LC Resonant Spark and Flame Signal Generator With Load Compensation
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Solution Overview
Problem
Existing combustion systems for gas heating require expensive high-voltage components to generate both spark ignition and flame sensing signals, which increases costs and complexity.
Innovation Solution
A low-cost generator using a low-voltage LC resonant circuit to produce high-voltage AC for flame sensing and rectified spark voltage, with a controller managing frequency and duty cycle for efficient spark and flame timing, and a compensation circuit to mitigate loading effects on the flame sensing network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a DCDC converter and switching circuit are used to generate high voltage for spark and AC signal for flame sensing, then the required functions are achieved, but the cost and device complexity increase due to requiring several high voltage parts
Solution Approach 1:
The patent combines the spark generation and flame sensing signal generation into a single LC resonant circuit. The same circuit that generates high voltage for spark ignition also produces the AC signal needed for flame sensing, eliminating the need for separate DCDC converters and switching circuits. This merging of functions directly reduces the number of high voltage parts required.
Solution Approach 2:
The LC resonant circuit is designed to serve multiple functions: it generates high voltage for spark ignition, produces AC signal for flame sensing, and can be controlled to provide both functions from a single circuit architecture. This multi-functionality approach allows one circuit to replace what would traditionally require multiple specialized components.
2Reliability
If high voltage parts are used to generate spark and flame sensing signals, then the required functions are achieved, but the cost increases
Solution Approach 1:
The patent employs low-cost LC resonant circuit components instead of expensive high voltage parts. By using standard inductors and capacitors in a resonant configuration, the system achieves high voltage generation and AC signal production using inexpensive, readily available components that can be easily manufactured and replaced if needed.
3Reliability
If flame sensing signal is transmitted through appliance wiring, then the sensing function is achieved, but the measurement precision decreases due to loading effect that reduces the AC signal level
Solution Approach 1:
The patent incorporates a compensation circuit that monitors the flame sensing signal and actively compensates for the loading effect caused by appliance wiring. The circuit detects the signal reduction and adjusts the output accordingly to maintain accurate flame sensing measurements despite the presence of long wiring runs.
Solution Approach 2:
The compensation circuit acts as an intermediary between the LC resonant circuit and the flame sensing network. It introduces corrective elements that offset the detrimental loading effect of the appliance wiring, effectively mediating the signal transmission to preserve measurement accuracy.
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 solution reduces costs by using low-voltage components, enhances efficiency with precise control of spark and flame voltages, and improves accuracy in flame sensing by minimizing signal reduction due to appliance wiring, achieving reliable and cost-effective operation.
Implementation Method 1
an inductive-capacitive (LC) resonant circuit 16 to generate the AC high voltage for flame sensing
Implementation Method 2
When FlameDrivePWM 15 is at a resonant frequency of the LC circuit 16 containing an inductor 17 and capacitor 18, a high voltage near sinusoidal waveform may be generated
Implementation Method 3
The AC voltage may be rectified to generate the spark voltage
Data Source
AI summary
A system for generating a high DC voltage for a spark to ignite a flame in a combustion device, and a high AC voltage for a flame rod to sense a flame in the device, from a low voltage for combustion device control. The system may be an inexpensive mechanism.