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Renewable Energy Questions/Discussion => Automation, Controls, Inverters, MPPT, etc => Topic started by: Wolvenar on May 10, 2012, 05:33:01 pm

Title: 24-12v 30 amp Falsely advertised ebay item?
Post by: Wolvenar on May 10, 2012, 05:33:01 pm
The listing
"30A DC-DC 24V to 12V Power Supply Converter"

But of course I can view what it said when I bought it.

Now, I don't think I need to even say much about that I really got.
I'll let the images to the talking.

It was like $10 so I am thinking that asking for a refund and returning it is not really worth the trouble.
I would like to hear what others think I should do. I am holding off on the feedback also until I get some ideas to guide me.
Title: Re: 24-12v 30 amp "isolation inverter" Falsely advertised ebay item
Post by: Wolvenar on May 10, 2012, 05:56:55 pm
Yeah that is a L7812 this is hooked only to the red (trigger) wire.
 
The other is an unknown IC that has had its face sanded off.
It appears to be wired as a voltage regulator.
 
Title: Re: 24-12v 30 amp "isolation inverter" Falsely advertised ebay item
Post by: rossw on May 10, 2012, 06:32:41 pm
Well, that explains the price. No isolation, just a linear reg.
Like you say, the $10 doesn't hurt as much as if it was $100... but you could still query through paypal - it clearly isn't what was described.
Title: Re: 24-12v 30 amp "isolation inverter" Falsely advertised ebay item
Post by: ghurd on May 10, 2012, 07:08:15 pm
Better named "Isolated from Reality"?
Or "Inverted Description"?

China...
Why would they bother to put in L1 in it?
Or stuck in such large caps?

Why would they put a 1A 7812 in a 5A board and call it a 10A?  LOL

Could the sanded off IC be a low efficiency 3-wire switcher?
(only name I can think of at the moment is 'simple switcher', not correct)

On a good note, that box is worth quite a bit!
G-
Title: Re: 24-12v 30 amp "isolation inverter" Falsely advertised ebay item
Post by: Wolvenar on May 10, 2012, 07:19:08 pm
@Ghurd, that unknown is a 5 pin,
It reminds me of the final amplification circuits of some older low end ( kraco etc) car stereos

But the way its wired looks surprisingly like an average lm317 based voltage reg.
It seems only 3 pins really do anything, and this is effectively a separate circuit it seems from the 7812
Title: Re: 24-12v 30 amp "isolation inverter" Falsely advertised ebay item
Post by: Wolvenar on May 10, 2012, 07:22:26 pm
BTW, that was not a typo in the title.
It was really sold as a 30 amp!

Anyone here that can read this Chinese?
Title: Re: 24-12v 30 amp "isolation inverter" Falsely advertised ebay item
Post by: ghurd on May 10, 2012, 08:25:39 pm
I will ask a guy, who knows a guy... might take a while.

David may have an easier time of it.
G-
Title: Re: 24-12v 30 amp "isolation inverter" Falsely advertised ebay item
Post by: ghurd on May 11, 2012, 07:29:38 am
Courtesy of Dave and his daughter.

Make sure you keep the output below 30A.  ::)
G-

[attachimg=1]
Title: Re: 24-12v 30 amp "isolation inverter" Falsely advertised ebay item
Post by: Wolvenar on May 11, 2012, 10:32:46 am
Wow thanks to all involved!
Title: Re: 24-12v 30 amp "isolation inverter" Falsely advertised ebay item
Post by: David HK on May 11, 2012, 07:03:18 pm
A couple of points to remember.

Many companies in China are notorious for spelling errors, omissions and general mistakes in English. On most occasions errors are not seen to be errors as you or I would see them. Lower budget operation very small companies only want to sell a product for the lucre that the Chinese love to play with - money, and the more the better. Larger and more international Chinese companies are getting better due to the fact that there is some oversight in product documentation.

Some companies use Google Translate into English and assume the end product is perfect English (American or the Queen's).


Regards,

David in HK
Title: Re: 24-12v 30 amp "isolation inverter" Falsely advertised ebay item
Post by: Rover on May 11, 2012, 07:35:11 pm
"Some companies use Google Translate into English and assume the end product is perfect English (American or the Queen's)."

Queen .. now that explains it :)

Freddy Mercury... Queen
"Galileo, Figaro - magnifico"

Rover