how to make two isolated 5V dc power supplies from single AC source

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gadget_freak

Joined Apr 27, 2016
4
Hi, I recently came across this problem, while working with my arduino project where in it was necessary to have two isolated 5V dc power supplies. For that i used two 5V smps supplies. Now, the question is IS IT POSSIBLE TO HAVE SUCH TWO ISOLATED SUPPLY FROM SINGLE AC SOURCE? I am newbie so i don't have much idea if it is practically feasible. Will appreciate if you can help with this.
 

DickCappels

Joined Aug 21, 2008
10,153
Yes, provided by isolated you mean the outputs of the supplies are isolated from the primary.

Also, you might want to consider whether your chosen configuration will require one or both of the power supplies to be isolated from ground too.
 

AnalogKid

Joined Aug 1, 2013
10,986
That is a little bit more effort. One way is to start with a power transformer that has two identical secondaries (*not* a single center-tapped secondary). Each secondary can power a separate 5 V regulator (LM7805, LM317, etc.) with complete output and ground isolation.

ak
 

AnalogKid

Joined Aug 1, 2013
10,986
Nothing will work better and cost less than two USB power adapters. The device you linked to is designed for a specific application, not general-purpose projects. And it is very expensive. You can buy two USB chargers on ebay for $4 total.

ak
 

Ramussons

Joined May 3, 2013
1,404
Hi, I recently came across this problem, while working with my arduino project where in it was necessary to have two isolated 5V dc power supplies. For that i used two 5V smps supplies. Now, the question is IS IT POSSIBLE TO HAVE SUCH TWO ISOLATED SUPPLY FROM SINGLE AC SOURCE? I am newbie so i don't have much idea if it is practically feasible. Will appreciate if you can help with this.
" IS IT POSSIBLE TO HAVE SUCH TWO ISOLATED SUPPLY FROM SINGLE AC SOURCE? "

Simply put, the answer is NO.
From further discussions and clarifications, it seems that the above question did not convey the actual requirement.
 

AnalogKid

Joined Aug 1, 2013
10,986
AND, the two symbols have different net name attributes, which are invisible except that they are printed on the schematic.

ak
 

jsallas

Joined May 17, 2016
9
Hello,

Could you specify the output power you need? Do you require any efficiency/peak current?
What application is this going to power?
You want to buy something or assemble yourself?
 
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