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Forum Index : Electronics : 6Kw Ozinverter build
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renewableMark Guru  Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
Hey Mad, I know you like the idea of the recycled wire twisted together. I'm wondering how much more room it will take up compared to battery cable. If it adds $130 odd for 8M of this and that fits in better I'de rather do that. Found this That looks better. Cheers Caveman Mark Off grid eastern Melb |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
According to this, 15 or 16 wires bundled together will fit through a hole that is 4.7 times the wire diameter. http://www.isgroup-international.com/pdfs/Wire_and_Cable_PDFs/wire_and_cable_technical_data.pdf Australian manufactured Tycab cable comes on a 70mm squared size that would be ideal. Two versions of the same cable. Double insulated welding cable (orange) that is a huge 17mm diameter. Tycab ZDU1221202. Single insulated (red or black) that is a much more reasonable 14mm diameter Tycab ZBD1221202 Its actually 10mm of copper with a 2mm plastic skin. This is obviously the same 70mm squared very fine stranded cable. Unfortunately the single insulated cable is only available on a 100 metre roll, so forget that. The welding cable is much more readily available cut by the metre, and you can slice off the outer orange skin leaving a white inner insulating layer that is very likely to be the same 14mm outside diameter as the single insulated cable. So with a bit of luck you might be just able to fit 15 or sixteen turns through a hole that is 4.7 x 14mm diameter (65.8mmm) Does that sound possible ? Cheers, Tony. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Mark, that second link for 70mm orange welding cable looks like the same stuff. Its expensive, so how about buying some 14mm diameter rope and see if it really fits, and you will then also know the exact length to buy. Cheers, Tony. |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
It looks like I have 83mm ID so far but need to do the final winding, (mylar is on already, so that should be fine. Cheers Caveman Mark Off grid eastern Melb |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
Good idea, 14mm rope will probably cost a bomb too, might take the roid to buggerings and do it there if they have some loose on a spool. Cheers Caveman Mark Off grid eastern Melb |
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Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
Mark first thing with that wire is it is on the small side, second how flexible is it? 70mm Welding wire would work out cheaper, I paid $100 for 9 M of 70mm. Any company that sells and services welders have it in stock, it has a tough orange layer on the outside and a soft silicon layer under that. You strip off the orange layer and you are left with a very soft and a extremely flexible cable with thousands of very fine wire in it. You will need at least 10m I think, better to buy a bit extra than too little, you also need to allow for at least one end to reach to the heatsink. Don't forget Lugs while you are at it, you could probably take it back to the welder people to crimp them on for you. Late last year I bought a hydraulic crimper on Ebay . The welding cable will squash flatter very easily too, so you can get more turns in than you would with anything else. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
WoooHoooo its going to fit !!! You will need to skin that cable first, but thats pretty easy. Other people here have already done that. That welding cable is heavy, but its very flexible. We double posted. Cheers, Tony. |
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| Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
If you are using 14mm wire you need to reduce that diameter by half the cable thickness on each side as that is the point that they touch each other. But yes it will fit with 1.5mm between each wire. If you are feeling adventurous you could try winding up recycled wire first and keep the hundred dollars for beer. Maybe warp has already posted the same, unless he is out looking at the moon and feeling strange urges. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
Better get some of this while your at it.  There are only 10 types of people in the world: those who understand binary, and those who don't. |
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oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
While it may be harder to do, I have found the recycled wire stays cooler than the welding wire. May be that the multi insulated wire has a lessor problem with skin penetration, or that it has better cooling because of less insulating skin, but it seems to never get very warm in my experience since Mad showed the way. It is a bitch to wind, but I think it is worth it, and the last 5 or 6 I have done, I have done this way.... sounds silly, but I think those ones are also the quietest ones too.... no idea why... at all. As you intimated, you only need do this once, so cost is not the issue... but I think it is better somehow. The links are a relic of the original design which was single sided. Both Clock and I have left the silk screen for legacy more than anything else I guess. In my bathtub built boards ( single sided of course), I used 0r resistors... but you should need nothing at all. .........oztules Village idiot...or... just another hack out of his depth |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
toroid mate, well actually it's a transformer, or will be when the primary goes on. The final wind should only drop the ID to just under 80mm as long as none have to overlap, I'll just have to be super vigilant to have it as tight and snug as possible. Cheers Caveman Mark Off grid eastern Melb |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
My friends at the lunatic asylum recommend basket weaving as being good therapy. Those of us that have developed a toroid fetish know real bliss. Cheers, Tony. |
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| Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
Don't know that toroids are good therapy, they lure you in like Sirens calling sailors and never let you go. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
You could be right about skin effect causing excessive heating in the primary. That would certainly do it. That will only occur if there is very significant high frequency ripple current at the PWM switching frequency reaching the transformer. If a non saturating series choke is working properly, there should be an almost clean 50Hz sine wave current with no higher frequencies present on the primary. I have no idea about the noises, unless its magnetostriction which can produce an audiable hum from the core at higher flux densities. If the windings are vibrating, it should be possible to feel that. Cheers, Tony. |
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Clockmanfr Guru Joined: 23/10/2015 Location: FrancePosts: 429 |
Mark, All links on the PCB's are already connected on the other side, all supplied PCB's are double sided. However, there are some serious nutters around the World who like to etch there own single sided PCB's, so I left the links showing on the silk screen. Hmmmm will probably remove the printing links on the commercially made boards such as yours. Note to self, must make a Note of this in the New book. Everything is possible, just give me time. 3 HughP's 3.7m Wind T's (14 years). 5kW PV on 3 Trackers, (10 yrs). 21kW PV AC coupled SH GTI's. OzInverter created Grid. 1300ah 48v. |
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| Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
Some of us etch double sided too, I must be a real nutter. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| Clockmanfr Guru Joined: 23/10/2015 Location: FrancePosts: 429 |
Mark just make it tidy in the centre of the toroid, and do ensure you can get s decent holding bolt through the centre that clamps the toroid down. Do not clamp the top of the holding bolt to the box/case, just use a nut and big washer with rubber insulator top and bottom to protect the Primary cable.   The below is a 6kW OzInverter toroid all fastened down  Here is some recent photos of a big OzInverter toroid base plate, bolt is 12mm diameter, for the 6kW OzInverter I normally use a 10mm diameter bolt. That's a blowing in 120mm fan.  I use fine stainless steel insect mesh, silicone glued to the inside, then the fan is bolted up.  As my Big OzInverters uses a single 75mm/2 primary cable of 10 turns, then there is a good cable gap for air to blow through and up the centre of the toroid. On paper it fits, but as you can see in the earlier photo, in reality things get messy.  Everything is possible, just give me time. 3 HughP's 3.7m Wind T's (14 years). 5kW PV on 3 Trackers, (10 yrs). 21kW PV AC coupled SH GTI's. OzInverter created Grid. 1300ah 48v. |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
Thanks Clockman, those link lines confused me, now you've explained it that makes sense. I'll need a different choke then if using 70mm. Cheers Caveman Mark Off grid eastern Melb |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I tried drawing it up twice normal size. Hole is drawn 160mm, and wires drawn around the outside of a 30mm washer. Fifteen turns are going to fit in there quite easily.  Cheers, Tony. |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
Thanks Warp, if the 4th wind goes on neatly it should be fine. If it has to overlap then I'm screwed. Cheers Caveman Mark Off grid eastern Melb |
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