Thermal Imager Shutter Circuit for Intrinsic Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thermal imagers used in hazardous and explosive environments face challenges in ensuring intrinsic safety due to potential ignition risks from electrical components, and existing solutions do not adequately control electrical energy to prevent fires.
Innovation Solution
A thermal imager design incorporating a shutter mechanism operated by a motor with controlled electrical energy, utilizing a capacitor, diode, and resistor circuit to limit voltage and current, ensuring the system is intrinsically safe by reducing electrical energy to nonincendiary levels, and including a Non-Uniformity Correction (NUC) process for recalibrating detectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the voltage supplied to the motor is increased to provide sufficient torque for the shutter mechanism, then the motor can move the shutter between positions, but the electrical energy may reach incendiary levels and cause fire in hazardous environments
Solution Approach 1:
The patent introduces an intermediary electrical circuit containing passive components (resistors, capacitors, diodes) between the power source and the motor. These components act as mediators that transform and limit the electrical energy, ensuring that even when high voltage is applied to the motor, the energy levels reaching potential ignition sources remain below incendiary thresholds, thus enabling sufficient torque while preventing fire hazards in explosive atmospheres.
Solution Approach 2:
The patent changes the electrical parameters (voltage, current, power) dynamically through the passive components in the circuit. By adjusting these parameters through resistance, capacitance, and diode characteristics, the system ensures that the motor receives sufficient power for operation while the overall energy levels in the system remain controlled below ignition thresholds, resolving the contradiction between force requirements and safety.
2Object-affected harmful factors
If the electrical energy in the circuit is controlled to nonincendiary levels for intrinsic safety, then fire prevention is achieved, but the motor may not have sufficient power to move the shutter mechanism
Solution Approach 1:
The patent segments the electrical circuit into multiple sections with dedicated passive components (resistors, capacitors, diodes) distributed throughout the power delivery path. This segmentation allows different portions of the circuit to handle different aspects of power management, ensuring that while the overall system remains intrinsically safe with limited energy, the motor section receives sufficient localized power for shutter actuation without creating ignition hazards.
Solution Approach 2:
The patent employs periodic or pulsed power delivery through the capacitor components in the circuit. The capacitors can store electrical energy and release it in controlled pulses to the motor, providing high power transiently when needed for shutter movement while maintaining lower average power levels that keep the system intrinsically safe and below ignition thresholds in hazardous environments.
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
The solution allows for safe operation of thermal imagers in hazardous environments by controlling electrical energy to prevent ignition, ensuring the system is intrinsically safe and capable of recalibrating detectors to maintain accurate thermal imaging.
Implementation Method 1
The electrical circuit comprises one or more of a capacitor, a diode, and a resistor
Implementation Method 2
The electrical circuit comprises one or more of a capacitor, a diode, and a resistor
Implementation Method 3
a motor operably connected to the shutter for moving the shutter between a first and a second position
Implementation Method 4
A thermal imager detects infrared radiation emitted from an object or scene within its field of view. It converts the infrared radiation emitted into electrical signals
Implementation Method 5
The microbolometer measures the energy on incident electromagnetic radiation and is typically a grid of heat sensors comprising vanadium oxide or amorphous silicon. Infrared radiation that strikes the vanadium oxide changes its electrical resistance
Data Source
AI summary
A thermal imager includes a detector, a lens, a shutter disposed between the detector and the lens, and a motor operably connected to the shutter for moving the shutter between a first and a second position. There is a source of electrical energy operably connected to one or more of the detector, lens and motor by an electrical circuit. The electrical circuit includes one or more of a capacitor, a diode, and a resistor.