Flame Sensing Circuit With Regulated Power for Fast Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flame sensing systems in heating appliances are bulky, slow, and expensive due to the use of low-frequency transformers, leading to potential gas leakage and fire hazards from delayed flame detection, and are inconsistent due to unregulated input power.
Innovation Solution
A flame sensing system with a power regulating device generating a regulated voltage, a flame current detector, and multiple level detectors to provide precise flame strength and presence signals, operating at higher frequencies for faster response and immunity to power fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If low-frequency transformers are used in conventional flame sensing systems, then the system can detect flame presence or absence, but the system becomes bulky, slow, and expensive with delayed response time
Solution Approach 1:
The patent changes the operating frequency parameter from conventional 50/60 Hz to high frequency (e.g., 400 Hz or higher). This parameter change enables the use of smaller, lighter transformers while achieving faster flame detection response time, directly resolving the contradiction between reliability and speed.
Solution Approach 2:
The patent replaces the conventional low-frequency electromagnetic transformer system with a high-frequency switching power supply system. This substitution eliminates the need for bulky low-frequency transformers and enables faster response through electronic switching, resolving both the speed and size constraints.
2Reliability
If low-frequency transformers are used in conventional flame sensing systems, then the system can operate, but the system becomes bulky and expensive
Solution Approach 1:
By changing the operating frequency to high frequency, the patent reduces the size and weight of the transformer. High-frequency transformers require smaller magnetic cores and windings, directly addressing the weight and size issues while maintaining flame detection capability.
Solution Approach 2:
The patent substitutes the heavy low-frequency transformer with a lightweight high-frequency switching transformer. This replacement dramatically reduces the weight of stationary components while preserving the essential flame detection function.
3Ease of operation
If unregulated input power is used in conventional flame sensing systems, then the system can function, but the flame sense output signal becomes inconsistent
Solution Approach 1:
The patent introduces a power regulating device as an intermediary between the input power source and the flame sensing circuitry. This intermediary component stabilizes the input voltage, ensuring consistent operation of the high-voltage generator and flame detection circuit, thereby resolving the output signal inconsistency issue.
Solution Approach 2:
The patent implements voltage regulation to maintain stable operating parameters despite input power variations. By controlling the voltage parameter through regulation circuitry, the system achieves consistent flame detection output while maintaining operational simplicity.
4Reliability
If conventional flame sensing systems are used, then the system can detect flame presence, but the response time is delayed causing gas leakage and fire hazards
Solution Approach 1:
The patent changes the frequency parameter to high frequency, enabling faster response time that prevents gas leakage and fire hazards. The high-frequency operation allows the system to detect flame absence almost immediately, eliminating the delayed response that causes safety hazards.
Solution Approach 2:
The patent replaces the slow mechanical/electromagnetic system with a high-frequency electronic system that provides immediate response. This substitution enables real-time detection and response to flame conditions, preventing the harmful effects of delayed detection.
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 enables rapid, precise, and reliable flame detection and strength measurement, reducing the risk of gas leakage and fire hazards while being compact and cost-effective.
Implementation Method 1
The transformer can provide a high voltage to the flame detection circuit and a flame current for a conductivity provided by the flame. In operation, when the flame is lit, the flame sensing system detects a current (e.g., alternating current (AC)) conducted from the flame sense probe, through the flame, and back to ground.
Implementation Method 2
The power regulating device can be electrically coupled to the flame sense probe and configured to generate a regulated voltage from an input voltage received from a power source and output the regulated voltage to the flame sense probe.
Data Source
AI summary
A flame sensing system, a flame sensing unit, and a method for sensing a flame are described. The flame sensing system includes a flame sense probe and a power regulating device. The power regulating device is configured to generate a regulated voltage from an input voltage received from a power source and to output the regulated voltage to the flame sense probe such that a flame current along a flame can be measured. The flame sensing system also includes a flame current detector to measure the flame current and generate an output voltage corresponding to the flame current, and a first level detector to generate a flame strength output signal based on the output voltage, where the flame strength output signal is indicative of a strength of a flame.