Car air conditioning based on Peltier elements. Homemade air conditioner based on Peltier elements. Air dryer based on Peltier elements

This article will help those people who have heard about the existence of portable Wi-Fi routers, but do not fully understand what it is and what this device is intended for. It is also suitable for those who have already decided to purchase a portable Wi-Fi gadget, but do not know how to choose correctly among the many models presented on our market.

Let's start with what kind of device this is and the scope of its application.

A portable Wi-Fi router is mobile device, which receives the operator’s network signal and relays the Internet via Wi-Fi networks. You can connect to it any device that can receive the Internet via Wi-Fi (phones, smartphones, tablets, laptops, desktop computers, TVs, IPTV players). Moreover, you can connect several devices at the same time. The portable Wi-Fi router operates in the 802.11 b/g/n standard (up to 150 Mbit/s). Range medium model 10-20 meters.

Portable routers can be used in cases where it is impossible to access regular cable Internet and for trips to places with limited access to the Internet (outdoors, fishing, to the country), going to a cafe, library, school. Convenient to take with you on business trips or for presentations. And most importantly, with such a device you can use the Internet even if there is no electricity in the network.

Each device of this type has its own advantages and disadvantages.

Advantages:

• Suitable for connecting via Wi-Fi to almost all devices.
• Own battery, does not require connecting additional power cords through other devices.
• Usually the Internet tariff is cheaper than mobile phones, smartphones.
• Stable good Wi-Fi signal.
• The ability to use the router both at home and outside the city.

Flaws:

• You'll have to carry another gadget in your pocket or purse.
• There is no auto-off mode (it’s easy to forget to turn off the device after finishing work).
• Short time battery life from 2 to 5 hours, even for models with large batteries no more than 12 hours.
• Some models may work unstably in rooms or car interiors with high temperature And high humidity. But this is a problem with many electronic gadgets.

Now you can move on to the purchase itself. How to choose the right device you need, because in our stores and websites there are now a large variety that allow us to receive the Internet we so need without wires. Approaching the choice of portable Wi-Fi router a lot of factors need to be taken into account.

• Decide on the choice of provider (operator providing services). An important factor is the coverage of a particular mobile operator.
• Availability of a connector for connecting an antenna (to increase the signal power of a portable device).
• Operating conditions, whether the device will be stationary or constantly move with you. The important factors here are dimensions, weight and autonomy (volume battery) portable wifi router.
• Read the operating instructions, technical characteristics and operating conditions of the device.

When purchasing in stores or communication stores, the sales manager will certainly help you. And when purchasing in online stores, it is better to use the provided filters that will make your choice easier. Or contact the online manager.

Thermoelectric Peltier cooler.

The principle of operation was borrowed from the net: The operation of Peltier elements is based on the contact of two conductive materials with different levels of electron energy 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, when practical application contact of two semiconductors is used.

Appearance of a Peltier element. When current is passed, heat is transferred from one side to the other. 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 jumpers. 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 cold side gets even lower. In single-stage elements, depending on the element type and current value, the temperature difference can reach approximately 70 K/

Description
The Peltier element is a thermoelectric converter, which, when voltage is applied, is capable of creating a temperature difference across the plates, that is, pumping heat or cold. The presented Peltier element is used for cooling computer boards (subject to effective heat removal), for cooling or heating water. Peltier elements are also used in portable and car refrigerators.

Peltier element operating on 12 Volts.

To heat up, you just need to change the polarity.
Dimensions of the Peltier plate: 40 x 40 x 4 millimeters.
Operating temperature range: from -30 to +70?..
Operating voltage: 9-15 Volts.
Current consumption: 0.5-6 A.
Maximum power consumption: 60 W.
A funny little thing, we connect 12v + - it cools, we change the polarity, it warms. It is used in many car refrigerators, at least this is what I have. You can attach a compact circuit to the glove compartment so that the chocolate doesn’t melt in the summer! For use and effective application you need to use a cooling radiator - as a test I used a radiator from a computer processor, possibly with a cooler. The better the cooling, the stronger and more effective the Peltier effect is. When connected to a 12v car battery, the current consumption was 5 amperes. In a word, the element is gluttonous. Since I have not yet assembled the entire circuit, but only carried out trial tests, without instrument temperature measurements. So, in the cooling mode, light frost appeared within 10 minutes. In heating mode, the water in the metal cup began to boil. The efficiency of this cooler is, of course, low, but the price of the device and the opportunity to experiment make the purchase justified. The rest is in the photo