Safe In-Wall AC to DC Transformers??

[petewill]

@BulldogLowell Yeah I was thinking about that too. I'm really trying to keep costs down though. When I hit the $25 price point it's almost as much as a standard z-wave switch when all the other parts and time are included.

[RJ_Make]

My only recommendation; (if you are going to put this in side a utility box, in the wall) might want to find a solution that has the 3 standard safety features. (OTP, OVP, SCP)

These work well, but you need to follow the data-sheet for noise and ripple control.

[petewill]

@ServiceXp Thanks! I wonder if I can steal one of those from an existing device. Any idea what those would be used on?

(OTP, OVP, SCP)

Also, is that Over Temp Protection, Over Voltage Protection and Short Circuit Protection??

These say they are certified and have temp, voltage and short circuit protection. Think it can be trusted?
http://www.ebay.com/itm/351418782712?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[sundberg84]

This post is deleted!

[Moshe Livne]

@petewill @ServiceXp here is the datasheet http://www.hlktech.net/product_detail.php?ProId=54

it seems to have SCP and OCP but the OTP part seems to be left to the elements. I don't see OVP. I understand nothing of this.... Again, these looks well made, none of the crude soldering and flimsy elements you can see in the other converters (including the ones you get from wall warts). However, it being fully enclosed hides most of the details.

[Didi]

@Moshe-Livne said:

@petewill @ServiceXp here is the datasheet http://www.hlktech.net/product_detail.php?ProId=54

I will give them a try and order some for testing in a flush box.

[Moshe Livne]

@Didi Shame you won't be able to get them for the 4th of July :-)

[petewill]

@Didi said:

I will give them a try and order some for testing in a flush box.

Great! Let us know what you find. Thanks for doing this!

[RJ_Make]

@petewill said:

@ServiceXp Thanks! I wonder if I can steal one of those from an existing device. Any idea what those would be used on?

(OTP, OVP, SCP)

Also, is that Over Temp Protection, Over Voltage Protection and Short Circuit Protection??

These say they are certified and have temp, voltage and short circuit protection. Think it can be trusted?
http://www.ebay.com/itm/351418782712?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Yes that is correct, and I don't think the HLK-OM01 has OTP, so for me, it's out. You looking for a 1 off transformer, or do you have some projects in mind?

[petewill]

@ServiceXp I was thinking about replacing a wall switch. So far all my projects have been outside a wall and I want to make sure I don't do anything stupid with this one. So, one off for now but I may make more in the future.

[DrJeff]

I'm seriously thinking it skipping all of these and build a transformerless circuit directly to the board like a true in wall switch, Pete do you want to share this project. I've been playing with this for a little while but haven't had time to put it all together. I can point you to all the places but a board will need to be designed for the switch, that's almost where I'm at! 😀

[sundberg84]

Just à thought... I have these cheap 1$ 240 to 5 v USB power adapters charging 5-6 different equipments every day. These was sent with the equipment as standard so why are they not be safe?

[tbowmo]

@sundberg84

Some of the aftermarket wallwarts on ebay are very flimsy builds.. Lot's of teardown videos around, describing the different problems with them (like isolation distances not being kept at correct sizes etc).

[Moshe Livne]

@tbowmo @petewill @didi @ServiceXp I think I found the perfect one!!!!
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2155823_-1
http://www.mouser.com/ds/2/260/GS05U-USB-spec-33533.pdf

it is made by meanwell, so not flimsy. has all protections. 8$ at jameco and mouser and I am sure my meanwell supplier on aliexpress can get it for me at half price... it is a shame that they do not sell the inside separately but nothing is perfect.
the only problem might be breaking it apart. Meanwell really make sturdy enclosures.
let me know what you think...

[Moshe Livne]

@sundberg84 I am using these as well, but not enclosed in a box or in the wall. Big difference.... when enclosed, the temp builds up and all the warning signs are hidden so its too late when you see smoke coming out of the wall. If a wall-wart combust on the outside of the wall chances are nothing serious will happen. If it does that inside the wall, with wooden frame nearby its a bit of a worry.

[sundberg84]

@tbowmo @Moshe-Livne Thx - good points.
Might be a good idea not to use them at all then... since you are not always home and can detect the smoke before its to late.
Hope this HLK-PM01 can be any good use... i dont want to pay 30$ and use z-wave in all in wall switches if i can do it cool and safe with mysensors... then you can play around with motion, light at the same time in the wall socket :)

[Moshe Livne]

@sundberg84 everything is a trade off... you take calculated risks all the time, weather you know it or not. With good external ventilation and not being overloaded I think these are safe enough. The meanwell wall wart is probably far superior but I am not sure I want to replace all my zillion wall warts. especially since it only comes with US plug i think and remains to be seen how easy it is to open.

[sundberg84]

Well, at the moment im building a relay much like the one in petewills video.
I used one of these cheap EU plugs from ebay/China.

Unforntually i got profe of how things can go if you do it wrong (and also proved my point above wrong). I removed the tiny cables to 240v and replaced it with thicker and longer cables... just in case. I must have used to much solder and got to close to another solder because when i powered it up - the plug lit ut like a blue firework for half a second before my main fuse couldnt take it anymore. :(

Well i was at a safe distance, and this is nothing to be proud of... but as a warning and "be safe"...
Even if this error for surtain was a man-made error I dont think i will be the last to try cheap wall wart plugs - so if we can find a satisfying "easy-to-use" converted that will be fine.

[petewill]

@DrJeff said:

I'm seriously thinking it skipping all of these and build a transformerless circuit directly to the board like a true in wall switch, Pete do you want to share this project. I've been playing with this for a little while but haven't had time to put it all together. I can point you to all the places but a board will need to be designed for the switch, that's almost where I'm at! 😀

That sounds great! I just don't know if I have the experience to do all that. I'm fine with soldering and following wiring diagrams but that's pretty much the limit to my knowledge. I have a couple other projects on the list before this one but I would be happy to help in any way I can. Also, how easy would it be for other people to replicate the finished product? I think it would be really cool if it could be easy enough for people to build themselves.

[petewill]

@Moshe-Livne said:

@tbowmo @petewill @didi @ServiceXp I think I found the perfect one!!!!
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2155823_-1
http://www.mouser.com/ds/2/260/GS05U-USB-spec-33533.pdf

it is made by meanwell, so not flimsy. has all protections. 8$ at jameco and mouser and I am sure my meanwell supplier on aliexpress can get it for me at half price... it is a shame that they do not sell the inside separately but nothing is perfect.
the only problem might be breaking it apart. Meanwell really make sturdy enclosures.
let me know what you think...

Those look good! The only problem I potentially see is that it's meant for external use. I would love to find a universal transformer that could be used for everything without having to modify it. Good find though!