#garfield Logs

Feb 26 2025

12:03 AM rue_mohr: is there nobody awake to talk to?
12:17 AM rue_mohr: or alive
03:12 AM rifraf: wow i am glad you guys worked out the windings, i was a bit lost with the inductance stuff
03:16 AM rifraf: though all the windings i have done are most definatly done by Volts per Turn as rue said to calculate turns amount, then add a few extra and trim if required.
03:18 AM rifraf: best transformers lately are 3 turn, with 50mm² wire, in theory around 3 Volts but in reality about 0.2V at very high current, like 1400A plus
03:20 AM rifraf: standard 240V input, rewired secondary coils on microwave oven transformers, amazing what you can do with them
08:00 AM rue_mohr: rifraf, 0.2 when shorted?
08:01 AM rue_mohr: rifraf, microwave transformers have a magnetic shunt, which messes with the ratio at high loads, did you mean with the shunt in?
09:33 AM VanUnamed_ is now known as VanUnamed
10:23 AM aandrew: I wonder how hard this is going to go.... 120:600 is 1:5, 48:240 is 1:5, but that means that 120V, 130 turn winding is looking at 0.95V/turn and 48V is going to be 2.7V/turn so I'm definitely going to saturate way earlier but it might work from a demonstration perspective
10:23 AM aandrew: I wont' have a center tap on the 600V side but that's fine for a demo
01:58 PM rifraf: rue for making a spot welder, thats why basically shorted out, amps were measured with clamp meter so the voltage must have dropped quite a bit, what you thin?
02:12 PM rifraf: shunt rue? the additional metal plates between the 2 windings? they were removed
03:44 PM rifraf: gah, first time aliexpress has let me down in long long time
03:44 PM rifraf: 2 cylinders with identical markings, one is 32mm and other is 40mmm stroke
03:48 PM Tom_L: we all making welders now???
03:48 PM Tom_L: that kinda sucks
03:52 PM rifraf: https://desire3d.com/images/public/Cyl1.jpg https://desire3d.com/images/public/Cyl2.jpg
03:52 PM rifraf: https://desire3d.com/images/public/Cyl3.jpg
03:52 PM rifraf: nah i have make all my welders for a few years
03:52 PM aandrew: speaking of welders, just saw this come up. I know nothing about laser welders, not buying anything, just interesting: https://www.kickstarter.com/projects/16159264/xlaser-the-ultimate-4-in-1-laser-welding-revolution
03:53 PM rifraf: got Spot, CD Stuid, Mig and converted stick
03:53 PM rifraf: and gonna leard TIG at new job
03:54 PM rifraf: Tom_L they have assemble wrong parts for sylinder, or put the wrong sticker on, could not happen with genuine Festo, but hey, the price was right.
04:01 PM Tom_L: gonna use it or get another one?
04:02 PM rifraf: have ask them to send a new one
04:02 PM rifraf: still sleeping though
04:02 PM Tom_L: 8am there?
04:02 PM rifraf: they are always good with stuff like this, will get refund and buy new, or maybe they send another
04:02 PM rifraf: 8am in AU yes, but about 2am in china
04:02 PM Tom_L: right
04:03 PM Tom_L: the world should have been flat
04:03 PM rifraf: it is if you talk to the right people
04:03 PM Tom_L: how you likin the new compressor?
04:04 PM rifraf: yep lovin it
04:04 PM rifraf: is much quieter but still makes noise under load
04:04 PM Tom_L: not for continuous use...
04:04 PM rifraf: holds pressure for days though
04:05 PM rifraf: but got cylinders pumping this morn with valves
04:05 PM rifraf: off to real work now though, have a good day
04:05 PM rifraf: or night
04:06 PM Tom_L: later
07:13 PM rue_mohr: AANDREW!, !!!!
07:13 PM rue_mohr: no! your not getting it!
07:13 PM rue_mohr: ONLY wind that transformer to 0.95V/turn
07:14 PM rue_mohr: not 2.7V/turn
07:14 PM rue_mohr: 48V will be 51 turns
07:14 PM rue_mohr: STAY AT 0.95V PER TURN
07:33 PM rue_mohr: I'm tired so I'm going to pull a no-no and sleep
08:02 PM aandrew: rue_mohr: I am getting it
08:03 PM aandrew: I'm saying I cannot comply so I have to derate the transformer
08:03 PM aandrew: if I am pulling the transformer apart I will do it right, but since I'm using it as-is I have to derate it instead, at least for the demo
08:03 PM aandrew: rue_mohr> I'm tired so I'm going to pull a no-no and sleep
08:04 PM aandrew: that is what I did yesterday. Went to bed at like 6pm
10:22 PM * VanUnamed eyes at rue_mohr with suspicion for having ruined his dream of converting dril for cheap.