Need help in understanding Brushless DC motors?

[abhi@eda]

hi all,i came across Brushless DC motors today as saw they are rated in Kv

say like 500kv,that's 500 RPM per 1 DC voltage

assume a BLDC motor with these specs

Operating Voltage: 44.4V (12S lipoly)
RPM: 510kv
Max Current: 70A
Max Power: 3100W
Idle Current: 1.9A
Resistance: 0.024ohms
Shaft: 6mm
Connector: 4mm bullet
Bolt Hole Spacing: 25/30mm
Bolt Thread: M3
Weight: 362g


it says operating voltage is 44.4V,so at that voltage the motor should run at speed of 510 * 44.4v = 22,644 RPM
am i right about it?isnt that the MAX voltage for that motor?

it can also run with less voltage..

Say i want the motor to run at around 2000RPM ,so 4 vold DC would do, 4 * 510 = `2000RPM,do you think it would run with that low voltage?

also can you tell me at 4 volt how much current it would consume?

 

[D.A.(Tony)Stewart]

Current is related to torque of acceleration and loading above the idle current, which you have not specified.

Starting and stopping voltage is motor dependant torque vs speed, load and stiction of bearings.

Looks like a good helicopter motor, since loading at starting RPM depends on acceleration factor and not wind, it could max out or be anything less.

 

[abhi@eda]

yes,it is a heli motor,but i'm confused about that 510Kv...

i think it says 510 RPM per 1 volt..

and another question

are BLDC motors connected to DC source directly or they need a controller circuit to drive them?