Hi!
I have some questions about an EDM circuit I've been thinking about.
I want to build an EDM machine, and I don't have experience enough to finish a circuit that's needed so I've been thinking I can use some existing stuff and put it together.
So I thought this could be a good place to start motor pulse controller.
And I have a variable PSU with 90v at 4.5 amps.
I changed the controller a little bit, I checked what pins on their implemented chip the pwm was coming from, then removed it and hocked up an Arduino to those pins so that I can control both the frequency and the pulse width.
Then I have a quite capable start I think.
Now here comes a few questions regarding this setup.
I have some questions about an EDM circuit I've been thinking about.
I want to build an EDM machine, and I don't have experience enough to finish a circuit that's needed so I've been thinking I can use some existing stuff and put it together.
So I thought this could be a good place to start motor pulse controller.
And I have a variable PSU with 90v at 4.5 amps.
I changed the controller a little bit, I checked what pins on their implemented chip the pwm was coming from, then removed it and hocked up an Arduino to those pins so that I can control both the frequency and the pulse width.
Then I have a quite capable start I think.
Now here comes a few questions regarding this setup.
- One thing I noticed while testing the output of the controller with my oscilloscope was that if I don't have a motor connected then the pulse isn't working, and I guess that's because the motor acts like a pull down resistor.
So the question is, since there will be some power on the output, what resistor should I use? or am I misunderstanding it completely? - Provided that this works as it should there is still one big thing missing as I understand it, that's some protection for when the circuit will short, so if the wire touches the workpiece I need to be sure that the complete circuit or PSU doesn't burn.
And on top of that I guess I the controlling software would need to know that this happened to so that it can stop moving, or back of a little.
Is there a good way to add this protection? - The last question, quite simply, am I forgetting something?