CN113224812A

CN113224812A - Switch control circuit

Info

Publication number: CN113224812A
Application number: CN202110466778.1A
Authority: CN
Inventors: 唐春国; 谢峰; 陈萼; 幸彩勤; 钟义礼
Original assignee: Shenzhen Lemi Technology Development Co ltd
Current assignee: Shenzhen Lemi Technology Development Co ltd
Priority date: 2021-04-28
Filing date: 2021-04-28
Publication date: 2021-08-06

Abstract

The application relates to a switch control circuit, including first switch circuit, MCU and signal control circuit, first switch circuit's input and the anodal of battery are connected, and first switch circuit's output and MCU are connected, signal control circuit is connected with MCU, load respectively, and signal control circuit is used for controlling the break-make of load place circuit. This application has the effect of extension switch life-span.

Description

Switch control circuit

Technical Field

The application relates to a photovoltaic off-grid technology field, in particular to a switch control circuit.

Background

The off-grid photovoltaic power generation system is widely applied to application places such as remote mountainous areas, non-electricity areas, islands, communication base stations, street lamps and the like, and is used for supplying power to portable power utilization equipment such as electric blowers and table lamps. The off-grid photovoltaic power generation system converts solar energy into electric energy under the condition of illumination, the MCU regulates and controls the electric energy, on one hand, the regulated energy is sent to a load, and on the other hand, the redundant energy is sent to the storage battery pack for storage; in the absence of illumination, the battery supplies power to the load.

The switches of off-grid photovoltaic power generation systems are typically connected in circuit with the load, resulting in a large current flowing through the switch. In the use process, the switch can generate large current at the moment of closing and opening, and the large current impacts the switch, so that the service life of the switch can be influenced.

Disclosure of Invention

In order to improve the service life of the switch, the application provides a switch control circuit.

The application provides a switch control circuit adopts following technical scheme:

the utility model provides a switch control circuit, includes first switch circuit, MCU and signal control circuit, the input of first switch circuit and the anodal of battery are connected, and first switch circuit's output and MCU are connected, signal control circuit respectively with MCU, load connection, signal control circuit is used for controlling the break-make of load place circuit.

By adopting the technical scheme, the storage battery supplies power to the MCU and the stable signal control circuit through the first switch circuit, and when the switch is closed, the signal control circuit controls the circuit where the load is located to be conducted, so that the load works. The first switch circuit is separated from a circuit where a load is located, the MCU and the stable signal control circuit are power utilization units of the circuit where the first switch circuit is located, the power utilization units are P = UI, under the condition that the voltage is constant, the current is in direct proportion to the power, the power of the MCU and the stable signal control circuit is small, the current flowing through the first switch circuit is small, the heat productivity is small, the impact on the switch at the moment of closing and opening is small, and the service life of the switch is further prolonged.

Optionally, the first switch circuit includes a sixth diode D6, a first switch K1, a forty-third capacitor C43, a sixty-sixth resistor R66, a thirty-third capacitor C33 and a sixty-fifth resistor R65, an anode of the sixth diode D6 is connected to the anode of the battery, a cathode of the sixth diode D6 is connected to one end of the first switch K1, the other end of the first switch K1 is connected to the MCU, an anode of the forty-third capacitor C43 is connected to the other end of the first switch K1, a cathode of the forty-third capacitor C43 is grounded, one end of the sixty-sixth resistor R66 is connected to the anode of the forty-third capacitor C43, the other end of the sixty-third capacitor C33 is connected to the anode of the thirty-third capacitor C33, the sixty-fifth resistor R65 is connected to the sixty-sixth resistor R66 in parallel, and an anode of the forty-third capacitor C43 is connected to the sixty-fifth resistor R65, and a cathode of the forty-fifth capacitor C43 is grounded.

By adopting the technical scheme, the forty-third capacitor C43, the sixty-sixth resistor R66, the thirty-third capacitor C33 and the sixty-fifth resistor R65 form a filter circuit, so that the stability of the output voltage of the storage battery can be improved.

Optionally, the signal control circuit includes a first MOS transistor Q1, a third MOS transistor Q3, an eighty-third resistor R83, a fifty-second resistor R52, a fifth diode D5, a twenty-second capacitor C22, and a sixty-second resistor R62, the grid electrode of the first MOS tube Q1 is connected with the MCU, the source electrode of the first MOS tube Q1 is connected with the load, the drain electrode of the first MOS tube Q1 is connected with the drain electrode of the third MOS tube Q3, the drain electrode of the third MOS tube Q3 is connected with one end of an eighty-third resistor R83, the other end of an eighty-third resistor R83 is connected with the load, the grid electrode of the third MOS tube Q3 is connected with the MCU, the source electrode of the third MOS tube Q3 is connected with one end of a fifty-second resistor R52, the other end of the fifty-second resistor R52 is grounded, the cathode of the fifth diode D5 is connected with the gates of the first MOS transistor Q1 and the third MOS transistor Q3, the twenty-second capacitor C22, the sixty-second resistor R62 and the fifth diode D5 are connected in parallel.

By adopting the technical scheme, the grid of the first MOS transistor Q1 and the grid of the third MOS transistor Q3 are connected with the MCU, the source of the first MOS transistor Q1 is connected with the load, one end of the eighty-third resistor R83 is connected with the other load, and the MCU controls the conduction and the cut-off of the first MOS transistor Q1 and the third MOS transistor Q3. When the first MOS transistor Q1 and the third MOS transistor Q3 are turned off, the circuit in which the load is located is disconnected, and the load stops operating.

Optionally, the display module further comprises a voltage sampling circuit and a voltage stabilizing output module, wherein the voltage sampling circuit is respectively connected with the storage battery and the MCU, and the voltage stabilizing output module is respectively connected with the first switch circuit, the MCU and the display module.

By adopting the technical scheme, the voltage-stabilizing output module supplies power to the display module, the voltage sampling circuit collects the output voltage of the storage battery, and when the output voltage is lower than a preset value, the MCU controls the voltage-stabilizing output module to stop outputting; meanwhile, the MCU controls the first MOS transistor Q1 and the third MOS transistor Q3 to be cut off, and a circuit where the load is located is disconnected, so that the over-discharge condition of the storage battery is reduced, and the service life of the storage battery is prolonged.

Optionally, the voltage stabilizing output module includes a second triode T2, a chip U7 with a model number of R1244N, and a peripheral circuit thereof, a base of the second triode T2 is connected to the MCU, a collector of the second triode T2 is connected to a CE pin of the chip U7, and an emitter of the second triode T2 is grounded.

Through adopting above-mentioned technical scheme, the battery supplies power for chip U7 through first switch circuit, and chip U7 output stable 3.3V voltage gives the display module assembly, and output voltage is stable, and is with low costs. The second triode T2 is connected with the CE pin of the chip U7, when the MCU controls the second triode T2 to be conducted, the CE pin of the chip U7 becomes low level, the chip U7 stops working, and the working of the chip U7 is controlled.

Optionally, the voltage sampling circuit includes a fifty-seventh resistor R57, a fifty-eighth resistor R58, and a twenty-third capacitor C23, one end of the fifty-seventh resistor R57 is connected to the battery, the other end of the fifty-seventh resistor R57 is connected to the MCU, one end of the fifty-eighth resistor R58 is connected to the other end of the fifty-seventh resistor R57, the other end of the fifty-eighth resistor R58 is grounded, and the twenty-third capacitor C23 is connected in parallel to the fifty-eighth resistor R58.

Through adopting above-mentioned technical scheme, MCU gathers the output voltage of battery through fifty seventeenth resistance R57, and twenty-three electric capacity C23 and fifty-eight resistance R58 play the filtering action, make the voltage of gathering more stable, more accurate.

Optionally, the photovoltaic charging system further comprises a second switch circuit, and the second switch circuit is respectively connected with the anode of the storage battery and the photovoltaic charging loop.

By adopting the technical scheme, the second switch circuit controls the on-off of the photovoltaic charging circuit, and when the photovoltaic charging circuit is not used, the photovoltaic panel is prevented from continuously supplying power to the storage battery by disconnecting the photovoltaic charging circuit, so that the overcharging condition can be reduced.

Optionally, the second switch circuit includes an eighty-first resistor R81, a second switch K2, an optical coupler U10 and a seventh diode D7, one end of the eighty-first resistor R81 is connected with the positive electrode of the battery, the other end of the eighty-first resistor R81 is connected with pin 1 of the optical coupler U10, one end of the second switch K2 is connected with pin 1 of the optical coupler U10, the other end of the second switch K2 is connected with pin 2 of the optical coupler U10, pin 2 and pin 3 of the optical coupler U10 are grounded, pin 4 of the optical coupler U10 is connected with the cathode of the seventh diode D7, and the anode of the seventh diode D7 is connected with the photovoltaic charging circuit.

By adopting the technical scheme, the second switch K2 is switched off, the current flows through the optocoupler U10, and the optocoupler U10 is switched on; the second switch K2 is closed, and opto-coupler U10 is by the short circuit, and opto-coupler U10 cuts to, and the switching-on and the switching-off of the steerable photovoltaic charging circuit of accessible opto-coupler U10. Meanwhile, the optocoupler U10 plays a role in isolation, so that the second switch circuit is separated from the photovoltaic charging loop, the power of the optocoupler U10 is low, the current passing through the second switch circuit is low, and the service life of the second switch K2 can be prolonged.

Optionally, the voltage stabilizing circuit comprises a primary voltage stabilizing module and a secondary voltage stabilizing module, the input end of the primary voltage stabilizing module is connected with the output end of the first switch circuit, the output end of the primary voltage stabilizing module is connected with the input end of the secondary voltage stabilizing module, and the output end of the secondary voltage stabilizing module is connected with the MCU.

Through adopting above-mentioned technical scheme, first switch circuit supplies power for MCU through voltage stabilizing circuit, and through the segmentation steady voltage of one-level voltage stabilizing module and second grade voltage stabilizing module, improve MCU supply voltage's stability.

Optionally, the primary regulator module includes a sixty-fourth resistor R64, a first triode T1 and a second diode D2, one end of the sixty-fourth resistor R64 is connected with the collector of the first triode T1, the other end of the sixty-fourth resistor R64 is connected with the base of the first triode T1, the collector of the first triode T1 is connected with the output end of the first switching circuit (1), the base of the first triode T1 is connected with the cathode of the second diode D2, the anode of the second diode D2 is grounded, the secondary regulator module includes a forty-sixth capacitor C46, a ninth capacitor C9, a forty-fourth capacitor C44, a forty-fifth capacitor C45 and a regulator U8, the 3 pin of the regulator U8 is connected with the emitter of the first triode T1, the 1 pin of the regulator U8 is grounded, the 2 pin of the regulator U8 is connected with the MCU, the primary pin of the forty-sixth capacitor C46 is connected with the primary pin of the power supply terminal U8, the secondary side of a forty-sixth capacitor C46 is grounded, the ninth capacitor C9 and the forty-sixth capacitor C46 are connected in parallel, the primary side of the forty-fourth capacitor C44 is connected with the 3 pin of a voltage regulator U8, the secondary side of the forty-fourth capacitor C44 is grounded, and the forty-fifth capacitor C45 and the forty-fourth capacitor C44 are connected in parallel.

By adopting the technical scheme, the first switching circuit supplies power to the first triode T1, the first triode T1 and the second diode D2 form a voltage stabilizing circuit, the emitter of the first triode T1 outputs 12V stable voltage, the 12V voltage is applied to the voltage stabilizing tube U8, and the voltage stabilizing tube U8 provides stable 3.3V voltage for the MCU, so that the voltage stability is improved.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the first switch circuit is separated from a circuit where the load is located, the MCU and the stable signal control circuit are power utilization units of the circuit where the first switch circuit is located, the power of the MCU and the stable signal control circuit is small, so that the current flowing through the first switch circuit is small, the heat productivity is small, the impact on the switch in the closing and opening moments is small, and the service life of the switch is further prolonged.

2. The voltage sampling circuit collects the output voltage of the storage battery, and when the output voltage is lower than a preset value, the MCU controls the conduction of the second triode T2 to enable the voltage stabilizing output module to stop outputting; meanwhile, the MCU controls the first MOS transistor Q1 and the third MOS transistor Q3 to be cut off, and a circuit where the load is located is disconnected, so that the over-discharge condition of the storage battery is reduced, and the service life of the storage battery is prolonged.

3. When not in use, the photovoltaic charging circuit is disconnected, the photovoltaic panel is prevented from continuously supplying power to the storage battery, and the overcharge condition can be reduced. Meanwhile, the optocoupler U10 plays a role in isolation, so that the second switch circuit is separated from the photovoltaic charging loop, the power of the optocoupler U10 is low, the current passing through the second switch circuit is low, and the service life of the second switch K2 can be prolonged.

Drawings

Fig. 1 is a block diagram of a switch control circuit according to an embodiment of the present application;

FIG. 2 is a circuit diagram of an MCU;

FIG. 3 is a circuit diagram of a first switching circuit;

FIG. 4 is a circuit diagram of a signal control circuit;

FIG. 5 is a block diagram of a switch control circuit according to another embodiment of the present application;

FIG. 6 is a circuit diagram of a voltage regulator circuit;

FIG. 7 is a circuit diagram of a voltage sampling circuit;

FIG. 8 is a circuit diagram of a regulated output module;

fig. 9 is a circuit diagram of the second switch circuit.

Description of reference numerals: 1. a first switching circuit; 2. a voltage stabilizing circuit; 21. a primary voltage stabilizing module; 22. a secondary voltage stabilizing module; 23. a filter capacitor bank; 3. a voltage stabilization output module; 4. a second switching circuit; 5. a signal control circuit; 6. a voltage sampling circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is further described in detail below with reference to fig. 1-9 and the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The embodiment of the application discloses a switch control circuit. Referring to fig. 1 and 2, the switch control circuit includes a first switch circuit 1, an MCU and a signal control circuit 5, an input terminal of the first switch circuit 1 is connected to an anode of the battery, an output terminal of the first switch circuit 1 is connected to the MCU, the signal control circuit 5 is respectively connected to the MCU and the load, and the signal control circuit 5 is used to control the on/off of a circuit where the load is located. Wherein, the MCU adopts a chip U5 with the model of GD32F103 RCT.

Referring to fig. 1 and 3, the first switch circuit 1 includes a sixth diode D6, a first switch K1, a forty-third capacitor C43, a sixty-sixth resistor R66, a thirty-third capacitor C33, and a sixty-fifth resistor R65, an anode of the sixth diode D6 is connected to an anode of the secondary battery, a cathode of the sixth diode D6 is connected to one end of the first switch K1, an anode of the forty-third capacitor C43 is connected to the other end of the first switch K1, a cathode of the forty-third capacitor C43 is grounded, one end of the sixty-sixth resistor R66 is connected to an anode of the forty-third capacitor C43, and the other end is connected to an anode of the thirty-third capacitor C33. One end of the sixty-five resistor R65 is connected with the positive electrode of the thirty-third capacitor C33, the other end of the sixty-five resistor R65 is connected with the positive electrode of the forty-third capacitor C43, and the negative electrode of the forty-third capacitor C43 is grounded.

The first switch K1 is closed, the storage battery supplies power to the MCU, the MCU works, and the whole off-grid photovoltaic power generation system is started; the first switch K1 is switched off, the MCU does not work, and the whole off-grid photovoltaic power generation system is closed. The power of the MCU is smaller than the power of the load, so that the current flowing through the first switch K1 is reduced, the heat generation is reduced, and the current surge applied to the first switch K1 at the moment of closing or opening is reduced, which can improve the service life of the first switch K1. And a forty-third capacitor C43, a sixty-sixth resistor R66, a thirty-third capacitor C33 and a sixty-fifth resistor R65 form a filter circuit, so that the stability of the output voltage of the storage battery can be improved.

Referring to fig. 1 and 4, the signal control circuit 5 includes a first MOS transistor Q1, a third MOS transistor Q3, an eighty-third resistor R83, a fifty-second resistor R52, a fifth diode D5, a twenty-second capacitor C22, and a sixty-second resistor R62, wherein the first MOS transistor Q1 and the third MOS transistor Q3 are N-channel MOS transistors, a gate of the first MOS transistor Q1 is connected to the MCU, a source of the first MOS transistor Q1 is connected to a negative electrode of the load, a drain of the first MOS transistor Q1 is connected to a drain of the third MOS transistor Q3, a drain of the third MOS transistor Q3 is connected to one end of the eighty-third resistor R83, another end of the eighty-third resistor R83 is connected to a negative electrode of the load, a gate of the third MOS transistor Q3 is connected to the MCU, a source of the third MOS transistor Q3 is connected to one end of the fifty-second resistor R52, another end of the second resistor R24 is connected to the ground, a cathode of the fifth MOS transistor Q5 and a cathode of the fifth diode Q5928, the twenty-second capacitor C22, the sixty-second resistor R62 and the fifth diode D5 are connected in parallel.

The gate of the first MOS transistor Q1 and the gate of the third MOS transistor Q3 are at a high level, the gate of the first MOS transistor Q1 and the gate of the third MOS transistor Q3 are turned on, the circuit where the load is located is turned on, and the load operates. The gate of the first MOS transistor Q1 and the gate of the third MOS transistor Q3 are at a low level, the gate of the first MOS transistor Q1 and the gate of the third MOS transistor Q3 are turned off, the negative electrode of the load is disconnected from the ground, the circuit in which the load is located is disconnected, and the load stops working. The MCU controls the on and off of the first MOS tube Q1 and the third MOS tube Q3, so that whether the load works is controlled, and the current of the load does not pass through the first switch K1 under the isolation action of the signal control circuit 5.

Optionally, referring to fig. 5, the switch control circuit further includes a voltage stabilizing circuit 2, a voltage sampling circuit 6, a voltage stabilizing output module 3, and a second switch circuit 4.

Referring to fig. 3 and 6, the voltage regulator circuit 2 includes a primary regulator module 21, a secondary regulator module 22, and a filter capacitor bank 23. The primary voltage stabilizing module 21 includes a sixty-fourth resistor R64, a first transistor T1, and a second diode D2, wherein the first transistor T1 is an NPN transistor. One end of the sixty-fourth resistor R64 is connected to the collector of the first transistor T1, and the other end is connected to the base of the first transistor T1. The collector of the first transistor T1 is connected to the first switch K1, the base of the first transistor T1 is connected to the cathode of the second diode D2, and the anode of the second diode D2 is grounded.

The secondary regulator module 22 includes a forty-sixth capacitor C46, a ninth capacitor C9, a forty-fourth capacitor C44, a forty-fifth capacitor C45, and a regulator tube U8. The model of the voltage-regulator tube U8 is CX7533, 3 pins of the voltage-regulator tube U8 are connected with an emitting electrode of the first triode T1, 1 pin of the voltage-regulator tube U8 is grounded, and 2 pins of the voltage-regulator tube U8 are connected with a power supply end of the MCU. The primary side of a forty-sixth capacitor C46 is connected with the pin 3 of a regulator tube U8, the secondary side of a forty-sixth capacitor C46 is grounded, a ninth capacitor C9 is connected with the forty-sixth capacitor C46 in parallel, the primary side of a forty-fourth capacitor C44 is connected with the pin 3 of a regulator tube U8, the secondary side of a forty-fourth capacitor C44 is grounded, and a forty-fifth capacitor C45 is connected with a forty-fourth capacitor C44 in parallel.

The filter capacitor bank 23 is connected in parallel with a forty-fifth capacitor C45, and the filter capacitor bank 23 includes a second capacitor C2, a third capacitor C3, a tenth capacitor C10, an eleventh capacitor C11, a fourth capacitor C4, a twenty-fifth capacitor C25 and a twenty-sixth capacitor C26 which are connected in parallel in sequence.

The first triode T1 and the second diode D2 form a voltage stabilizing circuit 2, the emitter of the first triode T1 outputs 12V voltage, the 12V voltage is applied to a voltage regulator tube U8, the voltage regulator tube U8 provides 3.3V working voltage for the MCU, and the filter capacitor group 23 plays a role in filtering. Through the sectional voltage stabilization, the stability of the MCU power supply voltage can be improved.

Referring to fig. 5 and 7, the voltage sampling circuit 6 is respectively connected with the storage battery and the MCU, and the voltage stabilization output module 3 is connected with the first switch circuit 1, the MCU and the display module. The voltage sampling circuit 6 comprises a fifty-seventh resistor R57, a fifty-eighth resistor R58 and a twenty-third capacitor C23, one end of the fifty-seventh resistor R57 is connected with the storage battery, the other end of the fifty-seventh resistor R57 is connected with the MCU, one end of the fifty-eighth resistor R58 is connected with the other end of the fifty-seventh resistor R57, the other end of the fifty-eighth resistor R58 is grounded, and the twenty-third capacitor C23 is connected with the fifty-eighth resistor R58 in parallel.

MCU gathers the output voltage of battery through the seventeenth resistance R57, and twenty-three electric capacity C23 and fifty-eight resistance R58 play the filtering action, make the voltage of gathering more stable, more accurate.

Referring to fig. 3 and 8, the regulated output module 33 includes a second transistor T2, a chip U7 of a type R1244N, and peripheral circuits thereof. The peripheral circuit comprises a twenty-fourth capacitor C24, a twenty-ninth capacitor C29, a twenty-sixth resistor R26, a thirty-third capacitor C30, a forty-third resistor R43, a twenty-fifth resistor R25, a twenty-seventh capacitor C27, a fourth diode D4, a thirty-first capacitor C31, a thirty-third resistor R30, a second inductor L2, a thirty-second capacitor C32 and a forty-second capacitor C42, a VIN pin of a chip U7 is connected with a first switch K1, a primary side of the twenty-fourth capacitor C24 is connected with the VIN pin of the chip U7, and a secondary side of the twenty-fourth capacitor C24 is grounded. The primary side of the twenty-ninth capacitor C29 is connected to the VIN pin of the chip U7, and the secondary side of the twenty-ninth capacitor C29 is grounded. One end of the twenty-sixth resistor R26 is connected to the primary side of the twenty-fourth capacitor C24, and the other end is connected to the CE pin of the chip U7. The primary side of the thirtieth capacitor C30 is connected to the CE pin of U7, the secondary side of the thirtieth capacitor C30 is grounded, and the GND pin of the chip U7 is grounded. One end of a twenty-fifth resistor R25 is connected with the BST pin of the chip U7, the other end of the twenty-fifth resistor R25 is connected with the primary side of a twenty-seventh capacitor C27, and the secondary side of the twenty-seventh capacitor C27 is connected with the LX pin of the chip U7. The cathode of the fourth diode D4 is connected to the LX pin of the chip U7, and the anode of the fourth diode D4 is grounded. One end of the forty-third resistor R43 is connected to the VFB pin of the chip U7, and the other end is grounded. One end of the second inductor L2 is connected with the LX pin of the chip U7, the other end of the second inductor L2 is connected with a VCC port, and the VCC port is used for supplying power to the display module. One end of a thirty-third resistor R30 is connected with a BST pin of the chip U7, the other end of the thirty-third resistor R30 is connected with a VCC port, and a thirty-first capacitor C31 is connected with a thirty-third resistor R30 in parallel. The primary side of a thirty-second capacitor C32 is connected with the VCC port, the secondary side of the thirty-second capacitor C32 is grounded, and a forty-second capacitor C42 is connected with a thirty-second capacitor C32 in parallel.

When the storage battery supplies power to the chip U7, the thirtieth capacitor C30 is charged firstly and then is applied to the CE pin of the chip U7 relatively slowly, so that the purpose of delayed starting is achieved, the influence of instantaneous voltage on the circuit and the chip U7 is reduced, and the stability of the circuit is improved. The chip U7 supplies power to the display module, and the display module displays the state information of the off-grid photovoltaic power generation system.

The second triode T2 is an NPN triode, the base of the second triode T2 is connected with the MCU, the collector of the second triode T2 is connected with the CE pin of the chip U7, and the emitter of the second triode T2 is grounded.

The second triode T2 is turned off, the CE pin of the chip U7 is at a high level, the chip U7 operates, and the LX pin of the chip U7 outputs 3.3V. When the sampling voltage is smaller than the preset value, the enable end of the MCU sends a signal to the base electrode of the second triode T2, so that the second triode T2 is conducted, the potential of the CE pin of the chip U7 is changed from high level to low level, and the chip U7 stops working. Meanwhile, the MCU controls the first MOS transistor Q1 and the third MOS transistor Q3 to be cut off, and a circuit where the load is located is disconnected, so that the over-discharge condition of the storage battery can be reduced, and the service life of the storage battery is prolonged.

Referring to fig. 9, the second switch circuit 4 includes an eighty-first resistor R81, a second switch K2, an optocoupler U10 and a seventh diode D7, one end of the eighty-first resistor R81 is connected to the positive electrode of the battery, the other end of the eighty-first resistor R81 is connected to pin 1 of the optocoupler U10, one end of the second switch K2 is connected to pin 1 of the optocoupler U10, the other end of the second switch K2 is connected to pin 2 of the optocoupler U10, pin 2 and pin 3 of the optocoupler U10 are grounded, pin 4 of the optocoupler U10 is connected to the cathode of the seventh diode D7, and the anode of the seventh diode D7 is connected to the photovoltaic charging circuit.

The second switch K2 is turned off, and the optical coupler U10 is turned on; the second switch K2 is closed, and opto-coupler U10 is by the short circuit, and opto-coupler U10 cuts to, and the switching-on and the switching-off of steerable photovoltaic charging circuit through switching-on and cutting-off of opto-coupler U10. When not in use, the photovoltaic charging circuit is disconnected, the photovoltaic panel is prevented from being incapable of continuously supplying power to the storage battery, and the overcharging condition can be reduced. Meanwhile, the optocoupler U10 plays a role in isolation, so that the second switch circuit 4 is separated from the photovoltaic charging loop, the current of the photovoltaic charging loop does not pass through the second switch K2, the power of the optocoupler U10 is low, the current flowing through the second switch circuit 4 is low, and the service life of the second switch K2 can be prolonged.

The implementation principle of the switch control circuit in the embodiment of the application is as follows: the first switch K1 is closed, the battery supplies power for chip U7, MCU, and MCU starts, and first MOS pipe Q1, third MOS pipe Q3 switch on, and load work, the operating current of load do not pass through first switch K1. The MCU has a power lower than that of the load, and reduces the current flowing through the first switch K1, and the current surge applied to the first switch K1 at the moment of closing or opening. Switch on and cut off the break-make of steerable photovoltaic charging circuit through opto-coupler U10, when not using, through making the disconnection of photovoltaic charging circuit, opto-coupler U10 plays isolated effect, make second switch circuit 4 and the separation of photovoltaic charging circuit, the electric current in photovoltaic charging circuit does not pass second switch K2, opto-coupler U10's power is little, the electric current of second switch circuit 4 of flowing through is little, second switch K2 is closed, the electric current impact that receives in the twinkling of an eye of disconnection diminishes, first switch K1 has been prolonged, second switch K2's life.

The working current of the load and the current of the charging loop can reach several amperes generally, and in the application, the current passing through the first switch K1 and the second switch K2 is 30mA, so that the current flowing through the first switch K1 and the second switch K2 is effectively reduced.

The foregoing is a preferred embodiment of the present application and is not intended to limit the scope of the application in any way, and any features disclosed in this specification (including the abstract and drawings) may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

Claims

1. A switch control circuit, characterized by: the power supply device comprises a first switch circuit (1), an MCU (microprogrammed control unit) and a signal control circuit (5), wherein the input end of the first switch circuit (1) is connected with the anode of a storage battery, the output end of the first switch circuit (1) is connected with the MCU, the signal control circuit (5) is respectively connected with the MCU and a load, and the signal control circuit (5) is used for controlling the on-off of a circuit where the load is located.

2. A switch control circuit according to claim 1, wherein: the first switch circuit (1) comprises a sixth diode D6, a first switch K1, a forty-third capacitor C43, a sixty-sixth resistor R66, a thirty-third capacitor C33 and a sixty-fifth resistor R65, wherein the anode of the sixth diode D6 is connected with the anode of the storage battery, the cathode of the sixth diode D6 is connected with one end of the first switch K1, the other end of the first switch K1 is connected with the MCU, the anode of the forty-third capacitor C43 is connected with the other end of the first switch K1, the cathode of the forty-third capacitor C43 is grounded, one end of the sixty-sixth resistor R66 is connected with the anode of the forty-third capacitor C43, the other end of the sixty-third capacitor C33 is connected with the anode of the thirty-third capacitor C33, the sixty-fifth resistor R65 is connected with the sixty-sixth resistor R66 in parallel, and the anode of the forty-third capacitor C43 is connected with the sixty-fifth resistor R65 and the cathode of the forty-third capacitor C43 is grounded.

3. A switch control circuit according to claim 1, wherein: the signal control circuit (5) comprises a first MOS tube Q1, a third MOS tube Q3, an eighty-three resistor R83, a fifty-two resistor R52, a fifth diode D5, a twenty-second capacitor C22 and a sixty-two resistor R62, the grid electrode of the first MOS tube Q1 is connected with the MCU, the source electrode of the first MOS tube Q1 is connected with the load, the drain electrode of the first MOS tube Q1 is connected with the drain electrode of the third MOS tube Q3, the drain electrode of the third MOS tube Q3 is connected with one end of an eighty-third resistor R83, the other end of an eighty-third resistor R83 is connected with the load, the grid electrode of the third MOS tube Q3 is connected with the MCU, the source electrode of the third MOS tube Q3 is connected with one end of a fifty-second resistor R52, the other end of the fifty-second resistor R52 is grounded, the cathode of the fifth diode D5 is connected with the gates of the first MOS transistor Q1 and the third MOS transistor Q3, the twenty-second capacitor C22, the sixty-second resistor R62 and the fifth diode D5 are connected in parallel.

4. A switch control circuit according to claim 3, wherein: the voltage stabilizing and outputting device is characterized by further comprising a voltage sampling circuit (6) and a voltage stabilizing and outputting module (3), wherein the voltage sampling circuit (6) is respectively connected with the storage battery and the MCU, and the voltage stabilizing and outputting module (3) is respectively connected with the first switch circuit (1), the MCU and the display module.

5. A switch control circuit according to claim 4, characterized in that: the voltage-stabilizing output module (3) comprises a second triode T2, a chip U7 with the model number of R1244N and a peripheral circuit thereof, the base electrode of the second triode T2 is connected with the MCU, the collector electrode of the second triode T2 is connected with the CE pin of the chip U7, and the emitter electrode of the second triode T2 is grounded.

6. A switch control circuit according to claim 4, characterized in that: the voltage sampling circuit (6) comprises a fifty-seventh resistor R57, a fifty-eighth resistor R58 and a twenty-third capacitor C23, one end of the fifty-seventh resistor R57 is connected with the storage battery, the other end of the fifty-seventh resistor R57 is connected with the MCU, one end of the fifty-eighth resistor R58 is connected with the other end of the fifty-seventh resistor R57, the other end of the fifty-eighth resistor R58 is grounded, and the twenty-third capacitor C23 is connected with the fifty-eighth resistor R58 in parallel.

7. A switch control circuit according to claim 1, wherein: the photovoltaic charging system is characterized by further comprising a second switch circuit (4), wherein the second switch circuit (4) is respectively connected with the anode of the storage battery and the photovoltaic charging loop.

8. A switch control circuit according to claim 7, wherein: the second switch circuit (4) comprises an eighty-first resistor R81, a second switch K2, an optical coupler U10 and a seventh diode D7, one end of the eighty-first resistor R81 is connected with the positive electrode of a storage battery, the other end of the eighty-first resistor R81 is connected with 1 pin of the optical coupler U10, one end of the second switch K2 is connected with 1 pin of the optical coupler U10, the other end of the second switch K2 is connected with 2 pins of the optical coupler U10, the 2 pins and the 3 pins of the optical coupler U10 are grounded, the 4 pins of the optical coupler U10 are connected with the cathode of the seventh diode D7, and the anode of the seventh diode D7 is connected with a photovoltaic charging circuit.

9. A switch control circuit according to claim 1, wherein: still include voltage stabilizing circuit (2), voltage stabilizing circuit (2) include one-level voltage stabilizing module (21) and second grade voltage stabilizing module (22), the input of one-level voltage stabilizing module (21) and the output of first switch circuit (1) are connected, and the output of one-level voltage stabilizing module (21) and the input of second grade voltage stabilizing module (22) are connected, the output and the MCU of second grade voltage stabilizing module (22) are connected.

10. A switch control circuit according to claim 9, wherein: the primary voltage stabilizing module (21) comprises a sixty-four resistor R64, a first triode T1 and a second diode D2, one end of the sixty-four resistor R64 is connected with the collector of the first triode T1, the other end of the sixty-four resistor R64 is connected with the base of the first triode T1, the collector of the first triode T1 is connected with the output end of the first switching circuit (1), the base of the first triode T1 is connected with the cathode of the second diode D2, the anode of the second diode D2 is grounded, the secondary voltage stabilizing module (22) comprises a forty-six capacitor C46, a ninth capacitor C9, a forty-four capacitor C44, a forty-five capacitor C45 and a voltage stabilizing tube U8, the pin 3 of the voltage stabilizing tube U8 is connected with the emitter of the first triode T1, the pin 1 of the voltage stabilizing tube U8 is grounded, the pin 2 of the voltage stabilizing tube U8 is connected with the power supply end of a forty, the primary side of the sixth capacitor C2 is connected with the pin 67 46 6 of the sixth capacitor U8, the secondary side of a forty-sixth capacitor C46 is grounded, the ninth capacitor C9 and the forty-sixth capacitor C46 are connected in parallel, the primary side of the forty-fourth capacitor C44 is connected with the 3 pin of a voltage regulator U8, the secondary side of the forty-fourth capacitor C44 is grounded, and the forty-fifth capacitor C45 and the forty-fourth capacitor C44 are connected in parallel.