Two-Wire Heater Temperature Limiting Without Discrete Sensors
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Solution Overview
Problem
Existing thermal systems with two-wire heaters face challenges in efficiently controlling temperature and reducing complexity and cost by relying on discrete temperature sensors, which can delay power shut-off and increase system complexity.
Innovation Solution
A temperature limiting device with a modular unit that includes a heater interface, power interface, and a controller with a sensor circuit to measure electrical characteristics of the two-wire heater, allowing for temperature calculation and power control to prevent overheating, thereby reducing the need for discrete sensors and enhancing response time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If discrete temperature sensors are used to monitor heater temperature, then temperature measurement capability is provided, but system complexity and cost increase
Solution Approach 1:
The patent combines the temperature sensing function with the existing two-wire heater by utilizing the heater's power wires to carry both power and temperature sensing signals. The temperature sensing is achieved by measuring the voltage drop across the heater element itself, eliminating the need for separate discrete temperature sensors and reducing system complexity.
Solution Approach 2:
The two-wire heater is designed to perform multiple functions: it serves as both the heating element and the temperature sensing device. By measuring the electrical characteristics (voltage, current, resistance) of the heater element, the system can determine temperature without requiring dedicated sensing components, thus reducing overall system complexity.
2Measurement precision
If discrete temperature sensors are used to monitor heater temperature, then temperature measurement capability is provided, but cost increases
Solution Approach 1:
The patent combines the temperature sensing function with the existing two-wire heater by utilizing the heater's power wires to carry both power and temperature sensing signals. The temperature sensing is achieved by measuring the voltage drop across the heater element itself, eliminating the need for separate discrete temperature sensors and reducing system complexity.
Solution Approach 2:
The two-wire heater is designed to perform multiple functions: it serves as both the heating element and the temperature sensing device. By measuring the electrical characteristics (voltage, current, resistance) of the heater element, the system can determine temperature without requiring dedicated sensing components, thus reducing overall system complexity.
3Measurement precision
If discrete temperature sensors are used in the thermal system, then temperature monitoring is achieved, but response time is delayed
Solution Approach 1:
The patent combines the temperature sensing function with the existing two-wire heater by utilizing the heater's power wires to carry both power and temperature sensing signals. The temperature sensing is achieved by measuring the voltage drop across the heater element itself, eliminating the need for separate discrete temperature sensors and reducing system complexity.
Solution Approach 2:
The system continuously monitors the electrical characteristics of the heater element and uses this feedback to determine temperature in real-time. The controller adjusts power delivery based on the measured temperature, creating a closed-loop control system that responds quickly to temperature changes without the delays associated with discrete sensors.
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 enables efficient temperature control and power management in thermal systems, reducing complexity and cost by directly measuring and limiting temperature, allowing for faster response times and integration with existing systems, while serving as a safety mechanism to prevent overheating.
Implementation Method 1
the two-wire heater has a varying temperature coefficient of resistance, and the performance characteristic is a resistance of the two-wire heater at a temperature
Implementation Method 2
Resistive heaters are used in a variety of applications to provide heat to a load
Data Source
AI summary
A thermal system includes a two-wire heater and a power switch. The power switch is to provide power to the two-wire heater from a power source based on a control signal. The thermal system includes a controller having a sensor circuit configured to measure an electrical characteristic of the two-wire heater. The controller is to calculate a temperature of the thermal system based on a change in the measured electrical characteristic and determine whether the temperature is greater than a temperature setpoint. The controller is to output the control signal based on the determination.