What is a Step UpTransformer?

A step-up transformer is one whosesecondary voltage is greater than its primary voltage. This kind of transformer"steps up" the voltage applied to it. For instance, a step uptransformer is needed to use a 220v product in a country with a 110v supply.

What is a Step DownTransformer?

Its the opposite of the above, andwould be used to run for example a 110v product in a country with a 220v mainssupply.

What 'Rating' Transformerdo i need?

This depends entirely on theproducts you will be using it with. Give the electrical retailer a detailedlist of all the products you will be using with it - and also their maximumoutputs. From this information he/she will be able to advise the correcttransformer rating needed.

A transformer converts alternatingcurrent (AC) from one voltage to another voltage. It has no moving parts andworks on a magnetic induction principle; it can be designed to"step-up" or "step-down" voltage. So a step up transformerincreases the voltage and a step down transformer decreases the voltage.

How does a step uptransformer or step down transformer work?

A transformer is made from two ormore coils of insulated wire wound around a core made of iron. When voltage isapplied to one coil (frequently called the primary or input) it magnetizes theiron core, which induces a voltage in the other coil, (frequently called thesecondary or output). The turns ratio of the two sets of windings determinesthe amount of voltage transformation.

An example of this would be: 100turns on the primary and 50 turns on the secondary, a ratio of 2 to 1.

Transformers can be considerednothing more than a voltage ratio device.

With a step up transformer or stepdown transformer the voltage ratio between primary and secondary will mirrorthe "turns ratio" (except for single phase smaller than 1 kva whichhave compensated secondaries). A practical application of this 2 to 1 turnsratio would be a 480 to 240 voltage step down. Note that if the input were 440volts then the output would be 220 volts. The ratio between input and outputvoltage will stay constant. Transformers should not be operated at voltageshigher than the nameplate rating, but may be operated at lower voltages than rated.Because of this it is possible to do some non-standard applications usingstandard transformers.

Single phase transformers 1 kva andlarger may also be reverse connected to step-down or step-up voltages. (Note:single phase step up or step down transformers sized less than 1 KVA should notbe reverse connected because the secondary windings have additional turns toovercome a voltage drop when the load is applied. If reverse connected, theoutput voltage will be less than desired.)

Step up transformersand step down transformers have a long life.

The primary components for voltagetransformation are the transformer's core and coil. The insulation is placedbetween the turns of wire to prevent shorting to one another or to ground. Thisis typically comprised of mylar, nomex, kraft paper, varnish, or othermaterials.

As a transformer has no movingparts, it will typically have a life expectancy between 20 and 25 years.