AnthonyL wrote:
On Fri, 30 Aug 2013 11:22:36 +0100, "Dave Plowman (News)"
wrote:

In article ,
AnthonyL wrote:
I'd like to know/measure the speed (rpm) of a small electric 3 blade
fan. Any easy ideas?
Is it mains or battery?

Sorry, should have said it was standard mains. Two speed.


If the motor doesn't have any brushes, and there's no gears it'll be
3000rpm or slightly below. Some of them are 1500rpm, and they have 4
pole motors.,

Otherwise, the model aircraft bods use non-contact tachometers, and for
a one-off measurement, you might be able to borrow one from a local
model shop.

--
Tciao for Now!

John.