{"id":6506,"date":"2019-10-27T11:58:36","date_gmt":"2019-10-27T15:58:36","guid":{"rendered":"https:\/\/dronebotworkshop.com\/?p=6506"},"modified":"2023-04-12T11:10:58","modified_gmt":"2023-04-12T15:10:58","slug":"peltier-effect","status":"publish","type":"post","link":"https:\/\/dronebotworkshop.com\/peltier-effect\/","title":{"rendered":"Peltier Effect Cooling Experiments"},"content":{"rendered":"\n

\"Download \"Parts<\/a> \"View<\/a><\/p>\n

A Peltier cooling device is a thermoelectric semiconductor component that can provide cooling with no moving parts. It\u2019s very easy to use and it can get very cold – and also very hot!<\/span><\/p>\n

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Today we will conduct a few experiments with a common and inexpensive Peltier cooling device.<\/span><\/p>\n

Introduction<\/span><\/h2>\n

The ability to cool air or exchange heat is critical in many situations. From computer chips that need to keep from overheating to spacecraft that need to withstand temperature extremes the design of cooling systems is big business.<\/span><\/p>\n

Most of us are familiar with air conditioning. By reducing temperatures and humidity they allow us to live and work in environments that would otherwise be uncomfortable or even unbearable. Even in cool climates air conditioners are used in data centers to keep equipment (and personnel) at a comfortable operating temperature.<\/span><\/p>\n

\"Peltier<\/p>\n

Conventional air conditioning employs a refrigerant or coolant which is circulated through pipes, pumps, evaporators, and condensers to remove heat and dispense it outside.\u00a0 It is efficient and effective, but it also takes up a lot of space.\u00a0<\/span><\/p>\n

There are also applications where conventional air conditioning is not practical or even possible.<\/span><\/p>\n

Enter the Peltier device. This semiconductor component can perform heat exchange without any moving parts. It is ideal for cooling down computer chips, as well as for building small cooling devices for personal use. It also is used in spacecraft as conventional air conditioning won\u2019t operate in a low-gravity environment.<\/span><\/p>\n

We won\u2019t be building any spacecraft in the workshop, at least not today. But we can use inexpensive Peltier devices top provide cooling for small projects, or just for some interesting and fun experiments.<\/span><\/p>\n

The Peltier Effect<\/span><\/h2>\n

In 1834 a French physicist named Jean Charles Athanase Peltier discovered that passing current through two dissimilar metals could create either a rise or fall in temperature at the junction of the two metals.\u00a0<\/span><\/p>\n

Peltier experimented with wires made of copper and bismuth. He found that when current flowed from copper to bismuth heat would be generated at the junction.\u00a0 He also found that the reverse was true, when the current flowed between bismuth and copper the junction grew colder.<\/span><\/p>\n

This phenomenon became known as the <\/span>Peltier Effect<\/span><\/i>.<\/span><\/p>\n

The Seebeck Effect<\/span><\/h3>\n

An effect closely related to the Peltier Effect is the <\/span>Seebeck Effect<\/span><\/i>.\u00a0<\/span><\/p>\n

The Seebeck Effect is named after German physicist Thomas Johann Seebeck who discovered the effect in 1821, however, it had actually been observed as far back as 1794 by Italian scientist Alessandro Volta. In case that name sounds familiar Volta is indeed the gentleman who the Volt is named after.<\/span><\/p>\n

The Seebeck Effect is essentially the opposite effect to the Peltier Effect. The Seebeck Effect describes the conversion of heat directly into electricity at the junction of different types of wire.<\/span><\/p>\n

A Peltier device can also be used as a Seebeck device and vice-versa, although the efficiency of both is limited. Both the Peltier and Seebeck effects fall into the category of <\/span>Thermoelectric Effects<\/span><\/i>.<\/span><\/p>\n

Modern Peltier Devices<\/span><\/h3>\n

Instead of using dissimilar metals modern Peltier devices make use of semiconductors.<\/span><\/p>\n

A semiconductor Peltier cooler consists of a collection of \u201clegs\u201d composed of P or N-type semiconductor material. A \u201cleg\u201d is constructed by creating several layers of substrate material, built up in order to have some height.<\/span><\/p>\n

\"Semiconductor<\/p>\n

These \u201clegs\u201d are arranged in a matrix, with alternating P and N-type material.<\/span><\/p>\n

A conductive sheet is placed below and above the matrix to provide electrical connections. The whole assembly is then sandwiched between a thermally conductive insulator, usually ceramic.<\/span><\/p>\n

This is the type of Peltier device that we will be experimenting with today.<\/span><\/p>\n

Issues with Peltier Modules<\/span><\/h3>\n

Peltier modules are very useful cooling devices, but they are far from perfect.<\/span><\/p>\n

The biggest issue with a Peltier module is its inefficiency. A Peltier cooler is nowhere near as efficient as a conventional coolant-based device.\u00a0 While they can be used to create small air conditioning units it would be impractical to use them to cool down an entire building.<\/span><\/p>\n

Another issue is lifespan. The Peltier module will not last forever, all thermoelectric coolers will experience decreased efficiency as they age. To be fair, conventional air conditioning systems also suffer the same drawback.<\/span><\/p>\n

TEC1-12706 Peltier Cooler<\/span><\/h2>\n

The Peltier device we are going to be using is a very common module, the TEC1-12706 Peltier cooler.<\/span><\/p>\n

This is a small device measuring 40mm x 40mm, I measured the thickness of my module at 3.75mm. This is a Standard size Peltier module, and you\u2019ll find that 40mm x 40mm is also a standard heatsink size.<\/span><\/p>\n

\"TEC1-12706<\/p>\n

The module has two leads, a red one and a black one. These are for powering it, I used a 12-volt power supply for my module. As Peltier modules are not very efficient you\u2019ll need a good amount of current to drive this, I recommend using a power supply capable of 6 amperes.<\/span><\/p>\n

Reading the Part Number<\/span><\/h3>\n

You can use other Peltier modules in the experiment as well. These modules have a standardized part number scheme, as illustrated below.<\/span><\/p>\n

\"Peltier<\/p>\n

The part number for my device breaks down as follows:<\/span><\/p>\n