I have a laptop with partially damaged internal fan. Dont want to buy new one. I am thinking of swapping the internal fan to a 12V fan. The 12V fan I have can fit as it is small. Internal fan is 5V.
Most solution out there
- uses external power supply to power 12V fan
- uses 5V from usb to power 12V fan
- uses laptop charger to power 12V fan but laptop is not connected
What I want
- power up 12V fan using laptop charge WITH laptop connected. 12V voltage level will be achieved using a step down converter with 19V laptop charger as input. OR connect in parallel to an existing 12V connection in motherboard circuitry.
- 5V usb is good idea but I want to operate the fan at its full power using 12V.
Point of doubt
- Laptop charger is already used to supply power to laptop. External load (fan) will definitely drain current but will it interfere with the normal laptop operation?
- can i use buck converter to step down voltage to power up 12V fan safely?
- is laptop charger capable of giving more juice even when it is already used on laptop?
Do please share your knowledge. Much appreciated. Thanks!