Black Gate Caps shock

[ssmith]

So there I was, shopping for bits and pieces in the electronics bazaar of downtown Tehran, Iran (I'm living here waiting to move to India, whose flag is now on my sig)... and I pop into a capicitor shop. Lo and behold, there were Black Gates nestled amid a pile of Rubycons and others.... mmm...
1x 35v 4700uf
and loads of 350v 150uf

so I asked the price... and it was 1,000 rials (about US$0.09) each... and I bought the 4700uf and 6 of the 150uf's..... the shop owner said they had just come in with a Rubycon order.

Quick Google search makes me think I got a wee bit of a bargain..... now all I have to do is figure out what I can use them for (filter on DC input to T-amp perhaps???)



(If anyone happens to be in or heading to Iran, I can tell you the address of the shop.... he has about 20 left of the 350v/150uf)

[EchoWars]

Hmmm...so we have counterfeit BlackGate's now?

[dhole]

Counterfiet ? because they are in Iran... ?

[Christer]

Actually, I was also thinking "counterfeit?", but because of the price, not the place. However, I got the impression the shop got them by mistake, so maybe they didn't pay much for them and didn't know what it was.

[lohk]

Black gates in Tehran
thats how wonderful
and strange
globalisation gets
crossing the Rubycon

so poetic
to have magic gates
to pass through
like in the old
persian tales

[ssmith]

I've no reason to think they're fakes.... They were in a Rubycon box, stacked with a load of other standard Rubycon boxes. They seem to have been in the shop a long time, and have a small layer of dust.
On the multimeter they test OK with resistance (it increases slowly).. for capacitance they all (the six 150uf's and the one 4700uf) test at dead-on 130uf.

The guy said he was selling them cheap because they'd been there for ages. I had the impression that he just bought a large stock, possibly from another shop owner who went bust.

I think I'll buy a few more and stick 'em in the post to people who have been so helpful to me on this board....

[Christer]

Originally posted by ssmith

On the multimeter they test OK with resistance (it increases slowly)..

Then you are probably measuring in the wrong way.

for capacitance they all (the six 150uf's and the one 4700uf) test at dead-on 130uf.

Maybe that is a good reason to at least suspect that one of them is faulty?

[ssmith]

Originally posted by Christer
Then you are probably measuring in the wrong way.

I used this guide as a reference -- "For electrolytics in the uF range or above, you should be able to see the cap charge when you use a high ohms scale with the proper polarity - the resistance will increase until it goes to (nearly) infinity".

Originally posted by Christer
Maybe that is a good reason to at least suspect that one of them is faulty?

Suspect the 4700uf one may be faulty.... I'll check if the shop can do tests....

[Christer]

Originally posted by ssmith


I used this guide as a reference -- "For electrolytics in the uF range or above, you should be able to see the cap charge when you use a high ohms scale with the proper polarity - the resistance will increase until it goes to (nearly) infinity".

OK, if you just wanted to test that it is charging, then it is OK.

I thought you were trying to measure leakage current or maybe ESR, since you talked about resistance.

[ssmith]

My last few days in Iran, so I popped back down to the bazaar to get a few last bits and pieces for my summer diyaudio holiday project, and also stopped in the caps shop to get a few more of the 150uf/350v just in case I ever work out what I can do with them.

The price has gone up :-( -- the shopowner told me he made a mistake selling them for US$0.09. They should be US$0.90, he apologised....
So I bought a few more. He also dug out other black gates -- he had a stock of WKZ 220uf+220uf 350v "heart of muse" caps. A bit more expensive at $3.00 each.

A bit of discussion and I realised that Rubycon clearly has a problem with its delivery system, because everytime it sends a batch of caps to the Iranian importer, all the 220/220uf-350v and 150uf/350v ones are black gates.
So the bazaar is full of just these two Black Gate models but at the same price structure of the rest of their standard rubycon prices.

The shop owner offered to sell me a box of 250 of the 150uf/350v ones (that's about $10,000 retail in the US) he had for $200. I don't have room in my suitcase, and can't be bothered to deal with eBay, so I'll leave them for an adventurous diyaudio reader to snap up.

So, any of you ever in Tehran, the shop is on Jomhuri St, near the Hafez intersection, in a gallery of electronics shops. At the entrance to the gallery on the street is a Panasonic TV shop and a magnets/inductor shop. The black gate shop is the second to last shop on the right on the street level. The electronic gallery is situated close to the small street ('Rom Street') that goes south between the walls of the French and Italian embassies.

Maybe someone who reads this is in the US marine corps, in which case you might be there fairly soon.....

stefan