Safe In-Wall AC to DC Transformers??

[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

[sundberg84]

This post is deleted!

[pradeepkumar]

This post is deleted!

[ferro]

Hi all,

Just by looking at previously mentioned link at Skippy's blog about Quick look at the hlk-pm01 I found he has recently posted next part - Revisiting the hlk-pm01. I think it is worth to read, dealing with resp. how to improve conducted emission of hlk-pm01.

Also there is a some recommendation to use VIGORTRONIX VTX-214-005-105 AC/DC PCB Mount Power Supply (Farnell #2401040). Not sure if someone is already using it in his projects.

[dbemowsk]

Someone here had passed the TSP-05 over to someone to review. I think they had asked one of the guys that did reviews of the HLK-PM01. Has anyone got a link to a review on these or can give their thoughts after using one?
https://www.aliexpress.com/item/TSP-05-replace-HLK-PM01-AC-DC-220V-to-5V-mini-power-supply-module-intelligent-household/32717871230.html?spm=2114.12010108.1000013.3.NDXqMR&scm=1007.13339.33317.0&pvid=e2a30af8-7732-428d-9a22-9a5def1f73cd&tpp=1

[DavidZH]

@ferro I've looked into thos Vigortonix devices. Those are nice! Unfortunately they're bigger than the HLK's.

But for the dimmer designers under us: they have miniature power supplies with built-in zero cross detectors! Looks very interesting!

[dpressle]

what do you guys say about this PSU? i really liked that the mains are separated much more then the HLK.
And how is the suggested full circuit use they have:

[ksya]

Is using a genuine HLK-PM01 safe when directly connected to mains? I see here that they used extra components for safety.

[MiKa]

Hi,
Varistor and fuse is always good to use as a protection ;)
Its lot of cases of start the fire in house from cheap AC/DC converters.
Regards,
MiKa