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Forum Index : Electronics : Inverter building using Wiseguys Power board and the Nano drive board
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| Solar Mike Guru  Joined: 08/02/2015 Location: New ZealandPosts: 1250 |
That looks great, big thermal mass to suck the heat out of your mosfets. You could almost get them drilled for water cooling, then all you need is a PC type water cooling pump and small radiator. Mike |
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KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 2245 |
Thanks, as a matter of interest, this Inverter was running at 1kW for 15 minutes with a thin 1 mm thick test Heat Bar, used for checking hole alignment and final sizing before getting a couple of 10 mm Bars made, and the thin sheet heat bars were still Cold. I no longer monitor Heat Sink over temps with the NANO, just the Toroids, as the HS never gets hot enough to warrant it, even when running above the Board Rated Power Level of 6kW per Power Board, or in my case, at 14kW for short periods in the Dual. NANO:Inverter V 8.4ks - Linux AvrDude GUI script V4.1 |
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| KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 2245 |
I tested a 3mm deep hole in the top of the HTB under the FETS, recessed screw through the bottom, and a nut on the top, the nut is pulled into the hole and held in firmly as the corners of the nut bight into the round hole, perfect. The recess hole is smaller than the blank plastic relief in the FET Heat tab, the Nut pull nicely below the surface of the Bar under the FET, clean, no ridges or high spots. Lay the Power Board over each HTB and it drops into place, put an insulating washer on the split LO side Bar screws and a Fibre or Metal washer over the HI side BAR screws, spin the nuts on and tighten, and there is a ton of clearance below the CAP boards, again off-the-shelf M3 nuts and bolts. When tightening the nuts, we are not so worried about over tightening onto a Silicon insulator, this is only true for what I call, "Live Bar mounting" of the FETs, IE the Drain connection to the FETs are connected to either +53v terminal (Long BAR), or TX1, TX2 terminals, Short (split) LO Side Bars, as no small single FET silicon insulators are used. When the bars are tightened down on to the Silicon insulation MAT on the Main Heat sink, the load is spread across a large area, 10mm thick 40mm wide Bars, and I have found that there is no need to reef down on those, it's not a small critical mechanical interface like the Heat tab of a FET, there is a lot of thermal mass protection in this configuration. So tomorrow I take these to the CNC guy and get the changes made for the final Heat Transfer Bars, I hope to include mounting for temperature sensors as well. Price should be way below the effort to do them manually, and it's so dam quick when everything just fits.  : Edited 2026-08-27 15:32 by KeepIS NANO:Inverter V 8.4ks - Linux AvrDude GUI script V4.1 |
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| Page 38 of 38 |
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