Re: Power supply for Servos - Light Bulbs

--- In CAD_CAM_EDM_DRO@yahoogroups.com, JanRwl@A... wrote:

>
> In a message dated 2/19/2005 11:26:23 P.M. Central Standard Time,
> cnc4me@g... writes:
>
> cold bulb draws more power when it heats up
>
>
> You DO mean "LESS power when hot", don't you? The R increases,

current

> lowers, in the milliseconds a light-bulb heats up! Cold, it draws

the MOST

> current (and power) for an instant!
>
>

First, I don't have much knoledge on this, and certainly nothing
outside my very limited experiance with my home-brew EDM.

But, if we are looking for a resistor to dump energy on a servo or
stepper the cold bulb would seem to dump lots, fast.

But.... on a plasma table, one can race to a corner, stop on a dime,
(get 9 cents change) and make a shart 90 deg turn, race to the next
corner...

For power supplies, if one motor is decelerating and the other is
acellerating, there is a use for the returned energy. but, on the
plasma, it is one axis comes to a dead stop before then next races
off. So, the second can't always spend the 9 cents change.

Dave