Another dodgy chinese ebay item - Page 1
Forum section: electronics / general

author: bigsky
author_rank: Regular Contributor
timestamp: October 28, 2016, 10:03:23 pm
content: Look atwww.ebay.co.uk/itm/Linear-power-25W-LPS-USB-amp-DAC-external-power-supply-with-digital-display/121963520205Do you see what I see (or don't see...)

author: GreyWoolfe
author_rank: Unknown
timestamp: October 28, 2016, 10:11:24 pm
content: Pfffft, ground wires are for sissies.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: October 28, 2016, 10:14:21 pm
content: I guess it's not connected to the top cover but without buying one and checking who knows?

author: bigsky
author_rank: Regular Contributor
timestamp: October 28, 2016, 10:27:26 pm
content: Quote from: RGB255_0_0 on October 28, 2016, 10:14:21 pmIt looks like it's not connected anywhereAnother thing missing is a CE mark!

author: ataradov
author_rank: Super Contributor
timestamp: October 28, 2016, 10:36:08 pm
content: Quote from: bigsky on October 28, 2016, 10:27:26 pmWhy would they place a mark if it is not compliant with CE? It is your responsibility to check compliance when importing things, not the seller's.

author: bigsky
author_rank: Regular Contributor
timestamp: October 28, 2016, 11:02:23 pm
content: Quote from: ataradov on October 28, 2016, 10:36:08 pmBecause they don't care about such details. There are plenty of non-compliant products with the Chinese Export label on them.Interestingly, the TO3-P LT1083 that this PSU uses is obsolete. Either they've got some old stock or it's a fake. Your guess is as good as mine.

author: ataradov
author_rank: Super Contributor
timestamp: October 28, 2016, 11:03:59 pm
content: Quote from: bigsky on October 28, 2016, 11:02:23 pmSo you are complaining that they did not put a bogus label?

author: VK3DRB
author_rank: Super Contributor
timestamp: October 28, 2016, 11:31:14 pm
content: It looks well made at first look and then you realise there is no earth. Life is cheap, but "To Be Rich is Glorious".Some years ago someone gave me an Italian made hair drier to fix after the owner got an electrical shock and it stopped working. Metal case. No earth. Mains active wire had fractured, touching the case. I was horrified and the owner was shocked. The owner could have been electrocuted if they were in bare feet on a wet floor. The meatheads who designed this thing had no understanding of mitigating risk or safety standards. I don't trust anything electrical products made in China or Italy.

author: bigsky
author_rank: Regular Contributor
timestamp: October 28, 2016, 11:44:41 pm
content: Quote from: ataradov on October 28, 2016, 11:03:59 pmNo, I'm just having a laugh !!

author: Someone
author_rank: Super Contributor
timestamp: October 28, 2016, 11:49:59 pm
content: Marketed to audio idiots who would possibly remove any ground connection anyway when their unbalanced connections have hum in them, its a cost saving for everyone involved as the manufacturer doesn't waste time putting in a part that the customer then spends time removing.

author: wraper
author_rank: Unknown
timestamp: October 28, 2016, 11:50:15 pm
content: Frankly there is no big reason to fuss about it being not earthed. It uses linear transformer and no Y capacitors between primary and secondary. Metal case you say? Take your average CE/UL marked DVD player and it is not earthed either, has Y capacitor(s) between primary and secondary and has metal enclosure.

author: bigsky
author_rank: Regular Contributor
timestamp: October 28, 2016, 11:59:19 pm
content: I doubt it complies with the rules for double insulation !

author: helius
author_rank: Super Contributor
timestamp: October 28, 2016, 11:59:37 pm
content: My understanding is that a device may be considered Class 2 (double insulated) if the line wiring is insulated by two layers all the way to the primary winding. There are strain relief and creepage issues too, but that is the main safety requirement.

author: Srbel
author_rank: Frequent Contributor
timestamp: October 29, 2016, 06:52:58 am
content: This morning I didn't even know what "Linear power 25W LPS USB/amp/DAC/external power supply with digital display" is, and now I have two.

author: ciccio
author_rank: Frequent Contributor
timestamp: October 29, 2016, 08:23:45 am
content: Quote from: VK3DRB on October 28, 2016, 11:31:14 pmIt must have been very, very old.. with an AC motor on the side.I've seen many "professional" hair dryers made in the 1960s by different manufactures, in Europe and the USA, with no earthing of the metal body, no double insulation and a potential shock hazard. It was the standard then.

author: julianhigginson
author_rank: Frequent Contributor
timestamp: October 29, 2016, 08:33:35 am
content: gah. looks like a switched secondary. I hate switched secondaries....as far as the safety goes, you would have an issue if the active wire disconnected at the PCB, and made its way to the case... possibly when fully assembled there's a piece of plastic or something similar fixed in place in there too, that will stop that. otherwise I also think it wouldn't pass electrical safety.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: October 29, 2016, 09:31:53 am
content: I just worked on ahttp://www.stantondj.com/stanton-cd-players/c324.htmland it's a 2-pin device (no earth) and had an earth connection to the chassis tied to the secondary side. I just put it back together yesterday and I didn't take any photos

author: wraper
author_rank: Unknown
timestamp: October 29, 2016, 09:35:48 am
content: Quote from: julianhigginson on October 29, 2016, 08:33:35 amDo you understand what "secondary" is. And there is nothing wrong with it. You can bring the device made for different mains voltage and easily modify it to work at the voltage you need.

author: bktemp
author_rank: Super Contributor
timestamp: October 29, 2016, 10:53:53 am
content: Quote from: RGB255_0_0 on October 29, 2016, 09:31:53 amNothing wrong with that, if it is build correctly. Many DVD players and other devices have a metal chassis and no earth connection:https://en.wikipedia.org/wiki/Appliance_classes#Class_IIIf you look at the pictures of the chinese power supply, if a single mains wire comes lose (wires soldered directly to a pcb break easily if there are a lot of vibrations), it can touch the chassis or if there is a fault inside to the mains switch (which has a metal lever!). Therefore it is not a class II device and should have an earth connection.

author: julianhigginson
author_rank: Frequent Contributor
timestamp: October 29, 2016, 11:11:51 am
content: Quote from: wraper on October 29, 2016, 09:35:48 amyes.secondary side of the transformer is the transformers output.switched secondary means the power switch breaks the secondary circuit, so the primary is always energised, even when the device is switched off...Really not a great idea. you save a dollar or so on the switch, and then waste power forever.Sent from my A0001 using Tapatalk

author: bigsky
author_rank: Regular Contributor
timestamp: October 29, 2016, 11:56:31 am
content: I don't think this item is switched secondary. If you look at the second photo you can see a pcb track from the switch to the voltage selection links, which are obviously on the primary side of the transformer.I would regard switched secondary as bad practice. As well as wasting power for the magnetising current, it can shorten the life of the transformer (OK, not by much as there's no load and so hopefully very little heat generated), so why do it.

author: P90
author_rank: Frequent Contributor
timestamp: October 29, 2016, 01:14:20 pm
content: Quote from: VK3DRB on October 28, 2016, 11:31:14 pmHey now... I have a TIG welder made in Italy... last time I checked, it's electrical, and it's a beautiful piece of kit... :>)So there...~ <-- tongue sticking out! Lol

author: wraper
author_rank: Unknown
timestamp: October 29, 2016, 01:25:03 pm
content: Quote from: julianhigginson on October 29, 2016, 11:11:51 amOpen your eyes and look on it again. I thought you were talking about the primary naming it as secondary.

author: P90
author_rank: Frequent Contributor
timestamp: October 29, 2016, 01:31:54 pm
content: Look closely, I think those dodgy caps are starting to bulge...

author: LazyJack
author_rank: Frequent Contributor
timestamp: October 29, 2016, 01:38:41 pm
content: Quote from: wraper on October 28, 2016, 11:50:15 pmIt is Ok to be not earthed, if it is double insulated. It may even have a metal case. But in this case it must not have an earthed IEC connector. It should have a two wire only mains plug.

author: P90
author_rank: Frequent Contributor
timestamp: October 29, 2016, 01:57:13 pm
content: Quote from: LazyJack on October 29, 2016, 01:38:41 pmBreak off the earth pin, there's your two wire mains plug. Problem solved. Next.

author: julianhigginson
author_rank: Frequent Contributor
timestamp: October 29, 2016, 10:28:38 pm
content: Quote from: wraper on October 29, 2016, 01:25:03 pmAaah the 2nd picture does make this pretty clear (I saw this on my phone before and had only looked at first photo..)I assumed a switch like that would never see mains.... now I'm actually pretty concerned about the product.

author: helius
author_rank: Super Contributor
timestamp: October 30, 2016, 01:56:58 am
content: Quote from: julianhigginson on October 29, 2016, 10:28:38 pmIt looks like a C&K switch, which are available in 250V rated versions. But many versions are only rated for 20V.

author: Cerebus
author_rank: Super Contributor
timestamp: October 30, 2016, 02:21:53 am
content: Quote from: helius on October 30, 2016, 01:56:58 amI doubt it, unless C&K stands forChina & Korea.

author: Someone
author_rank: Super Contributor
timestamp: October 30, 2016, 04:20:51 am
content: Quote from: Cerebus on October 30, 2016, 02:21:53 amC&K used to manufacture out of USA and Costa Rico (possibly also in UK?), but slowly over time a lot of it has been moved to China.

author: PartialDischarge
author_rank: Super Contributor
timestamp: October 30, 2016, 06:06:40 am
content: Quote from: VK3DRB on October 28, 2016, 11:31:14 pmTo be fair I must say the Italians do have a lot of niche electronic industries in which they are very good. Don't judge a whole country, not even a whole company based on a single mistake

author: jonovid
author_rank: Super Contributor
timestamp: October 30, 2016, 06:31:54 am
content: as i see it , maybe 220V electrocution is survivable in china?

author: P90
author_rank: Frequent Contributor
timestamp: October 30, 2016, 06:34:40 am
content: Quote from: jonovid on October 30, 2016, 06:31:54 am"YOU'RE DEAD" NOT "YOUR DEAD"Now that's a total FAIL!

author: Cerebus
author_rank: Super Contributor
timestamp: October 30, 2016, 01:02:44 pm
content: Quote from: MasterTech on October 30, 2016, 06:06:40 amI think the judgement of Italy probably comes from anyone who has had an Italian car or motorcycle."Ah, if Sir is considering using this in the rain - may I suggest a German, Japanese or British model? Of course if Sir is only going to use his motorcycle on straight roads that also adds the American models to consideration."

author: ciccio
author_rank: Frequent Contributor
timestamp: October 30, 2016, 01:39:07 pm
content: Quote from: Cerebus on October 30, 2016, 01:02:44 pmThis may be true for some manufacturers and many years ago. And it was, to my knowlwdge, the same for British models. Now Italians cars are built in Poland, Turkey, Serbia, France, USA, an some (not many) in Italy, and German and Japanese motorcycles are (I'm sure it were) built in Italy.It is diffucult to be generic.I've had 6 cars, all Ford, and the quality an reliability was better than Italian (FIAT) standard only for the first 3.I halso had a Brithish byke, and it was terrible...Returning to OP, using a grounded mains inlet with no internal ground connection is illegal. Period

author: SeanB
author_rank: Super Contributor
timestamp: October 30, 2016, 01:58:34 pm
content: Not all Italian work is shoddy, my father owned an Alfa, and good thing his neighbour was an Alfa mechanic, as he had a few house payments from it. As it was made from that wonderful hot rolled unpickled Russian steel they used in the 1980's Corrosolve also made money, and the panel beater side as well had a share.Not to mention the bridge that failed earlier that collapsed when a 100 ton load went across it.

author: Cerebus
author_rank: Super Contributor
timestamp: October 30, 2016, 02:02:56 pm
content: Quote from: ciccio on October 30, 2016, 01:39:07 pmThe little smiley at the end is a hint* that I might not have quite been being serious. Last time I was there they still had humour in Italy.And, anyway, it's never been true of British motorbikes. A British motorbike that didn't work in the rain would be as much use as a chocolate teapot - unless they were made only for export.*Actually, it's a bloody great signpost.

author: NottheDan
author_rank: Frequent Contributor
timestamp: October 30, 2016, 02:58:25 pm
content: Quote from: Cerebus on October 30, 2016, 02:02:56 pmYou would think that but considering that they used Lucas Electrical parts you couldn't even be certain that they wold work in the sunshine.

author: Kleinstein
author_rank: Super Contributor
timestamp: October 30, 2016, 03:49:48 pm
content: Besides the safety, the current rating is also strange. With a 22 V (2x12V) and 25 VA transformer you will not get 25 W out. More likely the transformer / rectifier combination is good for 0.6 A, or 1.2 A if using both 12 V turns in parallel, or maybe 0.8 A if using only one 12 V rail.

author: SeanB
author_rank: Super Contributor
timestamp: October 30, 2016, 04:21:23 pm
content: Quote from: NottheDan on October 30, 2016, 02:58:25 pmLucas was the pioneer in having daylight running lights, mostly because they were not going to work in the dark, in rain or every time you used the switch.

author: Bryan
author_rank: Frequent Contributor
timestamp: October 30, 2016, 09:28:39 pm
content: QuoteMeaning "Chinese Export"

author: wraper
author_rank: Unknown
timestamp: October 30, 2016, 10:13:24 pm
content: Quote from: Bryan on October 30, 2016, 09:28:39 pmWhich is myth.https://cemarking.net/chinese-export/

author: John Heath
author_rank: Frequent Contributor
timestamp: October 31, 2016, 03:33:06 am
content: Quote from: jonovid on October 30, 2016, 06:31:54 amThe power transistor is screwed to the bottom plate. That means the bottom plate is aluminum. If the bottom is aluminum then there is a good chance the top cover is also aluminum. If the ground wire were connected to the top cover then they would have to unplug the ground wire from the AC input plug to take pictures. I am not saying this is true however it is possible the ground was unplugged to remove the top cover take pictures of the inside.

author: RJFreeman
author_rank: Regular Contributor
timestamp: October 31, 2016, 04:02:23 am
content: Quote from: P90 on October 30, 2016, 06:34:40 amMaybe "Bring out your Dead"?

author: P90
author_rank: Frequent Contributor
timestamp: October 31, 2016, 04:59:15 am
content: Quote from: RJFreeman on October 31, 2016, 04:02:23 amPerhaps...

author: RJFreeman
author_rank: Regular Contributor
timestamp: October 31, 2016, 06:02:13 am
content: As toroidal transformers have the secondary wound directly over the primary (or vice-versa) a number of precautions have to be taken for them to be considered "double insulated" (and even then I would be cautious) - and there is no indication that the Transformer used here would meet (even) that spec:http://www.bingzi.com/epro-1.php?cid=124

author: CJay
author_rank: Super Contributor
timestamp: October 31, 2016, 10:40:59 am
content: Regardless of the not insignificant problems of safety, I would imagine the lovely low noise regulator would be somewhat negated by the digital display, given that most of them are multiplexed which would probably add it's own particular flavour of noise to the 'pure' audiophool electrickery available from this unit.

author: SteveyG
author_rank: Unknown
timestamp: October 31, 2016, 01:22:30 pm
content: Quote from: jonovid on October 30, 2016, 06:31:54 amYour drawing is missing the common double insulated configuration where you have a metal case (e.g. DVD player), but a secondary insulating layer under the PSU PCB, such as a thin sheet of plastic. The photo is not clear enough to show whether this is present.

author: ciccio
author_rank: Frequent Contributor
timestamp: October 31, 2016, 01:38:03 pm
content: Quote from: John Heath on October 31, 2016, 03:33:06 amIt is not allowed to have the Protective Earth conductor entering the device wired to a removable panel.It should be connected to the metal body, with a firm connection tha needs tools to be removed, and clearly marked with the correct symbol.They symply used the mains inlet and cable they had on hand.Best regards