降低了显示器待机和关机下的功率。(The invention discloses a circuit and a method for reducing standby and shutdown power of a display, when the display is in shutdown or standby, a display MCU module controls a direct-current voltage output control module to enable direct-current voltage output by an AC-DC power supply module to be lowered, a DC-DC switch module, and when the direct-current voltage output by the AC-DC power supply module is lowered, the DC-DC switch module disconnects the connection between the AC-DC power supply module and the DC-DC power supply module, so that the DC-DC power supply module cannot charge an energy storage module; the display MCU module controls the power supply module under shutdown and standby to work and receives the low direct-current voltage output by the AC-DC power supply module and then charges the energy storage module; when the display is turned off or in a standby state, the DC-DC power supply module is used for switching the charging of the energy storage module into the charging of the power supply module under the shutdown state and the standby state, the energy storage module supplies power to the display MCU module, and the power of the display under the standby state and the shutdown state is further reduced after the DC-DC power supply module stops working.)

1. A circuit for reducing standby and power-off of a display, comprising:

the AC-DC power supply module is used for converting alternating mains supply into direct current required by the display;

the output end of the DC-DC power supply module is connected with the input end of the energy storage module and is used for converting the high-voltage direct current into low-voltage direct current and supplying power to the energy storage module;

the input end and the output end of the DC-DC switch module are respectively connected with the output end of the AC-DC power supply module and the input end of the DC-DC power supply module and are used for controlling the on-off of the AC-DC power supply module and the DC-DC power supply module, and the DC-DC power supply module is turned off when the display is in standby or is turned off;

the energy storage module is used for supplying power to the display MCU module;

the input end and the output end of the direct current voltage output control module are respectively connected with the output end of the display MCU module and the input end of the AC-DC power supply module, and the direct current voltage output control module is used for controlling the level of direct current voltage output by the AC-DC power supply module and is controlled by the display MCU module;

the input end and the output end of the power supply module under shutdown and standby are respectively connected with the output end of the AC-DC power supply module and the input end of the energy storage module, and the input end of the power supply module is connected with the display MCU module and used for supplying electric energy output by the AC-DC power supply module to the energy storage module when the display is in standby or shutdown, and the power supply module is controlled by the display MCU module;

and the display MCU module controls the direct-current voltage output control module to enable the direct-current voltage output by the AC-DC power supply module to be lowered when the display is turned off or in standby, then the DC-DC switch module is switched off to enable the DC-DC power supply module to be switched off, and the display MCU module simultaneously controls the power supply modules in the turning-off and standby to supply the electric energy output by the AC-DC power supply module to the energy storage module.

2. The circuit for reducing standby and power-off of a display according to claim 1, wherein: the direct-current voltage output control module comprises a first switch tube, a second switch tube, a first resistor, a second resistor, a third resistor, a fourth resistor and a divider resistor; the first end of the first switch tube is connected with the output end of the display MCU module, the first end of the first switch tube is connected with the output end of the energy storage module through a first resistor, the second end of the first switch tube is grounded, the control end of the first switch tube is connected with the first end of the second switch tube, and the control end of the first switch tube is connected with the output end of the energy storage module through a second resistor; the second end of the second switch tube is connected with the divider resistor and then grounded, and the third end of the second switch tube is connected with the output end of the AC-DC power supply module through a third resistor; one end of the fourth resistor is connected with the divider resistor and then grounded, the other end of the fourth resistor is connected with the output end of the AC-DC power supply module, and the common connection point of the fourth resistor and the divider resistor is connected with the input end of the AC-DC power supply module.

3. A circuit for reducing standby and off power of a display according to claim 1 or 2, wherein:

the power supply module under shutdown and standby comprises a third switching tube, a fourth switching tube, a fifth switching tube, a sixth switching tube, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; the first end of the third switching tube is connected with the output end of the display, the first end of the third switching tube is connected with the output end of the energy storage module through a fifth resistor, the second end of the first switching tube is grounded, the control end of the third switching tube is connected to the first end of the fourth switching tube, and the control end of the third switching tube is connected with the output end of the energy storage module through a sixth resistor; the second end of the fourth switching tube is grounded, the control end of the fourth switching tube is connected with the first end of the fifth switching tube, and the control end of the fourth switching tube is connected with the output end of the AC-DC power supply module through a seventh resistor; the second end of the fifth switching tube is grounded, the control end of the fifth switching tube is connected with the first end of the sixth switching tube, and the control end of the fifth switching tube is connected with the output end of the AC-DC power supply module through an eighth resistor; the control end of the sixth switching tube is connected with the output end of the AC-DC power supply module, and the second end of the sixth switching tube is connected with the input end of the energy storage module.

4. The circuit for reducing standby and power-off of a display according to claim 3, wherein: the energy storage module comprises an energy storage capacitor, the negative electrode of the energy storage capacitor is grounded, the positive electrode of the energy storage capacitor is connected with the power supply end of the display MCU module, and the positive electrode of the energy storage capacitor is connected with the output end of the DC-DC power supply module and the output end of the power supply module during shutdown and standby.

5. The circuit for reducing standby and power-off of a display according to claim 3, wherein: the first switch tube and the second switch tube are both NPN type triodes.

6. The circuit for reducing standby and power-off of a display according to claim 3, wherein: the third switching tube, the fourth switching tube, the fifth switching tube and the sixth switching tube are all NPN type triodes.

7. A method for reducing standby and power-off of a display, comprising:

the direct-current voltage output control module is used for controlling the direct-current voltage output control module to lower the direct-current voltage output by the AC-DC power supply module when the display is turned off or in standby;

the DC-DC switch module disconnects the AC-DC power module and the DC-DC power module when the DC voltage output by the AC-DC power module becomes low, and closes the DC-DC power module, so that the DC-DC power module cannot charge the energy storage module;

the energy storage module is used for providing electric energy for the display MCU module;

the power supply module is used for controlling the display MCU module to work when the display enters shutdown or standby, and the power supply module charges the energy storage module after receiving the low direct-current voltage output by the AC-DC power supply module;

when the display enters shutdown or standby, the display MCU module controls the direct-current voltage output control module to enable the direct-current voltage output by the AC-DC power supply module to become low, and simultaneously controls the power supply module under shutdown and standby, the DC-DC power supply module is used for switching charging of the energy storage module into the power supply module under shutdown and standby to charge the energy storage module, and the energy storage module supplies power to the display MCU module.

Technical Field

The invention relates to the technical field of display devices, in particular to a circuit and a method for reducing standby and shutdown power of a display.

Background

The display is a display screen capable of displaying characters, graphics, images and animations, and generally refers to a display device connected to a host, and display screens of televisions and mobile phones are all regarded as displays, and the displays are more and more widely applied and have more and more functions. Energy conservation is an important social awareness in the world today, and refers to a series of actions that reduce energy consumption and increase energy utilization as much as possible. The energy-saving definition proposed by the world energy commission in 1979 is: all measures which are feasible technically, reasonable economically and acceptable environmentally and socially are adopted to improve the utilization efficiency of energy resources. At present, people can not leave computers for work, entertainment, study and other activities. In general, the display does not completely turn off the ac power during the standby and off states, so that a certain power consumption is also generated.

The working state of the display is mainly divided into three states of starting up, standby and shutdown. The power consumed by the display is relatively large when the display is turned on. When the standby state is very low, the MCU module of the display generally needs +5V power supply when the display is in standby state, and only needs to consume very low power consumption when the display enters the standby state and the power-off state. The existing circuit has partial circuits working when the display enters standby and is turned off, such as a direct current-direct current voltage reduction circuit of the display. This part of the circuit operation also generates a certain power consumption. The dc-dc voltage reduction circuit must be completely turned off in order to reduce the standby and off power consumption of the display even more.

Therefore, the circuit and the method for reducing the standby and shutdown power of the display are provided, the direct current-direct current voltage reduction circuit is completely closed when the display is in standby and shutdown, and the power consumption of the display in the standby and shutdown states is further reduced.

Disclosure of Invention

The invention aims to provide a circuit and a method for reducing standby and shutdown power of a display, so as to solve the problem of power consumption of the display in standby and shutdown states.

In order to achieve the purpose, the invention provides the following technical scheme:

a circuit for reducing standby and off power of a display, comprising:

the AC-DC power supply module is used for converting alternating mains supply into direct current required by the display;

the output end of the DC-DC power supply module is connected with the input end of the energy storage module and is used for converting the high-voltage direct current into low-voltage direct current and supplying power to the energy storage module;

the input end and the output end of the DC-DC switch module are respectively connected with the output end of the AC-DC power supply module and the input end of the DC-DC power supply module and are used for controlling the on-off of the AC-DC power supply module and the DC-DC power supply module, and the DC-DC power supply module is turned off when the display is in standby or is turned off;

the energy storage module is used for supplying power to the display MCU module;

the input end and the output end of the direct current voltage output control module are respectively connected with the output end of the display MCU module and the input end of the AC-DC power supply module, and the direct current voltage output control module is used for controlling the level of direct current voltage output by the AC-DC power supply module and is controlled by the display MCU module;

the input end and the output end of the power supply module under shutdown and standby are respectively connected with the output end of the AC-DC power supply module and the input end of the energy storage module, and the input end of the power supply module is connected with the display MCU module and used for supplying electric energy output by the AC-DC power supply module to the energy storage module when the display is in standby or shutdown, and the power supply module is controlled by the display MCU module;

and the display MCU module controls the direct-current voltage output control module to enable the direct-current voltage output by the AC-DC power supply module to be lowered when the display is turned off or in standby, then the DC-DC switch module is switched off to enable the DC-DC power supply module to be switched off, and the display MCU module simultaneously controls the power supply modules in the turning-off and standby to supply the electric energy output by the AC-DC power supply module to the energy storage module.

Further, the direct-current voltage output control module comprises a first switch tube, a second switch tube, a first resistor, a second resistor, a third resistor, a fourth resistor and a divider resistor; the first end of the first switch tube is connected with the output end of the display MCU module, the first end of the first switch tube is connected with the output end of the energy storage module through a first resistor, the second end of the first switch tube is grounded, the control end of the first switch tube is connected with the first end of the second switch tube, and the control end of the first switch tube is connected with the output end of the energy storage module through a second resistor; the second end of the second switch tube is connected with the divider resistor and then grounded, and the third end of the second switch tube is connected with the output end of the AC-DC power supply module through a third resistor; one end of the fourth resistor is connected with the divider resistor and then grounded, the other end of the fourth resistor is connected with the output end of the AC-DC power supply module, and the common connection point of the fourth resistor and the divider resistor is connected with the input end of the AC-DC power supply module.

Further, the power supply module during shutdown and standby comprises a third switching tube, a fourth switching tube, a fifth switching tube, a sixth switching tube, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; the first end of the third switching tube is connected with the output end of the display, the first end of the third switching tube is connected with the output end of the energy storage module through a fifth resistor, the second end of the first switching tube is grounded, the control end of the third switching tube is connected to the first end of the fourth switching tube, and the control end of the third switching tube is connected with the output end of the energy storage module through a sixth resistor; the second end of the fourth switching tube is grounded, the control end of the fourth switching tube is connected with the first end of the fifth switching tube, and the control end of the fourth switching tube is connected with the output end of the AC-DC power supply module through a seventh resistor; the second end of the fifth switching tube is grounded, the control end of the fifth switching tube is connected with the first end of the sixth switching tube, and the control end of the fifth switching tube is connected with the output end of the AC-DC power supply module through an eighth resistor; the control end of the sixth switching tube is connected with the output end of the AC-DC power supply module, and the second end of the sixth switching tube is connected with the input end of the energy storage module.

Furthermore, the energy storage module comprises an energy storage capacitor, the negative electrode of the energy storage capacitor is grounded, the positive electrode of the energy storage capacitor is connected with the power supply end of the display MCU module, and the positive electrode of the energy storage capacitor is connected with the output end of the DC-DC power supply module and the output end of the power supply module during shutdown and standby.

Further, the first switch tube and the second switch tube are both NPN-type triodes.

Furthermore, the third switching tube, the fourth switching tube, the fifth switching tube and the sixth switching tube are all NPN type triodes.

The invention also provides the following technical scheme, a method for reducing the standby and shutdown power of a display is characterized by comprising the following steps:

the direct-current voltage output control module is used for controlling the direct-current voltage output control module to lower the direct-current voltage output by the AC-DC power supply module when the display is turned off or in standby;

the DC-DC switch module disconnects the AC-DC power module and the DC-DC power module when the DC voltage output by the AC-DC power module becomes low, and closes the DC-DC power module, so that the DC-DC power module cannot charge the energy storage module;

the energy storage module is used for providing electric energy for the display MCU module;

the power supply module is used for controlling the display MCU module to work when the display enters shutdown or standby, and the power supply module charges the energy storage module after receiving the low direct-current voltage output by the AC-DC power supply module;

when the display enters shutdown or standby, the display MCU module controls the direct-current voltage output control module to enable the direct-current voltage output by the AC-DC power supply module to become low, and simultaneously controls the power supply module under shutdown and standby, the DC-DC power supply module is used for switching charging of the energy storage module into the power supply module under shutdown and standby to charge the energy storage module, and the energy storage module supplies power to the display MCU module.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, when the display is connected with an AC-DC power supply module, voltage enters the DC-DC switch module and then the DC-DC power supply switch module is turned on, the DC-DC power supply module outputs low voltage (5V) to charge the energy storage module after normal voltage reduction, and the power supply of the energy storage module supplies power to the display MCU module. And after the display MCU module works, the power supply module under shutdown and standby is controlled to work, and the display works normally. When the display enters a standby state or a shutdown state, the display MCU module drives the AC-DC power supply module by controlling the DC voltage output control module to reduce the DC voltage output by the AC-DC power supply module, the DC-DC switching module is enabled to close the DC-DC power supply module to work after the low voltage enters the DC-DC switching module, then the display MCU module controls to open the power supply module under shutdown and standby to work, the power supply module under shutdown and standby charges the energy storage module, and the energy storage module then supplies power to the display MCU. The DC-DC power supply module stops working when the display is in standby or shutdown, and the power of the display in standby or shutdown is further reduced after the DC-DC power supply module stops working when the display is in standby or shutdown.

Drawings

FIG. 1 is a block circuit diagram of the present invention;

fig. 2 is a circuit diagram of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, the present invention provides a technical solution: a circuit for reducing standby and off power of a display, comprising: the AC-DC power supply module is used for converting alternating mains supply into direct current required by the display; the output end of the DC-DC power supply module is connected with the input end of the energy storage module and is used for converting the high-voltage direct current into low-voltage direct current and supplying power to the energy storage module; the input end and the output end of the DC-DC switch module are respectively connected with the output end of the AC-DC power supply module and the input end of the DC-DC power supply module and are used for controlling the on-off of the AC-DC power supply module and the DC-DC power supply module, and the DC-DC power supply module is turned off when the display is in standby or is turned off; the energy storage module is used for supplying power to the display MCU module; the input end and the output end of the direct current voltage output control module are respectively connected with the output end of the display MCU module and the input end of the AC-DC power supply module, and the direct current voltage output control module is used for controlling the level of direct current voltage output by the AC-DC power supply module and is controlled by the display MCU module; the input end and the output end of the power supply module under shutdown and standby are respectively connected with the output end of the AC-DC power supply module and the input end of the energy storage module, and the input end of the power supply module is connected with the display MCU module and used for supplying electric energy output by the AC-DC power supply module to the energy storage module when the display is in standby or shutdown, and the power supply module is controlled by the display MCU module; and the display MCU module controls the direct-current voltage output control module to enable the direct-current voltage output by the AC-DC power supply module to be lowered when the display is turned off or in standby, then the DC-DC switch module is switched off to enable the DC-DC power supply module to be switched off, and the display MCU module simultaneously controls the power supply modules in the turning-off and standby to supply the electric energy output by the AC-DC power supply module to the energy storage module. The output end of the energy storage module is connected with the input end of the power supply module and the input end of the direct-current voltage output control module under shutdown and standby conditions.

The working principle of the power-on of the display is as follows: when the display is connected with the AC input, the AC-DC power module outputs a high voltage (normal operating voltage of the display) by default, and the high voltage in this embodiment is 24V. And after the high voltage enters the DC-DC switch module, the DC-DC power switch module is turned on. The DC-DC power supply module is a direct current-direct current voltage reduction circuit, and outputs low voltage (5V) to charge the energy storage module after the voltage is reduced normally. And the power supply of the energy storage module supplies power to the display MCU module. The output end of the MCU outputs a control level to close the power supply module under shutdown and standby operation after the MCU works, and the display works normally.

The working principle of the display is changed from normal operation to standby or power-off state: in order to ensure that other circuit modules of the display do not consume electric energy when the display enters standby or is turned off, the MCU module of the display can work normally, namely the DC-DC power supply module stops working when the display is in standby or is turned off. After the display enters a standby state or a shutdown state, the input end and the output end of the direct-current voltage output control module are respectively connected with the output end of the display MCU module and the input end of the AC-DC power supply module, the energy storage module can also provide electric energy, the output end of the display MCU module sends out a control level to control the direct-current voltage output control module, and the direct-current voltage output control module drives the AC-DC power supply module to reduce the direct-current voltage output by the AC-DC power supply module. The DC-DC switch module works under high voltage, and the DC-DC switch module is enabled to close the DC-DC power supply module to work after low voltage enters the DC-DC switch module. After the DC-DC power supply module is turned off, no electric energy is output, and at the moment, the display MCU module is powered by the energy storage module. And then the output end of the display MCU module sends out a control level to turn on the power supply module under shutdown and standby to work, and the power supply module under shutdown and standby charges the energy storage module and finally supplies power to the display MCU. The operation of the DC-DC power supply module is stopped at the time of standby and shutdown, and the operation of the DC-DC power supply module may generate energy consumption. The display MCU module switches the charging of the energy storage module by the DC-DC power supply module into the charging of the power supply module under shutdown and standby conditions to charge the energy storage module, the energy storage module supplies power to charge the display MCU module, and the power of the display under standby and shutdown conditions is further reduced after the DC-DC power supply module stops working when the display is in standby or shutdown conditions.

Further, in the embodiment of the present invention, with reference to fig. 2, the energy storage module is a capacitor C30. The resistor R23, the resistor R21 and the chip U3 form a DC-DC switch module; the DC-DC power supply module comprises a chip U3 and a peripheral circuit, and the U3 model is an EUP3484A voltage reduction chip; u1 is a controllable precision voltage-stabilizing source, U1 is TL 431; u2 is a photocoupler, model PC 817A. The working principle of the power-on of the display is as follows: after the display is switched on by alternating current, the AC-DC power supply module outputs a voltage of 24V, the anode of the capacitor C3 outputs a voltage of 24V, and the voltage of 24V is applied to the No. 2 pin of the DC-DC power supply module U3. And also to one end of R23. R23, R21 and U3 constitute a switch module of the DC-DC power supply module. When the high voltage 24V is input, the pin 7 of the U3 is high voltage after the voltage division of R23 and R21. The high voltage of pin 7 (high voltage to turn on U3) makes the DC-DC power module composed of U3 and peripheral devices work normally. After normal operation, the output voltage passes through the anode of the diode D4 and then to the cathode of the diode D4, and then charges the C30. C30 is the energy storage module. The +5V energy storage power supply of the C30 provides power for the display MCU.

Further, the dc voltage output control module includes a first switch Q4, a second switch Q3, a controllable regulator U1, a first resistor R33, a second resistor R32, a third resistor R1, and a fourth resistor R3; the first end of a first switch tube Q4 is connected with the output end (GPIO 2 port) of the display MCU module, the first end of a first switch tube Q4 is connected with the output end (5V power supply) of the energy storage module through a first resistor R33, the second end of the first switch tube Q4 is grounded, the control end of the first switch tube Q4 is connected with the first end of a second switch tube Q3, and the control end of the first switch tube Q4 is connected with the output end (5V power supply) of the energy storage module through a second resistor R32; the second end of a second switching tube Q3 is grounded through a voltage dividing resistor R2, the third end of a second switching tube Q3 is connected with the output end of an AC-DC power supply module through a third resistor R1 (the output end of the AC-DC power supply module is connected with an inductor L1, and the output end of an inductor L1 is connected with R1), the first end of the second switching tube is connected with the output end of an energy storage module (5V power supply) through a resistor R32, and the second end of the second switching tube Q3 is connected with the first end of a controllable voltage stabilizing source U1; one end of the fourth resistor R3 is connected with the divider resistor R2 and then grounded, the other end of the fourth resistor R3 is connected with the output end of the AC-DC power supply module (the output end of the inductor L1 is connected with the R3), and the common connection point of the fourth resistor R3 and the divider resistor is connected with the input end of the AC-DC power supply module. The second end of the controllable voltage-stabilizing source U1 is grounded, and the third end of the controllable voltage-stabilizing source U1 is connected with the output end of the AC-DC power supply module after sequentially passing through a photoelectric coupler U2 and a resistor R5. One end of a fourth resistor R3 is connected with a voltage dividing resistor R2, a common connection point of the fourth resistor R3 and the voltage dividing resistor is sequentially connected with a controllable voltage stabilizing source U1, a photoelectric coupler U2 and a feedback chip U4, and the voltage value of the output end of the AC-DC power supply module is adjusted through feedback of the feedback chip U4. R1 and R3 are connected in parallel, R3 and R2 are connected in series, the voltage value output by the AC-DC power supply module is determined by the voltage of a common connection point of R2 and R3, R2 and R3 have a voltage division effect, and when the direct-current voltage output control module works (when a display is in standby and is turned off), the AC-DC power supply module outputs +5V voltage; when the direct current voltage output control module does not work (when the display works normally), the AC-DC power supply module outputs +24V voltage.

The output end of the energy storage unit is +5V voltage, the voltage of +5V is respectively added to the c pole and the b pole of the first switching tube Q4 through one end of R32 and one end of R33, the second switching tube Q3 and the first switching tube Q4 are both NPN type triodes, and the first, second and control ends of the second switching tube Q3 and the first switching tube Q4 are respectively the b pole, the e pole and the c pole. The high potentials of the b pole and the e pole of the first switch tube Q4 make the c pole and the e pole of the first switch tube Q4 saturated and turned on, then make the b pole and the e pole of the second switch tube Q3 low potential, and then make the c pole and the e pole of the Q3 turned off. The c and e poles of Q3 are always off during power-up. The normal output high voltage 24V of the AC-DC module is ensured. After the display MCU is powered to normally work, the GPIO 2 outputs high potential to enable the c pole and the e pole of the Q4 to be always connected, the c pole and the e pole of the Q3 to be always cut off, and when the display MCU works normally, the direct-current voltage output control module does not work.

Further, in the embodiment of the present invention, the power supply module in shutdown and standby includes: a third switching tube Q8, a fourth switching tube Q7, a fifth switching tube Q6, a sixth switching tube Q5, a fifth resistor R37, a sixth resistor R36, a seventh resistor R35 and an eighth resistor R34; the first end of a third switching tube Q8 is connected with the output end (GPIO 1 port) of the display MCU module, the first end of the third switching tube Q8 is connected with the output end (+5V voltage) of the energy storage unit through a fifth resistor R37, the second end of the first switching tube Q8 is grounded, the control end of the third switching tube Q8 is connected with the first end of a fourth switching tube Q7, and the control end of the third switching tube Q8 is connected with the output end (+5V voltage) of the energy storage unit through a sixth resistor R36; the second end of the fourth switching tube Q7 is grounded, the control end of the fourth switching tube Q7 is connected with the first end of the fifth switching tube Q6, and the control end of the fourth switching tube Q7 is connected with the output end of the AC-DC power supply module through a seventh resistor R35; the second end of the fifth switching tube Q6 is grounded, the control end of the fifth switching tube Q6 is connected with the first end of the sixth switching tube Q5, and the control end of the fifth switching tube Q6 is connected with the output end of the AC-DC power supply module through an eighth resistor R34; the control end of a sixth switching tube Q5 is connected with the output end of the AC-DC power supply module, and the second end of the sixth switching tube Q5 is connected with the input end of the energy storage module.

The first, second and control ends of the third switch tube Q8, the fourth switch tube Q7, the fifth switch tube Q6 and the sixth switch tube Q5 are respectively a b pole, an e pole and a c pole, and the third switch tube Q8, the fourth switch tube Q7, the fifth switch tube Q6 and the sixth switch tube Q5 are all NPN type triodes. The output end of the energy storage unit is +5V voltage, one end of a resistor of a sixth resistor R36 and one end of a resistor of a fifth resistor R37 are respectively added to the c pole of Q8 and the b pole of Q8 in the +5V power-on process, so that the c pole and the e pole of Q8 are in saturated conduction, then the b pole of Q7 is in low potential, and the c pole and the e pole of Q7 are simultaneously cut off. After c and e of Q7 are cut off, the b and e poles of Q6 are at high potential, the e and c poles of Q6 are at high potential to be in saturated conduction, then the b pole and e pole of Q5 are at low potential, and then the e pole and c pole of Q5 are cut off. The e pole and the c pole of the Q5 are cut off, so that the power supply module in shutdown and standby is shut down.

Further, in the embodiment of the present invention, the energy storage module is an energy storage capacitor, a negative electrode of the energy storage capacitor is grounded, a positive electrode of the energy storage capacitor is connected to a power supply terminal of the display MCU module, and a positive electrode of the energy storage capacitor is connected to an output terminal of the DC-DC power supply module and an output terminal of the power supply module during shutdown and standby. The output end of the power supply module in shutdown and standby is the second end of a fourth switching tube Q5, and the output end of the DC-DC power supply module is connected with the anode of the energy storage capacitor through a diode D4.

Further, in the embodiment of the present invention, the first switching tube and the second switching tube are both NPN transistors; the third switching tube, the fourth switching tube, the fifth switching tube and the sixth switching tube are all NPN type triodes.

The display is converted from normal operation to standby or power-off state: when the display is turned off or in standby, the GPIO 2 port of the display MCU sends out a low level to be added to the b pole of the Q4, then the c pole and the e pole of the Q4 are cut off, and then the c pole and the e pole of the Q3 are in saturated conduction. After c and e poles of the Q3 are in saturated conduction, the resistors R1 and R3 form resistors which are connected in parallel, then the sampling voltage of the U1 is increased, and further the output voltage of the AC-DC power supply module is reduced. The low voltage is applied to one end of the R23, the voltage is divided by the R23 and the R21, the pin 7 of the U3 is at a low potential, the U3 stops working, and the anode of the diode D4 has no output voltage. After the DC-DC power supply module stops working, the power supply of the display MCU module is provided by the C30, the GPIO 1 port of the display MCU outputs a low level, the C pole and the e pole of the Q8 are cut off, then the C pole and the e pole of the Q7C are in saturated conduction, then the C pole and the e pole of the Q6 are cut off, and then the C pole and the e pole of the Q5 are in saturated conduction. The saturated conduction of the C and e poles of the Q5 turns on the low voltage output by the AC-DC power supply module, and then charges the C30 capacitor. And then power is supplied to the display MCU. The U3 reduces power consumption after it is deactivated, thus reducing power consumption after the display enters the standby and post-off states. This reduces the power of the display in standby and off states.

The display is converted from a standby state or a power-off state into a normal working state according to the circuit working principle: the process of the display entering the normal operation from the shutdown or standby state is opposite to the process of the display switching from the normal operation to the standby or shutdown state. The display MCU firstly sends out a high level from a GPIO 1 pin, then makes c e pole of Q8 saturated and turned on, then makes c e pole of Q7 turned off, then makes c e pole of Q6 saturated and turned on, and makes c e pole of Q5 turned off. The display MCU is powered by C30 after C e of Q5 is turned off. Then the display MCU inputs a high level through the GPIO 2 pin to make the c e pole of Q4 saturated and turned on, the c e pole of Q3 is turned off, R1 and R3 are not connected in parallel, and the AC-DC power supply outputs a high voltage (the normal working voltage of the display is 24V).

The invention discloses a method and a principle for reducing standby and shutdown power of a display, which comprise the following steps: providing a direct current voltage output control module, and enabling the direct current voltage output by the AC-DC power supply module to be lowered by controlling the direct current voltage output control module by the display MCU module when the display is turned off or in standby; the DC-DC switch module disconnects the AC-DC power module and the DC-DC power module when the DC voltage output by the AC-DC power module becomes low, and closes the DC-DC power module, so that the DC-DC power module cannot charge the energy storage module; the energy storage module is used for providing electric energy for the display MCU module; the power supply module is used for controlling the display MCU module to work when the display enters shutdown or standby, and the power supply module charges the energy storage module after receiving the low direct-current voltage output by the AC-DC power supply module; when the display enters shutdown or standby, the display MCU module controls the direct-current voltage output control module to enable the direct-current voltage output by the AC-DC power supply module to become low, and simultaneously controls the power supply module under shutdown and standby, the DC-DC power supply module is used for switching charging of the energy storage module into the power supply module under shutdown and standby to charge the energy storage module, and the energy storage module supplies power to the display MCU module.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.