Independent Peltier Elements for Laser Diode Thermal Control

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Solution Overview

Problem

Conventional Peltier cooler systems face reduced power supply efficiency and reliability when operating over a wider temperature range, particularly in military laser diode applications, as they require increased temperature differentials, leading to compromised performance and longevity.

Innovation Solution

A Peltier effect heat transfer system with electrically isolated semiconductor elements connected in series and parallel, featuring a controller that independently controls each element, allowing for variable current application and adaptive temperature management using multiple temperature sensors and look-up tables to maintain the laser diode chip within a specified temperature range across varying ambient conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single Peltier cooler is used to maintain laser diode chip temperature, then the temperature can be controlled within a specified range, but the operating temperature range is limited and power efficiency decreases when operating over wider temperature ranges

Engineering Contradiction:
Improveoperating temperature rangeVSAvoidpower efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The Peltier cooler is divided into multiple independent Peltier elements (first Peltier element, second Peltier element, etc.), each capable of being independently controlled. This segmentation allows the system to activate only the necessary elements based on ambient temperature conditions, maintaining temperature control efficiency while extending the overall operating temperature range.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically selects and activates specific Peltier elements based on ambient temperature conditions. The controller adjusts which elements are active and in what configuration (series or parallel) depending on the temperature range, optimizing power efficiency across different operating conditions while maintaining the laser diode chip within its specified temperature range.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If multiple stage Peltier coolers are used to increase temperature differential, then the operating temperature range is extended, but power supply efficiency is reduced and dissipated power increases

Engineering Contradiction:
Improvetemperature differential capabilityVSAvoidpower supply efficiency
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by stationary object

Solution Approach 1:

Instead of using multiple stages of Peltier coolers connected in series, the patent uses multiple independent Peltier elements that can be selectively activated. This approach achieves the same temperature differential capability while avoiding the cumulative power losses associated with multi-stage systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system activates only the necessary number of Peltier elements required to achieve the desired temperature differential, rather than always operating all elements or multiple stages. This partial action approach maintains temperature control while minimizing power consumption and improving power supply efficiency.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If multiple stage Peltier coolers are used to operate over wider temperature ranges, then the temperature differential is increased, but reliability of the Peltier cooler is reduced

Engineering Contradiction:
Improvetemperature range capabilityVSAvoidPeltier cooler reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system uses multiple independent Peltier elements where each element operates within its optimal temperature range. This segmentation prevents any single element from being subjected to excessive temperature differentials that would reduce reliability, while the combination of elements achieves the overall extended temperature range capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The controller dynamically changes the operating parameters (which elements are active, their connection configuration) based on ambient temperature conditions. This ensures that each active Peltier element operates within safe and reliable parameter ranges, preventing degradation and extending the overall system reliability across wide temperature ranges.

Inventive Principle:
Principle #35Parameter changes

4Device complexity

If a fixed reference voltage module is used to control Peltier cooler temperature, then the control is simple, but the system cannot adapt to varying ambient temperature conditions efficiently

Engineering Contradiction:
Improvecontrol system simplicityVSAvoidambient temperature adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The control system dynamically selects and activates specific Peltier elements based on ambient temperature sensor readings. This dynamic adaptation allows the system to efficiently handle varying ambient temperature conditions while maintaining relatively simple control logic through predefined activation rules for different temperature ranges.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses temperature sensors to continuously monitor both the laser diode chip temperature and ambient temperature. This feedback information is used by the controller to adjust which Peltier elements are active, creating an adaptive control system that responds to changing conditions while maintaining temperature control within the specified range.

Inventive Principle:
Principle #23Feedback

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

This solution enhances the operating range and power efficiency of laser transmitters, reduces thermal resistance, and increases reliability by selectively activating specific heat transfer elements, thereby maintaining the laser diode chip's temperature stability and extending the system's operational temperature range.

Implementation Method 1

a plurality of Peltier effect heat transfer elements, and wherein the heat transfer elements are independent such that each heat transfer element can be activated so as to yield Peltier effect heat transfer independently of each other heat transfer element

Methodology Applied
Scientific EffectPeltier effect: Peltier Effect

Data Source

PatentEP3207604B1Peltier effect heat transfer system
Publication Date: 2020.08.12 BAE SYSTEMS PLC
  • EP3207604B1 patent drawingFigure 1
  • EP3207604B1 patent drawingFigure 2
  • EP3207604B1 patent drawingFigure 3

AI summary

A Peltier effect heat transfer system (208) comprising: a plurality of heat transfer elements (301-308); wherein each heat transfer element (301-308) comprises at least one semiconductor element pair arranged to yield Peltier effect heat transfer, each semiconductor element pair comprising a P-doped semiconductor element (408) and an N-doped semiconductor element (410); and the heat transfer elements (301-308) are independent such that each heat transfer element (301-308) can be activated so as to yield Peltier effect heat transfer independently of each other heat transfer element (301-308).