Staggered Resistor Switching for Uniform Heating and Low EMI
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical resistor heating systems face inefficiencies in power distribution, leading to simultaneous energization of heating resistors, which can result in uneven heat generation and electromagnetic compatibility issues, such as harmonics and flicker generation.
Innovation Solution
An electrical resistor heating circuitry with an AC power source, multiple heating resistors arranged spatially, and switches that switch between ON and OFF states in a staggered manner, controlled by a power scheduler to adjust power levels non-simultaneously, ensuring efficient and uniform heat distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If multiple heating resistors are energized simultaneously, then the heating coverage is maximized, but electromagnetic interference and flicker increase
Solution Approach 1:
The patent applies periodic action by energizing heating resistors in alternating phases rather than simultaneously. The power scheduler activates different groups of resistors in sequential time intervals, creating a periodic heating pattern that maintains overall heating coverage while reducing peak electromagnetic interference and flicker effects associated with simultaneous energization of all resistors.
Solution Approach 2:
The patent segments the heating system into multiple independently controllable resistor groups. The power scheduler divides the plurality of heating resistors into different phases or groups that can be energized separately. This segmentation allows the system to maintain comprehensive heating coverage by activating different segments at different times, thereby reducing the harmful electromagnetic effects that occur when all segments are activated simultaneously.
2Productivity
If all heating resistors are energized at full power, then the heating efficiency is maximized, but power distribution uniformity decreases
Solution Approach 1:
The patent applies local quality by enabling the power scheduler to independently control the power level delivered to each heating resistor or resistor group. Different regions or phases of the heating system can receive different power levels based on local heating requirements, achieving uniform overall power distribution while maintaining high heating efficiency in areas that require maximum power.
Solution Approach 2:
The patent implements dynamics by making the power distribution to heating resistors adjustable and time-variable. The power scheduler can dynamically modify which resistors are energized and at what power levels, allowing the system to adapt power distribution in real-time to maintain uniformity across different spatial regions while preserving overall heating efficiency.
3Adaptability or versatility
If switches are used to control power to heating resistors, then power adjustment flexibility is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by designing the power scheduler to perform multiple functions: it controls the timing of resistor energization, adjusts power distribution levels, manages phase sequencing, and maintains overall system coordination. This multi-functional approach consolidates what could be multiple separate control mechanisms into a single universal controller, reducing overall device complexity while maintaining high power adjustment flexibility.
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
This solution achieves efficient, uniform heat generation with reduced electromagnetic interference, no flicker, and low harmonics, maintaining a constant power factor and impedance, while allowing for flexible spatial power distribution and inherent redundancy for fault tolerance.
Implementation Method 1
electrical resistor heating circuitry comprising an AC power source of at least one phase, a plurality of heating resistors provided in a spatial arrangement
Data Source
AI summary
Electrical resistor heating with an electrical resistor heating circuitry which includes an AC power source of at least one phase, a plurality of heating resistors provided in a spatial arrangement, and switches to connect the AC power source with the heating resistors generating ON and OFF power states. Power scheduling is provided to adjust the power fed from the AC power source to the heating resistors at a desired partial-power level by ON/OFF switching a number of switches, wherein the power scheduling causes at least some of the switches to switch between the ON and OFF states in a staggered manner so that energization of the partial-power level of different resistors takes place, at least partially, non-simultaneously.