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lolito_fr · 04-09-2004, 04:27 AM

I think you'd need a really large inductor to make any difference. (0.5H or more? based on a quick dI/dt calc).
A capacitor would work, but only if you devised a current limiting system to charge it, with a timer, like Groth says. Even so, you'd probably need a few 10000µF.

I would just try adding some series resistance: between 0.2 and 0.4Ω would limit startup current to 15A or so if you use the 5v rail. The blower would obviously run slower, as you would be dropping about 1v across the resistor.
You would need it to be rated for at least 5w, unless you put it in the air flow....

If you want to calculate the resistor value yourself, you ideally need to know the blower motor winding resistance. I'm just guesstimating 0.1-0.2Ω.

Edit: dont even think about running that thing on 12v, it would need well over 20A nominal, let alone startup :shrug:
And yes, it does needs a "shroud" (volute may be the correct word), which can just be box with a circular inlet hole

04-09-2004, 04:27 AM	#12
lolito_fr Cooling Savant Join Date: Dec 2003 Location: France Posts: 291	I think you'd need a really large inductor to make any difference. (0.5H or more? based on a quick dI/dt calc). A capacitor would work, but only if you devised a current limiting system to charge it, with a timer, like Groth says. Even so, you'd probably need a few 10000µF. I would just try adding some series resistance: between 0.2 and 0.4Ω would limit startup current to 15A or so if you use the 5v rail. The blower would obviously run slower, as you would be dropping about 1v across the resistor. You would need it to be rated for at least 5w, unless you put it in the air flow.... If you want to calculate the resistor value yourself, you ideally need to know the blower motor winding resistance. I'm just guesstimating 0.1-0.2Ω. Edit: dont even think about running that thing on 12v, it would need well over 20A nominal, let alone startup :shrug: And yes, it does needs a "shroud" (volute may be the correct word), which can just be box with a circular inlet hole Last edited by lolito_fr; 04-09-2004 at 04:58 AM.