11-09-2006, 03:23 PM
|
| | | Join Date: Dec 2005 Location: USA
Posts: 3,319
| |
English if just fine - question is just odd and not easy to come up with simple answer to/for.
A general tendency is to balance the operating characteristics needed for a motor to provide the needed power versus the voltage and current requirements. After a while, certain voltages and currents become "industry standard" which is why certain motor voltages are more common at certain periods during the evolution of CNC.
High current/low voltage motors provide greater torque BUT they tend to run at lower speeds due to winding considerations. ALso, they are costly to make drivers/amps for becasue high current drivers are EXPENSIVE. In their day, the high current drivers were darlington transistor based and high current darlingtons were hard to make and expensive.
High voltage/low current motors will run at much higher speed and torque is obtained via gearing as opposed to high current draw. SInce the currents being switched are lower, mosfets as opposed to high current darlingtons have become the standard pass element for such motor amps.
Inductrial servo motors typically and perhaps preferrably use HIGHER VOLTAGE/LOWER CURRENT motors for a very simple reason: it is easier and oftern cheaper to switch 100 volts at 1 amp than it is to switch 10 volta at a much higher current of 10 amps - especially at 20-30Khz switching speeds.
The "which is better, A or B???" type of question is difficult to answer completely and distinctly becasue there are so many exceptions that need to be considered.
For an industrial servo, I'd say 100 volts, 1 amp is better - servo amps are readily available that will address this switching need. Moreover and more importantly, this is a semi-standard motor voltage for this application anymore.
For a radio controlled car, 10 volts/10 amps is not a problem as controllers exist that can/will do that. Older CNC servos of this type are a bit more rare and not easy to get high current drivers for.  |
Linear Mode
