RC-Monster Forums - View Single Post

BrianG · 09:53 PM

Looking at the chip so the lettering is facing you, from left to right, the three terminals are input, ground, output. Even though the IC can supply 2A, it will only need to supply what the fan draws. Small fans usually pull no more than 0.25A, especially the slow ones. It is a 12v fan? What voltage do you want to run it at? I wouldn't go higher than 20% higher than its rated voltage or it may shorten its life. You can figure out how much power the regulator will dissipate by the formula:

regulator_dissipation = (supply_voltage - fan_voltage) * fan_current.

When the fan dies, it will most likely open circuit. And even if it does short out, the relatively tiny wires to the fan will act as a fuse and burn up, or the regulator itself will burn up.

	(#6)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	07.28.2006, 09:51 PM Looking at the chip so the lettering is facing you, from left to right, the three terminals are input, ground, output. Even though the IC can supply 2A, it will only need to supply what the fan draws. Small fans usually pull no more than 0.25A, especially the slow ones. It is a 12v fan? What voltage do you want to run it at? I wouldn't go higher than 20% higher than its rated voltage or it may shorten its life. You can figure out how much power the regulator will dissipate by the formula: regulator_dissipation = (supply_voltage - fan_voltage) * fan_current. When the fan dies, it will most likely open circuit. And even if it does short out, the relatively tiny wires to the fan will act as a fuse and burn up, or the regulator itself will burn up. Last edited by BrianG; 07.28.2006 at 09:53 PM.