Are USB 5v to 12v step up converters safe?

[amadeok]

Hi
I made i cooling pad with a 12v fan and im using a step up voltage converter. i'm worried whether its safe for the laptop . Can you tell me?
thanks

 

[Rdslw]

usually I would be sceptical, but fan under 1A should be fine. What power does it needs ?

 

[amadeok]

usually I would be sceptical, but fan under 1A should be fine. What power does it needs ?

Hi thanks for reply, this is the specs page: https://noctua.at/en/nf-a14-pwm/specification

 

[Rdslw]

usually I would be sceptical, but fan under 1A should be fine. What power does it needs ?

Hi thanks for reply, this is the specs page: https://noctua.at/en/nf-a14-pwm/specification

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((0,13 A) * (12 V)) / (5 V) =
0,312 amperes.
by adding safe margin on conversion efficiency we should not go above 0.5A.
I would say it's safe, as power is quite low, and USB is still some what protected.
I would use active hub, or USB phone charger to check. would be much safter and cheaper if something is wrong.

 

[Paperdoc]

By creating a DIY cooler using a 12 V fan, and then delving into how to get it power from a 5 V USB port, you have experienced why they sell laptop coolers that used 5 V motors and avoid the problems you have.

 

[amadeok]

By creating a DIY cooler using a 12 V fan, and then delving into how to get it power from a 5 V USB port, you have experienced why they sell laptop coolers that used 5 V motors and avoid the problems you have.

Sorry so you are saying that there is a risk?

 

[Paperdoc]

Not a big risk IF you do the voltage conversion correctly. As other have said, you will need to convert 5 VDC from a USB2 port that can supply that power at up to 0.5 A into 12 VDC. That means your output could be up to just over 0.2 A max, but allowing for loss of efficiency in the conversion, you should ensure that the 12 VDC fan you have used will not require any more than about 0.15A to run full speed.