Required





This application requires that the selected motor have
Kv =7000 rpm/12V =583.3 rpm/V
With this value in mind, you can search our standard product list and select a motor which has a Kv close to the one you have calculated. If one can not be found we can build a motor with a custom number of turns to specifically meet your needs.


150 watts




12 v




12.5 A




7000 rpm

Total Heat Dissipation Capability =

28.24 watts





Motor Specifications




36/38/4

As we have calculated, this motor can safely dissipate 28.24 watts of heat. You now have to calculate the losses in the motor and see if they are less than or equal to the amount the motor can safely dissipate.
In very simplified terms, a DC brushless motor's losses can be broken down into two major categories:
1) losses due to hysterisis and drag torque (V x Io) 2) losses due to the resistance in the motor's windings (I2 x R)


600 rpm/V


2.24 inoz/A


1.2 A


0.085 ohm


3.58 in


1.4 in


18.82 inˆ2

Total Heat Dissipation Capability =

28.24 watts





Losses



Power Loss at Speed (No Load)

36/38/4

The losses in the motor are 32.58 watts which are slightly more than 28.24 watts the motor can safely dissipate if it were running coninuously with no cooling. At this point the generator's duty cycle, mounting location, and cooling become important factors. You may also select a different motor and work through the calculations once again.


Io x Vg


14.00 watts

Torque Loss at Speed (No Load)

36/38/4


P1 x 1352/S


2.70 inoz

Power Loss due to Current

36/38/4


Ig2 x R


18.58 watts

Torque Loss due to Current

36/38/4


P2 x 1352/S


3.59 inoz


36/38/4

Regulator Efficiency (RgE) =

85.00%


22.50 watts


36/38/4



P1 + P2


32.58 watts


36/38/4


T1 + T2


6.29 inoz




Requriemtents After Losses



Total Power Required into Regulator


If you do select to use this motor as a generator, a 39.61 inoz input of torque power will be required to spin the motor's shaft and generate the desired torque


P + P3


172.50 watts

No Motor Loss Torque Required



Ptot * 1352/S


33.32 inoz




Ptot/Vg


14.79 A





T + T1 + T2


39.61 inoz


*** NOTE: The above calculations are merely for demonstration purposes..
