Alimentatori switching e carica batterie

What you always wanted to know about power supplies but never dared to ask

What are power supplies and why do they exist?

Electrical appliances do need a power source otherwise they would not work. The electricity mains, apart from batteries, is the usual power source we use. There are two different voltages used in the world's power systems, i.e. 110 volts (America) and 230 volts (Europe, Africa, Asia). Most consumer products, e.g. phones, mobile phones, organizers, calculators, and so on, need a much lower voltage and therefore the voltage needs to be transformed down. If there is enough room inside the product (e.g. printers, PCs) the transformer is built in, but if not an external power supply provides the appliance with the proper voltage. The advantages to the consumer are smallness and reduced weight since power supplies can be heavier than the product they serve.
On the other hand consumers are usually only interested in their product and do not want to think of how to power it. Actually some would think of power supplies as a necessary evil (or to put it in other words: The best power supply is no power supply). Since we are aware of that situation it is the prime goal of EGSTON to provide you with the least 'evil' possible.

What types of power supplies are there?

Until recently the only type of power supply used was the so-called linear type. These power supplies transform the voltage from 110 volts (or 230 volts) directly to the desired output voltage. The responsible part for this is the transformer consisting of an 'iron' core and many windings of a thin copper wire. The result is a more or less huge and heavy part. Because of these big (in the truest sense of the word) disadvantages such linear power supplies are bulky and quite unattractive.

With a technical trick these disadvantages can be avoided. The number of windings and thus the size of the transformer depend on the frequency of the voltage to be transformed (60 or 50 hertz). The higher the frequency the smaller the transformer. Switch mode power supplies utilize this behavior and increase the frequency dramatically up to 60,000 to 100,000 hertz. The result is a very small and light-weight transformer. Although this principle was known for quite a while its advantages were barely utilized. Therefore EGSTON developed a switch mode power supply (3.6 watts) which fits in an ordinary euro-plug (see picture). Till now this innovation is unparalleled by our competitors!

What exactly are the differences between switching and non-switching (linear) power supplies

What are the advantages of EGSTON's power supply?

What to consider when purchasing power supplies?

The consumer is protected by laws to a certain extent. There are several test standards, e.g. UL, CE, VDE (Germany), which have to be met by all producers. Power supplies without any of the above mentioned standards should never be purchased.

Almost every mobile phone has its own charging characeristic. The charging device has to be specifically designed for the mobile phone, otherwise it will dramatically shorten the life-time of the battery. EGSTON's travelcharger uses the original charging characterisic and thus will not harm the battery. In fact, sometimes we do even better and can prolong the life-time.

CAUTION! Most of the very cheap travelchargers use interior charging techniques which may harm the battery. Usually the user is not aware of the fact that the cheap travelcharger is the cause for the short life-time of the battery. According to our experience this is only true for very cheap products from the far east.