Hybrid Relay Circuit for Fine-Grained Heating Power Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heating element control systems, such as those using mechanical relays, offer limited granularity in adjusting heating power, typically providing only a few heating levels, which is insufficient for applications requiring finer control.
Innovation Solution
A circuit and system combining mechanical relays with solid-state relays, where the solid-state relay is controlled by a pulse-width modulated signal to provide a larger number of heating levels, while maintaining cost-effectiveness and space efficiency by using conventional mechanical relays for baseline heating power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multiple mechanical relays are used to control heating elements independently, then the system provides simple and cost-effective control, but the granularity of heating power adjustment is limited
Solution Approach 1:
The patent combines mechanical relays with solid-state relays (SSR) in a hybrid control system. The mechanical relay provides baseline heating power control while the SSR enables fine-grained power adjustment through PWM modulation, achieving both cost-effectiveness and high granularity of heating levels.
Solution Approach 2:
The patent replaces part of the mechanical relay system with a solid-state relay controlled by PWM signals. This substitution maintains the simple and robust mechanical relay structure for coarse control while introducing electronic PWM control for fine-grained adjustment, resolving the contradiction between simplicity and adjustment granularity.
2Adaptability or versatility
If a solid-state relay with PWM control is used to increase heating levels, then the granularity of heating power adjustment is improved, but the circuit complexity and cost increase
Solution Approach 1:
The patent segments the control function into two parts: the mechanical relay handles coarse-level switching for baseline heating power, while the solid-state relay with PWM control handles fine-grained adjustment. This segmentation allows the system to achieve high heating level granularity without requiring the entire system to be complex.
Solution Approach 2:
The mechanical relay serves multiple functions: it provides robust switching capability and establishes baseline heating levels. The solid-state relay complements this by providing fine-grained PWM control. This multi-functionality approach allows each component to be optimized for its specific role, reducing overall system complexity while achieving high adaptability.
3Measurement precision
If more heating levels are provided with finer granularity, then the control precision is improved, but the space required for circuitry increases
Solution Approach 1:
The patent replaces additional mechanical relays with a solid-state relay controlled by PWM signals. The SSR achieves fine-grained power control through electronic modulation rather than through multiple discrete mechanical switches, significantly reducing the space required for circuitry while maintaining high control precision.
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 combination allows for continuous adjustment of heating power, increasing the number of available levels and providing a cost-efficient, space-saving solution for heating element control.
Implementation Method 1
heating elements such as positive-temperature-coefficient (PTC) heating elements or resistive wire heating elements are employed
Data Source
AI summary
A circuit comprises a mechanical relay and a solid-state relay. The mechanical relay is configured to switch a first supply current of the first heating element on a first supply line. The solid-state relay is configured to switch a second supply current of a second heating element on a second supply line.