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Re: Powerstar W7 Inverter modification

PostPosted: Mon Jan 20, 2014 7:12 am
by brucedownunder
I'd like to buy the bigger ferrite core than I have . It's space for winding the wire on is only 55m ,,so 25mm square cable won't fit -and I'd reckon these things would crack if you try to force wire into them,?.

Where did you guys buy your "E" cores and what size ,please--maybe a link?

I've spent an hour searching the web --my head hurts ,lol.

Bruce

Re: Powerstar W7 Inverter modification

PostPosted: Mon Jan 20, 2014 8:36 am
by astro_optics
Hi brucedownunder,
you can try using two ferrites from old PC power supplies, the older the bigger, the better! I used two, one for each Low voltage leads going into the main toroids.
These are toroid not E-Cores, I tried them and they work fine on mine, with 9 loops of thick earth wire...still testing though, will vary the number of turns when I get time to see if any further improvement!
Need a better power meter to get some conclusive results, but it's indicating about 20W or a bit more on standby.

Re: Powerstar W7 Inverter modification

PostPosted: Mon Jan 20, 2014 11:09 am
by markhead
---COR ABOUT THE WHERE OF ECORES--- just ordered a couple of 65mm from Farnell/ Element 14 folk - they have what I hope will work and order code is 2103340 so just plonk that into the box and system will take you there instantly. No idea if it works or not but the shape looks ok and a 65x70 cube is hopefully correct. Cost is $11.69 +gst and freight $12.95 so best to buy 2 if you break one.Description of it is FERROXCUBE E65/32/27-3C90 and you can ring them on 1300 361 005. Cheers.

Re: Powerstar W7 Inverter modification

PostPosted: Mon Jan 20, 2014 11:30 am
by oztules
Bruce... something is not adding up.

My ecores are 65mmx65mm outside measurements.
The winding window is 45mm long x 12.7mm wide.... if yours is 55mm it's bigger again.
I used "medium size battery size cable".... ie 10mm diameter or ((10/2)^2)x3.1417.... or about 25x3=>75mmsq.

I can fit it in because I made a winding former from a block of wood the same size as the center leg of the ecore. Takes some grunting and bending and hammering to get it to shape, then slide it off and put in your ferrite.. so it is doable even in my 45X12.5mm window.

You can use any wire any size for testing, as your only going to pass small currents( a few amps..)... makes testing easier... then graduate to the thickest you can fit in there.... it only needs to be as thick as your transformer primary ( earth wire from memory), and you only need 3-4 turns.

You can fit that into a 55mm winding window with room to spare I would have thought.

However, if you want the same as mine then this is it.

http://www.ebay.com.au/itm/EE65-EE-Type ... 8c7&_uhb=1

I figure you will be scratching to use all of 30mm of your 55mm window with the earth wire you used for the winding.

It also depends on what your going to use the inverter for. If it suffers only short duty cycle high currents, then the earth wire will be enough.

If your going to use it for constant 4kw currents and above, you will need impressive batteries, and thicker wire.... 4kw is only 80 -90amps in a 48v system, so it's not really thick wire necessary.

For a 24v system, it gets serious quickly... hence the battery cable stuff I used for that coil.


.............oztules

Re: Powerstar W7 Inverter modification

PostPosted: Mon Jan 20, 2014 3:07 pm
by brucedownunder
Thanks John ,,,I made a mistake ,sorry about that --mine has a " window' of 38 x 38 with wire channels of 10mm, so it's maybe the former downsize from yours. Mine has an outside dimension of 55x55mm.

So, there ya go ,
Bruce makes another small mistake , but no worries,I'll get another ,,the kids inheritance suffers again..


Some nice replies from my post this morning ,thanks you very much fellows..

I have made the block of wood former up John,did that some weeks back,4 long tek screws and then hacksaw the drive heads off them and wrap some insulation tape around.

Thank you again John , I'll get there..

Bruce

Re: Powerstar W7 Inverter modification

PostPosted: Mon Jan 20, 2014 3:19 pm
by Warpspeed
Those E65/32/27 cores are made by both Philps (Europe) or TDK (Japan).
I believe the Farnell ones are Philips in 3C85 material if I remember correctly.

Re: Powerstar W7 Inverter modification

PostPosted: Mon Jan 20, 2014 3:37 pm
by beaujewel
oztules, I sent you an email, cheers.

Re: Powerstar W7 Inverter modification

PostPosted: Wed Jan 22, 2014 9:05 am
by angus1941
After reading the post from Oztules I bought a power jack lf 3000 12v for my campervan. I had a hf 2500w msw that was unreliable in starting the a/c and wouldn't run the induction hotplate. The power jack easily runs every thing, but with a standby current of 7.5-6 amps. A friend gave me a choke from a 150amp welder [ the hotplate draws 160 amps.] to try and on one winding it dropped to 2 amps, but on the other it was 0.6-1 amp.
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Re: Powerstar W7 Inverter modification

PostPosted: Wed Jan 22, 2014 9:22 am
by angus1941
sorry it should be 7.5-8 amps.

Re: Powerstar W7 Inverter modification

PostPosted: Fri Jan 24, 2014 4:16 pm
by beaujewel
I stumbled across another variation of this unit today. It has a solar regulator built in, avoiding the need for an external one.
Any thoughts?

http://www.ebay.com.au/itm/4-IN-1-OFF-G ... fde&_uhb=1