Safe In-Wall AC to DC Transformers??

[Yveaux]

@eni thanks for the heads up.
How did you discover that fakes exists, and do you know the internal differences?

[petewill]

@eni Thanks for posting this! I will update the first post with this info.

[Nca78]

I confirm about the fake ones. I just received a batch of fake ones from GREATWALL shop on aliexpress (seller with good reputation and used for many items on the MySensors shop...) and I'm filing a dispute right now, as the seller acknowledge they are different but pretend it's because HiLink is replacing their factory. Makes no sense if you replace your factory to set up a new line to build different modules :) This seller is also selling the Tenstar TP-0x modules pretending they "replace" the HLK so I suppose the one I received are tenstar modules disguised as HLK.

They are obviously fakes and lower quality, as can be seen from the pins (thinner, and with no blocking mecanism so pins go inside the module when pushed), obvious lower quality with the gray material filling and very different looking plastic.
I'll see how the dispute goes and after it's closed/solved I'll open one.

[eni]

@Yveaux I discovered differences, because my circuit was not acting the same always (the problem was a tps2115 power mux), then i compared different orders and its clearly visible that they differ..

I just opened a fake one and it actually looks like an genuie one, except some details and missing revision number on the pcb:

IMHO they did a great job faking this, it looks nearly the same and also works quite similar..

One of the sellers i buyed this was also "Greatwall Electronics", but they accepted the dispute whitout any comment..

[Nca78]

Same here, he accepted the refund quickly without making any comment.

The PCB looks similar but the components on it are not the same, for example the transformer is different, at the bottom on the fake one the "D3" component doesn't fit in the silkscreen rectangle while it does in a genuine hlk. It's this kind of "details" that can make the module unsafe, or generate much more noise/ripple at the output.
Yours seems to be a better copy than mine, as the input capacitor despite showing similar ratings is much smaller on it. Below it is the rectifier, on the genuine hlk it has the right markings, on the copy it looks like a fake as the mb6f text is just molded in plastic and not printed. The D2 diode has different markings between the two modules, too. Switching IC seems similar.
Removing cover on the fake one was very easy as it's not blocked by the pins, also the filling was not complete with gaps as seen in first picture and it went away easily mostly in big chuncks while with the original hlk it was harder to remove and I also had to break the cover to take everything out.

Fake on the left, notice the transformer similar to the one in eni's module. On the original module the transformer is similar to the one tested on lygte website.

[Yveaux]

@Nca78 Maybe you could contact Hi-link (http://www.hlktech.net/product_detail.php?ProId=54) to discuss about the issue?
They can confirm if it's genuine or a fake.
I did the same with Nordic a while ago and they were very cooperative on the subject.

[Nca78]

@Yveaux if I had a doubt I would, but seeing the internals I have no doubt. The product page of the seller now shows a tenstar module and he didn't even try to argue to keep the money.

[Yveaux]

@Nca78 maybe hi-link, like Nordic, will try to prosecute to get the fakes off the market, or maybe they're not even aware these exist.
What do you have to loose by contacting them?

[MattNY]

@petewill

Hi Pete,

I realize this long and valuable thread is quite old at this point, but I have referenced it several times and wanted to make you aware (if you aren't already) of a new tiny AC/DC board mount converter. I was about to buy a few HLK-PM03's and add the various fuses and other safety components this group decided on, when I ran across a very similar product in the Mouser catalog. I mention this because it appears to be a newly released item AND it's made by MeanWell (part # IRM-02-3.3) and I remember several people saying they wish MeanWell made a USB power adapter for PCB boards. Well, now they do AND you can buy it via Mouser in the US, so getting a fake probably would be a non-issue. I am about to buy several and I will try and report back with how they work. Thank you for this post - it's been a lifesaver!

MeanWell AC/DC 3.3v Module

• Matt

[petewill]

@MattNY Great, thanks for posting! Let us know how it goes and if you think it's good I'll add it to the first post in the thread.

[Nca78]

At least it has the pins logically positionned, with A/C input pins as far as possible from each others.
And SMD version can be very useful too...

[MattNY]

@Nca78

I saw that too - no idea why the HLK-PM modules have the A/C pins right next to one another! This module also appears to be silicone sealed for moisture/dust resistance.

[dbemowsk]

I didn't read through all the posts in the thread to know if these information links were posted already, but I read through these two and both contain excellent information. If these have been posted previously, please excuse the double post.

https://skippy.org.uk/quick-look-at-the-hlk-pm01/

http://lygte-info.dk/review/Power Mains to 5V 0.6A Hi-Link HLK-PM01 UK.html

[m26872]

@dbemowsk Infact that test was ordered by this thread (or another one in the forum, I don't remember exactly). :smiley: Don't worry about the double post, it's worth mentioning again.

[dbemowsk]

@m26872 Were both tests ordered by this forum? They are both excellent tests and give enough varying information where both should be looked at by people trying to use these.

One thing that was mentioned in the one from Skippy was the pin spacing on the incoming AC. I was actually surprised at this as I had previously bought some German made converters that had in incoming AC pins spaced out to the corners much like the DC out pins on the HLK models. It wouldn't be that hard for them to put those pins out to the edge. Looking at the bottom plate in some of the pics, there are already holes there, they would just have to modify the PCB slightly. If they did that, they would comply with the BS EN 60335 – “Household and similar electrical appliances. Safety. General requirements” standard of requiring at least 3mm between the hot and neutral leads. That was one of the reasons Skippy recommended using the MOV and thermal fuse.

[TD22057]

I have a question... referring to the first post, why is the varistor after of the fuses? I thought it was there to protect against surges in the AC lines which would makes me think that the varistor should be before the fuses. Thoughts?

[TD22057]

@TD22057 said:

I have a question... referring to the first post, why is the varistor after of the fuses? I thought it was there to protect against surges in the AC lines which would makes me think that the varistor should be before the fuses. Thoughts?

I answered (some what) my own question via Google. Here's a quote from an electronics site:

Fuse upstream of the MOV, but don't expect it to save the MOV. It will prevent your house from burning down after the MOV partly shorts and sits there glowing red hot.

So it seems like the original post is correct on the order.

[Nca78]

Yes varistors can have "catastrophic failure" when they can't handle the surge. In that case they will burn and form a short-circuit.

[OliverDog]

Hi guys.

Did you get any conclusion at all?

Between these both:
http://www.electrodragon.com/product/ac-85-265v-dc-5v-power-module/
https://pt.aliexpress.com/item/5-pcs-HLK-PM01-AC-DC-220V-to-5V-Step-Down-Power-Supply-Module-Intelligent-Household/32267273843.html?spm=2114.13010608.0.0.anpFsP

** the second seems genuine in the pictures.

Is one safer than the other?
Is one of them safe enough to in-wall use.

[hlksunny]

@eni
Hi,everyone,this is sunny from Hi-Link,we keep paying attention to this matter,but now to protect your rights,please contact with us directly to avoid purchasing the fake module,my email is sunny@hlktech.com ,our website is www.hlktech.net.
We will prosecute the company who make the fake modules with our logo to make the market clean.

Thank you for your effort and cooperation!
Sunny