Big transformer vs small transformer?

[convo_king89]

I remember using a transformer in school that could be placed on a desk for labs. We only used it for step down and I know if i could use it for step up. The the one for step up like 110 to 220 usually are big and on the ground. What’s the difference?

[Soteris]

A transformer is fundamentally incredibly simple and works the same way for stepping down or up, just in reverse. The difference between small and larger transformers is the amount of power running through them, mainly the two big problems that comes from that.

First of all is the danger of high voltage being able to cross increasing gaps of air so you need more layers of insulation and bigger distances between components to keep it from discharging. This increases the size really quickly as you start climbing up.

Secondly is the problem of heat and resistance. The more power you push through a wire the thicker it must be or the resistence will produce so much heat it will melt the wire. Also a problem with extension cords by the way so be careful if you connect a device that draws a lot of power to a very long extension cord because you might start a fire.

So larger transformers has large radiators to keep cool and a bunch of insulation and extra space to keep the electricity from escaping along with extra thick wires to make sure they dont become literal lightbulbs from all the heat. The results are the chunky behemoths you see where as your phone charger which handles much less power and also dont run 24/7 so can cool down between uses can be much more compact and use smaller wires and no radiators.

[horatiohornblower]

The difference is the amount of current they can handle. The larger one can handle more watts being drawn. Just like phone chargers are smaller than laptop chargers. They just don’t need to handle as much power flowing through them.

[convo_king89]

So if you were stepping up voltage from
110 to 220 to use a phone charger I guess you could use a table top transformer right?

[legalboxers]

one is used for larger appliances