Just received some UF4007 diodes from China purchased off Ebay. Compared to diodes of the same designation I got from Mouser they're slightly smaller with thinner leads.
Does anyone know if there's any difference in performance between devices from various manufactures or do they pretty much adhere to the same specs?
Seems like they would but I'm not really in the know when it comes to evaluating devices from different makers. Hoping someone here might have some inside Knowledge they could share...
Thanks,
TT
Does anyone know if there's any difference in performance between devices from various manufactures or do they pretty much adhere to the same specs?
Seems like they would but I'm not really in the know when it comes to evaluating devices from different makers. Hoping someone here might have some inside Knowledge they could share...
Thanks,
TT
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Just bought an irfp240 off ebay.
Lasted 10 minutes after I unplugged my soldering iron and glitched the amp.
Put in a RS Components part and been fine since despite trying my best to disturb the mains plugging and unplugging things.
The ebay ad said Vishay so I assumed it would be a genuine part.
It didn't take much to kill it.
Last time I buy electronic components off ebay.
Lasted 10 minutes after I unplugged my soldering iron and glitched the amp.
Put in a RS Components part and been fine since despite trying my best to disturb the mains plugging and unplugging things.
The ebay ad said Vishay so I assumed it would be a genuine part.
It didn't take much to kill it.
Last time I buy electronic components off ebay.
The commercial datasheets show the UF4007 has the DO-204AL Jedec case style, which has the same lead diameter as the case 59 for the 1N4007, which specifies a lead diameter of 0.71 to 0.86mm range.
If the lead diameter is not in that range then it is not a UF4007, and you should follow standard ebay process for misrepresented parts.
The lead diameter is a major influence on thermal resistance of the package, and so those diodes will have higher thermal resistance than bogey part, and hence lower power dissipation capability. The UF4007 already has a lower current capability than the 1N4007, as discussed in:
https://www.dalmura.com.au/static/Power%20supply%20issues%20for%20tube%20amps.pdf
PS. my ebayed UF4007 appear to have same lead diameter as 1N400x, but I don't have easy access to a micrometer at the moment.
If the lead diameter is not in that range then it is not a UF4007, and you should follow standard ebay process for misrepresented parts.
The lead diameter is a major influence on thermal resistance of the package, and so those diodes will have higher thermal resistance than bogey part, and hence lower power dissipation capability. The UF4007 already has a lower current capability than the 1N4007, as discussed in:
https://www.dalmura.com.au/static/Power%20supply%20issues%20for%20tube%20amps.pdf
PS. my ebayed UF4007 appear to have same lead diameter as 1N400x, but I don't have easy access to a micrometer at the moment.
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Thanks for the replies... True, I don't know where the parts from Mouser where actually made, but they seem to be more robustly constructed than what I received from Ebay.
I'll check the spec sheet as you recommended, but they seem to be off spec in comparison with the Mouser supplied parts...
TT
I'll check the spec sheet as you recommended, but they seem to be off spec in comparison with the Mouser supplied parts...
TT
As a pro audio shop owner, I never buy parts on ebay. False economy. Any savings I make are wiped out the first time a fake part blows up an amp. And if I send out a repair the customer has to bring back in a week, it is hard to recover that customer loyalty.
Mouser sells real parts, from real suppliers. I have had great service and experience with them over the last 30-40 years.
And does anyone know the performance difference between the Mouser part and the ebay part? No. Because no one knows what the ebay parts really are. They may claim to be UF4007, but are they really fast recovery diodes? Are they really 100v diodes? Are they really 1 amp diodes?
DOn't fool yourself thinking crooks won't fake cheap parts like diodes, they surely will.
Mouser sells real parts, from real suppliers. I have had great service and experience with them over the last 30-40 years.
And does anyone know the performance difference between the Mouser part and the ebay part? No. Because no one knows what the ebay parts really are. They may claim to be UF4007, but are they really fast recovery diodes? Are they really 100v diodes? Are they really 1 amp diodes?
DOn't fool yourself thinking crooks won't fake cheap parts like diodes, they surely will.
Certainly no need to apologize, even if I was offended, which I was not. I was just trying to point out that any determination of value changes when any of the inputs change significantly.
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