On October 24, 2014 at 12:34, Ernie Gilman said...
The company that makes the wall wart gets it through UL. It can then be used with ANY product which, because it's using a wall wart, does not have to deal with the time and expense of UL approval (at least not power voltage type approval) for their products. They can offer new products or modify their current ones without the expense of UL. This also makes it more affordable to make products for which there is little demand.
It just occurred to me that this is also why the wall wart very rarely has the same brand name as the product. I've gotten wall warts for one product confused with those for another product because of this, but hey: it was made by someone else!
Not really
1) UL certification is not strictly necessary (and so nothing stops a company from selling a product with out it)
2) UL certification can be applied to internal parts just as much as external (for example my desktops internal power supply has been UL certified)
3) UL certification is not only for power supplies
I think it is more for
1) ease of manufacture - think of a wireless router, you won't bring it with you on vacation, it is a fixed universal standardfor everywhere in the world, so it is easier for the manufacturer to build them all 100% the same and then add the right wart to the box depending on where it will be shipped
2) size - people are stupid and say "look how small ____ is" when it does not matter so removing the power supply helps with that
3) heat - power supplies run hot, having them external means it is one less issue to deal with in the design of the product.
But what ever the reasons for why external is better than internal it is not all that interesting.
Since Instead of something like the one on the left with the plug built into the wart and is a bitch to use the manufacturers of the warts could easily build something like the one on the right with a 6" or even 3" cable going to the plug and the issue of why use an external power supply would be mostly moot and the wart issue solved.
Last edited by Anthony on October 26, 2014 11:07.
