element14's The Ben Heck Show

Forum I have a 5v usb fan and I want to reduce the speed.

element14's The Ben Heck Show requires membership for participation - click to join

Actions

Forum Thread Details

State Not Answered
Replies 18 replies
Subscribers 31 subscribers
Views 7314 views
Users 0 members are here

Related

I have a 5v usb fan and I want to reduce the speed.

rayjai over 13 years ago

I have a 5v usb fan and I want to reduce the speed. how would I do it?

the fans on my laptop cooler is too loud.

thanks

Top Replies

YT2095 over 12 years ago +1

you could also use a simple 1n4001 diode in series with the positive wire, to drop .7 of a volt for each diode you use, doing it this way still lets you draw exactly the same amount of current (about 500ma…

Parents

0 Former Member over 13 years ago

Simplest thing to do might be to replace the 5V fan with a 12 volt fan that is the same size. The 12 volt fan will run slower from 5V. Just be sure it is not a brushless DC fan.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel

Reply

0 Former Member over 13 years ago

Simplest thing to do might be to replace the 5V fan with a 12 volt fan that is the same size. The 12 volt fan will run slower from 5V. Just be sure it is not a brushless DC fan.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel

Children

0 DaveLTX over 12 years ago in reply to Former Member

That's plain wrong .
A 12v BLDC can work down to 1.5V .

PWM with a TL494 into a N-channel mid power mosfet will do .
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 Former Member over 12 years ago in reply to DaveLTX

Hi Dave,

You are right. I was thinking of a brushless DC motor that requires 3 phase AC drive (a controller module), not the cheap brushless fans that just provide electronic commutation.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel