Sviluppo thc interno a uccnc

[Cosimo83]

Salve...
Da tempo sto valutando se sia possibile usare la tensione di uscita delle interfacce cnc dei generatori plasma con divisione 1:50 per farlo leggere a uccnc e far svolgere a uccnc la lettura con un set point impostabile in modo che possa fare lui su e giu della torcia escludendo cosi un thc esterno.... Qualcuno ci ha mai provato? Sarebbe fantastico risparmiare sull'acquisto di un thc esterno....

[cncdrive]

No, it's not possible. You need an external THC controller, sorry.

[Vmax549]

Playing with another controller I saw they used a Voltage to Freq convertor to do THC control. The THC board monitor ed teh Cut voltage and converted it to Freq which is feed in as an encoder signal(Freq). The controller then managed teh freq to do teh THC up and down inside teh controller. It was basically all just software running teh show. Once would think that teh UC300eth would have enough horspower to do teh same ??

I am goin to try it as a plugin BUT it would work great if the compare was done inside teh UC300eth processor as it can run very fast and smooth. May have to build a fast BOB to handle teh encoder side or maybe not. Just input teh encoder signal directly bypassing teh BOB ??

The THC board(MesaTHC300) is heavily isolated from teh Cut Voltage side so no worries of destroying the UC300eth or a UC400eth. ANd is cheap to buy.

Just a thought, (;-) TP

[cncdrive]

It is not harder (even cheaper) to generate the THC up/down signals from the arc voltage. With a reference signal (setpoint) from a potentiometer. Even a $0.2 window comparator (2 comparators) can do the job.
Since the UCCNC has the THC delay and other things implemented therefor a simple comparator circuit can work.
Converting to frequency is a more expensive solution. The only better thing with that would be that then it would be possible to provide the reference voltage from inside the software.

[Vmax549]

Yes but for something that is suppose to be so easy and cheap to do they sure charge a LOT of money for. IF teh UC300eth could do it all internally you could corner the THC control market.

(;-) TP

[Cosimo83]

Non si puo usare un ingresso analogico dell uc300 e convertire il valore dei bit in proporzione per dare un valore di voltaggio e comparando una dro di riferimento dire a uccnc di dare torcia su o torcia giu virtualmente con le funzioni di simulazione torcia su o torcia giu?

[Robertspark]

Terry the thcad was discussed here a little while ago this may or may not be of help to you

viewtopic.php?f=16&t=725&p=5178&hilit=Thcad#p5178

[cncdrive]

Yes but for something that is suppose to be so easy and cheap to do they sure charge a LOT of money for. IF teh UC300eth could do it all internally you could corner the THC control market.

Making a voltage to frequency converter is more complicated and more costy to build than to build a comparator circuit which produces the THC up/down signals.

[Vmax549]

The THCad 300v sells for $69 can do direct hookup to cut voltage and has a continous overload rating of 2500V. The rest of teh package would just be software/Firmware. Now what are they changing for a decent THC controller these days ?? (;-).

Just a thought, (;-) TP

[cncdrive]

A comparator costs about $0.2. A good quality potentiometer cost something like $3. A circuit board could be probably made for less than $10 in single or few boards quantity.
You can add some high voltage schottky or fast diodes for overvoltage protection...