PTC Heating Control Circuit for Fast Surface Temperature Rise
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Solution Overview
Problem
Traditional temperature control circuits for positive-temperature-coefficient heating components are slow in heating up the working surface due to a small temperature difference between the heating component and the working surface, resulting in a long heating time.
Innovation Solution
An accelerated initial heating control circuit is introduced, utilizing a single-pole double-through switch and temperature setting selector to adjust the voltage applied to the comparator, allowing for an initial higher setting temperature to rapidly heat the working surface, followed by a reduction to a normal setting temperature once the target temperature is reached, thereby increasing the heat transfer rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a traditional thermostat control circuit is used to maintain a constant temperature difference between the heating component and the working surface, then the temperature control is stable, but the heating time is long
Solution Approach 1:
The patent applies dynamics by making the temperature setting dynamic rather than static. The control circuit includes a timer that automatically adjusts the temperature setting in two stages: initially setting a higher temperature difference to accelerate heating, then reducing to a smaller temperature difference for maintenance. This dynamic adjustment resolves the contradiction between fast heating and stable temperature control.
Solution Approach 2:
The patent uses preliminary action by pre-setting a larger temperature difference at the beginning of the heating process. The timer controls the temperature-setting switch to initially connect to a higher temperature reference, enabling rapid heat transfer before switching to normal temperature control. This preliminary high-temperature phase accelerates heating without compromising subsequent stability.
2Productivity
If a larger temperature difference is maintained between the heating component and the working surface, then the heating rate increases, but the temperature control precision decreases
Solution Approach 1:
The patent applies periodic action through the timer that periodically switches the temperature setting between high and normal modes. The timer creates distinct heating phases: an initial high-temperature phase for rapid heating, followed by a normal-temperature phase for precise control. This periodic switching allows the system to enjoy both fast heating and precise temperature control at different times.
Solution Approach 2:
The patent segments the heating process into two distinct phases using the timer and temperature-setting switch. The first phase uses a larger temperature difference for rapid heating, while the second phase uses a smaller temperature difference for precise control. This segmentation allows each phase to optimize for its specific goal without compromising the other.
3Speed
If the temperature-setting voltage is increased to accelerate heating, then the heating speed improves, but the energy consumption increases
Solution Approach 1:
The patent applies the skipping principle by rushing through the initial heating phase with high power to quickly reach the target temperature, then switching to low-power maintenance mode. The timer controls the temperature-setting switch to initially connect to a higher temperature reference, enabling rapid heating, then automatically switches to normal temperature control to minimize energy consumption during the maintenance phase.
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 approach significantly reduces the heating time by maintaining a larger temperature difference between the heating component and the working surface, ensuring the working surface is rapidly heated and maintained at the target temperature.
Implementation Method 1
Heating components with a positive temperature coefficient may use an alloy resistor, such as metal-ceramic heater, metal wire, and so on. A noteworthy characteristic of positive-temperature-coefficient heating components (hereinafter referred to the heating components) is that their resistance continues to become larger with an increasing temperature.
Implementation Method 2
Thermal conductor 2 transmits heat from heating component 4 at the center of the product to working surface 3 on the outside of the product.
Implementation Method 3
In the positive half-cycle of the AC power, SCR 206 is switched on, and heating component 208 begins heating.
Data Source
AI summary
Traditional temperature-control products have the problem that the temperature of the working surface reaches the setting temperature too slowly when heating up or recovering from a temperature drop. A traditional temperature control circuit and temperature-settings selector components are modified to solve this problem. When heating begins, the modified circuit increases the initial setting temperature to be above the target setting temperature. The modified circuit then adjusts the setting temperature by measuring the heating power consumption. Once the working surface of the temperature control product reaches the initial setting temperature, the heating power consumption drops and the modified circuit reduces the temperature setting to the target setting temperature. The temperature control product can rapidly achieve the target temperature. A positive-temperature-coefficient heating component is used in the temperature control product.