Re: [CAD_CAM_EDM_DRO] Re: Servo motor HP for Bridgeport

sutherland_oz@... wrote:

> Hi all, message #29580 refers to chopper drives being the stepper
> answer, but an Oz firm Oatley Electronics,
> http://www.oatleyelectronics.com/ says that the answer is to use a
> constant current source, (kit #K142C) I'm about to build a small CNC
> mill for home use & would appreciate any comments, Ian S.

A chopper drive is, indeed, a form of constant current source. A TRUE
constant current source, of course, would provide infinite voltage
until winding current came up to the setpoint. this would destroy the
motor. So, any way of allowing full DC voltage to be applied until
current reaches the setpoint is effectively a practical CC source.
If they are advocating a resistive CC source, forget it. there is no
benefit, and the energy loss will be a major annoyance, unless you
need a space heater.

Jon