Ohmic enable relay lopgic

rodw wrote:

[quote="bevins" post=144256
I don't have a thcad-5. I just have thcad. Is there firmware on the thcad and up gradable to thcad5? lol,
?

I was thinking later that if you had a THCAD-10 spare, a 48 Volt isolated power supply is the same price as the 24 volt one I used. A 470k resistor would set the full scale to 52 volts or a 4.52k resistor would give full scale of 50.2 volts. Either would be perfect![/quote]

I could get another thcad and get a 48volt PS, but will the old way work? I already have everything. I got the isolated 24v power supply and relays and a thcad.

Whats the major advantages to the supercharged THC?

You can set a THCAD10 to 24V full scale with a 140K series resistor
(I would use 140K 1/2 W or two 69.8K 1/4 W in series)

PCW wrote:

You can set a THCAD10 to 24V full scale with a 140K series resistor
(I would use 140K 1/2 W or two 69.8K 1/4 W in series)

But you guys are talking another thcad? One for thc and other for ohmic sensing?

Bevins, yes, I posted seperately about our experiments here
forum.linuxcnc.org/plasma-laser/37311-hy...-to-do-ohmic-sensing

So I just need to order another thcad. I may give this a try. Although I still do not know the benefits this gives over the other scenario other than better isolation?

Tommy, I think so. This is a plot I just did of an ohmic sense event. Pin to watch is ohmicsense.ohmic-on which is the probe signal. But the blue plasmac probe follows it as well



Here we turn the signal on at 18 volts and off at 5 volts. Plasmac probes back very slowly until it breaks contact so the off threshold is the important one and you can see its not triggered until all the noise subsides. I think it would be interesting if you set a low on threshold and smashed the probing at high velocity to speed up job cycle times.

I am getting a spurious probe signal reported by Plasmac on the first probe after opening a new file. I suspect either Phill or I are not setting a default value correctly. It does not bother plasmac, it still continues but I need to look further.

Stop already........ I'm ordering another thcad....

the probe signal is very clear
so no bouncing at the peek hole