Cooking Appliance Temperature Control Using Dynamic Power Modulation
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Solution Overview
Problem
Existing cooking appliances struggle with maintaining precise temperature control, often overshooting or undershooting set temperatures due to the on/off power heating method, leading to inconsistent cooking results.
Innovation Solution
A method and system using a TRIAC switching device to control the heating element with power input strategies that adjust power levels based on desired temperatures, incorporating formulas for on and off times to maintain consistent temperature, and adjusting power based on temperature change rates and ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If on/off power heating method is used, then the heating element can be controlled with simple binary states, but the temperature repeatedly overshoots the set temperature causing large fluctuations
Solution Approach 1:
The patent applies dynamics by transitioning from static binary on/off control to dynamic multi-level power control. The heating element operates at multiple power levels (e.g., 100%, 75%, 50%, 25%, 10%, 5%, 1%) rather than just two states, allowing continuous adjustment of heating intensity to match the dynamic thermal requirements of the cooking chamber and maintain consistent temperature.
Solution Approach 2:
The patent changes the control parameter from binary on/off states to continuous power level percentages. By adjusting the power delivery parameter across a spectrum from 1% to 100%, the system can precisely control the heating rate and respond to temperature changes, eliminating the temperature overshoot and fluctuation problems inherent in binary control.
2Measurement precision
If microprocessor controls power on and off rapidly, then temperature consistency improves to within 10°F, but the set temperature is still repeatedly passed during heating and cooling phases
Solution Approach 1:
The patent applies partial action by delivering only the necessary portion of maximum power required to reach and maintain the target temperature. Instead of always operating at full power or completely off, the system delivers partial power levels (e.g., 25%, 50%, 75%) that are sufficient to achieve the desired temperature without overshooting, thereby maintaining stability while avoiding repeated temperature excursions.
3Productivity
If heating element is powered at predetermined high-power level continuously, then heating efficiency is high, but temperature overshoots requiring complete power shutdown
Solution Approach 1:
The patent applies dynamics by making the power level adaptive rather than static. The system continuously monitors temperature and dynamically adjusts power delivery from high levels during heating phases to lower levels during maintenance phases, optimizing both heating efficiency and temperature control precision throughout the cooking process.
Solution Approach 2:
The patent implements periodic action through cyclic adjustments of power levels based on temperature feedback. The system alternates between higher power levels when temperature is below target and lower power levels when approaching or at target, creating a periodic control pattern that maintains temperature stability while preserving overall heating efficiency.
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 system achieves minimal temperature fluctuation, maintaining desired temperatures within a narrow range (2-4°F) over extended cooking periods without resorting to zero power, resulting in more consistent and precise cooking.
Implementation Method 1
a heating element for heating the cooking chamber
Implementation Method 2
Applicant has discovered a way to use a switching device (e.g., a TRIAC) for greater power control
Data Source
AI summary
A method for controlling a cooking temperature within a cooking appliance is described. The preferred method includes setting a desired cooking temperature (T) for the cooking appliance via a temperature setting input, and operating the heating element to raise an internal temperature within the cooking chamber based on a power input strategy. Preferably, the power input strategy includes selecting an initial power (PO) between 50% and 100% power, powering the heating element at the initial power using an on/off cycle of N milliseconds based on the formulas:on time=(Pi)·N milliseconds; andoff time=(100−Pi)·N milliseconds;then, reducing the initial power to a reduced power (Pr) as the rising internal temperature within the cooking chamber approaches the desired cooking temperature, wherein the reduced power (Pr) is between 1% and 99% power. Finally, the desired temperature is maintained within the cooking chamber.