I changed two controllers/transformers earlier for a friend. I was there to do six. I connected the first two and well, they blew up .
My Rule of Thumb for ordering in the cheep (Chinese) online shops: If it’s electric, comes in contact with skin or food it’s probably dangerous.
You say this like a lot of the stuff you buy from Aussie shelves isn’t bought in bulk from the exact same suppliers as Aliexpress. You just need to do the work to find reputable stores. If it’s the cheapest price available, and the store has a bunch of random numbers in its name, pawbably give it a miss.
The difference is testing and warranty.
If you buy it local, it has to adhere to ACCC guidelines.
They will import 50, do local quality control, send back the defective ones and sell what is left at a markup.
If you think QC is happening locally, then I have a bridge across the Yangtze to sell you bestie.
Only one? I want to buy in bulk.
The store will be liable for any and all damages to life and property which incurs from selling faulty products though.
There’s significantly more risk when purchasing directly from a Chinese supplier. It’s borderline impossible to hold a foreign company with no actual presence in your country accountable for damages.
Sorry for pointing something out…
Sorry, it just came across as the whole “China makes low-quality goods” racism that’s been around for decades at this point.
China does make a LOT of really low quality goods. However…
… those goods are made to the quality specified by the importer / wholesaler / buyer…
… because ‘cheap’ goods are often preferred over ‘more expensive but higher quality’ goods…
… by the people who buy them.Which is probably what happened in this case!
I *think* that most Ming dynasty vases are still ‘under warranty’!
That’s just a product of them making a LOT of goods for the world. If you have a flagship smartphone, it was probably made in China.
No. Not really.
If ‘crap’ is made, it won’t be sold unless people wish to buy ‘crap’.
My point is that the quality of goods made in China has got *nothing* to do with racism and *everything* to do with buyers’ price expectations, buyers’ notions of acceptable quality, and market forces.
In this instance, the buyer (not the OP) ‘took a chance’ with a cheaper product which failed immediately. If sufficient buyers of this product demand and obtain refunds, the manufacturer would be forced to either stop making them or possibly increase their unit price with a concomitant increase in quality.
The reason that smartphones of high quality come out of China is because that is what is demanded by the buyers and with regard to the price they are willing to pay.
Stuff you buy from physical Aussie store shelves have been validated to meet our standards though. Doesn’t stop me from buying plenty of stuff from AliExpress though
Other way around. Hence recalls.
Your saying I’ll be shocked at by the low resistance deals? Ohm my god! You could not induce more topical current event news.
Your comment Hertz me.
you really put me in laplace ; it really resonated with me, and since I’m open to feedback I’ll attenuate the frequency
Please, now it megahertz
I’ve bought heaps of 240VAC rated items from AliExpress and not had a problem. They’re definitely cheaply made for the most part, and I generally give them a once over to identify any glaring issues… but I’ve got heaps of stuff out there working just fine.
Is it possible you got the wired mains to the low voltage side? I remember a box of LED drivers I bought came with the 240V side using red+black, and the low voltage side using brown+blue that looked awfully similar. Had one go pop before we busted it open and realised the version that came on the unit had the wiring colours the exact opposite. What made life even harder is that the top cover was symmetrical and had been put on back to front… so 240V was on the “correct” colour side.
Fourth reply. I’m seriously doubting myself now.
Third reply. Ok I can see the L and N and also the + and - symbols on the board. I’m currently having trouble remembering which way around I went. But I did pull the first one apart before connecting the second one. I’m “rather” sure I had it the correct way around.
Second reply mate. Having had a quick look, one would assume that the transformer would be at the 240 end in my mind anyway. But I really don’t know.
Nah mate. The transformer is usually used as an inductor for the switch mode conversion.
It looks like you have it right though. The big brown cap should be rated for 250v + and will be on the mains AC side.
The DC side will have lower voltage rated smoothing caps.
Post the link to the device or better photos and I’ll have a closer look for you.
I’m seriously thinking that I got it backwards. I connected it according to the writing on the enclosure. But as TRK said, he has had them back to front due to the same thing. The guts can be placed into the enclosure either way and I reckon that’s what’s happened.
I left them at my friends house also.
The L and N are for Live and Neutral - the 240V end. The small black chip is a bridge rectifier with its big brown capacitor.
Oh I hear you mate. The thing is that the unit was closed up with the markings for mains and output clearly marked on the casing. After reading TRK 's input, I think that the guts were placed the wrong way around.
Basically I connected the 240 to the DC output terminals.
I contacted my friend earlier to explain this. I admitted that it was my error even though I followed the markings on the casing.
She’s ok about it and has thrown them all away.
Bugger! I would never have considered opening the device to check the internal connection before hooking it up. Ouch. You had a word with the supplier?
Hmmmm. Yes quite possible I suppose. I didn’t investigate any further. It’s a love job and my second visit already. I thought it was going to be a simple swap over, but some of the existing lights were 240 v AC. That’s when I told her to order the controllers, and then they came without 240 v plugs. So it was all annoying to be honest. She’s going to Bunnings to buy new stuff.
I wonder if we can tell from the photo if it is indeed the wrong way around.
Oddly this doesn’t deter me at all, but I don’t buy mains connected components off aliexpress. Tons of DC stuff and I’ve never had an issue
Pretty much anything that has the capacity to kill you should be avoided for the most part on these sites. Which is to say, most if not everything.
If you dont aim for the cheapest, you can buy pretty much anything you want there without worries
Sounds reasonable.
The insulation between the windings was probably non-existent.
Also… uh… TO-263 packages are surface mount and likely require heat dissipation of some kind. There is a chance that heat sinking isn’t required, but it’s standard practice to at least ground the tab. (Using the package like that for quick at home projects is fine. Putting it in a production power supply like that is just silly.)
Throw the rest of those powes supplies you have directly in the bin. It’s not worth the risk with those shitty transformers and that poor design. It would really suck if a failure mode sent mains voltage through what you are powering. (It needs a full teardown to say for certain though.)
No worries. They were bought by the home owner.
@DiaDeLosMuertos I bought the cheapest thing on the market from someone who’s not contractually obliged to look after me, and bad things happened!
Colour me surprised…
Why do you have to be so hostile with no provocation
I didn’t buy them.
