What is the Difference Between Seebeck Peltier and Thomson Effect

Madhu

1 year ago

The key difference between Seebeck Peltier and Thomson effect is that Seebeck and Peltier effects require the presence of two materials, whereas Thomson effect does not require the presence of two materials because it can occur in a homogeneous system of one substance.

Although there are three major effects known as Seebeck effect, Peltier Effect, and Thomson effect, Seebeck and Peltier effects are considered the same due to their close similarities.

1. Overview and Key Difference
2. What is Seebeck Effect
3. What is Peltier Effect
4. What is Thomson Effect
5. Seebeck vs Peltier vs Thomson Effect in Tabular Form
6. Summary – Seebeck vs Peltier vs Thomson Effect

What is Seebeck Effect?

Seebeck effect is a phenomenon that describes a temperature difference between two different electrical conductors or semiconductors that produce a voltage difference between the two substances. When electricity is created between a thermocouple upon the subjecting of their ends to a temperature difference between the ends, it is also known as the Seebeck effect thermocouple. It can be reversed as well. E.g. When there are cold and hot junctions of the circuit that are interchanging, the direction of the current can change. In other words, the thermoelectric effect is reversible.

The mathematical formula for the Seebeck effect can be given as V = αΔT, where V is the Seebeck voltage, T is the temperature, and α is the Seebeck coefficient. The occurrence of the Seebeck effect is caused by the difference in the temperatures of the two ends of a thermocouple. This leads to the flow of electricity from the hot metal to the cold metal.

What is Peltier Effect?

The Peltier effect takes place upon the creation of a temperature difference between the junctions by applying a voltage difference between the terminals. In other words, in this effect, the temperature difference can be created between the junctions upon the flow of current across the terminals. For example, upon the connection of a copper wire and bismuth wire in an electric circuit, heat is generated at the point where the current is passing from copper to bismuth. Thereafter, a drop in temperature takes place when the current passes from bismuth to copper. This is a reversible effect in nature.

What is Thomson Effect?

Thomson effect can be described as the evolution or absorption of heat upon passing of an electric current through a circuit containing a single material with a temperature difference along the length. This can transfer heat as superimposed on the common production of heat that is associated with the electrical resistance to current in conductors.

There are two types as positive Thomson effect and negative Thomson effect. When the hot end occurs at a high potential, and the cold end occurs at a low potential, it is called the positive Thomson effect. If this is the other way around, we call it the negative Thomson effect.