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USB Power

Delphawi

Sep 4, 2012
3
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Sep 4, 2012
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Hello

I need to connect some (or all) of three components I have to a Laptop USB port to use it as a power for the circuit . The power specifications for them are the following:
First one DC12V , 0.18A
Second one DC05V , 0.17A
Third one DC12V , 0.14A

How can I use the USB power to make my circuit work ? how many components I can run using a single USB cable ?

Thanks in advance
 

BobK

Jan 5, 2010
7,682
Joined
Jan 5, 2010
Messages
7,682
That is a total power of 4.7W. A USB 2.0 port can supply only 2.5W and a USB 3.0 port can supply only 4.5W. So you are out of luck even at 100% efficiency for converting the 5V power to 12V.

Bob
 

BobK

Jan 5, 2010
7,682
Joined
Jan 5, 2010
Messages
7,682
You would use a DC-DC converter. But as I already explained, you cannot draw enough power from a USB port to power the devices you want.

Bob
 
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