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Split Voltage

renfley

Mar 6, 2013
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Hey guys.. quick question for you..

My goal is simple, i want to used a laptop power cord to power two 5 volt devices,
one being a raspberry pi and the other is the lcd control board.

Does anyone have any ideas or solution they could offer?
 

davenn

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Sep 5, 2009
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well for a start tell us what is the voltage rating of the Laptop power adaptor ?


Dave
 

renfley

Mar 6, 2013
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the adaptor in question is an old IBM

Input: 100-240v ~ 1.5A-0.9A 50/60hz

Output: 16v 4.5A
 

Harald Kapp

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You will need a 5V regulator. Otherwise you will fry your boards.
What are the power requirements of the boards?
For up to ~100mA a simple linear regulator based on an 7805 can do.
If you need more than ~100mA per board you will want to use a switch mode regulator like e.g. this one.
 

Harald Kapp

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In your first post you mentioned 2 5V devices. According to your latest satement, you will need two separate regulators: 1*5V + 1*12V.

By power requirements I meant: what is the current consumption of the boards?
 

BobK

Jan 5, 2010
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The Raspberry PI can be powered by any 5V USB plug charger. You can get these for a couple of bucks.

And are you sure you need that monitor board? The Raspberry Pi has hdmi video built in.

Bob
 
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