I am asking for a friend of mine who is helping me hook up a THC on my crossfire table. I have a older razor cut 45 no CNC ports or torch fire port. Question is he knows how and we’re to hook the wires up for for the THC and the torch on and off but he’s wondering about Arc ok signal? Does anyone know where to hook wires up for this inside the plasma cutter? Thanks for your time and I hope I wrote this all right and it’s understandable.
Welcome.
The THC installation manual on the main site contains this information.
https://www.langmuirsystems.com/thc/guide
If you search razor weld wiring in the magnifying glass up above there is many topics covering that scenario.
This topic happens to be pinned to the top of the forum.
You will not need Arch okay to move.
Two pairs of wire
one pair spliced into the trigger of the razor weld torch
One pair right to the lug nuts where your main clamp and main torch lead enter the razor weld which are for measuring raw voltage for the THC
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This signal is not used in a FireControl system. It can be left disconnected.
We are no hooking up a THC from langmuirsystems. We are using a proma Sd and runing mach 3 with the razer cut 45 plasma would this be the same and we wouldn’t need this arch ok signal?
The Mach3 profiles I’ve seen don’t use the ARC Ok signal, but, I believe, there are configuration options to use it if you feel the need.
Here’s an older post maybe this will be helpful to you.
I am not using Arc OK signal, running Mach3 and it works a peach!
Also, I opted to use THC3T-02 not Proma. Above posts and links provide valuable information on the subject.
One thing you will find on this conversion is that, since Langmuir used 5V for it’s OUT signal power rail, limit switches and sense signals like (ARC OK to take a random example) must be 5V logic and, since the MACH3 IN signal pins require about 7mA to trip, you need to change resistors on the MACH3 USB board to use the IN signals. It can be done and is documented on the forum. Search for “MACH3 resistors” if you need to go this route.
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Unfortunately It doesn’t exactly contain the information. It’s primarily focused on the Langmuir THC integration and focuses heavily on properly handling the divided voltage. The question is where would one connect an arc ok signal (if they chooses to utilize one), on the plasma side of the connection.
It’s hard to tell at this point but it was me who changed the title of this post.
The original poster had left out some crucial information in the title in the first post. So I added it in.
It wasn’t till the original posters second post that they included the information about it being specifically for a proma sd and mach 3.
So in context of that this information was missing till the 4th post down. That’s probably why my second post includes standard langmuir THC information.
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I know their build. They’re not running the Hijacked USB voltage, powering the old Langmuir black board with an independent 5v rail and and the I/O with 24v The Fans/ fan control and additional accessories are all powered with 12v rail. All power supplies including the 36v was replaced by proper meanwell PS. Drivers are all updated G203 and everything is getting proper grounding and EMI/EMF filtering and shielding. 3mm ferrites are added to all signal lines and they’re using double shielded and properly drained cables with ferrites. As proper as it can get. It’s a new box built with internal emf coating. All wires are replaced with proper terminals/soldering/Triple wall heat shrink. 8 acceptable busbars terminal splitters were used scraping the split OEM wiring. The db9 ports all have EMI filters and the correct drain.
I believe the question isn’t asking where on the Langmuir eco system would one connect an arc ok signal but where is the best way to pick up the signal on the Torch side of the system. One line goes to ground and line goes to your input pin of choice now where I’m the razorcut do you or would you make the connection. Answers that have linked to The above threads just say to ground the arc ok signal and isn’t specific as to the best way to accomplish this.
Welcome to the forum!
IF you have a Mach3 system, you could use any one of the IN1-4 pins, configure Mach3 to use it, and modify the board to use 5V signalling.
IF you have a FireControl system there is NO pin available (at least documented) to use for this function and NO software that will use it.
If the only way to achieve an ark ok signal is to piggyback off the divided voltage then that would I guess answer the question. But I’ve heard of others doing it without.
If this is the question then, as far as I know, the only ARC OK signal I’m aware of is generated by the THC3T-02 module after sensing a sufficient arc voltage. I do not know about the Proma unit or if any particular plasma cutter also generates a similar signal. In this context, however, I would trust the THC module more, simply because it needs to recognize a valid voltage to operate properly. The PC doesn’t particularly care about this aspect of the operation.
The Arc ok signal is redundant. But I found a unique solution to the problem utilizing a CT ring, high current IC and an ESP32 with a dry contact relay. Voltage parameters/tolerance can be set with a simple User interface within the AP and it can also trigger the arc ok signal via BLE or TCP if needed to avoid pin neglect. But, it’s a long way to light up a “digital” led. However this set up would also allow one to record the arc data to later enhance cut efficiency. It could transmit this data or trigger a physical Arc ok light via MQTT the light could change color or intensity based on readings.
In fact, I think you can easily make a $25 ESP based THC with traditional Voltage reduction if you don’t mind logging into the UI or using BLE to set voltage. It would interpre voltage swings or even Step/Dir much faster then the older low core ARM or ATMega based controllers could dream of…Like 180,000 steps per second faster.
He said, redundantly…
Which problem??? The problem of how to generate this unnecessary signal?