Control system
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Solution Overview
Problem
Existing control systems for thermo-electric coolers (TECs) face challenges in miniaturization due to high power dissipation and complexity, particularly with linear current sources and digital controllers, which are not compatible with small-scale applications and struggle with dynamic temperature control across wide ranges.
Innovation Solution
A controller system that includes a voltage selection circuitry to minimize potential difference across the current source, using analogue circuitry for non-linear control and a current boost mechanism to provide additional current when needed, allowing for efficient and localized thermo-electric cooling or heating with reduced power dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If linear current sources are used to drive TEC, then continuous current control is achieved, but power dissipation becomes too high for miniaturized transistors
Solution Approach 1:
The patent employs pulse-width modulation (PWM) to convert continuous current control into periodic pulsed action. The current source switches between on and off states at high frequency, with the duty cycle determining the average current. This periodic switching enables continuous effective current control while allowing the actual current to be zero during off-periods, dramatically reducing power dissipation in the current source transistors.
Solution Approach 2:
The patent introduces dynamic voltage selection where the voltage supplied to the TEC is dynamically adjusted based on operating conditions. By selecting from multiple voltage levels (e.g., 5V, 3.3V, 1.8V, 1.2V), the system optimizes the voltage across the TEC to minimize power dissipation in the current source while maintaining required current control capability across different temperature ranges and load conditions.
2Adaptability or versatility
If digital controllers are used for wide temperature range control, then dynamic temperature control is improved, but device complexity increases with ADCs, DACs, clocks and processors
Solution Approach 1:
The patent extracts the complex digital control functions (ADC, DAC, processing) from the miniaturized TEC controller and relocates them to an external host system or separate control device. The embedded controller retains only essential functions: temperature sensing, PWM generation, and voltage selection. This extraction dramatically reduces the complexity and size of the integrated controller while preserving dynamic temperature control capability through communication with the external system.
Solution Approach 2:
The patent implements a universal voltage selection mechanism that serves multiple functions: minimizing power dissipation in the current source, adapting to different TEC operating ranges, and enabling efficient heat pumping across wide temperature differences. The same voltage selection circuitry that optimizes power consumption also enables the system to operate effectively across the full temperature range without requiring separate control circuits for different operating modes.
3Adaptability or versatility
If voltage compliance is increased to drive current through TEC across wide temperature ranges, then adaptability is improved, but power dissipation in current source increases
Solution Approach 1:
The patent implements dynamic voltage selection where the voltage supplied to the TEC is adjusted in real-time based on the operating temperature range and required current. The system selects from multiple discrete voltage levels (e.g., 5V, 3.3V, 1.8V, 1.2V) to match the specific operating conditions. This dynamic adjustment ensures adequate voltage compliance for wide temperature range operation while minimizing power dissipation by using the lowest sufficient voltage at any given moment.
Solution Approach 2:
The patent changes the voltage parameter dynamically based on operating conditions. By monitoring temperature and current requirements, the system transitions between different voltage levels to maintain optimal power efficiency. For example, at lower temperature differences requiring less voltage headroom, the system switches to lower voltage levels, thereby reducing power dissipation in the current source while still maintaining the ability to drive required currents.
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
Enables the miniaturization of TEC control cells, allowing for scalable and efficient independent temperature control across multiple locations with reduced power consumption and increased reliability.
Implementation Method 1
Thermo-electric cooling makes use of the Peltier effect in which electric current passing across the junction of two dissimilar conductors causes, depending on the direction of current flow, a heating effect or a cooling effect
Data Source
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AI summary
A controller for a thermo-electric cooler is disclosed. The controller comprises a current source for providing current for driving the thermo-electric cooler and a plurality of voltage supply connections for providing a plurality of different voltages for driving current controlled by the current source through the thermo-electric cooler. Voltage selection circuitry is provided for selecting a voltage from the plurality of different voltages, when connected, and for applying the voltage selected to the thermo-electric cooler. When selecting the voltage from the plurality of different voltages, the voltage selection circuitry is configured to select the voltage that, when compared to the other voltages of the plurality of voltages, minimises a potential difference across the current source.