Machine plasma torch IPTM-80 and ohmic sensor

Hi all

i bought a cheap plasma  Herocut Cut55i and i have machine plasma torch IPTM-80 like this
 
 

i try to do ohmic Hypersensing with a MESA THCAD-10 on my cnc table

Can you explain how physicali connect ohmic sensor?

Can i do ohmic ring something like that to the copper shield
 

or it is impossible on this type of torch and all that remains is floating switch?

thank you


 

Here is how I did it. 
forum.linuxcnc.org/show-your-stuff/56269...sensing-with-iptm-60
TLDR; Disconnect the ground lead in the plasma torch cable. Measure voltage between material ground and torch tip.

thank you. sorry don't see this thread. too difficult for me but i will try

Yeah the thread is long and full of failed attempts and iterations.
That's my development cycle, sadly.
The last post summarizes it. And this post show the performance forum.linuxcnc.org/show-your-stuff/56269...m-60?start=20#336805 It keeps performing like that even on water and rusty pieces.

Because the torch is the way it is, the ground leads in the torch, used during the arc start, needs to be cut and a small voltage applied which one measure to detect contact with the material. The rest is implementation and packaging in a nice format.
If you are willing to do surgery on the long cable to the torch you can cut it open and access the ground leads in there.
Instead, I made a short extension cable where all modifications were done.

I also used two separate voltage readers but I don't think that is necessary.
One uses the built-in voltage port, one measures directly between material ground and torch tip.
I will cut some parts later today so I can compare the voltage output of the two.
Of course, Mesa's THCAD cards can be used, the full voltage version.

I'm not good at electronics. i will try implement a hypersensing circuit from plasma-cnc-primer docs with yours schematic. similarly, without surgery in a long cable.

for ohmic sense i only have thcad-10. i have thcad-300 but i used it for THC in this plasma cutter with 1:1 devider.

I found almost all the components (FY0022 + FY0023 connector,24VDC >20A relay ). but i can't find Isolated dc-dc converter with on/off signal.

I only found this recom dc-dc converter and bought it from tme.eu
www.tme.eu/en/details/rs3k-2424sz_h3/dc-dc-converters/recom/
I see that Mouser, Digikey, Farnell and those big ones have the item.
Can't find it on cheap places ebay, alix etc.

i only found URB2424S-3WR3 Hi-Link on aliexpress. specs in attachmentDoes it fit?

 

You have to compare with the data sheet of the recom www.tme.eu/Document/cd1b5f2ae4e38e422d024220d341ab42/RS3KZ.pdf
It looks like Ctrl is reversed? Apply voltage to switch off? Or am I wrong. One want the module to be off and actively switch on.