Re: Power Supply and Capacitor Questions Help!!

Jon,

You might want to check your numbers. Kt is always 1.351 * Kv.

13A * 60V = 780 Watts of input power.
1500 RPM * 8320 in-oz / 1351 = 9237.6 Watts of output power!

Kt = 1.351 * 40 = 54 in-oz / Amp.
At 13A, torque is a more realistic 702 in-oz and output power becomes
780 Watts, indicating motor efficiency was not taken into account.

Assuming 85% efficiency, speed with a 702 in-oz load would be 1275
RPM. This would result from a 9V drop across the armature resistance
at 13A, leaving 51V for the "ideal" motor (60 - 9 = 51). Use the
actual armature resistance to calculate this accurately.

Mariss

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:

> Ah, Kv = 40, so 60 V will give about 1500 RPM. 40 In-Lb/amp is the
Kt. At
> 13 A that is 520 In-Lb (8320 In-Oz for the stepper crowd!), and at
20 Amps
> (max for the Gecko) it is 800 In-Lb. You may have to use 2" belts
to couple
> the motors. They sound strong enough to do direct drive, but a
coupling
> that
> can handle that sort of torque will be a bear!
>
> Jon