Safe In-Wall AC to DC Transformers??

[Didi]

Powersupplies arrived :smiley:

[Moshe Livne]

@Didi sharpening your knives and putting the plier in the fire?

[scalz]

aaaaaaah, you are lucky, I have not received mine yet!!!
I am thinking about something for OVP and OTP:

• at my job we use MCP9509 for OTP. As OTP is for output load (and not for input I think), it could be possible to use MCP9509 and P Mosfet to cut off the load if any temp problems occurs. I think it could be sufficient like this.
• for OVP, why not using a varistance at the input??? And then if a problems, your fuse in your electrical service box would blow.

I think this module has others protection.. so maybe it could do the job. I am not sure but like this I think it couldn't burn. It is just an idea as I am not expert. But can't wait to see how it is inside!!!

[rvendrame]

Mine arrived too. But I don't have equipment / knowledge to test it properly. So I will go for "real-life test". The wall boxes / wires here are fire-proof (and placed into brick walls), so the risk of real fire is reduced.

And I'm running my Arduino-dimmers for 6 months now, all powered by really cheap phone charges, so hopefully these modules will be a bit safer ;-)

[Moshe Livne]

@rvendrame would be interested to see how you wire everything together

[petewill]

@Moshe-Livne said:

@petewill @didi found a cheaper source:
http://www.tme.eu/en/details/gs05e-usb/mains-power-supplies/mean-well/
shipping to the US 9.90. still ridiculously expensive but not as bad as mouser

Cool, thanks!

@Didi can't wait to hear how they work! That was fast shipping!!

[Bertb]

Hi,
I am new here and decided to join this forum, because of this interesting discussion.
Some weeks back, I was looking for a cheap AC-DC converter and ran into the Hi-Link modules. The have very nice specs, but I discovered that there are no stamps to prove it.

I too plan to bring an offer to the gods of AC-DC, so I will build a module into a safe box and see what happens when I start annoying it.

I'd like to finish for now with a remark to rvendrame, if I may:
It is true that stone is very difficult to ignite, but fire and heat also melts the plastic coating of the elektric wires and this can lead to high currents that are just not high enough to blow the fuse in the mains fusebox and this can ultimately lead to fire elsewhere in your house.

Regards,
Bert

[rvendrame]

@Bertb, thanks for the advise!

[Atomfire]

I have also bought the Hi-Link modules, 10 arrived today, they seem very well built, but I have yet to try them.

[Qu3Uk]

I got some hi-link modules a while back on a "I might need these in the future" type deal.

I was wondering though how to protect the connections. I got some fuses+pcb holders to add extra protection however there is going to be at least 4 points which will be exposed.

Can I just cover the joints with hot glue to stop them from making contact with anything? Call me paranoid but I like to be extra safe.

[ThinkPad]

@Qu3Uk For covering solder connections you can use 'heatshrink'. Kind of 'plastic' tubes that you put around a wire, apply heat (keep a lighter/match underneath (not in the flame) for example) and it shrinks around the connection.

See also https://en.wikipedia.org/wiki/Heat-shrink_tubing

[Jan Gatzke]

@Qu3Uk You could protect the high voltage part of the circuit by mounting a plastic plate under the pcb using some spacers and screws. This way it would be impossible to touch the dangerous spots. I would not recommend hot glue because you never know how well it isolates. I don't think you will find electrical specs for hot glue. ;)

[Qu3Uk]

@Jan-Gatzke Ah yeah that's probably a neater option as well I think. Sure I can find something suitable like that.
I have heatshrink but I just figured it wouldn't 100% cover the solder joints on the PCB.

[rvendrame]

@Qu3Uk , is a small plastic box a option? Maybe some 3D-printed, with some ventilation holes on two sides, as small as the PCB + components?

[Moshe Livne]

@Qu3Uk there is something called liquid tape. It's expensive.... Cool stuff though

[scalz]

@Moshe Livne. thank you for the trick. I didn't know this. it could be very useful sometimes.

[Moshe Livne]

@Qu3Uk Also, worse comes to worse, use PU construction adhesive. very messy but they are rated for electrical conductivity and fire. if you ever want to take this off, you are in big trouble....

[Qu3Uk]

@rvendrame Waiting on some boxes but I'm also wanting to protect the connections inside the box, figure it'll also be a little neater maybe.

[Moshe Livne]

@Didi Any initial results? curiosity is killing me....

[Didi]

@Moshe-Livne said:

@Didi Any initial results? curiosity is killing me....

Sorry Moshe no tests,i was in holidays with my kids