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Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1631

Posted: 07:55am 06 Dec 2025

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Went upto Rogers after work today and what a learning experience it was helping solder on the wire to the board

So VS1 & VS2 now have 50sqmm wire on each pad and had enough length off the toroid wire for the battery connect so 65sqmm

So the 50sqmm wire for VS1 & Vs2 will be bent down to attach to each choke, now we did measure the inductance using Rogers meter and both chokes came in a 24uH within a point of each other so good to see they are matched.

Now I did mention about charging the caps before turn on and suggested the battery connect would do it and got told well the inrush of current to charge the caps will show the fireworks

and a bleed resistor is required to limit the current on the positive rail to charge the caps. So lesson learned and that is one thing I never read in all the reading on this inverter.

So one step closer.

Regards Bryan

Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1631

Posted: 06:54am 10 Dec 2025

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Well in my gear I did find 3 off 40 watt 200ohm resistors that all measure within 3 ohms so I could use one of them to slowly charge the caps before the first turn on.

Now for members that have build this inverter how did you guy's go about charging the caps

Regards Bryan

Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1631

Posted: 09:02am 17 Jan 2026

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G'Day Guy's,
Well finally had an afternoon to work on this inverter after work today and after installing the fan got the box in it's new home and got the Anderson Connector all done

So getting closer...

Cheers Bryan

rogerdw
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Joined: 22/10/2019
Location: Australia
Posts: 952

Posted: 09:29am 17 Jan 2026

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That's looking good Bryan, definitely getting closer.

Cheers, Roger

Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1631

Posted: 08:04am 18 Jan 2026

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Well got a bit more done today and it was taking 3 steps forward and one step back

Found some old terminal block so cut it in half and screwed them onto the perspex plate only to find one of the closures was buggered

So that idea is going to be scrapped and I'll machine up some new terminal blocks.

Then got onto the finish soldering the brain board and soldered up the lcd board where silly me didn't see the front holes on the nano aren't used and lost a couple of pads desoldering.

So went and grabbed another Nano and soldered everything in properly and found out the hard way where last time I had to use my good laptop to program the nanos last time as both the linux and my shed computer wouldn't program the Nano.

I will get more done thru the week and hopefully next weekend it will be finished then the fun can start and see if it will power my mig welder.

Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1631

Posted: 07:21am 25 Jan 2026

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Well as it cooled down had a day in the shed and this inverter is 95% done

Now call this timing from Poida or what as I do still need to wire up VFB and didn't even think about the stepdown transformer so I am glad this came out

Now a few years I did get a stepdown transformer and it's sat on my computer desk in the house for years but should fit the bill

Found some 3mm long threaded bolts and the nuts to suit but the thread isn't 3mm more likely a BA size. so with some 6mm perspex mounted to the din rail the lcd can be mounted.

So just got the AC side to sort out, VFB and the on/off switch. Also still got to tension all the bolts and insulate them with that yellow tape.

ON talking with Roger about charging the caps before turn on I do have 3 40 watt 200 ohm resistors

So by wiring them in parallel got the ohm's down to around 60 off memory which will limit the inrush current to 300mA which should suit the task I did solder the rear battery pads with some wires to bring the battery voltage for the 15 DC stepdown board so I'm thing take a rail off that to charge the caps from my shed battery and when the battery voltage is reached connect the anderson connector and turn the inverter on.

Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1631

Posted: 10:49pm 25 Jan 2026

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Well got a couple of hours before it heats up today and got the datasheet for that myrra transformer

Now off memory the grey cells are starting to return and on the AC output shouldn't 5uf be put across the output ?

I do need to make up a pcb for the transformer which can also mount the AC output via those 4mm pcb ones I have here and that 5uf cap once I find one can go on the board too.

So it got to 47C in my shed today and all I'm missing is that 5uf capacitor now if I may ask Roger as he has helped in this build to come over and have a look at my work so we can start this inverter and just let it go for many years.

The only thing I need to change to goto 48 volts is the 15 volt step down converter to suit 48 volts but at 5K for a 24 volt 1,000AH hour battery one will do for now.

Now this inverter will power my shearing shed so I can finally get over the line to distilling and making a product every likes
Edited 2026-01-26 17:24 by Bryan1

Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1631

Posted: 04:58am 30 Jan 2026

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Well working on the inverter last night I did notice I had the Anderson connector upside down and I am glad I found it, anyway turning it around and clamping it back didn't take long.

So got onto finishing the AC board and got mounted then got onto the AC wires and for the wire just stripped a couple of metres of 3 phase 32 amp wire I had here and with one lead from the toroid it went thru the hole of this energy meter then back to the AC board.

A few little jobs left like make the wires for the VFB connection and fix the temp sensor wire on the toroid as it did pull out when I was tensioning the connections. Also got the earth to sort out.

So tomorrow will be the big day to see if my hard work has paid off

Now don't know why Aussie post has become snail mail as had one Ali package sitting at Adelaide airport since Last Saturday and that SSD 128gig HD coming from Brisbane from Umart is still there after 4 days.

Cheers Bryan
Edited 2026-01-30 15:24 by Bryan1

Godoh
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Joined: 26/09/2020
Location: Australia
Posts: 607

Posted: 12:28am 31 Jan 2026

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Good luck with the switch on and testing.
This has been a long project I hope it works first time and no smoke gets out
Pete

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