cheapest and safest way to step down from 230V to 5V 600mA

kubeek

Joined Sep 20, 2005
5,724
If you want to do it safely, then use something from a reputable manufacturer and not some random parts desoldered from old boards.
 

MrAl

Joined Jun 17, 2014
7,659
That is not an option, the pcb has to draw the supply from mains.
Hi,

If it is a one-off piece, then you do have another option if you dont mind a little extra work.
You can take apart a standard wall wart and use the transformer inside.
Look for transformer mounting techniques online.

If you carefully cut along the seam you can get these apart pretty easy.
The inside usually contains either a regular transformer or a circuit with a high frequency transformer If it is a circuit, it will be on a board already that you would have to mount to your board.

Various possibilities here.
 

Thread Starter

abc14

Joined Oct 15, 2017
123
Hi,

If it is a one-off piece, then you do have another option if you dont mind a little extra work.
You can take apart a standard wall wart and use the transformer inside.
Look for transformer mounting techniques online.

If you carefully cut along the seam you can get these apart pretty easy.
The inside usually contains either a regular transformer or a circuit with a high frequency transformer If it is a circuit, it will be on a board already that you would have to mount to your board.

Various possibilities here.
No it would scale up eventually, possible 100 of devices. I don't mind putting in work to make it safe and cheap
 

kubeek

Joined Sep 20, 2005
5,724
I buy them online, don't de-solder them. Do you have any suggestions ?
I understand that, the post was aimed at the questionable source where you buy them. Parts with no datasheet, 500% price range and with blurred out watermarks in the photos are something I just would not dare use.
 

Uilnaydar

Joined Jan 30, 2008
118
Buy something that has the appropriate underwriting/certification for your region.
My bad... didn't think of certs. TS, my part recommendation is from a US-centric viewpoint. Those Farnell links might have certs/underwriting to your region if you aren't US based.
 

RichardO

Joined May 4, 2013
2,271
Buy something that has the appropriate underwriting/certification for your region.
dl324 has a good point. Getting safety agency approval for your own design can be both painful and expensive. It can also take a while -- especially if you are doing for the first time. Just finding and understanding the applicable standards is a lot of work.

Been there, done that and have the scars to prove it. :eek: Fortunately, my customers paid for the certifications.
 

MrAl

Joined Jun 17, 2014
7,659
That's what a wall-wort plugs into.
So put the wall-wort in the box and run a cord to it.
Hi,

Not a bad idea really, but it may be hard to somehow get the wall wart mounted properly and i think it would look more like a hack than anything else. Something i would do, except in a production environment where the final project has to look professional.

But that idea leads to anther idea, to use an approved computer power supply. These things are meant to be mounted inside another box and so would look like a professional product once completed. These things have a cord connector for a regular computer power cord, so i think it would work pretty nice. That is, unless the AC power is needed for another part of the circuit too which would then require either another AC input or mod of the computer power supply.
Computer power supplies come pretty small, or at least they used to, but just what the smallest is i dont know and hopefully it would not be too big for his project.
 
Top