| The transformer is an electrical device, which | | | | But if your device is a computer, a printer or a |
| transforms voltage through magnetic coupling with | | | | VCR, you will need a transformer. Both of these |
| no moving parts. It consists of a magnetic core, | | | | category of appliances and devices can be run by |
| with two or more coupled windings, which either | | | | a transformer, but only the electric appliance can |
| steps up or steps down the incoming voltage. This | | | | be run with a converter. A word of caution in |
| is done by the transfer of energy from one | | | | here is that, while transformers are designed for |
| circuit to the other, through the magnetic core. | | | | long term continuous operation, converters on the |
| These windings are generally termed as Primary | | | | other hand can operate for an hour or two at a |
| and Secondary windings. The electromagnetic field | | | | time.In order to understand this better, we must |
| thus created under goes a process of expanding | | | | understand the formation of a AC voltage. The |
| and collapsing around the conductor and this | | | | alternating current voltage appears as a |
| changes the induced current, with the formation | | | | sine-wave, and depending upon the country you |
| of an out put from the secondary coil, either | | | | are in, the frequency of this sine-wave is either |
| stepping up or stepping down the input voltage.In | | | | 50Hz or 60Hz. Now, if you look at a converter |
| order to understand the function of a | | | | output, you would see that the upper half of the |
| transformer, only two sets of windings are | | | | sine-wave has been chopped off, where-as, in a |
| considered. When the main AC voltage is applied | | | | transformer the sine-wave remains in-tact. The |
| to the input of such an electrical device, the | | | | electrical devices, like, iron, heater, a hair dryer, |
| alternating current in the Primary winding creates | | | | etc, would run with such a converter, but a |
| a time varying magnetic flux in the core. This | | | | computer, a printer or a VCR can be damaged if |
| induces an AC voltage in the secondary coil, which | | | | you attempt to operate those with a |
| is either the step up or step down voltage of the | | | | converter.The frequency is the number of times |
| device. The terms, step up and step down are | | | | the alternating voltage alternates each second. |
| used with respect to the input voltage of the | | | | One such alternating cycle is termed as Hertz, |
| device. Therefore, if your equipment has been | | | | having Hz as the short form. This cycling wave is |
| specified as input voltage 110 Volts AC, and if you | | | | termed as a Sinusoidal Wave. In the U.S. and the |
| are in one of those countries where the mains | | | | rest of North and Central America, with some |
| power supply is 220 Volts AC, you will need a | | | | parts of South America, the alternating current |
| step down transformer to run your equipment.In | | | | suppy is 60Hz. In Europe and rest of the world it |
| high tension power transmission, where huge | | | | is 50Hz.There is a similar electrical device called |
| towers carry the cables which brings the power | | | | Inverter. The purpose of this equipment is to |
| to cities, towns and villages, step up transformers | | | | convert Direct Current (DC) voltage to Alternating |
| are used as the power leaves the power stations | | | | Current voltage. This device has many |
| and as they approach the destinations, the | | | | applications, for example, to provide appropriate |
| voltage is stepped down to the required mains | | | | limited AC power supply to devices like, electric |
| supply, before it is distributed amongst the | | | | fans, lights, etc. This inverter takes the DC |
| consumers. The reason for stepping up the | | | | voltage from a battery, like a heavy duty car |
| power as they leave the power station is for the | | | | battery and converts that into an appropriate AC |
| fact that,as it travels down the long power | | | | voltage. Such supplies are limited because of the |
| cables, there are power losses in the way, and | | | | capacity of the battery capability and depending |
| the supply can reach the destinations in a proper | | | | upon the battery the ampere-hour of the output |
| specified power level to be stepped down as | | | | can be increased, resulting in longer period of |
| required by the consumers. In this application | | | | operation. The battery will need charging once it |
| there are good many use of transformers are | | | | discharges.There are variable transformers, which |
| made.The transformer is the most simplest of all | | | | are known as Variacs. The principle is that the |
| electrical devices and its basic principle has not | | | | output voltage of this transformer can be |
| changed over the last 100 years, though the | | | | manually varied with a fixed voltage as its input. |
| material used in such transformers and its design | | | | For example, with a 110 Volt AC supply at the |
| continue to improve. It has a very important | | | | input, you can vary the output voltage from 0 to |
| application in transforming electrical energy, both | | | | 110 Volts AC. The typical applications of these |
| for consumer use and power transmission. In a | | | | transformers are in testing devices for its lower |
| similar way, audio frequency transformers have | | | | and higher input voltage operation levels, quality |
| been used in earlier experiments in development | | | | control in testing equipment in burn-in condition, |
| of telephones. These are still found in many | | | | temperature and lighting control, etc.Transformers |
| electronic devices. The transformers come in | | | | are essential devices to operate any electrical or |
| various sizes, depending upon the application it is | | | | electronic equipment. As far as main supply |
| required for. It comes in the size of a thumb nail | | | | voltage is concerned, if you are visiting Europe or |
| to huge units for the power transmission | | | | any other country in Asia, the devices that you |
| applications of national power grids. They all | | | | are taking with you will not operate in the mains |
| operate with the same basic principles.The core of | | | | supply voltage available in those countries. It is |
| the transformer, as we have seen above, may | | | | therefore necessary that you take with you the |
| be made with various materials. These include:Air - | | | | right device which can provide you with the right |
| This is ideal for high frequency transformer, with | | | | operating voltage for your equipment.110-220 Volt |
| application in Radio Frequencies and provides least | | | | Electronics - A multisystem TV is a TV capable |
| coupling.Iron - All so called iron core transformers | | | | of receiving and displaying different video |
| are steel. Various additives are made to improve | | | | systems like PAL, SECAM and NTSC. You'll be |
| the magnetic properties, as for example the | | | | able to operate a multisystem TV in 99% of the |
| magnetic permeability. The degree of | | | | world. Their dual voltage design allows them to be |
| magnetisation of a material required for a linear | | | | plugged into either a 110 voltage source or a 220 |
| response to an applied magnetic field is termed as | | | | voltage source. In some cases, the plug on the |
| Permeability.Ferrite - This is used to get a very | | | | television will not fit your country's outlet, so an |
| high degree of permeability and excellent high | | | | inexpensive plug-adapter will be needed. They can |
| frequency performance.Etc.The converter and the | | | | generally be picked up at an electronics store such |
| transformer are both electric conversion products, | | | | as for $1.95. With a multisystem TV, such as a |
| that enables you to run electric devices in foreign | | | | plasma, CRT tube type, LCD or DLP, you'll likely |
| lands. As discussed earlier, if your electric device | | | | need a codefree (sometimes called region free) |
| requires 110 Volts AC to run, you will need a | | | | DVD player. These exist in many forms. When |
| transformer to step up the 220 volts AC supply | | | | used with a PAL-NTSC TV you'll be able to see |
| voltage to 110 Volts AC before you can switch | | | | the full 625 lines of resolution available in the PAL |
| on that device that you have.What is the | | | | system and the full 525 lines used in the USA |
| difference between a converter and a | | | | NTSC system. There exists a converting type of |
| transformer? If the device you are going to | | | | DVD player which is codefree in that it can read |
| operate is a high power heating element or | | | | all of the world's 6 regions and both standards, |
| mechanical motor such as a hair dryer or iron, | | | | PAL and NTSC. 140,000 other products are |
| you will need a converter to run those appliances. | | | | available here: Tel. |