Testing the legitimacy of power electronics

[Belrmar]

Basically ebay and aliexpress are cheap, but usually not so reliable. What are your favorite ways to spot if a component is original?

[BravoV]

Basically ebay and aliexpress are cheap, but usually not so reliable. What are your favorite ways to spot if a component is original?

Its cheap, as you said, buy one, test up to rated specification to verify, as simple as that.

And no, by visually especially from the web page that the images probably were copied and copied from internet, definitely will not guarantee anything.

Also even you have the physical thing in your hand, you just can not easily to spot the good vs bad/fake ones visually especially at the ICs and components nowdays.

Also regarding seller's feedbacks, its only useful for reliable shipping, NOT for reliable product.

My 2 cents.

[Belrmar]

Get an insulation meter good for 2.5kV, and that will give you an idea about the safety of the product.

Well that would be good for transformers, but i am more interested about ic's and power transistors

[Belrmar]

Its cheap, as you said, buy one, test up to rated specification to verify, as simple as that.

Yout mean to , for eample, trace the curve and try to match it to the datasheet?

[T3sl4co1l]

By buying from Digikey or Mouser...

You're welcome to create a parts receiving and inspection program, but you will quickly find you are wasting hundreds of thousands of dollars to save a thousand here and there.

There is good reason why reputable sellers are more expensive yet are in no danger of dying out!

And if you mean not even corporate, but for your own own few euros of projects?  Give me a break, you've wasted as much value in your own time as you could ever stand to save from those sources. The economic choice is simple: find a second job to fill your time, so instead of asking questions you can afford real parts, to use in, uh, what little free time you have left.

Tim

[wraper]

Get an insulation meter good for 2.5kV, and that will give you an idea about the safety of the product.

Well that would be good for transformers, but i am more interested about ic's and power transistors

If the price is way lower than at reputable places, most likely they will be counterfeits. As of how to check, there are some visual ways. Rough surface which look like grinded, inaccurate logo, different font, other inaccuracies in marking and package. Sometimes they may be blacktopped or grinded, then blacktopped and new marking applied. In such case it usually can be removed by rubbing with acetone or even IPA.

[IanMacdonald]

A common problem is remarking of parts to make it appear they are higher specification versions than they are. In this case they're probably genuine parts, just not the ones claimed. A recent example was the remarking of XLSemi 35v switching regulators to sell as 50v versions. Since this is easy to do, it is rife.

If you get something like a TIP42c where the 'C' looks like it's in a different typeset, be suspicious.