Speaker
Description
It is essential to precisely control the various thermodynamic variables if novel quantum states and transport properties are to be characterized in modern experimental physics. Traditional cryogenic systems, however, are usually too expensive, tend to be bulky, and do not have the flexibility needed for use in specially constructed laboratory setups. In order to overcome this limitation, a low-cost, compact, and highly stable temperature control unit based on a microcontroller has been developed using solid-state thermoelectric cooling. The system makes use of a multi-stage stacked Peltier arrangement, combining a high-power TEC112715 module with a low-power TEC112706 module, in order to counteract passive thermal back-conduction and to achieve deep sub-zero temperatures. The control function is carried out by an Arduino UNO which applies a Proportional-Integral-Derivative algorithm organized within a four-phase finite state machine. A high-resolution PT100 resistance temperature detector, together with a MAX31865 analog-to-digital converter, ensures accurate and linear sensing. The thermal profiles and the automatically set temperatures are handled by a custom asynchronous Python-based Graphical User Interface, allowing for real-time data logging and visualization. Experimental verification showed that the system has a symmetric range of operation from -30°C to 50°C. Tests carried out to assess continuous operation found that the digital tracking error remained within an exceptionally small range of ±0.04°C. The thermodynamic precision of the unit was independently checked by carrying out a temperature-dependent current-voltage characterization of a 1N4148 silicon diode, thus confirming the highly predictable thermal control that is appropriate for delicate physical measurements.
| Nature of work | Experimental |
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