Development of a Thermoelectric Insulin Storage Box with a TRIAC-based Automatic Transfer Switch

Abstract

Insulin is highly sensitive to temperature variations, and improper storage can significantly reduce its therapeutic effectiveness. Household refrigerators often have unstable temperature profiles, and power interruptions further compromise safe storage. This study presents the design and experimental evaluation of an insulin storage box that uses a thermoelectric cooling system integrated with a TRIAC-based Automatic Transfer Switch (ATS) to maintain uninterrupted temperature regulation during power outages. The cooling system uses Peltier modules with liquid-assisted heat dissipation to maintain thermal stability. Experiments under empty, half-filled, and fully loaded conditions showed that the system consistently maintained the recommended insulin storage temperature range of 2°C–8°C, reaching a minimum of 2°C. Increasing the thermal load reduced the temperature gradient across the Peltier modules, slightly lowering performance, but temperature stability remained within acceptable limits. The TRIAC-based ATS ensured continuous operation by automatically transferring the load to a secondary power source during supply interruptions. Results confirm the system’s suitability for reliable insulin storage in areas with unstable power availability.