Re: Plasma Voltage Servo

Tom, Aspaguy,

I'm not familiar with plasma cutting systems. Where is this
voltage "taken from"? Is there a "tap" on the unit somewhere?

Thank you in advance.

Ballendo

--- In CAD_CAM_EDM_DRO@y..., "ths992001" <thscarince@h...> wrote:
> WRT plasma arc voltage vs torch to work distance:
>
> Once I read an Amercan Welding Society paper on this subject.
> According to this article, the arc voltage wavform is something of
a
> sawtooth. At the beginning of the cycle the arch starts at the top
> of the material at a certain voltage. As it rapidly burns its way
> down the face of the cut, the voltage ramps up to some peak at the
> bottom surface of the material. At this point, the arc jumps back
to
> the top surface and the cycle begins again.
>
> This means that the average arc voltage may not be an ideal
> indication of the torch height in all conditions (material,
> thickness, feed rate, amps, target height...). The author proposed
> using the "peak low" (the base of the sawtooth) voltage as this
best
> represents the actual height under varying conditions.
>
> Got an extra op amp for an averaging peak (or valley, in this case)
> detector Mariss? Seriously, his design will probably do the trick
> just fine in the real world.
>
> Tom Scarince