Fake primary capacitors

[Pentium4]

Re: Fake primary capacitors

Fake NCC cap, has a Hermei/Jamicon style vent. Looks pretty horrible, except the bottom of it doesn't look too bad

[ben7]

Re: Fake primary capacitors

Fake NCC cap, has a Hermei/Jamicon style vent. Looks pretty horrible, except the bottom of it doesn't look too bad

Wow that sucker has high ESR.

Try blowing it up, and video tape it. That vent looks like it wouldn't work that well ... notice the middle of it.

[Behemot]

Re: Fake primary capacitors

Seems like made in 1995. Is it possible it jsut went bad?

[c_hegge]

Re: Fake primary capacitors

That capacitance is still in spec, but yeah, with ESR that high, I'd toss it into a fire and see what it does.

[Pentium4]

Re: Fake primary capacitors

I bought the cap new off a crap Chinese site because I was curious. Out $1.99, no big deal. Should I blow it up or dissect it?

[c_hegge]

Re: Fake primary capacitors

Blow it up. It's more fun

[Pentium4]

Re: Fake primary capacitors

How shall I do it?

[kaboom]

Re: Fake primary capacitors

Like this:

[domas]

Re: Fake primary capacitors

that's a HV cap, so it is more tricky. Typically you can bang lytics by overvoltaging them with AC, lets say with linear transformer of 24V and enough amps. I guess this one would explode on AC too.

[Behemot]

Re: Fake primary capacitors

I think you can use transformer welder just fine It passes on "enough amps"

[Pentium4]

Re: Fake primary capacitors

Like this:

[c_hegge]

Re: Fake primary capacitors

I was gonna say toss it into a fire

[momaka]

Re: Fake primary capacitors

I bought the cap new off a crap Chinese site because I was curious. Out $1.99, no big deal. Should I blow it up or dissect it?

I would dissect it, fill it up with water (piss would be funnier, but probably too gross for most people), then seal it again (with ductape, of course), and see how it performs.

I say there is a chance it might do better.

[ttn328]

Re: Fake primary capacitors

Sorry for off topic.
Some Chinese companies can fake rating on their cheap caps, could they also fake rating or specs on semiconductor products such as diode,... say they up a general purpose 1N4007 to FR107 or something ? It is serious, many fast recovery diodes are used in PSU.

[Behemot]

Re: Fake primary capacitors

There is too many fakes of everything. I would not worry about 1A diodes but more like high-power transistors and diodes. If you make the junction half or quarter the size it should be, it hardly does 20, 30 amperes etc.

[tom66]

Re: Fake primary capacitors

Sorry for off topic.
Some Chinese companies can fake rating on their cheap caps, could they also fake rating or specs on semiconductor products such as diode,... say they up a general purpose 1N4007 to FR107 or something ? It is serious, many fast recovery diodes are used in PSU.

I wouldn't be entirely surprised if this happens with smaller devices.
It definitely happens with larger ones, see: http://sound.westhost.com/counterfeit.htm

[Th3_uN1Qu3]

Re: Fake primary capacitors

FR107s are cheap enough for the chinese not to bother. On the other hand, i've seen plenty of PSU designs where a 1N4007 has been used in place of a fast recovery diode. Of course, it eventually failed.

[tom66]

Re: Fake primary capacitors

FR107s are cheap enough for the chinese not to bother. On the other hand, i've seen plenty of PSU designs where a 1N4007 has been used in place of a fast recovery diode. Of course, it eventually failed.

I've seen fake 5mm LEDs (re-cased 3mm LEDs) so it wouldn't surprise me. Those were small signal LEDs, maybe 5 pence (~6 euro cents) each in volume.

[eccerr0r]

Re: Fake primary capacitors

I've seen fake 5mm LEDs (re-cased 3mm LEDs) so it wouldn't surprise me. Those were small signal LEDs, maybe 5 pence (~6 euro cents) each in volume.

I really need to see a picture of these...

[kc8adu]

Re: Fake primary capacitors

i have seen those.
while the optical charecteristics would stink in most cases the die is the same between 3mm and 5mm.
its no surprise from folks who make fake eggs.
http://www.chinahush.com/2009/04/24/...-chicken-eggs/