Welcome to the Open Hardware Plasma Cutter project. The goal is to eventually design an inverter based plasma cutter power supply capable of being used on...
For the first design, I was thinking a power supply close to this: 5-20 amps at 90 vdc closed circuit 270-330 open circuit volts 120 at ~30 amps apparent or...
It's very crude, ie no component values, but it gives you an idea what the project will eventually become. It's under files/schematics/ Suggestions?...
Hi, this is a great project. I had been looking into building an inverter type welder myself. Sadly I don't have a background in electronics. My understanding...
There are various different cores that will work, mainly powdered ferrites or ceramics. The characteristics for a high frequency transformer are very...
... If possible, I would like to see the voltage directly from the secondary, with no load and cutting load. I would also like some pictures of the inside,...
The schematic is very incomplete and it wont function, at least not as a plasma cutter. There is no current inrush limitiation on the line side. This is often...
... Well, it is an early version. I'm still considering wether to use a triac or a relay for the inrush limiting resistor. Triacs are close to the price of...
I just reviewed the posts and looked over the schematic, and have to say "you guys are NUTS!" (but maybe I am too ;-) Jerry Biehler is right when he says that...
... I wouldn't consider labor a cost because this is a hobby/educational project. Also, being a very low production run (ie. 1), surplus parts can be used...
After calculating the delta I(inductor) for a forward converter, I've decided to switch to a full bridge topology. Although this introduces transient...
Have you thought about using a furnace ignitor as the source? They have built-in sensors and such. Of course, they may not handle being hooked up next to the...
... I'm not an EE so no real comments on the circuit. I wonder though, would it be useful to have a general discussion about how plasma cutters work in...
... about how ... metal ... The electrode in a plasma torch is actually inside the torch itself (negative). The metal cup on the outside is the HF/HV...
Since you went to all the work to post your schematic, I'm guessing that you wouldn't mind some contstructive comments. First of all, I'm glad you decided...
... Of course not. Actually, I was hoping for feedback on the design. ... Curiously enough, the Lincoln and the Harbor Freight both use dual transistor...
Includes MOSFET snubber and gate drive transformer, nothing on page 3 yet (GDT drive). Changes: Relay instead of SCR for inrush current limiting Fixes: P...
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the ohpc group. File : /schematics/v1.1 ...
ohpc@yahoogroups.com
Mar 20, 2006 4:59 am
25
The baby went to bed early tonight so I actually had a few minutes to get online! I see that you are starting to think about driving your MOSFETS! Have you...
... Not yet, although I hoped we could get by using a surplus MOSFET, but I will start to look soon (starting with your recommendations). The nice thing with...
... Alright, Of the three MOSFET's you suggested, the second (IRFP31N50L) looked most suitable. The first was lacking as far as current and thermal ...
Started work on the controller, values for R_LEB, R_DPRG, and R_SLOPE still need to be calculated Changes: Shunt for current sensing instead of hall effect...
Have you looked at using a high side gate drive IC (IR2113 $2.86). You don't have the issues with flux walk using a gate drive IC. I don't see anything at the...
... You don't have the issues with flux walk using a gate drive IC. ... Always thought it was more trouble than it was worth (high side gate drives)....
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