#### duff beer dragon

##### Junior Members

( that example is probably wrong, can't find any of those types of equations online to check it against )

where V is always going to be the voltage of the mains or supply,

and P is the power consumed by the appliance, in watts,

other than doing the equation - how can you find a current rating ( value I ) for any particular appliance.

Something sounds very wrong to me about power consumption of electricity but I can't put my finger on it yet - something to do with the current being the rate of flow.......

so if you had two 50 watt speakers and you pulled in the max. current to achieve that power output, then this then will cost you less in terms of electricty units than if you had two 100 watt speakers at full burn.

Here's the bit that doesn't make sense -

you can swap to a great degree your speakers over and keep the same stereo or amplifyer -

how come those same circuits are able to handle such divergent current rates?

Build a high-voltage transformer right - take minimal mains power in, and bump the voltage right up - how to do that, so you're paying the same amount of money for the electricty, but you have a higher voltage ; or, depending on how that equation works, how about lowering the voltage - there's only two other elements to the equation,

that means it should be fairly simple to get a very high current rating just by being able to alter the voltage, and therefore a far higher power output, at a low power price.

Anyone got any links to webpages with those high school equations on them?........