How to Undervolt a Fan Inside a Small Device?

kony wrote:
ric wrote:
kony wrote:

I dont' know how much further that particular fan will
tolerate a voltage drop so I can't help much. Past a
certain point a larger resistor will prevent it from
spinning up which obviously should be avoided.

Placing a cap in parallel with the resistor seems to cure startup
problems.

"Cure"?
To what extent?
I mean, does it actually allow a lower working RPM then or
just offset the overly high resistance?

This is an interesting idea, do you have an example of what
gain there will be for any particular fan?

This is probably just plain dangerous to the rest of your system.
It would depend on "giving a kick" at turn-on, provided that the
power supply had a rapid rise time. If the fan ever gets stalled
in normal operation the kick is not there, and the thing just sits
and encourages the rest of the system to cook.

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