Power supply control system for air quality monitoring

Abstract

The utility model provides a power supply control system for monitoring air quality. The power supply control system comprises a solar power supply module, a lithium battery and a power supply switching circuit, the output end of the solar power supply module is connected to the first input end of the power supply switching circuit, and the positive electrode of the lithium battery is connected to the second input end of the power supply switching circuit; the power supply switching circuit comprises a PMOS tube Q1, a diode D1, a resistor R4, a resistor R5, a triode Q5, a PMOS tube Q6, a resistor R10, a resistor R9, a manual switch SW1, a triode Q9, a capacitor C2, an ambient light intensity detection circuit, a first drive circuit, a second drive circuit and a comparison control circuit. The environment light intensity detection circuit is used for detecting the sunlight intensity of the environment where the current air quality monitoring device is located and outputting a light intensity detection signal to the comparison control circuit, and the control output end of the comparison control circuit is connected to the control input end of the first drive circuit and the control input end of the second drive circuit.

Description

Technical Field

[0001] The utility model relates to a power supply system of air quality monitoring equipment, in particular to a power supply control system used for air quality monitoring. Background Art

[0002] As people's requirements for the environment increase, there is an urgent need to accurately monitor outdoor and indoor air quality and take corresponding countermeasures based on the monitoring results.

[0003] Especially for outdoor air quality monitoring equipment, the stability of its operation is not only the stability of the networking of various sensors and data transmission equipment, but also the stability of the power supply of outdoor air quality monitoring equipment is the basis of the stability of various sensors and data transmission equipment. In the prior art, the traditional way to power outdoor air quality monitoring equipment is to lay out the corresponding power supply lines at the monitoring points, and then supply power after rectification and voltage reduction through the mains. Although this method has good stability, it is costly and the flexibility of the monitoring equipment is poor.

[0004] With the development of technology, people gradually proposed a combined power supply method based on solar energy and batteries. Solar power supply is limited by the influence of light. When the light is insufficient, batteries are needed to supplement the power supply. When the light is sufficient, solar energy is used to supply power to the air quality monitoring equipment and charge the batteries. However, this method requires reliable switching, that is, the smoothness of the switching, and the switching interval should not be too long. In addition, the accuracy of the switching needs to be maintained to avoid switching failures. The switching circuit in the prior art has poor smoothness, a long switching interval, and a relatively complex structure. It is often controlled by a chip. Although the integrated chip can simplify the circuit structure, it relies on the established control logic. Moreover, even if it is controlled by the chip, it is necessary to ensure power supply, otherwise the switching cannot be completed. It is often necessary to set an auxiliary power supply circuit or an auxiliary power supply. If the auxiliary power supply is not set, the battery is still needed to supply power to ensure the smoothness of the switching, so the battery cannot get a good rest. On the other hand, at the initial power-on of the entire switching system (i.e., it has just been put into use and has not yet been powered on), the entire control logic needs to be set by workers on site. If the setting is wrong, the entire system cannot work.

[0005] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Utility Model Content

[0006] In view of this, the purpose of the utility model is to provide a power supply control system for air quality monitoring. When the outdoor air quality monitoring equipment is powered by solar energy and batteries, it can achieve smooth switching between batteries and solar modules based on the intensity of ambient light, thereby ensuring the stability of the entire air quality monitoring equipment, and during the switching process, there is no need to set the chip and auxiliary power supply, and the cost is reduced. On the other hand, there is no need for manual control logic setting at the initial power-on moment, thereby avoiding the situation where manual control logic settings are incorrect.

[0007] The utility model provides a power supply control system for air quality monitoring, comprising a solar power supply module, a lithium battery and a power supply switching circuit;

[0008] The output end of the solar power supply module is connected to the first input end of the power supply switching circuit, and the positive electrode of the lithium battery is connected to the second input end of the power supply switching circuit;

[0009] The power supply switching circuit includes a PMOS tube Q1, a diode D1, a resistor R4, a resistor R5, a transistor Q5, a PMOS tube Q6, a resistor R10, a resistor R9, a manual switch SW1, a transistor Q9, a capacitor C2, an ambient light intensity detection circuit, a first drive circuit, a second drive circuit and a comparison control circuit;

[0010] The source of the PMOS tube Q1 serves as the first input end of the power supply switching circuit, the drain of the PMOS tube Q1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the load, the source of the PMOS tube Q1 is connected to the gate of the PMOS tube Q1 through the resistor R4, the gate of the PMOS tube Q1 is connected to the collector of the transistor Q5 through the resistor R5, the emitter of the transistor Q5 is grounded, and the base of the transistor Q5 is connected to the control output end of the first drive circuit;

[0011] The source of the PMOS tube Q6 serves as the second input end of the power supply switching circuit, the drain of the PMOS tube Q6 is connected to the load, the source of the PMOS tube Q6 is connected to the gate of the PMOS tube Q6 through the resistor R9, the gate of the PMOS tube Q6 is connected to the collector of the transistor Q9 through the resistor R10, the emitter of the transistor Q9 is grounded, the base of the transistor Q9 is grounded through the capacitor C2, the base of the transistor Q9 is connected to the gate of the PMOS tube Q6 through the manual switch SW1, and the base of the transistor Q9 is connected to the control output end of the second drive circuit;

[0012] The ambient light intensity detection circuit is used to detect the sunlight intensity of the environment where the current air quality monitoring device is located and output a light intensity detection signal to the comparison control circuit. The control output end of the comparison control circuit is respectively connected to the control input ends of the first drive circuit and the second drive circuit.

[0013] Further, the ambient light intensity detection circuit includes a diode D2, a photoresistor IDR, a resistor R14 and a resistor R13;

[0014] The anode of the diode D2 is connected to the drain of the PMOS tube Q6, the cathode of the diode D2 is connected to one end of the resistor R14 through the photoresistor IDR, the other end of the resistor R14 is grounded through the resistor R13, and the common connection point between the resistor R13 and the resistor R14 serves as the output end of the ambient light intensity detection circuit, and the common connection point between the cathode of the diode D2 and the photoresistor IDR is also connected to the drain of the PMOS tube Q1.

[0015] Further, the comparison control circuit includes a resistor R11, a resistor R12, a resistor R15, and a comparator U1;

[0016] One end of the resistor R11 is connected to the common connection point between the cathode of the diode D2 and the photoresistor IDR, the other end of the resistor R11 is grounded through the resistor R12, the common connection point between the resistor R11 and the resistor R12 is connected to the inverting end of the comparator U1, the non-inverting end of the comparator U1 serves as the input end of the comparison control circuit, the power supply end of the comparator U1 is connected to the cathode of the diode D2 and the common connection point of the photoresistor IDR through the resistor R15, and the output end of the comparator U1 serves as the control output end of the comparison control circuit.

[0017] Further, the first driving circuit includes a resistor R1, a resistor R2, a resistor R3, a transistor Q2, a transistor Q3, a transistor Q4, a resistor R16 and a resistor R6;

[0018] One end of the resistor R1 is connected to the source of the PMOS tube Q1, the other end of the resistor R1 is connected to the collector of the transistor Q2, the base of the transistor Q2 is connected to one end of the resistor R16, the other end of the resistor R16 serves as the control input end of the first drive circuit, the emitter of the transistor Q2 is connected to the base of the transistor Q3, the collector of the transistor Q3 is connected to the source of the PMOS tube Q1 through the resistor R2, the emitter of the transistor Q3 is grounded, the collector of the transistor Q3 is connected to the base of the transistor Q4, the emitter of the transistor Q4 is connected to the source of the PMOS tube Q1 through the resistor R3, the collector of the transistor Q4 is connected to one end of the resistor R6, and the other end of the resistor R6 serves as the control output end of the first drive circuit.

[0019] Further, the second driving circuit includes a resistor R7, a resistor R8, a resistor R17, a transistor Q7 and a transistor Q8;

[0020] The collector of the transistor Q7 is connected to the source of the PMOS tube Q6 through the resistor R7, the base of the transistor Q7 is connected to one end of the resistor R17, the other end of the resistor R17 serves as the control input end of the second drive circuit, the base of the transistor Q7 is grounded through the capacitor C3, the emitter of the transistor Q7 is connected to the base of the transistor Q8, the emitter of the transistor Q8 is connected to the source of the PMOS tube Q6 through the resistor R8, and the collector of the transistor Q8 serves as the control output end of the second drive circuit.

[0021] Furthermore, a capacitor C1 is included, one end of the capacitor C1 is connected to the source of the PMOS tube Q1, and the other end of the capacitor C1 is grounded.

[0022] The beneficial effects of the utility model are as follows: through the utility model, when the outdoor air quality monitoring equipment is powered by solar energy and batteries, a smooth switch between the battery and the solar module can be achieved based on the intensity of the ambient light, thereby ensuring the stability of the entire air quality monitoring equipment, and during the switching process, there is no need to set the chip and the auxiliary power supply, and the cost is reduced. On the other hand, there is no need to manually set the control logic at the initial power-on moment, thereby avoiding the situation where the control logic is set incorrectly by humans. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0024] Figure 1 It is the principle diagram of the utility model. DETAILED DESCRIPTION

[0025] The utility model is further described in detail below:

[0026] The utility model provides a power supply control system for air quality monitoring, comprising a solar power supply module, a lithium battery and a power supply switching circuit;

[0027] The output end of the solar power supply module is connected to the first input end of the power supply switching circuit, and the positive electrode of the lithium battery is connected to the second input end of the power supply switching circuit; wherein the solar power supply module is represented by VS in the accompanying drawings, which is a prior art and is not described in detail here, and the lithium battery is represented by VB;

[0028] The power supply switching circuit includes a PMOS tube Q1, a diode D1, a resistor R4, a resistor R5, a transistor Q5, a PMOS tube Q6, a resistor R10, a resistor R9, a manual switch SW1, a transistor Q9, a capacitor C2, an ambient light intensity detection circuit, a first drive circuit, a second drive circuit and a comparison control circuit;

[0029] The source of the PMOS tube Q1 serves as the first input end of the power supply switching circuit, the drain of the PMOS tube Q1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the load, the source of the PMOS tube Q1 is connected to the gate of the PMOS tube Q1 through the resistor R4, the gate of the PMOS tube Q1 is connected to the collector of the transistor Q5 through the resistor R5, the emitter of the transistor Q5 is grounded, and the base of the transistor Q5 is connected to the control output end of the first drive circuit;

[0030] The source of the PMOS tube Q6 serves as the second input end of the power supply switching circuit, the drain of the PMOS tube Q6 is connected to the load, the source of the PMOS tube Q6 is connected to the gate of the PMOS tube Q6 through the resistor R9, the gate of the PMOS tube Q6 is connected to the collector of the transistor Q9 through the resistor R10, the emitter of the transistor Q9 is grounded, the base of the transistor Q9 is grounded through the capacitor C2, the base of the transistor Q9 is connected to the gate of the PMOS tube Q6 through the manual switch SW1, and the base of the transistor Q9 is connected to the control output end of the second drive circuit;

[0031] The ambient light intensity detection circuit is used to detect the sunlight intensity of the environment where the current air quality monitoring device is located and output a light intensity detection signal to the comparison control circuit, and the control output end of the comparison control circuit is respectively connected to the control input end of the first drive circuit and the second drive circuit; through the above structure, when the outdoor air quality monitoring equipment is powered by solar energy and batteries, it is possible to achieve a smooth switch between the battery and the solar module based on the intensity of the ambient light, thereby ensuring the stability of the entire air quality monitoring equipment, and during the switching process, there is no need to set the chip and the auxiliary power supply, and the cost is disclosed. On the other hand, there is no need to manually set the control logic at the initial power-on moment, thereby avoiding the situation where the control logic is manually set incorrectly.

[0032] The manual switch SW1 is an existing self-resetting normally open manual switch.

[0033] In this embodiment, the ambient light intensity detection circuit includes a diode D2, a photoresistor IDR, a resistor R14 and a resistor R13;

[0034] The anode of the diode D2 is connected to the drain of the PMOS tube Q6, the cathode of the diode D2 is connected to one end of the resistor R14 through the photoresistor IDR, the other end of the resistor R14 is grounded through the resistor R13, and the common connection point between the resistor R13 and the resistor R14 serves as the output end of the ambient light intensity detection circuit, and the common connection point between the cathode of the diode D2 and the photoresistor IDR is also connected to the drain of the PMOS tube Q1.

[0035] In this embodiment, the comparison control circuit includes a resistor R11, a resistor R12, a resistor R15, and a comparator U1;

[0036] One end of the resistor R11 is connected to the common connection point between the cathode of the diode D2 and the photoresistor IDR, the other end of the resistor R11 is grounded through the resistor R12, the common connection point between the resistor R11 and the resistor R12 is connected to the inverting end of the comparator U1, the non-inverting end of the comparator U1 serves as the input end of the comparison control circuit, the power supply end of the comparator U1 is connected to the cathode of the diode D2 and the common connection point of the photoresistor IDR through the resistor R15, and the output end of the comparator U1 serves as the control output end of the comparison control circuit.

[0037] In this embodiment, the first driving circuit includes a resistor R1, a resistor R2, a resistor R3, a transistor Q2, a transistor Q3, a transistor Q4, a resistor R16 and a resistor R6;

[0038] One end of the resistor R1 is connected to the source of the PMOS tube Q1, the other end of the resistor R1 is connected to the collector of the transistor Q2, the base of the transistor Q2 is connected to one end of the resistor R16, the other end of the resistor R16 serves as the control input end of the first drive circuit, the emitter of the transistor Q2 is connected to the base of the transistor Q3, the collector of the transistor Q3 is connected to the source of the PMOS tube Q1 through the resistor R2, the emitter of the transistor Q3 is grounded, the collector of the transistor Q3 is connected to the base of the transistor Q4, the emitter of the transistor Q4 is connected to the source of the PMOS tube Q1 through the resistor R3, the collector of the transistor Q4 is connected to one end of the resistor R6, the other end of the resistor R6 serves as the control output end of the first drive circuit, wherein the transistor Q4 is a P-type transistor.

[0039] In this embodiment, the second driving circuit includes a resistor R7, a resistor R8, a resistor R17, a transistor Q7 and a transistor Q8;

[0040] The collector of the transistor Q7 is connected to the source of the PMOS tube Q6 through the resistor R7, the base of the transistor Q7 is connected to one end of the resistor R17, the other end of the resistor R17 serves as the control input end of the second drive circuit, the base of the transistor Q7 is grounded through the capacitor C3, the emitter of the transistor Q7 is connected to the base of the transistor Q8, the emitter of the transistor Q8 is connected to the source of the PMOS tube Q6 through the resistor R8, and the collector of the transistor Q8 serves as the control output end of the second drive circuit, wherein the transistor Q8 is a P-type transistor.

[0041] In this embodiment, a capacitor C1 is also included, one end of which is connected to the source of the PMOS tube Q1, and the other end of the capacitor C1 is grounded. The capacitor C1 adopts an existing large capacitor, which can reduce the peak and fill the valley on the one hand, and maintain the comparator working (maintaining time in milliseconds) even if the solar energy is cut off.

[0042] The principle of the utility model is further described below:

[0043] First of all, the photoresistor IDR is an electronic component that is sensitive to light. As the light intensity increases, its resistance decreases, and as the light intensity decreases, its resistance increases;

[0044] When the voltage at the in-phase end of the comparator U1 is greater than the voltage at the inverting end, it indicates that the light is strong and the solar power supply module can output enough electric energy to provide to the load, and the comparator U1 outputs a high level. When the voltage at the in-phase end of the comparator is less than or equal to the voltage at the inverting end, it indicates that the light is weak at this time, and the electric energy output by the solar power generation cannot meet the load demand, and the comparator U1 outputs a low level.

[0045] When the power is initially turned on, the staff only needs to press the manual switch SW1, SW1 is turned on, the capacitor C2 is charged until it is fully charged, the transistor Q9 is turned on, and then the PMOS tube Q6 is turned on. At this time, due to the effect of capacitor C2, even if the manual switch SW1 is restored to disconnection, its transistor Q9 still remains turned on for a certain period of time (the time is determined by the capacitance of the capacitor, and the capacitance of the capacitor is determined according to the actual state to determine the event that requires capacitor C2 to maintain the conduction of transistor Q9). During the time period when capacitor C1 is turned on, the comparator determines the intensity of the current ambient light, thereby determining whether the solar power supply module can provide sufficient electrical energy. If so, the comparator outputs a high level, at this time the transistor Q7 is turned on, the transistor Q8 is turned off, and then the transistor Q9 is turned off, the lithium battery does not supply power, and at the same time, the transistor Q2 is turned on, the transistor Q3 is turned on, and then the transistor Q4 is turned on, the transistor Q5 is turned on, the PMOS tube Q1 is turned on, and the solar energy circuit is powered. When the solar energy supply is insufficient, the comparator outputs a low level, Q2, Q3, Q4, Q5 and Q6 are all turned off, and the solar energy does not supply power. The function of capacitor C3 is to delay the setting time when U1 outputs a high level to make the transistor Q7 turn on. When the comparator outputs a level, C3 delays a certain time to make the transistor Q7 turn off. This is because the comparator U1 needs to maintain a low level state. The delay time is in microseconds and is set by setting the value of C3. When the transistor Q7 is turned off, Q8, Q9 and Q6 are turned on, and then the lithium battery is powered. Therefore, through the above, there is no need to manually set the control logic, and smooth switching of the two power supplies of the lithium battery and the solar power supply module can be achieved.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A power supply control system for air quality monitoring, characterized in that: It includes a solar power supply module, a lithium battery and a power supply switching circuit; The output end of the solar power supply module is connected to the first input end of the power supply switching circuit, and the positive electrode of the lithium battery is connected to the second input end of the power supply switching circuit; The power supply switching circuit includes a PMOS tube Q1, a diode D1, a resistor R4, a resistor R5, a transistor Q5, a PMOS tube Q6, a resistor R10, a resistor R9, a manual switch SW1, a transistor Q9, a capacitor C2, an ambient light intensity detection circuit, a first drive circuit, a second drive circuit and a comparison control circuit; The source of the PMOS tube Q1 serves as the first input end of the power supply switching circuit, the drain of the PMOS tube Q1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the load, the source of the PMOS tube Q1 is connected to the gate of the PMOS tube Q1 through the resistor R4, the gate of the PMOS tube Q1 is connected to the collector of the transistor Q5 through the resistor R5, the emitter of the transistor Q5 is grounded, and the base of the transistor Q5 is connected to the control output end of the first drive circuit; The source of the PMOS tube Q6 serves as the second input end of the power supply switching circuit, the drain of the PMOS tube Q6 is connected to the load, the source of the PMOS tube Q6 is connected to the gate of the PMOS tube Q6 through the resistor R9, the gate of the PMOS tube Q6 is connected to the collector of the transistor Q9 through the resistor R10, the emitter of the transistor Q9 is grounded, the base of the transistor Q9 is grounded through the capacitor C2, the base of the transistor Q9 is connected to the gate of the PMOS tube Q6 through the manual switch SW1, and the base of the transistor Q9 is connected to the control output end of the second drive circuit; The ambient light intensity detection circuit is used to detect the sunlight intensity of the environment where the current air quality monitoring device is located and output a light intensity detection signal to the comparison control circuit. The control output end of the comparison control circuit is respectively connected to the control input ends of the first drive circuit and the second drive circuit.

2. The power supply control system for air quality monitoring according to claim 1, characterized in that: The ambient light intensity detection circuit includes a diode D2, a photoresistor IDR, a resistor R14 and a resistor R13; The anode of the diode D2 is connected to the drain of the PMOS tube Q6, the cathode of the diode D2 is connected to one end of the resistor R14 through the photoresistor IDR, the other end of the resistor R14 is grounded through the resistor R13, and the common connection point between the resistor R13 and the resistor R14 serves as the output end of the ambient light intensity detection circuit, and the common connection point between the cathode of the diode D2 and the photoresistor IDR is also connected to the drain of the PMOS tube Q1.

3. The power supply control system for air quality monitoring according to claim 2, characterized in that: The comparison control circuit includes a resistor R11, a resistor R12, a resistor R15, and a comparator U1; One end of the resistor R11 is connected to the common connection point between the cathode of the diode D2 and the photoresistor IDR, the other end of the resistor R11 is grounded through the resistor R12, the common connection point between the resistor R11 and the resistor R12 is connected to the inverting end of the comparator U1, the non-inverting end of the comparator U1 serves as the input end of the comparison control circuit, the power supply end of the comparator U1 is connected to the cathode of the diode D2 and the common connection point of the photoresistor IDR through the resistor R15, and the output end of the comparator U1 serves as the control output end of the comparison control circuit.

4. The power supply control system for air quality monitoring according to claim 1, characterized in that: The first driving circuit includes a resistor R1, a resistor R2, a resistor R3, a transistor Q2, a transistor Q3, a transistor Q4, a resistor R16 and a resistor R6; One end of the resistor R1 is connected to the source of the PMOS tube Q1, the other end of the resistor R1 is connected to the collector of the transistor Q2, the base of the transistor Q2 is connected to one end of the resistor R16, the other end of the resistor R16 serves as the control input end of the first drive circuit, the emitter of the transistor Q2 is connected to the base of the transistor Q3, the collector of the transistor Q3 is connected to the source of the PMOS tube Q1 through the resistor R2, the emitter of the transistor Q3 is grounded, the collector of the transistor Q3 is connected to the base of the transistor Q4, the emitter of the transistor Q4 is connected to the source of the PMOS tube Q1 through the resistor R3, the collector of the transistor Q4 is connected to one end of the resistor R6, and the other end of the resistor R6 serves as the control output end of the first drive circuit.

5. The power supply control system for air quality monitoring according to claim 1, characterized in that: The second driving circuit includes a resistor R7, a resistor R8, a resistor R17, a transistor Q7 and a transistor Q8; The collector of the transistor Q7 is connected to the source of the PMOS tube Q6 through the resistor R7, the base of the transistor Q7 is connected to one end of the resistor R17, the other end of the resistor R17 serves as the control input end of the second drive circuit, the base of the transistor Q7 is grounded through the capacitor C3, the emitter of the transistor Q7 is connected to the base of the transistor Q8, the emitter of the transistor Q8 is connected to the source of the PMOS tube Q6 through the resistor R8, and the collector of the transistor Q8 serves as the control output end of the second drive circuit.

6. The power supply control system for air quality monitoring according to claim 1, characterized in that: It also includes a capacitor C1 , one end of which is connected to the source of the PMOS tube Q1 , and the other end of the capacitor C1 is grounded.

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