Ceramic Tube Inductor With Zero Temperature Coefficient
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inductors are sensitive to temperature variations, limiting their effectiveness in high-temperature environments and requiring complex, costly electronics for signal conditioning, which complicates their use in harsh conditions.
Innovation Solution
An inductor design featuring a hollow ceramic tube with a metal target rod and a coil outside, using an LC resonant circuit with coaxial cables to separate the electronics from the sensing element, allowing operation in harsh environments up to 200°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional inductor design is used, then the inductor can function as a passive electronic component, but it becomes sensitive to temperature variations and requires complex electronics for signal conditioning
Solution Approach 1:
The inductor is segmented into distinct functional components: a hollow nonconductive tube (ceramic or plastic), a target rod inside the tube, and a coil outside the tube. This segmentation allows each component to be optimized for its specific function and enables the sensing element to operate independently in harsh environments while electronics remain separate.
Solution Approach 2:
The hollow nonconductive tube serves as an intermediary between the target rod and the coil, providing electrical isolation while allowing magnetic field interaction. This intermediary enables the target rod to move freely inside the tube without electrical contact, reducing friction and wear while maintaining the inductive sensing function.
2Temperature
If the inductor operates in high-temperature environments, then it can function in harsh conditions, but temperature variations affect its accuracy and sensitivity
Solution Approach 1:
The patent changes the physical parameters of the inductor components to achieve temperature insensitivity. The hollow nonconductive tube and target rod are selected with specific thermal expansion coefficients that compensate for temperature-induced changes in the coil's inductance, maintaining measurement precision across a wide temperature range from -65°C to 200°C.
Solution Approach 2:
The inductor uses composite construction combining different materials with complementary properties: the hollow tube is made of ceramic or plastic with specific thermal properties, the target rod is made of a different material with matching thermal expansion characteristics, and the coil is wound with temperature-stable wire. This composite approach enables the assembly to maintain dimensional stability and electrical characteristics across extreme temperatures.
3Reliability
If complex electronics are used for signal conditioning, then the inductor can operate in harsh environments, but the cost and size increase
Solution Approach 1:
The sensing function is extracted from the electronics and embodied in the passive inductor structure itself. The hollow nonconductive tube with target rod and coil forms a self-contained sensing element that generates the measurement signal without requiring active electronic components in the harsh environment, allowing electronics to be located remotely where conditions are benign.
Solution Approach 2:
The patent creates a simplified model of the sensing function using passive electromagnetic components rather than complex active electronics. The inductor structure itself becomes the sensor, copying the measurement function from traditional electronic sensors to a passive electromagnetic field-based system that is inherently more robust in harsh 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 inductor maintains accuracy and sensitivity while being compact and cost-effective, enabling remote signal processing and reducing the need for complex electronics in extreme temperatures.
Implementation Method 1
a coil wound on the outside of the hollow ceramic tube and including a first end and a second end
Implementation Method 2
An LC resonant circuit including the inductor
Data Source
AI summary
An inductor for use as a passive electronic component. The inductor has a hollow ceramic tube, a metal target rod located inside the hollow ceramic tube, a coil wound on the outside of the hollow ceramic tube and including a first end and a second end, and a first terminal engaging the first end of the coil and a second terminal engaging the second end of the coil. The metal target rod is fixed relative to the coil at a position so that the inductor has a zero temperature coefficient. Also provided is an LC resonant circuit including the inductor.