As shown in the fig1pictures below, there are little few appearance differences between TEC and TEG, but their principles and applications are not the same.
Fig 1. The photo of TEC and TEG
Based on semiconductor materials, a thermoelectric cooler (TEC) can be used as an electronic component of a small heat pump. Through by adding a little low DC voltage to both ends of TEC, heat quantity will flow from one end to the other, and at the same time, the temperature of one end will decrease and the other end will rise. It is noteworthy that as long as the current direction is changed, the heat flow direction will also be changed, so one piece of TEC can simultaneously achieve two functions: cooling and heating. And TEC can be used for precise temperature control.
A thermoelectric generator (TEG) is based on “Seebeck effect” to concert transform heat into electricity directly. In an open circuit with two different conductors, if there are temperature differences between its two contacts, this circuit will produce electromotive force, meaning that with the temperature gradient moving from high temperature region to low temperature region, thus the thermal electron in an object can produce electric current or charge accumulation.Therefore, TEG can be used for power supplies of radios, televisions, tape recorders, computers, and some other devices.
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