These things take time and lots of work so don't expect to see it before the end of this year.
ROGER CARR
Monday, February 14, 2011
Pulse Arc Update
My function generator which came a long way with me went up in a plume of smoke. I had to replace it and bought a Rigol DG1022. It's a nice generator but pricey. I am going to use this generator to play with different waves to see if I can get the correct waveforms for the pulse arc welder. I am thinking of designing a new board from scratch, its already halfway drawn on a piece of paper :). The Budget is also a little low on funds and I will start to buy components as soon as possible. This welder will use much smaller and easy to get capacitors.
These things take time and lots of work so don't expect to see it before the end of this year.
ROGER CARR LET ME KNOW THAT FUTURE ELECTRONICS SELLS THE IRFP2907PBF MOSFETS FOR $3.60, THANKS ROGER.UPDATE: FUTURE ELECTRONICS CHANGED THEIR PRICE TO $6.00.....DO NOT BUY FROM THEM!!!!
These things take time and lots of work so don't expect to see it before the end of this year.
ROGER CARR
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The new Rigol function generator you got is half the price of a comparable Agilent unit. Rigol makes some pretty good stuff.
ReplyDeleteGreat tip on the MOSFETS! Roger is a friend of mine.
Thanks again for sharing such an awesome project!
RL
I wonder if they raised their prices because of the earthquake in Japan?
ReplyDeleteThe last time I checked, they had between 2500 and 3000 in stock. They were $3.00 when I started this project and shot up in price because of greediness.
ReplyDeleteNewark has them for $4.92 each as long as you buy more than ten. They drop to $3.92 in quantities above 100. If several people go in on an order of these MOSFETS, they can take advantage of the quantity discount.
ReplyDeleteHello!
ReplyDeletesorry for poor English, I use Automatic translator for Google.
looked at with interest your progress.
You - well done!
which results in welding of gold?
Did I try?
at work I use PUK, really want to own the same, but expensive.
began to do only the capacitor model, but realized that this is not enough to control the shape and length of pulses
if I can design an analog PUK?
can show the picture?
using argon?
Yours sincerely,
Michael.
Michael,I have not tested it on gold yet. I don't know if you mean "I" or "you" but if you designed one you can send it to my email sprbok@gmail.com. If you have information about the pulses they use, I will appreciate some information.
ReplyDeletesorry, no information about the characteristics of the pulse.
ReplyDeletePUK new, under warranty, sealed.
opening is not possible.
We use argon. with welding result is better.
less gas in the weld
to design your solenoid thought that argon can be used?
How about using IRFP3077PBF as a substitute or even IRFP4368PBF. The former looks a close substitute. The latter, per IR, is an upgrade with a higher current rating and lower Rds (1.85mOhms vs 4.5 mOhoms). Would it be practical to use 10 in parallel and reduce the cost some? The overall resistance would be comparable and current handling slightly reduces (3500A vs 3800A by my quick calcs)
ReplyDeleteAnd it looks like these parts are more readily available.
The IRFP4368PBF will definitely work. Its a little more expensive and will cost about the same for 10. Installing 10 will make life a little easier. I'm not so sure about the IRFP3077PBF though. It will not work in the charging circuit for this welder.
ReplyDeleteWhat would be a problem with using a "hybrid" capacitor. I tried a Legacy 3.0 Farad and an Absolute 3.5 Farad but both measured below 0.65 Farad. A Boss 3.5 Farad measured less than 0.1 Farad and was 4" in diameter. Hybrid capacitors are smaller and my welder has a 3" thickness or diameter limit. If a hybrid cap managed to measure 5, 6 or 8 Farad, what would be the adverse impact on the welder. Blown mosfets maybe? Last resort is a complete remounting of the internal components to accomodate a larger physical diameter cap, assuming I can find a true 3 Farad the welder was designed for.
ReplyDeleteHuntersplace