Plasma Primer updated 23 March 2020

Thanks to help from Phill, the Plasma Primer has had a fairly significant update in Version 2.9 (Master branch)

This incorporates user feedback from many users, the hypersensing method using a THCAD-5 for ohmic sensing I have been using for a while, Tommy's notes about a simple ArcOK circuit, and many notes based on my observations of common problems users have experienced, a section on RS485 connection to Hypertherm machines, a chapter on Plasma machine selection and many things I have forgotten about that went in there during this update

Users building or considering building a plasma table are advised to take the time to read this document and refer to it during their build.

I think now this document is by far the most comprehensive documentation about plasma cutting publicly available today.

Thanks to the hundreds of users who have contributed.

Also in conjunction with this, the hypersensing comonent (called ohmic.comp) is deployed with a 2.9 build and is documented here (and also if you type man ohmic.comp)