Integrated Temperature Control Module With Inter-Channel Isolation
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Solution Overview
Problem
Existing temperature control devices in PLC systems face challenges in independently setting operations for each module, leading to inefficiency and increased manufacturing costs due to the need for inter-channel working voltage and isolation, which complicates the configuration and affects PID control performance.
Innovation Solution
A temperature control apparatus that integrates a thermocouple input module and transistor output module as a single module, utilizing input-side and output-side isolators with opto-isolators and solid-state relays to achieve inter-channel isolation without requiring a separate PCB plane configuration for each channel, thereby reducing manufacturing costs and space constraints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If separate input module and output module are used in PLC, then each module can be independently configured, but the temperature control device occupies two PLC base slots and increases complexity
Solution Approach 1:
The patent combines the temperature input module and transistor output module into a single integrated temperature control module that occupies only one PLC base slot. This merging eliminates the need for separate configuration of multiple modules while maintaining all necessary functions, thereby reducing device complexity and installation space without sacrificing operational independence.
2Device complexity
If a single module integrates temperature input and transistor output functions, then PLC base slot occupation is reduced to one slot, but it becomes difficult to secure inter-channel isolation characteristics
Solution Approach 1:
The patent divides the single integrated module into separate input and output channels with dedicated isolation mechanisms. Each channel is electrically isolated using opto-isolators and solid-state relays, ensuring that signals from different thermocouples do not interfere with each other. This segmentation maintains inter-channel isolation characteristics while keeping the module compact and integrated.
Solution Approach 2:
The patent introduces opto-isolators and solid-state relays as intermediary components between the thermocouple input channels and the transistor output. These intermediaries provide electrical isolation while allowing signal transmission, thereby securing inter-channel isolation characteristics without requiring separate PCB plane configurations for each channel.
3Reliability
If separate hardware is configured for each input channel to secure isolation, then inter-channel isolation is achieved, but manufacturing cost increases significantly
Solution Approach 1:
The patent implements a universal isolation architecture where opto-isolators and solid-state relays are shared across multiple input channels within the single module. This multi-functional approach provides inter-channel isolation for all channels while avoiding the need for duplicate isolation hardware in each channel, thereby significantly reducing manufacturing costs compared to fully separate hardware configurations.
4Ease of manufacture
If multiplexer is used to overcome manufacturing cost and space constraints, then cost and space are reduced, but inter-channel working voltage requirement cannot be satisfied
Solution Approach 1:
The patent uses opto-isolators as intermediary components that can handle inter-channel working voltage requirements. These opto-isolators provide electrical isolation while maintaining signal integrity, allowing the single integrated module to satisfy both cost/space constraints and inter-channel working voltage requirements that a simple multiplexer cannot achieve.
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 reliable inter-channel isolation, reduces manufacturing costs, and ensures high reliability for industrial applications by integrating thermocouple input and transistor output functions within a single module, while maintaining effective PID control performance and minimizing temperature measurement errors.
Implementation Method 1
utilizing input-side and output-side isolators with opto-isolators
Implementation Method 2
utilizing input-side and output-side isolators with solid-state relays
Data Source
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AI summary
A temperature control apparatus includes an analog to digital converter to convert measurement values transmitted from a plurality of temperature sensors, a control means comparing the measurement value transmitted from the AD converter with a preset desired value to perform PID calculation and an output unit transmitting a pulse width modulation control signal. Input-side isolators located between each of the plurality of temperature sensord and the AD converter are used to isolate the temperature sensors and are sequentially operated by the control means.