Vehicle PTC Heater Staging for Preheating Without Cold Air
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Solution Overview
Problem
Conventional Positive Temperature Coefficient (PTC) heaters require the blower to be activated first, leading to initial discharge of cold air and potential overheating issues, as they take time to heat up and are deactivated when the blower is turned off, making them inefficient for quick air heating.
Innovation Solution
A multistage control system that activates the first stage of the PTC heater via an Electronic Control Unit (ECU) signal, with the second and third stages controlled by relevant controllers, allowing preheating regardless of blower activation, using relays to manage the stages and battery voltage conditions for safe and efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the PTC heater is activated only after the blower operates, then overheating is prevented, but cold air is discharged into the passenger compartment during the initial heating period
Solution Approach 1:
The patent activates the first stage of the PTC heater before the blower operates, performing preliminary heating action. The control unit allows the heater to run in advance, preheating the air inside the heater housing, so that when the blower starts, warm air is immediately supplied to the passenger compartment instead of cold air.
Solution Approach 2:
The PTC heater is divided into multiple stages (first, second, and third stages) with different power levels. The first stage operates before and during blower activation for preheating, while higher stages are activated subsequently based on battery voltage conditions, allowing gradual heating without immediate full power that would cause overheating.
2Productivity
If the PTC heater operates while the blower is deactivated, then preheating can occur, but the heater may overheat due to windless conditions
Solution Approach 1:
The system performs preliminary heating action by activating the first stage before blower operation, but limits the heating duration and power level during this preheating phase. The control unit monitors operation time and battery voltage to prevent excessive heat accumulation during windless conditions.
Solution Approach 2:
The heater operates dynamically with different control strategies based on blower status. When the blower is off, only the first stage operates at reduced power for limited time. When the blower activates, higher stages can be engaged, and the control system continuously adjusts operation based on real-time conditions to prevent overheating.
3Reliability
If the PTC heater takes 20 seconds to heat up after blower activation, then safe operation is ensured, but the heating response time is delayed
Solution Approach 1:
The control unit activates the first stage of the PTC heater before the blower operates, performing preliminary heating. This advance action reduces the heating delay from 20 seconds to a much shorter period, as the heater core is already warm when air circulation begins.
Solution Approach 2:
The system prepares the heating element in advance by activating it during the period before blower operation. This beforehand cushioning ensures that when the blower activates, the heater is already at or near operating temperature, eliminating the cold air discharge period and providing immediate heating response.
4Object-generated harmful factors
If the blower is turned off to prevent cold air discharge, then cold air blowing is avoided, but the PTC heater is deactivated along with it
Solution Approach 1:
The system performs preliminary heating by activating the PTC heater before blower operation. This allows the heater to reach operating temperature while the blower is still off, so when the blower activates, warm air is immediately supplied without needing to turn the heater off and on again, maintaining continuous heating function.
Solution Approach 2:
The control system dynamically manages the independent operation of the heater and blower. The heater can operate in different modes: preheating mode (blower off, heater on), heating mode (both on), and the system continuously adjusts based on temperature sensors and user requirements, allowing flexible operation without rigid coupling between heater and blower activation.
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
Prevents cold air discharge during initial operation by preheating the vehicle interior and avoids overheating, ensuring efficient and safe heating by managing stage activation based on battery voltage and time delays, enhancing the practicality of the PTC heater.
Implementation Method 1
Positive Temperature Coefficient (PTC) heater that contains heating elements relevant to a first, second, and third stages
Implementation Method 2
Positive Temperature Coefficient (PTC) heater
Data Source
AI summary
A multistage control system of a Positive Temperature Coefficient (PTC) heater for a vehicle is disclosed with a PTC heater that contains heating elements relevant to a first, second, and third stages. An Electronic Control Unit (ECU) outputs a control signal to a first relay, which switches the first stage into an ON and OFF state, for controlling the operation of the first stage of the PTC heater. A heater controller outputs control signals to a second relay and third relay, respectively, for controlling the operation of the second and third stages of the PTC heater, only if the first stage of the PTC heater is in activation via the ECU, wherein the second relay and the third relay each switch the second and third stages into an ON and OFF state.