Solar Tracker Bidirectional Limit Switch Using MOSFET and Inclinometer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solar tracking systems lack efficient bidirectional limit switch mechanisms to accurately control the rotation of solar panels about a rotation axis, failing to effectively stop and reverse the electric motor operation at predetermined tilt angles.
Innovation Solution
A bidirectional limit switch device comprising MOSFET-type actuator transistors, diodes, and an inclinometer connected to a controller, which detects positive and negative tilt angles and applies inverted voltage to allow the electric motor to reverse direction after stopping, utilizing an H-bridge circuit for bidirectional control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional solar tracking system is used without a bidirectional limit switch mechanism, then the system structure is simpler, but the system fails to accurately control and reverse motor operation at predetermined tilt angles
Solution Approach 1:
The control system is segmented into distinct functional modules: inclinometer for angle detection, bidirectional limit switch device for limit detection, H-bridge circuit for motor control, and MOSFET transistors for switching control. Each module performs a specific function, allowing precise control at predetermined tilt angles while maintaining manageable system complexity through modular design
Solution Approach 2:
The bidirectional limit switch device acts as an intermediary between the inclinometer and the H-bridge circuit. It receives tilt angle signals from the inclinometer and translates them into control signals for the H-bridge circuit, enabling precise motor reversal at predetermined angles without requiring direct complex communication between the sensor and motor control circuits
2Adaptability or versatility
If bidirectional limit switch device with MOSFET transistors and H-bridge circuit is implemented, then motor reversal control at predetermined angles is achieved, but the circuit complexity increases
Solution Approach 1:
The H-bridge circuit serves multiple functions: it controls motor rotation in both directions, implements bidirectional limit switching, and enables motor reversal at predetermined tilt angles. The MOSFET transistors function as both switching elements and protection devices. This multi-functionality reduces the need for separate dedicated components, managing circuit complexity while achieving versatile bidirectional control
Solution Approach 2:
The system dynamically adjusts motor operation based on real-time tilt angle feedback from the inclinometer. The bidirectional limit switch device dynamically switches between forward rotation, reverse rotation, and stopping states based on the predetermined positive and negative tilt angles, allowing the system to adapt its behavior to current operational conditions
3Measurement precision
If limit switch mechanism is added to stop motor at predetermined angles, then tracking precision is improved, but the device structure becomes more complex
Solution Approach 1:
The bidirectional limit switch functionality is merged with the motor control circuitry. The same H-bridge circuit that controls motor direction also implements the limit switching function. The inclinometer serves dual purposes: providing feedback for tracking control and triggering the bidirectional limit switch at predetermined angles. This merging reduces the need for separate limit switch mechanisms, improving tilt angle detection precision without proportionally increasing device structure complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise control of solar panel tilt, stopping the motor at predetermined angles and reversing direction with an inverted voltage, enhancing the tracking efficiency and reliability of solar trackers.
Implementation Method 1
The actuator comprises MOSFET-type first and second actuator transistors and first and second diodes. Each of the first and second actuator transistors has a drain terminal, a source terminal and a gate terminal.
Implementation Method 2
The first and second diodes are respectively connected in parallel between the drain terminals and the source terminals of the first and second actuator transistors, thereby providing a bypass current path from the source terminals of the first and second actuator transistors to the first and second terminals of the electric motor.
Implementation Method 3
the feed circuit comprises an H-bridge circuit including first and second branches and MOSFET-type first, second, third and fourth feed circuit transistors. In the H-bridge circuit, the first and second feed circuit transistors are connected in series in the first branch
Implementation Method 4
an inclinometer fixed to the pivoting structure and connected to the controller to detect an actual physical positive or negative tilt angle of the solar panel with respect to a horizontal plane
Data Source
AI summary
The solar tracker having a bidirectional limit switch device comprises at least one solar panel (10) supported on a pivoting structure (12) tiltable in opposite first and second directions about a rotation axis (13) by a DC electric motor (M) a controller (14) and an actuator (15) controlling actuation of the electric motor (M), an inclinometer (16) fixed to the pivoting structure (12) and connected to the controller (14) to detect an actual physical positive or negative tilt angle of the solar panel (10) with respect to a horizontal plane, and a feed circuit (17) to apply a voltage having a selected polarity to the actuator (15) to produce rotation of the electric motor (M) either in the first direction or in the second direction. The actuator (15) comprises MOSFET-type first and second actuator transistors (Q1, Q2), each having a drain terminal (D), a source terminal (S) and a gate terminal (G), the first and second actuator transistors (Q1, Q2) having the drain terminals (D) respectively connected to first and second terminals (A, B) of the electric motor (M), the source terminals (S) respectively connected to first and second output terminals (1, 2) of the feed circuit (17), and the gate terminals (G) connected via the controller (14) to the inclinometer (16), and first and second diodes (D1, D2) connected in parallel between the drain terminals (D) and the source terminals (S) of the first and second actuator transistors (Q1, Q2) providing a bypass current path from the source terminals (S) of the first and second actuator transistors (Q1, Q2) to the first and second terminals (A, B) of the electric motor (M), and wherein either the first or the second actuator transistor (Q1, Q2) is put in an off state causing stop of the electric motor (M) upon receiving a positive or negative limit signal delivered by the inclinometer (16) when tilting of the pivoting structure (12) reaches a positive or negative limit tilt angle (PLTA, NLTA), the bypass current path provided by the corresponding first or second diode (D1, D2) allowing the electric motor (M) to turn in an opposite direction when an inverted voltage is applied.