Good evening.

I recently purchased this active suction SMD pick-up tool from AliExpress:

seller's image

When it arrived, it seemed to work fine. However, when I opened it up (to investigate the feasibility of adding a switch), I was less than impressed with the build quality and safety of the unit. (I was also staggered at the amount of empty space inside, but that's beside the point.)

The inside looked like this:

inside the unit

Closer examination showed obvious green corrosion on the ends of the wires; poor soldering; and damage due to a lack of strain relief:

close up

I also noted that the capacitor was rated for 100V, which is far less than the operating voltage of the unit. Tests determined that the AC voltage drop across the capacitor was far less, however this probably did not take peak voltage into account.

At the very least, I would need to fix the solder joints and heatshrink the exposed contacts for safety. Either that, or demand a refund from the seller - and if I'm going to complain, I need to know what exactly I'm complaining about. I need to know if this device can legally be sold.

Therefore, my questions are:

  1. Does this device break any specific UK laws or regulations, that I could complain to the seller about?

  2. Do I need to replace the capacitor with a higher voltage one? If so, what voltage? I'm running on a standard ~240V supply, but I gather capacitive droppers should ideally be rated higher than that.

  3. Presumably I need to add a fuse of some sort? (Again, does the lack of a fuse violate UK law?)

  • 3
    \$\begingroup\$ It looks to have an american style 120VAC plug on it, so that's not going to meet UK standards... \$\endgroup\$ – JRE Jul 16 '18 at 17:43
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    \$\begingroup\$ What exactly do you think is unsafe here? All the dangerous stuff is enclosed in a insulating case. There is a strain relief on the cord as it enters the case. There should therefore be little motion of the wires inside, and therefore little need for additional strain relief. What exactly is your (perceived) problem here? \$\endgroup\$ – Olin Lathrop Jul 16 '18 at 17:48
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    \$\begingroup\$ I have the impression that items purchased from AliExpress can sometimes be better thought of as a starter kit for a project rather than a finished item. \$\endgroup\$ – Andrew Morton Jul 16 '18 at 18:05
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    \$\begingroup\$ Maybe not illegal, but aren't plugs in the UK required to have a fuse? And, a 120VAC plug makes it likely it was designed with that voltage in mind. \$\endgroup\$ – JRE Jul 16 '18 at 18:11
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    \$\begingroup\$ You are asking about complaining to the seller and demand a refund. On what basis other than not obeying UK law? If he needs not to obey any of these, there is nothing to complain about. \$\endgroup\$ – PlasmaHH Jul 16 '18 at 20:33

Superficially that looks like a 'standard' triac dimmer circuit, and the capacitor isn't going to see more than a few 10's of V at worst.
The live wiring, although exposed inside the case, is not exposed outside the case - so isn't any more unsafe than it would be if the circuit was built on a PCB.
The oxide on the grey-insulated wire is probably from an aggressive flux in the solder. Not ideal, not particularly dangerous.
The quality of soldering looks something like I did when I was 10 years old, but I guess you get what you pay for ...

  • 1
    \$\begingroup\$ But the wires are half snapped off! A stiff breeze would knock them clear. \$\endgroup\$ – Sod Almighty Jul 16 '18 at 17:56
  • \$\begingroup\$ @SodAlmighty If you're referring to the grey wire then it looks to me as though it's been that way from the start. I'm not denying that it looks awful (and I'd be embarrassed to charge money for it), but I couldn't point to a particular product-safety issue ... \$\endgroup\$ – brhans Jul 16 '18 at 19:01
  • \$\begingroup\$ @brhans the 10 year old doing the soldering could well be true - how else do they meet such cheap prices, oh yes quality control... \$\endgroup\$ – Solar Mike Jul 16 '18 at 22:03

1) what makes you think it is intended for sale in the UK? You bought it on AliExpress so 99.9% chance it comes directly from China where they don't have proper safety regulations and/or ignore those regulations.

Since you imported the device from China it is basically your responsibility to decide if it is safe (enough) for your purposes.

You will not find this device for sale in UK shops because indeed it does not meet basic safety regulations. If a seller still sells it (s)he would be violating UK safety laws.

2) This is not a capacitive dropper but probably a TRIAC based dimmer circuit. Since the DIAC (small blue device) will probably take care that the capacitor never sees more than 50 V it might be "safe" to leave the capacitor in there. If you want to play it safe use a capacitor rated for 400 V. It is not that critical since there's always the resistor in series with that capacitor.

3) A fuse is never a bad idea. I don't know about UK law but since there could be a fuse in the mains plug already that could be enough "for legal purposes" (bit since these are often several amps, it might not do much to protect this circuit).

  • \$\begingroup\$ They offer the item to buyers in the UK, and ship to the UK. Therefore, are they not (at least theoretically) obliged to adhere to UK laws and regulations, no matter how ill-advised my purchasing decision? \$\endgroup\$ – Sod Almighty Jul 16 '18 at 17:54
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    \$\begingroup\$ It it the responsibility of the importer to check compliance with safety laws, and also to do the CE paperwork and attach a CE mark if they plan to sell the device on in the UK. The importer is also responsible for paying import duties and VAT. It sounds like you were the importer in this case. \$\endgroup\$ – Jack B Jul 16 '18 at 18:03
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    \$\begingroup\$ ..obliged to adhere to UK laws and regulations No, they're not. They're not a UK based seller and therefore don't need to meet the applicable rules. I mean, how would the police enforce that? Sue a seller in China? Not going to happen. Shop at UK stores and notice how these "unsafe" products cannot be bought and also notice how identical items are more expensive, that's for paying the seller for doing all the official import paperwork. \$\endgroup\$ – Bimpelrekkie Jul 16 '18 at 18:39

No it does not pass UK/Euro safety laws.

Basically a single fault (e.g. ingress of liquid) could cause dangerous voltages to become exposed.

Even though there is no metal case to be earthed, the of appliance ought to be double insulated to meet safety standards. It only just qualifies as being single insulated, as far as I can see.

is there mains voltage on that pot? Is it even rated for that? Is the shaft metal or plastic?

Also, is there any fuse at all? It looks remarkably easy for the live conductors to short together. What protection is there for the supply circuits?

Appallingly shoddy, even by Chinese standards. Fix it or ditch it.

  • \$\begingroup\$ I've got a house full of appliances that you could argue might expose dangerous voltages if liquid got into them. But they're all perfectly safe and they all pass safety regulations. \$\endgroup\$ – Finbarr Jul 16 '18 at 21:45
  • \$\begingroup\$ The case of liquid ingress is just an example. There is a clear requirement for double insulation if there is no safety earth. In some cases this takes the form of (say) a plastic layer over exposed mains on a circuit board, and indeed that would not protect against liquid, but it can be called "double insulated" at least. But this example doesn't have any type of double insulation at all. The outer case counts as one layer. There are clearly exposed live voltages inside that case. This is never in a million years up to UK/Euro safety standards. \$\endgroup\$ – dmb Jul 16 '18 at 21:52

If the unit does not bear the CE marking (minimum standard) (not to be confused with the china export mark) then it should not be used here in the UK. As low voltage directive applies to electrical equipment.

I would advise a fuse to protect cable flex. I can't recommend fuse size as we have no wattage or current draw provided here.


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