Thermoelectric coolers (TEC) operate by the Peltier effect (which also goes by the more general name thermoelectric effect). The device has two sides, and when DC current flows through the device, it brings heat from one side to the other, so that one side gets cooler while the other gets hotter.
An H bridge is an electronic circuit that can be used for loads such as motors to be driven in both directions, forward and backwards. H bridges are available as integrated circuits but here, we will explain H-bridge build from discrete component. We will see which problems may occur during control and how to fix those problems. H-bridge is modeled as 4 switches that can be controlled to achieve various voltage forms to the load. In real design, switches are made by transistors.