Search found 64 matches

by sparks
Mon Apr 18, 2005 4:46 am
Forum: Tools and Construction
Topic: 3 To 1 Phase
Replies: 11
Views: 5911

re: 3 To 1 Phase

Now that would be cheating, wouldn´t it? Besides, theres not much point in using an electric motor driving the 3-phase alternator, rectify, chop it up to AC again and via a transformer get the volts´n amps at suitable freq. There is a pricetag on high amp. HF switching components that makes it les...
by sparks
Sat Dec 25, 2004 5:59 pm
Forum: Tools and Construction
Topic: 3 To 1 Phase
Replies: 11
Views: 5911

Re: 3 To 1 Phase

A friend who welds al-alloys every day for a living is visiting over x-mas, maybe something useful may come out of our late night brainstorms.
At least he can add some do&dont´s when i comes to al-welding.
by sparks
Tue Nov 30, 2004 12:55 pm
Forum: Tools and Construction
Topic: 3 To 1 Phase
Replies: 11
Views: 5911

Re: 3 To 1 Phase

Actually, when it comes to DC welding with car alternators the best thing to do is to deltaconfigure the windings for max current capacity and replace the rectifier with external diodes capable of handling both the current and the higher OCV. However, the question was how to get 1-phase AC (needed f...
by sparks
Thu Nov 11, 2004 3:31 am
Forum: Tools and Construction
Topic: 3 To 1 Phase
Replies: 11
Views: 5911

Re: 3 To 1 Phase

In this case the point was to get one-phase ac from a 3-phase alternator to use for welding. As long as its dc-welding theres no problem, but if ac is required (Al) one has to find a way to distribute the load over all 3 phases. This way to solve the problem adds alot of weight to the alternatorweld...
by sparks
Sat Aug 14, 2004 11:43 am
Forum: Tools and Construction
Topic: 3 To 1 Phase
Replies: 11
Views: 5911

3 To 1 Phase

I finally found some of my papers about phase conversion. Maybe someone has already written about it, but heres what i found. It's easy to get fooled by the magnetic flows i a 3-phase transformer. Actually it works just like 3 separate transformers, one for each phase. It's ok to make a 3-phase tran...
by sparks
Wed Aug 04, 2004 2:48 am
Forum: Valved pulsejet forum
Topic: Metals
Replies: 9
Views: 3446

One of the "start-kabooms" my little engine makes would crack just about anything.
I even thought my bedroomwindow was in danger when i first started it 4 meters away.
But i may consider cheramic coating on some hot-spots.
by sparks
Wed May 19, 2004 4:08 am
Forum: Tools and Construction
Topic: painting pulse jet
Replies: 9
Views: 3734

Something tells me you have not realised the unexpected things plain one-colour anodizing may have to surprise you when you think things are OK ;-)
But it's fun to anodize, thats for sure.
Sometimes it even looks nice too.
by sparks
Wed May 19, 2004 3:49 am
Forum: Tools and Construction
Topic: just kidding,but i have a serious question bout anodizing
Replies: 6
Views: 2774

Another name and a regulated powersupply will make things easier.
by sparks
Wed May 19, 2004 3:31 am
Forum: Valved pulsejet forum
Topic: fuel pump info needed
Replies: 2
Views: 2170

Oilburnerpump?
It can give you all the pressure you will ever need.
by sparks
Wed May 12, 2004 11:44 am
Forum: Valved pulsejet forum
Topic: My 35 kg trust pulsejet
Replies: 1
Views: 1809

I have found the location of the sparkplug to be critical sometimes due to variations in fuel/air mixing at different points in the engine. Now i use "sparkprobes" when testing and it makes it very easy to find the right place for the sparkplug. However, none of my probes have survived for any lengt...
by sparks
Tue May 04, 2004 6:22 am
Forum: Tools and Construction
Topic: Homemade TIG Welder
Replies: 19
Views: 34173

I'm pretty sure the answer is hidden somewhere in the forum-archives at www.diywelder.com But i haven't had the time to read it all.
by sparks
Tue May 04, 2004 6:18 am
Forum: Valved pulsejet forum
Topic: Pulsed Outboard Motor?
Replies: 42
Views: 18169

Actually not entirely fruitless. The pat. appl. number on the picture did lead to som documents in one of the searchable patent archives (cant remember the url, but i may still have it somewhere) . Unfortunately they were in some special-TIFF format requiring a viewer that for some reason didn't ins...
by sparks
Tue May 04, 2004 2:53 am
Forum: Valved pulsejet forum
Topic: Pulsed Outboard Motor?
Replies: 42
Views: 18169

Bruno, do you have any ideas where i could find more about the McCOLLUM monster?
My websearches have been fruitless.
Did it ever get out on the market.
If it was just a "brainfart", it sure was a most beatiful one!
by sparks
Tue May 04, 2004 2:34 am
Forum: Tools and Construction
Topic: Homemade TIG Welder
Replies: 19
Views: 34173

I´m afraid i dont have any news more than a short note about 3 to 1 phase transformers. I asked a friend who went to the same school as i did years ago and he remembered the same thing. Anyway, a deepdive into his piles of books gave nothing. There is one more person i can think of that could have ...
by sparks
Wed Apr 14, 2004 2:47 am
Forum: Valveless pulsejet forum
Topic: Test run with an Audience
Replies: 2
Views: 1996

Good luck !
I'm sure you will get the attention from even the most uninterrested in the audience.
I know everyone who for the first time really feels a sound (cutting through their bones and brains ;-)) will remember it for quite some time.
That's one of the things that make pulsejets so special.