Is this the same effect used in portable coolers and CPU coolers?

Yes, exactly. Commercial Peltier coolers consist of many such junctions connected electrically in series and thermally in parallel. This simulator shows the operation of a single junction, which is the fundamental unit. The main limitation in real devices is efficiency, as Joule heating and thermal conduction counteract the cooling effect.

Why does the Seebeck voltage disappear when I make the temperatures equal?

The Seebeck voltage is generated by a temperature difference. It is directly proportional to ΔT (V = S ΔT). When ΔT is zero, there is no driving force for charge carriers to diffuse from the hot to the cold side, so the net voltage output is zero. This highlights that it's the gradient, not the absolute temperature, that matters.

Can I use this same device to both generate power and cool something at the same time?

No, not simultaneously. A single thermoelectric device operates in one mode at a time. It either uses electrical work to pump heat (Peltier cooler) or uses a heat flow to generate electrical work (Seebeck generator). The process is reversible, but the energy conversion direction is determined by whether you prioritize an input current or an input temperature difference.

What are the key simplifications in this model?

This model assumes an ideal junction with constant material properties. It primarily shows the primary Peltier and Seebeck effects. In reality, parasitic effects are significant: current flow causes Joule heating everywhere in the conductors, and heat conducts back from the hot side to the cold side, reducing the net cooling or voltage generated.

Peltier & Seebeck (Schematic)

Current pumps heat across junction; ΔT drives toy mV — same couple, two modes.

About this model

At the heart of this interactive schematic lies the fundamental thermoelectric effect, demonstrating how temperature differences and electric currents are interconvertible in a circuit made of two dissimilar conductors. The simulator visualizes a single thermocouple junction, the basic building block of thermoelectric modules. It operates in two distinct modes. In the Peltier mode, applying an external voltage drives an electric current across the junction. This current actively pumps heat from one side to the other, creating a temperature difference (ΔT). The magnitude of this cooling or heating is governed by the Peltier coefficient, Π, where the heat transfer rate Q̇ is proportional to the current: Q̇ = ±ΠI. Conversely, in the Seebeck mode, the user establishes a temperature gradient across the junction. This thermal imbalance induces a measurable voltage, the Seebeck voltage (V_seebeck). This voltage is directly proportional to the temperature difference and the material's Seebeck coefficient, S: V_seebeck = S ΔT. The simulator simplifies real-world complexity by modeling a single, ideal junction with constant material properties, ignoring secondary effects like Joule heating and thermal conduction for clarity. By toggling between modes and adjusting current or temperature, students directly observe the reversible nature of thermoelectric energy conversion, reinforcing the first law of thermodynamics and the concept of energy conservation in coupled thermal-electrical systems.

Who it's for: High school and introductory undergraduate physics or engineering students studying thermodynamics, solid-state physics, or energy conversion principles.

Key terms

Thermoelectric Effect
Peltier Effect
Seebeck Effect
Thermocouple
Seebeck Coefficient
Peltier Coefficient
Junction
Heat Pump

How it works

Thermoelectric modules in CPU chillers and Mars rovers reuse the same thin junction idea.

Frequently asked questions

Is this the same effect used in portable coolers and CPU coolers?: Yes, exactly. Commercial Peltier coolers consist of many such junctions connected electrically in series and thermally in parallel. This simulator shows the operation of a single junction, which is the fundamental unit. The main limitation in real devices is efficiency, as Joule heating and thermal conduction counteract the cooling effect.
Why does the Seebeck voltage disappear when I make the temperatures equal?: The Seebeck voltage is generated by a temperature difference. It is directly proportional to ΔT (V = S ΔT). When ΔT is zero, there is no driving force for charge carriers to diffuse from the hot to the cold side, so the net voltage output is zero. This highlights that it's the gradient, not the absolute temperature, that matters.
Can I use this same device to both generate power and cool something at the same time?: No, not simultaneously. A single thermoelectric device operates in one mode at a time. It either uses electrical work to pump heat (Peltier cooler) or uses a heat flow to generate electrical work (Seebeck generator). The process is reversible, but the energy conversion direction is determined by whether you prioritize an input current or an input temperature difference.
What are the key simplifications in this model?: This model assumes an ideal junction with constant material properties. It primarily shows the primary Peltier and Seebeck effects. In reality, parasitic effects are significant: current flow causes Joule heating everywhere in the conductors, and heat conducts back from the hot side to the cold side, reducing the net cooling or voltage generated.

Continue with similar topics in this category — or all 46 in Thermodynamics.

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About this model

How it works

Frequently asked questions

Related simulators

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Peltier & Seebeck (Schematic)

About this model

How it works

Frequently asked questions