Guru
Joined: 13/10/2014
Location: AustraliaPosts: 1860
| Posted: 04:17am 04 Aug 2024 |
I was going to start building the toroid cases first, so glad I didn't, instead I built a 5 wheel Base that will support the cases that make up the inverter.
The frame is built with 90mm x 35mm pine, has three internal braces using the same timber, supporting the toroids on each side of the base, the top and bottom covers are 7mm ply.
I incorporated 2 x 100mm 240vac fans in the base, one for each toriod transformer.
The two fans are sandwiched between very thick dense rubber blocks that have some weight to them, but very springy texture, don't know what it is, but I removed them from some 12v LifePO4 battery boxes, they supported 4 heavy 3,2v cells on all sides.
The two 240v fans are wired in series when the temperature relay not energized, and they are absolutely silent - seriously silent when mounted between rubber blocks like this. In series, these fans exaggerate the natural convection air flow through and around the toriods, when Inverter AC is on, these fans run silently all the time.
I have found after a year and more of running a similar air flow setup on the existing single toroid, having this exaggerated convection air flow around and through the Toroid at all times makes an amazing difference to long term toroid running temperatures.
When the Nano controller Toroid temperature control kicks in, it enables a 12v 0.8W relay in the Base housing, this relay switches the Two fans from series to parallel connected for toroid cooling, and once again, the lack of any bearing or AC motor noise through the case is amazing. Once the toroids are mounted and the toriod cover is fitted, I doubt I will even hear this very high Air flow.
The light weight five wheel Base fully supports two x 3 stacked toriod transformers and 4 chokes, the fifth wheel means it will never sag, it supports two of us standing on it with ease, and I can lift it easily with one hand.
My plan to build two toroid cases has changed, now just a single removable cover over the two toroidal transformers and four 6 stack toriod ring chokes, these simply sit on the base, and no, they do not and can not move, no mounting hardware needed except for a simple mount for each choke.
Like most of us, I'm sure the plans will change slightly as the build continues.
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Edit - a five wheel base, not six
Edited 2024-08-05 17:59 by KeepIS