Safe In-Wall AC to DC Transformers??

[scalz]

Hi,

I found an application notes from enocean regarding power supplies design. I think it could be helpful, and good to remember, so I share the link.
http://www.enocean.com/fileadmin/redaktion/pdf/app_notes/AN101_POWER_SUPPLY_LAYOUT_2015.pdf

[rvendrame]

I'm currently studying this doc STEVAL-ILL004V1 AN2263 AppNote .pdf. I should prototype something over next week if family allows.

[scalz]

Hi. interesting link, I will read it when I will have time. It looks like u2008 or u2010 which are obsolete now (I have some in stock, cheap on aliexpress) but I didn't know your ref. thanks

[rvendrame]

@scalz, I'm trying to porting the capacitor-resistor power supply concept from that doc to our mySensor world. Specially for 1-wire dimmer, as described in chapter 3.1.

[scalz]

@rvendrame : I tried something similar once. I didn't remember exactly how all was connected but with triac, in one wire, even if I was not toggling anything, I had brown reset at start (maybe I could find my schem). With two wire, I had no problem but a little flickering (zero cross detection done by arduino). Maybe it was that which restarted. Next, I did another test with mosfet pwm, in one wire config again. This time, it started ok, and as I was increasing pwm it restarted for pwm = 170-200 (I don't remember exactly) .But I jumped onto another project I am finishing.
I will follow your results with interest as your link is interesting , and at my home it is one wire too.

[rvendrame]

@scalz, with the 1-wire circuit , the maximum you can reach is like 80% - 90 % of light bright, as you need to keep the triac/mosfet "off" for a short period, in order to recharge the PSU capacitor. Maybe that explained why it re-started on your test at PWM 170-200. (and would also confirm that it works 'as designed', good to know)

[ThinkPad]

I would be careful when stripping cheap USB-powersupplies and tucking them into a box in the wall. Read this page: http://www.lygte-info.dk/info/indexUSB UK.html and this page: http://www.lygte-info.dk/info/usbPowerSupplyTest UK.html to see how badly constructed some of these powersupplies are.

He also explains how he is testing those powersupplies: http://lygte-info.dk/info/usbPowerSupplyTestHow UK.html
Very informative i must say.

[Moshe Livne]

@ThinkPad Fascinating read.... If you read through the thread you will see that we actually go to the same conclusion. The meanwell charger should be good - they are respectable company and it has the 3 safeties we were looking for. It is not a very common charger - I have never seen it being sold before.

[petewill]

@ThinkPad Thanks for posting. It's good to see how the tests are performed. Unfortunately I don't have the equipment or skill to know how to test. Hopefully we will be able to find a safe one that we can all use.

@Moshe-Livne have you been able to find the meanwell chargers from anywhere besides jameco?

[Yveaux]

@petewill Mouser carries them, and also the european version (GS05E-USB). Please see here.

[Sparkman]

@ThinkPad Thanks for posting that. Great info there. Looks like you get what you pay for with the cheap power supplies.

Cheers
Al

[Didi]

@ThinkPad said:

I would be careful when stripping cheap USB-powersupplies and tucking them into a box in the wall.

Thanks for the information.The most powersupplies are horrible.
The engineers have developed them must go to jail.
Safety must be the major goal not the price.

[petewill]

@Yveaux Thanks. I was hoping there would be a cheaper way to get these. With shipping it's pretty pricey. Probably not as pricey as a fire though...

[Moshe Livne]

@petewill I have a supplier on ali that sells meanwell reasonably cheap. I used to buy all the power supplies for the LED lights I made from him. I will ask him for a quote. The downside is that he ships everything DHL.... still might be cheaper. where are you located?

[petewill]

@Moshe-Livne Ok, thanks! I live in Colorado, USA.

[jemish]

so finally....plz...tell me which power supply is the best to put inside in the wall?

I want required 5v for Relay, arduino mini, and radio.

[Moshe Livne]

@petewill My supplier is not selling these :-(
apparently they are new
@jemish It is still a work in progress. @didi will do some tests and we are trying to get some more for testing.
Based on http://www.lygte-info.dk/info/indexUSB UK.html I would choose the apple one (http://lygte-info.dk/review/USBpower Apple USB power adapter UK.html)... But YMMV. I am not sure it has OTP

[Yveaux]

@jemish Be safe and buy something like: http://www.recom-international.com/pdf/Powerline-AC-DC/RAC03-SCR_277.pdf
Live on the edge (having a decent fire insurance) and tear down a USB charger or buy one of the few $$ versions from China .

[Moshe Livne]

I have asked the guy who made this excellent list to test the meanwell - hopefully he will oblige. I still haven't been able to find anything with OTP even remotely in this price bracket....

@petewill said:

@ThinkPad Thanks for posting. It's good to see how the tests are performed. Unfortunately I don't have the equipment or skill to know how to test. Hopefully we will be able to find a safe one that we can all use.

@Moshe-Livne have you been able to find the meanwell chargers from anywhere besides jameco?

[jemish]

@Yveaux this RECOM AC to DC converter will safe or not for put it to in the wall.

because I have to start live HOME Automation.