Cut50p modifications

[Mehmet]

I was hoping to see something creative done with a coin.

Bob

At first I didn't understand what "I was hoping to see something creative done with a coin" means, then I realized that I didn't add a link and I think you are talking about it. Both translation and link are difficult sometimes

Arduino_THC_CUT50.zip

drive.google.com

 

[plasma50]

Thank you very much everyone for sharing your experiences.
I wonder if it is not better to use this transformer as an arc sensor:

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What do you think?

 

[EBME2]

I think you are looking for the lack of DC cutting current which signals the pilot arc to start. A transformer wouldn’t measure the DC cut current. From memory I think there is already a current transformer on the main board.

Andy

 

[plasma50]

I think you are looking for the lack of DC cutting current which signals the pilot arc to start. A transformer wouldn’t measure the DC cut current. From memory I think there is already a current transformer on the main board.

Andy

Thanks Andy.
I have a CUT50M and I was hoping for a current proportional to HF.
For a certain result I bought this 10A Hall effect switch.
https://it.aliexpress.com/item/4001339967947.html
When it arrives I will create a circuit similar to your reverse engineering but with a separate power supply and a linear photocoupler to take the voltage for the THC . If everything works out I will post the results here.

 

[plasma50]

This is a draft of what I would like to do

 

[EBME2]

This is a draft of what I would like to do View attachment 325023

Looks ok to me, only thing I would say is I never positively identified the diode, it was a bit of a guess as the markings were hidden under the component and didn’t really want to take it out. It was a bit of an educated guess given the markings I could see.

Hope it works out.

Andy

 

[EBME2]

Just a thought you may be able to simplify your circuit by changing Q1 to a Darlington transistor and using one relay rather than two. I think the only reason the original circuit used a 12v and a second high power relay was due to the relatively low power available on the 12v rail in the Cut 50. Your external PSU does not have this limit. TIP 142 Darlingtons used to be my transistor of choice, but a long time since I have played.

 

[plasma50]

Thanks for the doubts expressed on the diode I also believe that it is a transil diode that I have not found so I took this: 1.5KE6.8A
What you said about Q1 is true but I use a relay to have a galvanic separation from the original circuit of the CUT50M.

I took a few steps forward:
1) Hall effect sensor installed.
2) Fixed the pilot arc power point.
3) Placed the PSU.
4) It's a bit rough but I created and mounted the PCB.

The K-CS010BT sensor has NC open collector output, I thought it was NO, so after testing I had to change the wiring diagram ( and PCB ) to make Q1 (and K2) remain conducting when the its output is at 0.

Here are some photo:

 

[Mehmet]

@plasma50
Hello, I am measuring the cutting current with the transformer. I bought RCS09K but defective output didn't work. Since the plasma output is square wave, it is sufficient to receive a triggerable signal as a result of rectification with the transformer output bridge. Of course the Hall sensor is better

There is one more detail, make sure to install the capacitors in the photo in Andy's first message. I had to change the big relay 2 times. The relay stuck and couldn't release it. I think there was an arc in the relay from high frequency, then I noticed these capacitors and applied them.

I don't remember the capacitor values exactly, I bought one from the one emi filter and the other was a 1kv capacitor, I think if I turn on the machine, I will look at the values

Good luck

 

[plasma50]

@Mehmet
Many thanks.
Where should I place the 1Kv capacitor?
From what you say I assume it needs to be paralleled to protect the relay contact.

 

[Mehmet]

@plasma50
Just as you have drawn, but don't do it on the relay or pcb (pilot arc power point and plasma + output) just do it inside the machine.
It absorbs high frequencies before they reach the relay.

 

[najla]

@Mehmet
greetings, my name is dizt from Indonesia,
thank you for sharing the project along with the schematic, I'm in the process of making the THC Arduino, design code and the code I took from regeg this link.
please enlighten me whether the output from B4B-PH-K (on your schematic) is the same as arc OK

thank you

 

[Mehmet]

please enlighten me whether the output from B4B-PH-K (on your schematic) is the same as arc OK

Hello dizt
The drawing where the B4B-PH-K is located is a drawing for the pilot arc feature, it is not related to THC, I think you asked for the voltage divider or I understood it that way, because I am using the translation for English.

You can't read voltage for arduino from B4B-PH-K, it just has an output to control board to feed the board and boost the amperage when the current read when cutting metal reaches 10A, and this is to add pilot arc feature to the plasma, not read voltage for THC.

To read voltage from plasma with Arduino, you need to make a voltage divider with 2 resistors. I shared a drawing in the message above.

greetings to indonesia