Author Topic: testing the egs002 inverter board  (Read 147618 times)

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Offline oztules

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Re: testing the egs002 inverter board
« Reply #15 on: March 13, 2016, 05:30:11 am »
Efficiency is the problem with those kinds of efforts.

I have found a better way... not what I wanted to do... but the animal in me got out.... ( and I was lazy and could not be bothered with jamming in an scr to shut it off on overload..... other wise it retries too fast using the temp contact without a latch)

Here is the relevant picture. ( click to see properly )

5220-0

I got the razor blade out and removed the 393... shorted pins 7 to 8 and then made a jumper from 1 to 4.
This gets the inhibit pins of both the drivers and the main chip to turn off (/ or on depending how you want to  say it I guess) ... unequivocally.... ie they no longer get to inhibit anymore.

Then use the current IFB input as designed. It then behaves with no problems.
I cant understand why they used the 393 in the first place, unless the IFB signal from their resistive sense was too small, but they needed to get the timing correct so that the IFB pin on the main ship got the message first, but that is not the case. They decided to inhibit in three places at the same time..... and failed miserably. Not noticed with EI transformers ( but for odd noises), but lethal for torroids..... now it is fine, and I can use the current o/load in the chip to do the stop... test.... stop ... test etc, then turn off needing hard start.

The current transformer ( CT) has plenty of output, and needs attenuation and a small filter to behave nicely.
This is using the board at the start of this thread.

I still prefer the temp TFB pin for on  and off at this stage.

Now it seems I can try all I might, but cannot fool it into blowing the fets.... up to 2.5kw at least.

2kw ( 2 fets/leg) and it runs for quite a while before it starts to warm up much at all ( 10 mins), and thats with no other cooling... very useable now.

Will still make the new board when I get to it, just so I can go full power to 8kw or more.... we'll see when I get some time.

Will post some pics when I can get the camera to talk to the computer again...... something squiffy at the present time.

It does look like a very simple and cheap way of getting a very solid little  inverter.... for pennies really.

This is the first draft of  what the board will look like not using the pre-made board, but with the three isolated supplies, opto's and chip... still have to put on the CT and voltage feedback stuff..... should fit......

[ Specified attachment is not available ]



................oztules
Flinders Island...... Australia

Offline ClockmanFrance

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Re: testing the egs002 inverter board
« Reply #16 on: March 13, 2016, 01:56:48 pm »
Looking good 'oztules', looking good!......... I do love the way you logically charge in with scalpel in hand, so to speak.....

ooohhhh,.......... Joined Aliexpress today ........... got some of those 8010 32pin SMD chips heading this way.  Now this will get interesting.

Offline RFburns

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Re: testing the egs002 inverter board
« Reply #17 on: March 13, 2016, 02:29:00 pm »
Nice work Oz  :) .Be interested to see how much load you can get out of the standard commercial board drivers but 2-3kw is pretty good (but 5-8Kw would be the ducks!) for the price $8-10 Aus an old Aerosharp transformer.
Get With It ,Get Over It , Get On With It ...Or Leave

Cheap and reliable wont be fast.
Cheap and fast wont be reliable.
Reliable and fast wont be cheap.

Offline oztules

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Re: testing the egs002 inverter board
« Reply #18 on: March 13, 2016, 03:37:00 pm »
RF.. will try three fets today perhaps, and see how they fare...... I may be selling them short, but it does not feel like 8kw is possible for long with the standard board drivers..... and I don't get excited about driver chips either..... just a hangover from bad experiences with them.

Frackers, those DCDC converters look good... not the dual output ones though... they share a common.
Also, when you see how simple a roll your own pwm solution is, you will want to use that instead.

Clockman, it is looking like a simple new board and a tranny and output card will do what we have already..... few hundred dollars less.

...........oztules
Flinders Island...... Australia

Offline oztules

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Re: testing the egs002 inverter board
« Reply #19 on: March 14, 2016, 12:24:58 am »
Well, the sad news is...... that I have proved myself totally wrong.

After messing about all day using different numbers of fets etc.... I am back to where i started, but with 24 fets running from the driver chips....... and the problem is... they are running really very very well..

In fact after running 30 mins at 2400 watts, the heat sinks were between stone cold, and less than skin temp.... there was some air movement inside the shed...... but gee it was impressive.

So I looks like I may not have to build the new boards after all.
After cutting out the 393, and making only 1 chip responsible for shutting things down, the results are rather stunning... and shot fets are a thing of the past... tried everything I can, but no faulting.... and yes the current limiter works fine too now.

With 3 fets, it was no problem to get 4400watts out of it starting a air compressor with a  fairly full tank....ie used 18-19 amps( @240v) in start, and settled back to 6-7 amps running ( 2hp el cheapo motor ).. I was impressed...... no voltage sag at all that the meter registered , then hooked up the house to it........ running 1 huge fridge, one 700 liter freezer, water pump ( 1hp) 2000w microwave oven for 2 min at the same time, and 2 televisions and wall warts......and computers....darn impressive.

With 6 fets, the drivers still kept the wave form fairly good, and heat was not prevalent at all..... less than the PJ in fact for the same loads.. so all the things I did and said about these drivers is mute and wrong..... it was the wrong resistors on the gate that caused the problems.

It looks as if I need not make the new board, as it seems to be hard to better the current situation.

More solid testing is needed, and the 290 amp old style welder should feature in this, as that stops most inverters ( and 13hp honda generators can't run it when you pull the trigger either). If it can pull that off while running the house loads, then it will be as good as the PJ, and if it does it with even less heat... then better.

So we need 1 small board, one modified egs002 board, one monster transformer...1 fet board........ and we have a very very competitive unit.
Will get the pics out of the camera somehow soon.

One really wonder at how some of the manufacturers justify their pricing... they really would struggle to beat these things from the looks of it.

Questions and comments??

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

Flinders Island...... Australia

Offline RFburns

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Re: testing the egs002 inverter board
« Reply #20 on: March 14, 2016, 01:05:11 am »
Oz..
Wow that’s pretty impressive  8) and certainly looks like they are easily worth the $8-9 Aus . I look forward to the welder test  :)
Its always nice to be wrong in the right way.
Get With It ,Get Over It , Get On With It ...Or Leave

Cheap and reliable wont be fast.
Cheap and fast wont be reliable.
Reliable and fast wont be cheap.

Offline oztules

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Re: testing the egs002 inverter board
« Reply #21 on: March 14, 2016, 02:32:58 am »
Yes, impressive is the word.
Used the big mig on setting 6 .. range 2 high set..... maximum current was in the 25-30 amp@240v range..... stable voltage on the DVM.... cro might be more interesting.... but not much to see I suspect.... recovery in less than .05 seconds or more.

So it ran at 30x240= 7000w or more...... intermittent usage, so can probably do it all day... a long weld would have blown the 68A circuit breaker I was using for protection. In the 1/2 second mode, it would probably take 150-200 amps before letting go.

I was fixing a big cryovac machine for folks over here, and tested it on that. With cold oil, and first turn on for the day, the digital peak amp meter went off the 40a scale, then settled back at 8 amps.... so start up cold oil is in the  40X240=9600 watts... must have lasted for 1/4 to 1/2 a second I guess, as the machine had no hesitation in any way to fie up.... damn impressive stuff.... and it looks so childish too.

The weakest link at the moment is the single  big torroid, it would be happy at 3kw all day, but not for long periods above that.
I am starting to get comfortable with it now... no fets blowing, and this time I am trying..... impressed.... yes.

Camera has died completely... dammit it had some good pics too.

Clockman/frackers... may be time to get ready to do some boards............. the fet board of the 10kw unit will be the one to copy I think.... big resistors and no messing with sub boards.


.................oztules
Flinders Island...... Australia

Offline ClockmanFrance

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Re: testing the egs002 inverter board
« Reply #22 on: March 14, 2016, 03:05:58 am »
"So we need 1 small board, one modified egs002 board, one monster transformer...1 fet board........ and we have a very very competitive unit."

My hat is duly raised.

I will be interested in how you lay the big FET Power board out.
I like the simple way the PJ board is designed, but would really like to get rid of all that excess solder everywhere, perhaps some simple straps soldered on?

Same with the AC connections bit on the control card.

Perhaps I am leaping ahead a bit too quick. ?

Hi Oztules........Photo....... The PJ 10kW board, which I am about to add those 2 new caps.

The Old PJ 2013, 10kW Power board, single main double sided board at 278mm long by 172mm wide, standard solder resistors, 0.5w 20k and 47r. 24off MOSFETS 4310. 6 centre positioned can capacitors 10000uf 80v, 60mm high by 35mm dia. Heat sinks 80mm x 25mm 12 fin, max length 268mm and the other for the Toroid Primary is split into 2 half’s.

I would be happy to take this apart and have re-made. Might open the tracks and beef up in a few places?
 As I said the Caps at those dims are now classed as 100v, the heatsinks are a pain they do not seem to be a stock size and there electrical connection to the board needs some looking into.    But now I have AliExpress..........

Offline ClockmanFrance

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Re: testing the egs002 inverter board
« Reply #23 on: March 14, 2016, 03:10:45 am »
If its allright with you 'oztules' I will fit your new & modified boards to my New BigOzinverter 38kg torroid.

I do have a PJ 15kW set ready, but I am always up for a challenge.

Photo......Underside of the PJ 10kW Power Board

Offline frackers

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Re: testing the egs002 inverter board
« Reply #24 on: March 14, 2016, 03:34:30 am »
According to NZ Post they have left the country of origin - been at that status for the last week :(
Robin Down Under (or are you Up Over!)

Offline oztules

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Re: testing the egs002 inverter board
« Reply #25 on: March 14, 2016, 03:49:31 am »
Yep, those are the boards I referred to..... I would use the same layout, but with slightly bigger tracks, and more room between the fet pads ... I think they are a bit close for comfort.

Other than that they are sensibly layed out... I like them, heavier copper or more solder would be all you can do really..... they seem to work just fine when you think about it.

I will tidy up the board and endeavour to give you as much information as I can so you can emulate it if you wish.

Tomorrow will give it a big run at 2.5kw element and 1.5kw element. It has no cooling at the present, but there was air movement today in the shed, and that must have contributed to the cold heat sinks.... 4kw should warm them up surely..... the transformer will at that rate, as I used thinner wire than normal for the primary... it was just a quick test... thats my excuse at the moment anyway.

They do look promising I must say..... have to think what else I must add to the board before the next one.

Still have to find a idiot proof way of shutdown and start up without relying on the temp input... haven't even bothered to look really yet.

When it is pulling 3-4kw, you feel a bit queezy the first time you interrupt it.. but the temp terminal does it well.

I do think it is worth a shot anyway Clockman.


.... all because the sma wouldn't play properly.........you have really suffered for it.



................oztules
Flinders Island...... Australia

Offline ClockmanFrance

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Re: testing the egs002 inverter board
« Reply #26 on: March 14, 2016, 04:22:38 am »
"I will tidy up the board and endeavour to give you as much information as I can so you can emulate it if you wish".

Yes Please.

PCB layout and making, gosh back to school for me again, all my old PCB stuff/ programs was DOS, late 1980's, pushed into windows shell.
So I have to start again, new tanks, new chems, new masks, new blank boards etc, hmm........  or do I just send a scan of each side, modified/altered on the PC and send the real size scans away to someone,  just fits on a sheet of A4 paper, to be PCB ed?

".... all because the sma wouldn't play properly.........you have really suffered for it."

'oztules' you gave me that extra knowledge and confidence to do my own Inverter that puts SMA to shame. Thanks!
Although, after promising, they still have not put the cash into my Bank account, Trading Standards folk still on them.

If you like I can start a new Topic on this forum about the BigOzInverter Build once I get those EGS002 boards.




Offline oztules

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Re: testing the egs002 inverter board
« Reply #27 on: March 14, 2016, 04:25:29 am »
Tried to use a tablet camera...... eeesssshhh...

But crappy pics are better than no pics I guess.

Here we are tonight trying the 4kw tests.... it stayed scary cool.... but there was a gentle breeze working through the workshop, but after 10 mins, the heat sinks were cool..... and the heat from the coils was intense... as per pic below

5228-0

The camera did not pick up the low light meters well... but if you try you can see the figures

5230-1

5232-2

pic of the coils and transformer still warming up

5234-3

We can see it doing a happy 4000w ... with no effort on the temp front at all... I am dead set amazed at what I am seeing... it is so cold.... and yet there is not that much of a breeze in the work shop..... staggered at this stage.... bit too good to be true.... why are these things not all over the net??

And this is the tiny unit doing all of this......

[ Specified attachment is not available ]

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

Flinders Island...... Australia

Offline oztules

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Re: testing the egs002 inverter board
« Reply #28 on: March 14, 2016, 06:51:53 pm »
Well today it is becoming particularly scary good.
I am running the house on it, ie fridges, freezers, tv, computers, 2500watts of hot water. this was humming away nicely at 27-3200 watts for an hour or so, temp held fine at less than 50C..( 20khz low side heat sink... hotter than the rest??). no fans.... placed a 120mm fan near the high freq low side heat sink, as it was the only one warm, the rest were at least 10C less than it. The 50hz legs were basically cold. The fan was running with 40ohms in series with a 12v source... slow running silent.

The it was time to boil the water in her 3000w kettle...... fired it up, no changes sound wise, no real jump in temp... it ran for the next few minutes at about 6kw.... ( 3kw jug takes no time to boil)

So it runs the 6kw without a problem, the 68A o/load just hung on @ 120 amps for the 2 minutes or so as expected ( thats how o/loads work... they do not blow at 68 amps), it is still running at 3kw now as I type, ans will for the next hour or so until the hot water shuts off, then back to 500-1.3kw depending on fridges and freezers. With the slow speed fan just moving the air, the temp of the hotter leg dropped down to 28C.... happy puppy here..

The simple little thing is nearly ready for prime time...... yes I'm gobsmacked.


dazed and confused as ever....

.................oztules
Flinders Island...... Australia

Offline frackers

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Re: testing the egs002 inverter board
« Reply #29 on: March 14, 2016, 06:58:31 pm »

Hi Oztules........Photo....... The PJ 10kW board, which I am about to add those 2 new caps.


Looks like the legs of the MOSFETs are splayed out on that board - much more than on mine which has the daughter boards. Also mine has 4 identical daughter boards (same revision) but the toroid drivers ones have a ferrite bead on the gate but the ones on the supply heatsink don't. I haven't checked the values of the passive components on the boards.

Talking of MOSFETs, is there a benefit of going to the TO-247AC cased 4110 rather than the TO-220AB ? Seems to be no price hit but if they are not cooking in the first place...


Robin Down Under (or are you Up Over!)