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Ebay electronic components?

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HazzWold 1993

Thu May 27 2010, 01:15AM

Registered Member #2563 Joined: Mon Dec 21 2009, 10:17AM
Location: Australia
Posts: 280

Can anyone here give any feedback to what sort of quality you can expect from buying components of Ebay? i know it obviously varies seller to seller but like. is it worth trusting the cheaper things, or just paying for known quality.. in my case im after some IRFP250's for a ZVS Mazzilli driver.

Eg.

Where as from electronics stores in town they ask around $10 per peice...

ScotchTapeLord

Thu May 27 2010, 02:12AM

Registered Member #1875 Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635

A general rule of thumb for anything is that "You get what you pay for."
That doesn't stop me from finding the cheapest deals, though.
Unfortunately, it doesn't stop the "counterFET" shrapnel from flying across the room, either.

I'd consider myself very lucky to find an electronics store near me with IRFP250s, even if they are priced ridiculously... in fact, I'd be surprised if the people at an electronics store near me even know what a MOSFET is!

It can't hurt to buy a few cheap ones for prototyping and such, but when you want to finalize something, maybe box it up and make it look nice, you'll probably want to consider going for what you know is the real deal.

Matt Edwards

Thu May 27 2010, 03:22AM

Registered Member #2838 Joined: Fri Apr 30 2010, 07:55PM
Location: tehachapi, CA
Posts: 333

Forget the 250's and go strait for the IRFP460's. Trust me, you will thank me for it later...

Mads Barnkob

Thu May 27 2010, 05:13AM

Registered Member #1403 Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968

I have received IRFP460s from marymar6688 that would die or break down way before their maximum ratings, belived to be fakes, I advice you to stay away from that seller.

I have had good luck with another ebayer called Thaishopetc, never had anything that didnt work to specs from them,

Proud Mary

Thu May 27 2010, 09:12AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Trade protection rather than concern over MTBF is the main driver of "anti-counterfeiting" rhetoric.

As with the American Minuteman ICBMs whose Missile Guidance Sets were found to be built using low grade parts obtained from local Radio Shack outlets, counterfeiting narratives are a convenient means of re-locating responsibility for poor performance and dishonesty to a remote position in the component supply chain - usually to a location in a disliked foreign competitor nation such as China, which now manufactures the greater part of the world's supply of electronic components, both good and bad.

With these caveats in mind, and purposefully avoiding the use of the word 'counterfeit,' we should consider the types of parts likely to be passed off as something they are not, which may include:

1. Bona fida parts created in, or diverted from, licensed manufacture - Licensee Chow Mein Manufacturing Co works late, does product over-runs, etc, without the knowledge of Hamburger Corporation. Fraud involves senior management of Chow Mein, and probably contract supervisors from Hamburger. There is no reason to suppose that this class of 'counterfeits' should be any less good than those manufactured without breaking the terms of the license.

2. Quality control rejects which component factories generate by the skip load. Substandard parts scheduled for recycling are intercepted and diverted. Can be perpetrated at any level from corporate down to the lone opportunist who simply drives off with a skip load of parts.

3. Unlawful disposal of hazardous waste. A hazardous waste disposal contractor receives payment for disposing of hazardous material in a lawful way, but in fact re-sells it in the electronics market without reference to its hazardous status.

4. Rubbish dump harvesting. This is quite common in Russia, where obsolete military parts of the former USSR such as thermionic valves have been disposed of in open cast rubbish dumps. Who hasn't bought Russian valves without water damage to the cardboard containers at one time or another?

5. Actual 'counterfeiting' - a part is copied, manufactured, and labeled as the real thing. Involving significant capital investment, this must be the least common and least profitable 'counterfeiting' scenario, since all that's evaded is the manufacturing license fee, whilst taking on board all the costs and liabilities of industrial plant.

Costly, uncommon components are the least likely to be 'counterfeited', and cheap, common, consumer ones the most likely,
with all sorts of variations and permutations of the basic modus operandi above to be expected.

Ebay sellers are no more likely to be selling 'counterfeit' electronic components than anybody else. Ebay has provided legitimate manufacturers and wholesalers with a means of lawfully disposing of existing non-RoHS and other non-compliant parts which can no longer be used for selling into the consumer electronics sector in the EU, and would otherwise have been a total loss.

And if in doubt, and the labour is worth it, it is often only the work of a few minutes to test the static and dynamic characteristics of components and verify them against the data sheet, before committing them to an important project. That's what I do.

uzzors2k

Thu May 27 2010, 12:05PM

Registered Member #95 Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308

I've never had anything but positive purchases on ebay, that said I do watch what I buy. There are actually sellers who make a living doing this, and want pleased costumers. One seller I'm very fond of is Sure-Electronics, they have all sorts of digital components and boards, and at great prices too. My package will arrive in just two weeks in most cases.

IamSmooth

Thu May 27 2010, 01:10PM

Registered Member #190 Joined: Fri Feb 17 2006, 12:00AM
Location:
Posts: 1567

Most electronic components I have gotten have worked flawlessly. Recently, I purchased a rectifier that was listed as 80A. Someone pointed out that he did not think the casing for the item was for an 80A device. I looked into it further and confirmed that this was an 8A device, and the seller had been selling it (deliberately or due to his lack of knowledge) as an 80A unit. If you search for an item, check that the datasheet corresponds to the part number. The user Goldenopportunities is a big seller of mosfets, igbts and diodes.

Dalus

Thu May 27 2010, 02:11PM

Registered Member #639 Joined: Wed Apr 11 2007, 09:09PM
Location: The Netherlands, Herkenbosch
Posts: 512

Sometimes your lucky sometimes your not. Personally I've been lucky most of the times

Hon1nbo

Thu May 27 2010, 03:42PM

Registered Member #902 Joined: Sun Jul 15 2007, 08:17PM
Location: Pacific Northwest USA
Posts: 1042

The only time I ever had a problem was with glass items, as shipping is a problem.
But for electronics, I've never had a problem. But the advice presented by others here is very good: reference part numbers, look at feedback, if it's too good to be true be very wary (though that does happen legitimately from time to time).

The only things I absolutely will NOT attempt to buy on eBay unless circumstance requires are safety devices: optoisolators, EPO switches, dead man's controllers, etc. the only time I violate that rule is when it will not be used as a safety device.

Anyways, once you find a good seller that has a good supply I'd stick with him. If you're a good customer of his, more than likely if there is a problem he'd be more inclined to help you out as then you'd return.

-Jimmy

teravolt

Thu May 27 2010, 06:18PM

Registered Member #195 Joined: Fri Feb 17 2006, 08:27PM
Location: Berkeley, ca.
Posts: 1111

I have bought moast of my fets from ebay and have not had any problems with conformity or function. if you use paypal you are sumwhat protected. I have also found that just googling or going to a electronics outfit lile Allied can be cheaper. At one point I bought 1000 1n4007 on ebay for 9$ and then recently I went back to ebay for more and found that it was cheeper at Allied for 2000. fets are a good buy geraly at ebay I use thease

they are over 500 watt devices

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