AC-DC converter

Thread Starter

praondevou

Joined Jul 9, 2011
2,942
I'm looking for a tiny AC-DC converter 120VAC to 5VDC. It doesn't have to have more than 50mA output current.

I found this http://www.recom-international.com/pdf/Powerline-AC-DC/RAC01_02-SC.pdf on Digikey, but $14 is too expensive. There are some which are not isolated for $6, but I wanted them to be isolated.

main thing here is they have to be CHEAP.
Has anyone had this problem and found something? I don't want to build one by myself because it's going to be more expensive (component count).

Thanks
 

Thread Starter

praondevou

Joined Jul 9, 2011
2,942

iONic

Joined Nov 16, 2007
1,650
This is much too big, but now that you brought up the idea I'll have a look inside to see how big the circuit is, I have several of those.

Thanks
They don't leave much room for spare change in there so the case dimensions are pretty much what you have inside.
 
Last edited:

Kermit2

Joined Feb 5, 2010
4,162
How are you going to satisfy your polar opposite requirement?

If one with a transformer is to big, you need a switching supply, if they are too expensive, then you need a non isolated supply, if you must have isolated then you are back to the transformer type.

???
 

Thread Starter

praondevou

Joined Jul 9, 2011
2,942
Buy thousands, they'll be much cheaper.
:D Would you mind giving me loan for that?

If one with a transformer is to big, you need a switching supply, if they are too expensive, then you need a non isolated supply, if you must have isolated then you are back to the transformer type.
Problem is the 60Hz transformer, they are too big. They sell 5V wall chargers for $2, new. That means they could produce such converters. It's all a question of quantity. What I'm looking for is simply not being mass produced, that seems to be the problem...:)

Rohm also has the BP5063-5 for $8.86 USD in single quantities.
It's non-isolated, there is also one for $6,60, the BP5034D5, also non-isolated.

Thanks for the input , guys.
 

Thread Starter

praondevou

Joined Jul 9, 2011
2,942
I think I finally found the transformer isolated solution. It has to be CHEAP so I opened one of these chinese USB chargers which you can get for $1.50 on ebay.

It's some kind of a super-simple smps, I'm curious to find out how it works. The secondary part certainly can be made smaller. They also will need a voltage regulator, since the output voltage can vary quite a bit. (+-0.5V)

 
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