Re: [CAD_CAM_EDM_DRO] Re: QUESTION ABOUT SERIES OR PARALLEL ON STEPPERMOTORS - ref post 52721
Posted by
Raymond Heckert
on 2003-02-14 19:09:23 UTC
Jon, that's actually a very good description of how a saturable reactor
controls current, as in the Bridgeport SERIES I CNC. The drive current
passes through the reactor, on it's way to through the Full-Wave bridge.
The reactor cores are driven into saturation when more current is called
for, by a sense current from the ACC board. The saturable reactor is thus
biased magnetically to control the current.
RayHex
----------
controls current, as in the Bridgeport SERIES I CNC. The drive current
passes through the reactor, on it's way to through the Full-Wave bridge.
The reactor cores are driven into saturation when more current is called
for, by a sense current from the ACC board. The saturable reactor is thus
biased magnetically to control the current.
RayHex
----------
> From: Jon Elson <elson@...>snip>. . . . . . . But, if you run it at the very upper end of
>
> the margin, the primarysnip>
> current will go up, the laminations will be pushed to higher flux than
> the design was set
> for, and it will run hot. One way to check this is wire a 100 W light
> bulb in series with the
> primary, and fiddle with the taps or use a Variac to adjust voltage.
> Don't put any load on
> the secondary. When you are within the transformer's V-T margin, it
> will draw very little
> current, and the light bulb might flash momentarily when the power is
> turned on, but will
> then go out. The transformer will be drawing just a few milliamps.
> When the voltage is
> turned up (or the adjusting tap is moved to a lower setting) you will
> reach a point where
> suddenly, with very little change in applied voltage, the current will
> go up dramatically.
> This is when the iron is driven into saturation, and no longer produces
> the inductance that
> prevents current from flowing in the primary.