A small, solar-powered, low-power electromagnetic flowmeter

Abstract

This utility model discloses a small, solar-powered, low-power electromagnetic flowmeter, comprising a small solar charging circuit, an over-discharge protection circuit, a low-power microprocessor circuit, a low-power display circuit, and a button circuit. The small solar charging circuit uses a small solar panel to charge a supercapacitor; once fully charged, the charging is disconnected, and the small solar panel directly powers the electromagnetic flowmeter. The over-discharge protection circuit compares the solar voltage and the supercapacitor voltage divider at its input to determine if the circuit is over-discharged and switches the power supply accordingly. The microcontroller controls the excitation circuit to generate low-frequency pulses to excite the coil, producing a regularly changing magnetic field. The synchronous sampling circuit acquires the flow velocity signal, amplifies and filters it synchronously, and then performs analog-to-digital conversion to convert the analog signal into a digital signal. The low-power display circuit displays the instantaneous flow velocity and instantaneous flow rate. The button circuit is used to modify various parameters of the electromagnetic flowmeter and can also trigger the wake-up state of the low-power display circuit.

Description

Technical Field

[0001] This utility model relates to a small solar power supply technology, specifically to a small solar power supply low-power electromagnetic flowmeter. Background Technology

[0002] Electromagnetic flowmeters are typically used in remote locations such as river monitoring, oilfield pipelines, and agricultural irrigation. These flowmeters are often installed at long distances, scattered in sparsely populated areas, making long-distance direct power supply via power cords inconvenient. They rely on external power sources (220V AC or 24V DC), resulting in high wiring costs in these field applications like oilfields, agricultural irrigation, and wastewater treatment. Battery power, on the other hand, requires frequent replacements, is inconvenient to maintain, and can cause environmental pollution to rivers and farmland. These issues have led to the design of a small, solar-powered, low-power electromagnetic flowmeter. This reduces deployment and maintenance costs, eliminating cable laying costs in remote areas (such as farmland, oilfields, and mountain rivers). It requires minimal maintenance, and its solar-powered + energy storage design allows for continuous operation for many years without frequent battery replacements or manual inspections. Utilizing wide-temperature components (-40℃~85℃) and IP68 protection, it can operate stably in desert, polar, and humid environments. Completely reliant on solar energy, it reduces the use of generators or batteries, aligning with green energy policies. Summary of the Invention

[0003] This invention provides a small, low-power electromagnetic flowmeter powered by solar energy. Using solar power, the flowmeter employs a constant voltage method to track the maximum power point of the solar panel through a solar charging circuit, maximizing the utilization of the solar panel's output power. When the voltage generated by the solar energy exceeds a certain set threshold, it enters a constant current charging mode; when it falls below the threshold, it enters a trickle charging mode. When the internal voltage is higher than the voltage generated by the solar energy, the charging chip shuts off. If the internal voltage is too low, it switches to direct external solar power. The microcontroller circuit generates a low-frequency pulse signal through the I / O port to control the MOSFET to conduct, generating an excitation signal that energizes the coil, creating a magnetic field on both sides of the pipe, and simultaneously activating flow signal acquisition. The display screen uses a normally off mode, reducing overall power consumption and enabling stable operation even in environments without sunlight for extended periods until the next solar charging cycle.

[0004] To achieve a double number, the technical solution of this utility model is as follows:

[0005] A small, solar-powered, low-power electromagnetic flowmeter includes a small solar charging circuit, an over-discharge protection circuit, a microcontroller circuit, an excitation circuit, a synchronous sampling circuit, a low-power display circuit, and a keypad circuit. Its features are:

[0006] The small solar charging circuit uses a small solar cell to charge the supercapacitor. Once fully charged, the charging is disconnected, and the small solar cell directly supplies power to the electromagnetic flowmeter.

[0007] The over-discharge protection circuit is connected to the solar voltage and the supercapacitor voltage divider at its input terminal for comparison to determine whether the current circuit is over-discharged and to switch the power supply accordingly.

[0008] The microcontroller controls the excitation circuit to generate low-frequency pulses to excite the coil, producing a regularly changing magnetic field.

[0009] The synchronous sampling circuit acquires the flow velocity signal, amplifies and filters it synchronously, and then performs analog-to-digital conversion to convert the analog signal into a digital signal.

[0010] The low-power display circuit is used to display instantaneous flow rate and instantaneous flow volume;

[0011] The button circuit is used to modify various parameters of the electromagnetic flowmeter and can also trigger the wake-up state of the low-power display circuit.

[0012] The beneficial effects of this utility model are:

[0013] (1) This utility model is a small solar-powered low-power electromagnetic flow meter. The combination of solar energy and supercapacitor enables it to work completely off-grid. It is suitable for remote farmland, oil pipelines, mountain rivers and other areas without power grids, saving the high cost of cable laying.

[0014] (2) This utility model is a small solar-powered low-power electromagnetic flow meter. Through the design of low-frequency pulse excitation and synchronous sampling circuit and low-power display circuit, combined with continuous solar energy replenishment, the equipment can run continuously for 3-5 years without manual intervention, reducing maintenance costs.

[0015] (3) This utility model is a small solar-powered low-power electromagnetic flow meter. The whole system relies on clean energy, avoiding lead-acid battery pollution and carbon emissions from diesel power generation. The photovoltaic panel has a lifespan of more than 20 years, which is in line with the global carbon neutrality target. Attached Figure Description

[0016] Figure 1 is a module diagram of the small solar-powered low-power electromagnetic flowmeter of this utility model.

[0017] Figure 2 shows the solar charging circuit of the small solar-powered low-power electromagnetic flowmeter of this utility model.

[0018] Figure 3 shows the protection circuit of the small solar-powered low-power electromagnetic flowmeter of this utility model.

[0019] Figure 4 shows the microcontroller circuit and button circuit of the small solar-powered low-power electromagnetic flowmeter of this utility model.

[0020] Figure 5 shows the low-power display circuit of the small solar-powered low-power electromagnetic flowmeter of this utility model. Detailed Implementation

[0021] As shown in Figure 1, a small, solar-powered, low-power electromagnetic flowmeter includes a small solar charging circuit, an over-discharge protection circuit, a microcontroller circuit, an excitation circuit, a synchronous sampling circuit, a low-power display circuit, and a button circuit. The small solar panel charges a supercapacitor with a power density exceeding 10,000 W / kg and a cycle life of up to 500,000 cycles. The total charge is greater than 3Wh, enabling long-term operation of the electromagnetic flowmeter. The microcontroller circuit controls the excitation circuit to generate low-frequency pulses to excite the coil. Simultaneously, the sampling circuit acquires the flow velocity signal, amplifies and filters it synchronously, and then performs analog-to-digital conversion to transform the analog signal into a digital signal. The microcontroller processes the digital signal to calculate the current instantaneous flow velocity and flow rate, which are then displayed through the low-power display circuit. The button circuit is used to modify various parameters of the electromagnetic flowmeter and can also trigger the wake-up state of the low-power display circuit.

[0022] As shown in Figure 2: A constant voltage method is used to track the maximum power point of the solar cell, ensuring that the charging power reaches its peak at different temperatures. When the solar voltage is higher than the internal supercapacitor voltage, the capacitor is charged. If the capacitor voltage is lower than 66.7% of the set constant voltage charging voltage, the solar charging circuit automatically enters trickle charging mode, at which point the charging current is 15% of the set constant current charging current. When the capacitor voltage is greater than 66.7% of the set constant voltage charging voltage, the solar charging circuit enters constant current charging mode. When the input voltage drops, the charging chip automatically enters sleep mode, and the internal circuit is shut down, which reduces current consumption and extends standby time. There are two status indicator pins: a charging status indicator pin and a charging completion indicator pin, for easy viewing of the current charging status and solar power supply status.

[0023] As shown in Figure 3: The comparator is connected to the solar voltage and the voltage divider of the supercapacitor respectively. The comparison is used to determine whether the current circuit is over-discharged, and the power supply is switched to ensure the normal operation of the electromagnetic flowmeter.

[0024] As shown in Figure 4: When the measurement starts, the microcontroller generates a low-frequency pulse signal through the I / O port to control the MOSFET to turn on, generate an excitation signal, energize the coil, and generate a magnetic field on both sides of the pipe. When the excitation starts, synchronous sampling is started to convert the small voltage signal into a digital value of the flow rate signal.

[0025] As shown in Figure 5: The low-power microprocessor circuit is interconnected with the display screen through a communication interface. The display screen shows the current flow rate, current flow velocity, cumulative amount, and electrode resistance. After a period of no button operation, the display screen automatically turns off to reduce power consumption.

Claims

1. A small, solar-powered, low-power electromagnetic flowmeter, comprising a small solar charging circuit, an over-discharge protection circuit, a microcontroller circuit, an excitation circuit, a synchronous sampling circuit, a low-power display circuit, and a keypad circuit, characterized in that: The small solar charging circuit uses a small solar cell to charge the supercapacitor. Once fully charged, the charging is disconnected, and the small solar cell directly supplies power to the electromagnetic flowmeter. The over-discharge protection circuit is connected to the solar voltage and the supercapacitor voltage divider at its input terminal for comparison to determine whether the current circuit is over-discharged and to switch the power supply accordingly. The microcontroller controls the excitation circuit to generate low-frequency pulses to excite the coil, producing a regularly changing magnetic field. The synchronous sampling circuit acquires the flow velocity signal, amplifies and filters it synchronously, and then performs analog-to-digital conversion to convert the analog signal into a digital signal. The low-power display circuit is used to display instantaneous flow rate and instantaneous flow volume; The button circuit is used to modify various parameters of the electromagnetic flowmeter and can also trigger the wake-up state of the low-power display circuit.

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