The Peltier module can be used in 4 different schemes: as a heating element (in incubators...), as a cooling element (in refrigerators...), to generate electricity (generator...), and also using the Peltier element you can generate water . This is what my article will be about.

Peltier element is a thermoelectric converter, the operating principle of which is based on the Peltier effect - the occurrence of a temperature difference when an electric current flows. In English-language literature, Peltier elements are designated TEC (from the English Thermoelectric Cooler - thermoelectric cooler).

The opposite effect of the Peltier effect is called the Seebeck effect.

Operating principle

The operation of Peltier elements is based on the contact of two conductive materials with different electron energy levels in the conduction band. When current flows through the contact of such materials, the electron must acquire energy in order to move to a higher energy conduction band of another semiconductor. When this energy is absorbed, the contact point between the semiconductors cools. When current flows in the opposite direction, the contact point between the semiconductors heats up, in addition to the usual thermal effect.

When metals come into contact, the Peltier effect is so small that it is unnoticeable against the background of ohmic heating and thermal conductivity phenomena. Therefore, in practical applications, contact between two semiconductors is used.

A Peltier element consists of one or more pairs of small semiconductor parallelepipeds - one n-type and one p-type in a pair (usually bismuth telluride, Bi2Te3 and silicon germanide), which are connected in pairs using metal bridges. Metal jumpers simultaneously serve as thermal contacts and are insulated with a non-conductive film or ceramic plate. Pairs of parallelepipeds are connected in such a way that a series connection of many pairs of semiconductors is formed with different types conductivity, so that at the top there are one sequence of connections (n->p), and at the bottom the opposite (p->n). Electric current flows sequentially through all parallelepipeds. Depending on the direction of the current, the upper contacts are cooled and the lower ones are heated - or vice versa. Thus electricity transfers heat from one side of the Peltier element to the opposite and creates a temperature difference.

If you cool the heating side of the Peltier element, for example using a radiator and fan, then the temperature of the cold side becomes even lower. In single-stage elements, depending on the element type and current value, the temperature difference can reach approximately 70 °C.

Advantages and disadvantages

The advantage of the Peltier element is its small size, the absence of any moving parts, as well as gases and liquids. By reversing the direction of the current, both cooling and heating are possible - this makes it possible to thermostat at ambient temperatures both above and below the thermostat temperature. Another advantage is the absence of mechanical parts and the absence of noise.

The disadvantage of the Peltier element is its lower efficiency than that of compressor refrigeration units using freon, which leads to high power consumption to achieve a noticeable temperature difference. Despite this, developments are underway to increase thermal efficiency, and Peltier elements have found wide application in technology, since without any additional devices Temperatures below 0 °C can be realized.

The main problem in constructing Peltier elements with high efficiency is that free electrons in a substance are simultaneously carriers of both electric current and heat. The material for the Peltier element must simultaneously have two mutually exclusive properties - it conducts electric current well, but poorly conducts heat.

In Peltier cell batteries, it is possible to achieve a theoretically very large temperature difference, more than 70 degrees Celsius, therefore it is better to use a pulsed temperature control method, thanks to which energy consumption can also be reduced. In this case, it is desirable to smooth out current ripples to extend the service life of the Peltier element.

Application of Thermoelectric Module: in water coolers, cooling systems for computers or microcircuits of various small-sized devices, in electric thermal generators, cooling of video cards, north or south bridges, car refrigerators, air coolers, Arduino, for cooling CCD matrices and infrared photodetectors, in electric thermal generators, in thermostats, in scientific laboratory instruments, thermal calibrators, thermal stabilizers. In general, where it is required to achieve temperature differences of more than 60 degrees.

Peltier plate dimensions and consumption characteristics

Dimensions of Peltier plates and consumption characteristics (power consumption, voltage, current, maximum temperature difference). The markings of these thermoelectric generators may be different on different sites, it all depends on the manufacturer (for example: TEG1-241-1.4-1.2; CP1.4-127-06L domestic; TB-127-1.4-1.5 Frost-72; SP1848-27145; Seebeck thermogenerator TEP1-142T300). The characteristics, in turn, will not differ much, but some indicators do not differ significantly.

Qmax	Umax	Imax	dTmax	Dimensions, (mm)
(W)	(IN)	(A)	(hail)	A	B	H
36,0	16,1	3,6	71	30,0	30,0	3,6
36,0	16,1	3,6	71	40,0	40,0	3,6
62,0	16,3	6,2	72	40,0	40,0	3,9
65,0	16,7	6,3	74	40,0	40,0	3,9
80,0	16,1	8,0	71	40,0	40,0	3,4
80,0	16,1	8,0	71	48,0	48,0	3,4
94,0	24,9	6,1	70	40,0	40,0	3,9
115,0	24,6	7,6	69	40,0	40,0	3,6
120,0	24,6	7,9	69	40,0	40,0	3,4
131,0	24,6	8,6	69	40,0	40,0	3,3
172,0	24,6	11,3	69	40,0	40,0	3,2
156,0	15,7	16,1	70	48,0	48,0	3,4
223,0	15,5	23,4	68	55,0	59,0	3,3
310,0	24,6	20,6	69	62,0	62,0	3,2

DIY USB Refrigerator (Peltier Module)

To build our mini-fridge, we need to find or buy a Peltier element (you can read what it is and how it works below) and two radiators.

This very Peltier element, I tore it out of a broken computer, it stood there between the processor and the cooler. I cleaned off the old thermal paste from it. In a nutshell - this Peltier element when applied to it direct current begins to work as follows: one side of it begins to heat up, and the other begins to cool down; if you change the polarity of the power source, then the sides of the element will behave in the opposite way!

Next, I took two massive radiators from an unnecessary amplifier. Then I lubricated the element with new thermal paste, which I bought at a radio store, and clamped the Peltier element between the radiators. The use of thermal paste in this case is mandatory!
Connected the wires to the element from USB cable and plugged it into the computer - one radiator began to heat up, and the second began to cool down! So, everything is in order!

The material I used to glue the refrigerator together is similar to compressed foam or porous plastic. In general, the material can be anything, its main quality is thermal insulation.
The glass is organic and looks quite fragile, but in fact the material is durable.
Glue - superglue.

Then, for convenience, I made a magnetic clasp.
It turned out fine - a bottle of mineral water could easily fit in there.

Generator - generating electricity using a Peltier element

Pros of this generator:

— Fuel is anything that burns or heats.
— USB output 5 Volt, 500mA.
— Does not depend on the sun, wind, etc.
- Simple and strong design that can last forever.
— You can cook food on it while your phone is charging.
- Versatility.
— Anyone can assemble it at home in 1 evening (even an AvtoVAZ employee =)).
- Cheap design.

I didn’t invent it, there are commercial copies that are much better than mine. For example, BioLite CampStove, its price is 7900 rubles. My copy was made in a hurry for writing this article and further experiments.

The basis is the Peltier element. This is a thermoelectric module used in water coolers and portable refrigerators, and it is also used to cool the processor. When voltage is applied to it, one side cools and the other heats up. On the contrary, we will heat one side to generate electricity.

The main principle is that one side heats up and the other remains unchanged, for maximum efficiency you need a temperature difference of 100 degrees Celsius.

Let's get started!


We will need:
— Peltier element, I used TEC1-12710
- Unnecessary power supply from the computer
Anyone, even the one that burned down, and everything burned out except the body
- Voltage regulator
DC-DC Boost Module, Input voltage 1-5 Volts, output always 5V.
— Radiator (the bigger the better), preferably with a 5V cooler, because The radiator will gradually heat up. In winter this is not a problem, since you can put the radiator on ice.
— Thermal paste
- Set of tools

TEC1-12710 module, rated at 10 A (less or more). But the more powerful ones will be larger. The higher the current, the more efficient and expensive it is. I bought it from Aliexpress for about 250 rubles. In our electronics stores, this costs about 1,500 rubles.

The module is designed for a maximum voltage of 12V, but it does not output that much due to low efficiency when we use it in the opposite direction, i.e. to receive current.

In order for there to be a stable 5 volts and devices to be charged safely, you need a step-up stabilizer. It starts producing 5 Volts when there is still only 1 Volt on the Peltier element. You can know that everything is ready for charging by the lit LED on the module.


You can assemble your own, but I decided to trust the Chinese, they offer a ready-made module with a USB output for 80 rubles. on the same site.

Let's gut our power supply. I had to make additional holes for better air circulation (the power supply was very old).

The main principle is that air is sucked in from below and comes out through the top. Simply put, you need to make a regular stove. Don't forget to provide a hole for throwing wood chips and a stand for a pot or mug for boiling water, if you need it.


Next, you need to attach the Peltier module with a radiator to a flat wall, after first evenly applying thermal paste. The tighter the contact, the better. The side where the model is written is cold, it is to this side that we apply the radiator. If you mix it up, the module will not output voltage; in this case, you just need to swap the wires.


We solder the boost converter and find where to hide it. You can generally leave it hanging on the wires, but you definitely need to insulate it, for example, put heat shrink on it.

Let's put everything together. This is what you should get:

How it works?

We throw branches, wood chips, in general, everything that burns inside. Then we light it up. The fire heats the walls of the stove and the Peltier element, which is on one of these walls. The other side of the element, which is on the radiator, remains at outside temperature. The greater the temperature difference, the greater the power, but don't overdo it.

Maximum efficiency is achieved already with a difference of 100 degrees. Over time, the radiator begins to heat up and will need to be cooled. You can throw snow, pour water on it, place the radiator on ice or in water, or place a mug of cold water on it. There are many options, the simplest is a cooler, it will take away some of the power, but due to cooling the overall result will not change.


DO NOT expose the element to high temperatures, it may burn out and burn out. The documentation indicates a maximum temperature of 180 °C, but there is no need to worry too much, with good cooling and with simple firewood nothing will happen to it.

If you are not lazy and do everything right, you will get such a simple wood chipper on which you can heat food, boil, water and charge your gadgets at the same time.

It can be used at home if there is a power outage by placing a candle inside. By the way, if you connect LEDs to it, the light will be much brighter than from the candle itself.

In any place where you can find something burning, you will have electricity, heat and the ability to conveniently cook food, using less fuel compared to a fire.

First tests!

After work I went into the forest, the sun had almost set, the brushwood was wet, but the stove paid off 100%.

The result exceeded all my expectations. Immediately after the wood chips burned, the indicator came on, I connected the phone and it began to charge. Charging was stable.

The converter didn't strain at all. I also took with me a cooling pad for the laptop, it has 2 coolers and LEDs, it should consume a decent amount. I connected it, everything spins, glows, and the breeze blows. I also took a USB fan and connected it at the end, when there were only coals left. Everything is spinning great, I don’t even know what else to try.

Result:

Everything works great, it gives out its gender Ampere. Still, you need a cooler, because... in half an hour the radiator heated up to about 40 degrees, in the summer it will be even more. Let yourself spin.

The flames shoot high up, I personally don’t need such a fire, I will cover some of the holes so that it burns more slowly.

I will do everything new, I will take as a basis a standard wood chipper that is made from tin cans, but I will make it from thicker metal and rectangular in shape. I’ll buy a good radiator with a cooler of a suitable shape and try to make a collapsible version so that it takes up less space when carrying it.

Producing drinking water using a Peltier module

The thermocouple (Peltier module) operates on the reverse principle of a thermocouple - the appearance of a temperature difference when electric current flows.

How does the Peltier element work?

It is quite simple to use a Peltier module, the principle of which is to release or absorb heat at the moment of contact different materials when the energy flow of electrons passes through it before and after contact, it is different. If it is less at the outlet, it means heat is generated there. When electrons in contact are inhibited by an electric field, they transfer kinetic energy to the crystal lattice, heating it up. If they accelerate, heat is absorbed. This occurs due to the fact that part of the energy is taken from crystal lattice and it cools down.

To a large extent, this phenomenon is inherent in semiconductors, which is explained by the large difference in charges.

The Peltier module, the application of which is the topic of our review, is used in the creation of thermoelectric cooling devices (TECs). The simplest of them consists of two p- and n-type semiconductors connected in series through copper contacts.

If electrons move from a semiconductor "p" to "n", at the first junction with a metal bridge they recombine, releasing energy. The next transition from the semiconductor "p" to the copper conductor is accompanied by the "pulling" of electrons through the contact by an electric field. This process leads to energy absorption and cooling of the area around the contact. Processes occur in a similar way at the following transitions.

By placing heated and cooled contacts in different parallel planes, a practical implementation of the method will be obtained. Semiconductors are made from selenium, bismuth, antimony or tellurium. The Peltier module houses a large number of thermocouples placed between aluminum nitride or aluminum oxide ceramic plates.

Factors influencing the efficiency of TEM

• Current strength.
• Number of thermocouples (up to several hundred).
• Types of semiconductors.
• Cooling rate.

Larger values ​​have not yet been achieved due to low efficiency (5-8%) and high cost. For a TEM to work successfully, it is necessary to ensure effective heat removal from the heated side. This creates difficulties in the practical implementation of the method. If the polarity is reversed, the cold and hot sides reverse each other.

Advantages and disadvantages of modules

The need for TEMs arose with the advent of electronic devices requiring miniature cooling systems. The advantages of the modules are as follows:

• compactness;
• no moving joints;
• the Peltier module has a reversible operating principle when changing polarity;
• simplicity of cascade connections for increased power.

The main disadvantage of the module is low efficiency. This manifests itself in high power consumption to achieve the required cooling effect. In addition, it has a high cost.

Application of TEM

The Peltier module is used primarily for cooling microcircuits and small parts. A start was made for cooling elements of military equipment:

• microcircuits;
• infrared detectors;
• laser elements;
• crystal oscillators.

The Peltier thermoelectric module gradually began to be used in household appliances: to create refrigerators, air conditioners, generators, and thermostats. Its main purpose is to cool small objects.

CPU cooling

The main components of computers are constantly being improved, which leads to an increase in heat generation. Together with them, cooling systems are being developed using innovative technologies and modern controls. The Peltier module has found application in this area primarily in cooling microcircuits and other radio components. Traditional coolers can no longer cope with forced overclocking modes of microprocessors. And increasing the frequency of processors makes it possible to increase their performance.

Increasing the fan speed results in significant noise. It is eliminated by using a Peltier module in a combined cooling system. In this way, leading companies quickly mastered the production of efficient cooling systems, which began to be in great demand.

Heat is usually removed from processors by coolers. The air flow can be sucked in from outside or come from inside the system unit. The main problem is that the air temperature is sometimes insufficient for heat removal. Therefore, TEM began to be used to cool the air flow entering the system unit, thereby increasing the efficiency of heat transfer. Thus, the built-in air conditioner is an assistant to the traditional computer cooling system.

Aluminum radiators are attached to both sides of the module. From the cold plate side, cooling air is pumped into the processor. After it takes the heat, another fan blows it out through the module's hot plate heatsink.

Modern TEM is controlled electronic device with a temperature sensor, where the degree of cooling is proportional to the heating of the processor.

Activating processor cooling also creates some problems.

1. Simple Peltier cooling modules are designed for continuous operation. Lower power consumption also reduces heat dissipation, which can cause the chip to overcool and subsequently freeze the processor.
2. If the operation of the cooler and refrigerator are not properly coordinated, the latter may switch to heating mode instead of cooling. The additional heat source will cause the processor to overheat.

Thus, for modern processors We need advanced cooling technologies with control over the operation of the modules themselves. Such changes in operating modes do not occur with video cards, which also require intensive cooling. Therefore, TEM is ideal for them.

Do-it-yourself car refrigerator

In the middle of the last century, the domestic industry tried to master the production of small-sized refrigerators based on the Peltier effect. Existing technologies of that time did not allow this to be done. Nowadays the limiting factor is mainly high price, but attempts continue, and success has already been achieved.

Widespread production of thermoelectric devices allows you to create a small refrigerator with your own hands, convenient for use in cars. Its basis is a “sandwich”, which is made as follows.

1. A layer of heat-conducting paste type KPT-8 is applied to the upper radiator and the Peltier module is glued to one side of the ceramic surface.
2. Similarly, another radiator is attached to it from the bottom side, intended for placement in the refrigerator chamber.
3. The entire device is tightly compressed and dried for 4-5 hours.
4. Coolers are installed on both radiators: the upper one will remove heat, and the lower one will equalize the temperature in the refrigerator chamber.

The refrigerator body is made with a heat-insulating gasket inside. It is important that it closes tightly. You can use a regular plastic tool box for this.

12V power is supplied from the vehicle system. It can also be done from a 220 V network alternating current, with power supply. The simplest AC to DC conversion circuit is used. It contains a rectifier bridge and a ripple-smoothing capacitor. It is important that at the output they do not exceed 5% of the nominal value, otherwise the efficiency of the device is reduced. The module has two outputs made of colored wires. A “plus” is always connected to red, and a “minus” to black.

The power of the TEM must correspond to the volume of the box. The first 3 digits of the marking indicate the number of pairs of semiconductor microelements inside the module (49-127 or more). expressed by the last two digits of the marking (from 3 to 15 A). If the power is not enough, you need to glue another module onto the radiators.

Note! If the current exceeds the power of the element, it will heat up on both sides and quickly fail.

Peltier module: electrical energy generator

TEM can be used to generate electricity. To do this, it is necessary to create a temperature difference between the plates, and the thermocouples located between them will generate electric current.

For practical use you need a TEM with at least 5 V. Then you can use it to charge mobile phone. Due to the low efficiency of the Peltier module, a DC-DC boost converter will be required. To assemble the generator you will need:

• 2 Peltier modules TEC1-12705 with plate size 40x40 mm;
• converter EK-1674;
• aluminum plates 3 mm thick;
• water pan;
• heat resistant glue.

Two modules are placed between the plates with glue, and then the entire structure is fixed to the bottom of the pan. If you fill it with water and put it on fire, you get the required temperature difference, which produces an EMF of the order of 1.5 V. By connecting the modules to a boost converter, you can increase the voltage to 5 V, which is necessary to charge the phone battery.

The greater the temperature difference between the water and the lower heated plate, the more efficient the generator is. Therefore, we must try to reduce the heating of the water different ways: make it flow-through, replace it with fresh one more often, etc. An effective way to increase the temperature difference is to cascade the modules, when they are layered one on top of the other. Increasing the overall dimensions of the device allows you to place more elements between the plates and thereby increase the overall power.

The generator's performance will be sufficient to charge small batteries, operate LED lamps or radio. Note! To create thermal generators, you will need modules capable of operating at 300-400 0 C! The rest are only suitable for trial testing.

Unlike other means of alternative generation of electricity, they can work while driving if you create something like a catalytic heater.

Domestic Peltier modules

TEMs of their own production appeared on our market not so long ago. They are highly reliable and have good characteristics. The Peltier module, which is in wide demand, has dimensions of 40x40 mm. It is designed for a maximum current of 6 A and voltage up to 15 V.

A domestic Peltier module can be purchased for a low price. At 85 W, it creates a temperature difference of 60 0 C. Together with a cooler, it is able to protect a processor from overheating with a power dissipation of 40 W.

Characteristics of modules from leading companies

Foreign devices are presented on the market in greater variety. To protect processors from leading companies, a PAX56B Peltier module is used as a refrigerator, the price of which, complete with a fan, is $35.

With dimensions of 30x30 mm, it maintains the processor temperature no higher than 63 0 C with a power output of 25 W. For power supply, a voltage of 5 V is sufficient, and the current does not exceed 1.5 A.

The PA6EXB Peltier module is well suited for cooling the processor, providing normal temperature conditions with a dissipation power of 40 W. The area of ​​its module is 40x40 mm, and the current consumption is up to 8 A. In addition to its impressive dimensions - 60x60x52.5 mm (including the fan) - the device requires free space around it. Its price is $65.

When the Peltier module is used, specifications it must meet the needs of the cooled devices. It is unacceptable that their temperature is too low. This can lead to moisture condensation, which can be harmful to electronics.

Modules for the manufacture of generators, such as, are distinguished by higher power - 72 W and 108 W, respectively. They are distinguished by markings, which are always applied to the hot side. The maximum permissible temperature of the hot side is 150-160 0 C. The greater the temperature difference between the plates, the higher the output voltage. The device operates at a maximum temperature difference of 600 0 C.

You can buy a Peltier module inexpensively - about $10 or less per piece, if you look hard enough. Quite often, sellers significantly inflate their prices, but you can find them several times cheaper if you buy them on sale.

Conclusion

The Peltier effect has now found application in the creation of small refrigerators necessary for modern technology. The reversibility of the process makes it possible to produce micropower stations that are in demand for charging batteries of electronic devices.

Unlike other means of alternative power generation, they can operate while driving if a catalytic heater is installed.

A Peltier element is usually called a converter that is capable of operating from a temperature difference. This happens by flowing electric current through conductors through contacts. For this purpose, special plates are provided in the elements. Heat passes from one side to the other.

Today, this technology is in demand primarily due to its significant heat transfer power. Additionally, the devices can boast of compactness. The radiators installed on many models are weak. This is due to the fact that the heat flow cools quite quickly. As a result, the desired temperature is constantly maintained.

This element has no moving parts. The devices operate absolutely silently, and this is a definite advantage. It should also be said that they can be used for a very long time, and breakdowns occur extremely rarely. The simplest type consists of copper conductors with contacts and connecting wires. Additionally, there is an insulator on the cooling side. It is usually made from ceramic or

Why are Peltier elements needed?

Peltier elements are most often used to make refrigerators. Usually we are talking about compact models that can be used, for example, by motorists on the road. However, this is not the end of the range of applications of the devices. IN Lately Peltier elements began to be actively installed in sound and acoustic equipment. There they are able to perform the functions of a cooler.

As a result, the device amplifier is cooled without any noise. For portable compressors, Peltier elements are indispensable. If we talk about the scientific industry, scientists use these devices to cool the laser. In this case, it is possible to achieve significant stabilization of the study wave of LEDs.

Disadvantages of Peltier models

It would seem that such a simple and effective device has no drawbacks, but there are some. First of all, experts immediately noted the low penetration capacity of the module. This indicates that the person will have certain problems, if he wants to cool a device that operates from a network with a voltage of 400 V. In this case, a special dielectric paste will partially help solve this problem. However, the current breakdown will still be high and the winding of the Peltier element may not withstand it.

Additionally, these models are not recommended for use in precision electronics. Since the design of the element contains metal plates, the sensitivity of the transistors may be impaired. The last disadvantage of the Peltier element is the low efficiency. These devices are not capable of achieving a significant temperature difference.

Module for regulator

Making a Peltier element for a regulator with your own hands is quite simple. To do this, you should prepare two metal plates in advance, as well as wiring with contacts. First of all, conductors are prepared for installation, which will be located at the base. They are usually purchased with the "PP" marking.

Additionally, for normal temperature control, semiconductors should be provided at the output. They are necessary in order to quickly transfer heat to the top plate. To install all elements, you should use a soldering iron. To complete the Peltier element with your own hands, last of all, connect two wires. The first is mounted at the lower base and fixed at the outermost conductor. Contact with the plate should be avoided.

Next, attach the second wire at the top part. Fixation is also carried out to the outermost element. In order to check the functionality of the device, a tester is used. To do this, two wires need to be connected to the device. As a result, the voltage deviation should be approximately 23 V. In this situation, much depends on the power of the regulator.

Refrigerators with thermistor

How to make a Peltier element with your own hands for a refrigerator with a thermistor? Answering this question, it is important to note that the plates for it are selected exclusively from ceramics. In this case, about 20 conductors are used. This is necessary so that the temperature difference is higher. You can increase it up to 70%. In this case, it is important to calculate

This can be done based on the power of the equipment. A refrigerator using liquid freon is ideal in this case. The Peltier element itself is installed near the evaporator, which is located next to the motor. To install it, you will need a standard set of tools, as well as gaskets. They are necessary in order to protect the model from the starting relay. Thus, the cooling of the lower part of the device will occur much faster.

To achieve a temperature difference (Peltier effect) with your own hands, you may need at least 16 conductors. The main thing is to reliably insulate the wires that will be connected to the compressor. In order to do everything correctly, you must first disconnect the refrigerator dryer. Only after this is it possible to connect all contacts. Once installation is complete, the voltage limit should be checked using a tester. If the element malfunctions, the thermostat is the first to suffer. In some cases it occurs

Model for refrigerator 15 V

You can make a Peltier refrigerator with your own hands with small modules. The modules are attached mainly near the radiators. In order to securely fasten them, experts use corners. The element should not lean against the filter, and this should be taken into account.

To complete a Peltier thermoelectric module with your own hands, the bottom plate is mainly chosen from stainless steel. Conductors, as a rule, are used with the marking "PR20". They can withstand a maximum load of 3 A. The maximum temperature deviation can reach 10 degrees. In this case, the efficiency can be 75%.

Peltier elements in 24 V refrigerators

Using a Peltier element, you can make a refrigerator with your own hands only from conductors with good sealing. At the same time, they must be stacked in three rows for cooling. The operating current in the system must be maintained at 4 A. You can check it using a conventional tester.

If you use ceramic plates for the element, the maximum temperature deviation can be achieved at 15 degrees. The wires to the capacitor are installed only after the gasket has been placed. You can attach it to the wall of the device in different ways. The main thing in this situation is not to use glue, which is sensitive to temperatures above 30 degrees.

Peltier element for car cooler

To make a high-quality auto-refrigerator with your own hands, a Peltier module (module) is selected with a plate whose thickness is no more than 1.1 mm. It is best to use non-modular wires. Copper conductors will also be required for operation. Their capacity must be at least 4A.

Thus, the maximum temperature deviation will reach 10 degrees, this is considered normal. Conductors are most often used with the marking "PR20". They have recently shown themselves to be more stable. They are also suitable for various contacts. A soldering iron is used to connect the device to the capacitor. High-quality installation is only possible on the relay block gasket. The differences in this case will be minimal.

How to make an element for a drinking water cooler?

A DIY Peltier module (element) for a cooler is quite simple. It is important to select only ceramic plates for it. At least 12 conductors are used in the device. Thus, the resistance will be maintained high. The connection of elements is usually carried out using soldering. There must be two wires for connecting to the device. The element must be attached to the bottom of the cooler. In this case, it may come into contact with the cover of the device. In order to exclude cases short circuits, it is important to fix all wiring on the grille or housing.

Air conditioners

The Peltier module (element) is made with your own hands for an air conditioner only with class “PR12” conductors. They are chosen for this task mainly because they cope well with low temperatures. At most, the model is capable of producing a voltage of 23 V. The resistance indicator will be at the level of 3 ohms. The temperature difference reaches a maximum of 10 degrees, and the efficiency is 65%. Conductors can only be laid in one row between sheets.

Manufacturing of generators

You can make a generator using a Peltier module (element) with your own hands. Device performance will increase by a total of 10%. This is achieved due to greater cooling of the motor. The device can withstand a maximum load of 30 A. Due to the large number of conductors, the resistance can be 4 ohms. The temperature deviation in the system is approximately 13 degrees. The module is attached directly to the rotor. To do this, you must first disconnect the central shaft. In many cases the stator does not interfere. To prevent the rotor winding from heating up from the inductor, ceramic plates are used.

Cooling a video card on a computer

To cool the video card, you should prepare at least 14 conductors. It is best to select copper models. Their heat conductivity coefficient is quite high. To connect the device to the board, non-modular type wires are used. The model is mounted near the video card cooler. To secure it, small ones are usually used.

To fix them, you can use regular nuts. The appearance of excessive noise during operation indicates that the device is not working properly. In this case, it is necessary to check the integrity of the wiring. You also need to inspect the conductors.

Peltier element for air conditioner

To make a high-quality Peltier element with your own hands for an air conditioner, double plates are used. Their minimum thickness should be at least 1 mm. In this case, you can hope for a temperature deviation of 15 degrees. After equipping the modules, the performance of air conditioners increases on average by 20%. Much in this situation depends on the ambient temperature. The stability of the mains voltage should also be taken into account. With minor interference, the device can withstand a load of approximately 4 A.

When soldering conductors, they should not be placed too close to each other. To properly complete Peltier modules with your own hands, the input and output contacts must be installed only on one of the two plates. In this case, the device will be more compact. A serious mistake in this situation would be to connect the module directly to the unit. This will lead to inevitable damage to the element.

Installing the module on a capacitor

To install it yourself, it is important to evaluate the power of the capacitor. If it does not exceed 20 V, then the element should be mounted with conductors marked “PR30” or “PR26”. In order to fix the Peltier module (element) on the capacitor with your own hands, use small metal corners.

It is best to install them four on each side. In terms of performance, the capacitor can ultimately add plus 10%. If we talk about heat losses, they will be insignificant. The efficiency of the device is on average 80%. For high voltage capacitors modules are not calculated. In this case, even a large number of conductors will not help.

Refrigeration equipment has become so firmly established in our lives that it is even difficult to imagine how we could manage without it. But classic refrigerant designs are not suitable for mobile use, for example, as a traveling cooler bag.

For this purpose, installations are used in which the operating principle is based on the Peltier effect. Let's briefly talk about this phenomenon.

What it is?

This term refers to a thermoelectric phenomenon discovered in 1834 by the French naturalist Jean-Charles Peltier. The essence of the effect is the release or absorption of heat in the area where dissimilar conductors through which electric current passes are in contact.

In accordance with the classical theory, there is the following explanation for the phenomenon: electric current transfers electrons between metals, which can accelerate or slow down their movement, depending on the contact potential difference in conductors made of different materials. Accordingly, with an increase in kinetic energy, it is converted into thermal energy.

On the second conductor, a reverse process is observed, requiring replenishment of energy, in accordance with the fundamental law of physics. This occurs due to thermal vibration, which causes cooling of the metal from which the second conductor is made.

Modern technologies make it possible to produce semiconductor elements-modules with maximum thermoelectric effect. It makes sense to briefly talk about their design.

Design and principle of operation

Modern modules are a structure consisting of two insulating plates (usually ceramic), with serially connected thermocouples located between them. A simplified diagram of such an element can be found in the figure below.

Designations:

• A – contacts for connecting to a power source;
• B – hot surface of the element;
• C – cold side;
• D – copper conductors;
• E – semiconductor based on p-junction;
• F – n-type semiconductor.

The design is made in such a way that each side of the module is in contact either p-n or n-p transitions(depending on polarity). Contacts p-n heat up, n-p – cool down (see Fig. 3). Accordingly, a temperature difference (DT) occurs on the sides of the element. To an observer, this effect will look like a transfer of thermal energy between the sides of the module. It is noteworthy that changing the power polarity leads to a change in hot and cold surfaces.

Rice. 3. A – hot side of the thermoelement, B – cold side

Specifications

The characteristics of thermoelectric modules are described by the following parameters:

• cooling capacity (Q max), this characteristic is determined based on the maximum permissible current and the temperature difference between the sides of the module, measured in Watts;
• maximum temperature difference between the sides of the element (DT max), the parameter is given for ideal conditions, the unit of measurement is degrees;
• permissible current required to ensure maximum temperature difference – I max;
• the maximum voltage U max required for the current I max to reach the peak difference DT max ;
• internal resistance of the module – Resistance, indicated in Ohms;
• efficiency coefficient - COP (abbreviation from English - coefficient of performance), essentially this is the efficiency of the device, showing the ratio of cooling to power consumption. For inexpensive elements this parameter is in the range of 0.3-0.35, for more expensive models it approaches 0.5.

Marking

Let's look at how typical module markings are deciphered using the example of Figure 4.

Figure 4. Peltier module marked TEC1-12706

The marking is divided into three meaningful groups:

1. Element designation. The first two letters are always unchanged (TE), indicating that this is a thermoelement. The next one indicates the size, there may be the letters “C” (standard) and “S” (small). The last number indicates how many layers (cascades) there are in the element.
2. The number of thermocouples in the module shown in the photo is 127.
3. The rated current is in Amperes, for us it is 6 A.

The markings of other models of the TEC1 series are read in the same way, for example: 12703, 12705, 12710, etc.

Application

Despite the rather low efficiency, thermoelectric elements are widely used in measuring, computing, and household appliances. Modules are an important operating element of the following devices:

• mobile refrigeration units;
• small generators to generate electricity;
• cooling systems in personal computers;
• coolers for cooling and heating water;
• dehumidifiers, etc.

Let us give detailed examples of the use of thermoelectric modules.

Refrigerator using Peltier elements

Thermoelectric refrigeration units are significantly inferior in performance to compressor and absorption analogues. But they have significant advantages, which makes their use advisable under certain conditions. These advantages include:

• simplicity of design;
• vibration resistance;
• absence of moving elements (except for the fan blowing the radiator);
• low noise level;
• small dimensions;
• ability to work in any position;
• long service life;
• low energy consumption.

These characteristics are ideal for mobile installations.

Peltier element as an electricity generator

Thermoelectric modules can work as electricity generators if one of their sides is subjected to forced heating. The greater the temperature difference between the sides, the higher the current generated by the source. Unfortunately, the maximum temperature for the thermal generator is limited; it cannot be higher than the melting point of the solder used in the module. Violation of this condition will lead to failure of the element.

For mass production of thermal generators, special modules with refractory solder are used; they can be heated to a temperature of 300°C. In ordinary elements, for example, TEC1 12715, the limit is 150 degrees.

Since the efficiency of such devices is low, they are used only in cases where it is not possible to use a more efficient source of electrical energy. However, 5-10 W thermal generators are in demand among tourists, geologists and residents of remote areas. Big and powerful stationary installations, powered by high-temperature fuel, are used to power gas distribution units, equipment of meteorological stations, etc.

To cool the processor

Relatively recently, these modules began to be used in CPU cooling systems personal computers. Considering the low efficiency of thermoelements, the benefits of such structures are rather doubtful. For example, to cool a 100-170W heat source (fits most modern models CPU), you will need to spend 400-680 W, which requires the installation of a powerful power supply.

The second pitfall is that an unloaded processor will release less thermal energy, and the module can cool it below the dew point. As a result, condensation will begin to form, which is guaranteed to damage the electronics.

Those who decide to create such a system on their own will need to carry out a series of calculations to select the power of the module for a specific processor model.

Based on the above, using these modules as a CPU cooling system is not cost-effective; in addition, they can cause failure computer equipment out of service.

The situation is completely different with hybrid devices, where thermal modules are used in conjunction with water or air cooling.

Hybrid cooling systems have proven their effectiveness, but the high cost limits the circle of their admirers.

Air conditioner based on Peltier elements

Theoretically, such a device will be structurally much simpler than classic climate control systems, but it all comes down to low performance. It’s one thing to cool a small volume of a refrigerator, another thing to cool a room or the interior of a car. Air conditioners using thermoelectric modules will consume more electricity (3-4 times) than equipment running on refrigerant.

Regarding use as automotive system climate control, then the power of a standard generator will not be enough to operate such a device. Replacing it with more efficient equipment will lead to significant fuel consumption, which is not cost-effective.

In thematic forums, discussions on this topic periodically arise and various home-made designs are considered, but a full-fledged working prototype has not yet been created (not counting the air conditioner for a hamster). It is quite possible that the situation will change when modules with more acceptable efficiency become widely available.

For cooling water

The thermoelectric element is often used as a coolant for water coolers. The design includes: a cooling module, a thermostat-controlled controller and a heater. This implementation is much simpler and cheaper than a compressor circuit; in addition, it is more reliable and easier to operate. But there are also certain disadvantages:

• water does not cool below 10-12°C;
• cooling takes longer than its compressor counterpart, therefore, such a cooler is not suitable for an office with big amount workers;
• the device is sensitive to external temperature, in a warm room the water will not cool to the minimum temperature;
• Installation in dusty rooms is not recommended, as the fan may become clogged and the cooling module may fail.

Tabletop water cooler using Peltier element

Air dryer based on Peltier elements

Unlike an air conditioner, the implementation of a dehumidifier on thermoelectric elements quite possible. The design is quite simple and inexpensive. The cooling module lowers the temperature of the radiator below the dew point, as a result, moisture contained in the air passing through the device settles on it. The settled water is discharged into a special storage tank.

Despite the low efficiency, in this case the efficiency of the device is quite satisfactory.

How to connect?

There will be no problems with connecting the module; you need to apply power to the output wires. constant pressure, its value is indicated in the datasheet of the element. The red wire must be connected to the positive, the black wire to the negative. Attention! Reversing the polarity reverses the positions of the cooled and heated surfaces.

How to check the Peltier element for functionality?

The simplest and reliable way– tactile. It is necessary to connect the module to the appropriate voltage source and touch its different sides. For a working element, one of them will be warmer, the other colder.

If you don’t have a suitable source at hand, you will need a multimeter and a lighter. The verification process is quite simple:

1. connect the probes to the module terminals;
2. bring the lit lighter to one of the sides;
3. We observe the readings of the device.

In the working module, when one of the sides is heated, an electric current is generated, which will be displayed on the device display.

How to make a Peltier element with your own hands?

It is almost impossible to make a homemade module at home, especially since there is no point in doing so, given their relatively low cost (about $4-$10). But you can assemble a device that will be useful on a hike, for example, a thermoelectric generator.

To stabilize the voltage, it is necessary to assemble a simple converter on the L6920 IC chip.

A voltage in the range of 0.8-5.5 V is supplied to the input of such a converter; at the output it will produce a stable 5 V, which is quite enough to recharge most mobile devices. If a conventional Peltier element is used, it is necessary to limit the operating temperature range of the heated side to 150 °C. To avoid the hassle of tracking, it is better to use a pot of boiling water as a heat source. In this case, the element is guaranteed not to heat above 100 °C.

Well, all the graphs are drawn, all the tables are filled out, now you can dream. In general, if you estimate the energy consumption on a hike to the maximum, you get the following:
GPS navigator - 0.3 W x 10 h = 3 W*h per day;
camera (Canon DSLR) - 8 Wh battery for 4 days = 2 Wh per day;
video camera (video recorder for capturing interesting moments of the trip, about 1 hour of video per day) - 1.6 Wh per day;
cellular telephone- about 0.2 W*h per day;
led flashlight to illuminate the parking lot in the evening - 2 W*h per day.
Total we get: 3 + 2 + 1.6 + 0.2 + 2 = 8.8 Wh per day. Taking into account the losses when charging the batteries of these devices and unexpected expenses, you can easily round this figure to 10 Wh per day, which is approximately equal to three AA NiMH batteries (3.2 Wh each). We will assume that this is the amount of electricity that allows you to comfortably travel along a previously planned route without limiting your creative urges. This calculation is more or less correct for a solo outing or a group of two people. If there are more people, then an additional consumer is added for each person, be it a cell phone or another camera. I think that for each “extra” participant you can safely add 1 Wh, that is, for a group of 6 people, a comfortable level of energy consumption will be 14 Wh or about 4.5 AA batteries. Let's assume that the hike lasts 10 days, then for a group of 2 people you will need 100 Wh of energy, this is 31 NiMH batteries with a total weight of 31 x 31.5 = 976.5 g. That is, almost 1 kg of batteries. If you take alkaline batteries, the best ones give out 2.2 Wh and you will need 45 of them. I don’t know their weight, but even if they are 25 g each, the total adds up to more than a kilogram. For a group of 6 people, the total amount of electricity is 140 Wh, which is almost 44 batteries weighing 1386 g or 64 batteries weighing even more. If you take with you LiPo batteries, such as modelers use, then for two people it will be a battery weighing 100 Wh ÷ 160 Wh/kg = 0.625 kg or 625 g. For a group of 6 people, the mass of the LiPo battery will be 875 g .
Now let's figure out how things are going with the thermogenerator. Let’s say we have a TEC1-12709 module (or modules), heat it no higher than 150 °C, cool it in a stream with a temperature of 15 °C, that is, on the cold side it will be 20 °C, the temperature difference is 150 - 20 = 130 °C. For such a value of temperature difference I do not have an efficiency indicator, I will have to count. We take two maximum values ​​on the graph of efficiency versus current for TEC1-12709, for example 13.6 mW/°C for an average temperature difference of 71 °C and 15.7 mW/°C for 87 °C and calculate by what amount the efficiency has increased at increasing the temperature difference by 87 - 71 = 16 °C. It turns out to be 2.1 mW/°C. And then in proportion: if an increase in the difference of 16 °C led to an increase in efficiency by 2.1 mW/°C, then an increase in the difference by 130 - 87 = 43 °C will lead to an increase in efficiency by (43 x 2.1) ÷ 16 = 5.6 mW/°C. This means that the efficiency at a temperature difference of 130 °C will be equal to 15.7 + 5.6 = 21.3 mW/°C. As a result, we get 21.3 x 130 = 2769 mW or 2.8 W. This value is quite close to reality, judging by the fact that in some video experiments two modules produced 4...6 W. In order to obtain 10 Wh of energy using one module, the generator must operate for 10 ÷ 2.8 = 3.57 hours, and for 14 Wh - 5 hours. That is, if you use a thermogenerator consisting of 2 Peltier elements, then generating electricity even for a large group does not take very long.
The only major problem with generating electricity while camping using this method is heat dissipation on the cold side. The best and most optimal is water cooling, since water has a high heat capacity. In this regard, water tourists are luckier than cyclists: their method of transportation is connected specifically with water, and if you think through the design of the generator (it’s very strange why it has not yet been thought out and implemented on an industrial scale), then they can generate electricity while driving. The generator is partially submerged in water and partially floats on the surface. Fuel is loaded into the furnace as it is consumed, and everything is cooled with water from the outside. Fuel is collected and prepared at the rest stop.
If you don’t want to bother with collecting firewood and pine cones, then you can think about the design of a gas stove. It's worth doing a little math here. So we have:
liquefied gas cylinder for gas burners with fuel weighing 450 g;
composition: isobutane - 72%, propane - 22%, butane - 6%, in terms of weight this is 324 g, 99 g and 27 g, respectively;
the calorific values ​​for these gases are 49.22 MJ/kg, 48.34 MJ/kg and 49.34 MJ/kg, respectively.
After multiplication and addition, we have 22.07 MJ in one liquefied gas cylinder. We take the efficiency of our generator to be 1%, therefore we get 220 kJ as electricity, which is 61.3 Wh. What can you compare it to? Well, for example, with 19 NiMH AA batteries. Not a lot and quite expensive, gas is not cheap.
Since using gas is expensive, you can come up with something using liquid fuel, such as gasoline. I scoured the Internet a little for a cheap catalyst for catalytic burners, but I couldn’t find anything other than chromium (VI) oxide obtained from ammonium dichromate. Yes, and not everything is so smooth with it, but if you wish, through a certain amount of experimentation you can achieve stable positive results here too. Catalytic heating pads made in China most likely use trace amounts of platinum group elements. If only there was a catalyst like in this heating pad, but larger for Peltier elements. The result would be a compact and lightweight generator. The calorific value of gasoline is 44.5 MJ/kg, density 0.74 kg/l, from one liter of gasoline we have 33 MJ of energy, at 1% efficiency this is 330 kJ or 91.6 Wh of electricity (28 AA batteries). A more budget option, but still collect and prepare what is available in nature free fuel is naturally more profitable, and it does not have one very unpleasant feature, inherent in those stocks that are bought in the store - it does not run out at the most inopportune moment.