Thermoelectric cooler is a device that transfers heat by using electrical energy with Peltier effect. Thermoelectric cooler can be applied to many application due to its rapid change of temperature and ability to set certain degree of temperature by controlling the amount of current flow. Conventional thermoelectric cooler, however, has limit in its application variety since its operation is restricted with heating up or cooling down just one plate.
If there is a system that divides a thermoelectric cooler to numerous small thermoelectric coolers and controls each of them independently and simultaneously, it is possible to make various thermal expression in two dimensional plane and used in multiple applications. Since thermoelectric device is current-driven device, as the number of small thermoelectric cooler to control increases, amount of required current increases, resulting overcurrent issue. Also because small thermoelectric device has low resistance, power dissipation problem occurs with parasitic resistance.
In this study, a system of controlling multiple thermoelectric coolers in two-dimensional array independently and simultaneously is developed by using bypass circuit to prevent overflowing current and low on-resistance power switch to minimize power dissipation. Finally, a cane-shape blind assisting equipment for object detection is fabricated by attaching the developed two dimensional thermal expression method on the handle of white cane and use it to explain the position and distance of objects around the user.