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johnmc Senior Member Joined: 21/01/2011 Location: AustraliaPosts: 282
Posted: 09:54am 06 Jul 2018
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Mark when I was a 3rd year motor mechanic I removed the battery charger of a nearly new ford prefect with out switching off the battery charger.
Net result blew, the front out of the battery and I had to clean up acid from all over the engine so you are right, to be be careful of the hydrogen.
cheers johnjohnmc
johnmc Senior Member Joined: 21/01/2011 Location: AustraliaPosts: 282
Posted: 09:58am 06 Jul 2018
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Warpspeed wrote
Connect up the secondary through a 1K resistor to an audio signal generator, and monitor the voltage with an oscilloscope. A definite peak in voltage will be found at the parallel resonant frequency.
Thanks john johnmc
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 10:10am 06 Jul 2018
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Showing your age there mate! (Ford prefect)
How is your build going?Cheers Caveman Mark Off grid eastern Melb
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 10:42am 06 Jul 2018
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Sorry Mark probably my fault the resistor goes from Gate to Source the 2 outside legs.
John I bet you still remember how sharp the Hydrogen bang is.There are only 10 types of people in the world: those who understand binary, and those who don't.
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 12:32pm 06 Jul 2018
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Nick, John, and others doing the 75Hz test.
The frequency indicating knob on many signal generators can be a fair way off, and cannot really be trusted. If you have a proper digital frequency counter, that would be perfect.
Lacking that, once you have found the exact peak in amplitude, you might try triggering the oscilloscope sweep to the 50Hz mains instead of the 75Hz signal generator. At exactly 75Hz the screen display should be stationary. The 50Hz mains is actually quite a stable frequency source, it does vary, but not by very much. Cheers, Tony.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 10:30pm 06 Jul 2018
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Nah Mad, that was my fault. Third time's a charm.
I wish we were able to edit posts, those previous drawings are wrong and confusing, and I just worked out you can't report your own post to get them deleted. Cheers Caveman Mark Off grid eastern Melb
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 10:45pm 06 Jul 2018
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Just to confuse you a little more, you don't have to but probably a good idea to include a 47 Ohm (or close to it) resistor between the + output of the CC and the MOSFET gate.There are only 10 types of people in the world: those who understand binary, and those who don't.
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 10:08am 07 Jul 2018
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Mark, you can edit or even delete anything in the post (its still there but without content). BUT, you can only do that before anybody posts a reply to it. Once you have a reply only Gizmo can delete it and he won't do it unless its offensive. I did ask him once...
I use the 'preview post' feature a lot, my syntax is not always making much sense Klaus
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 06:48am 20 Jul 2018
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Had a fiddle with the choke I did with Warp the other day. I put it in series with the 2x stacked ferrite. Got 0.6A No load draw, pretty happy with that. Nice clean wave. NO hum from torroid at idle or any load. BTW when I just used one ferrite it hummed really bad, two ferrites and still hummed but not too bad, the difference with both ferrite and big iron core is amazing, you can't hear the torroid at all.... nothing. I could have tried it without the ferrite or less winds but hey, if it aint broke don't fix it.
Time to cram it in a box and hook up to the transfer switch plug on house.
The one that is painted white is the aerosharp one, it's made from two of the bigger ones stacked side by side and glued/clamped together. They tend to give nasty friggin metal splinters the little rotters so I painted the little dog so it wouldn't do that.
Why both? I remember Poida was saying the ferrite cleans up high frequency mess so I added it to the iron core that won't saturate. Warps calculations and testing showed that the double stacked ferrite (4x halves clamped together)saturated at 40A. The Iron core was well above 100A, not sure how mugh higher as he couldn't test any higher, but it had no signs of signal altering, could be 150?? so I'm well above any load I'll ever place on the machine. Edited by renewableMark 2018-07-21Cheers Caveman Mark Off grid eastern Melb
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 07:22am 20 Jul 2018
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Looking good there Mark.
It should run much more happily now that it has a decent non saturating iron choke, and the transformer has been tuned to 75Hz.
Well done! Cheers, Tony.
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 07:31am 20 Jul 2018
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Nice job there Mark. I confirm your findings with the choke core splinters, ouch .
My non saturating iron core choke, like yours, saturated at 130 Amps with 18 turns and a 2mm gap.You could perhaps guesstimate the figures for your choke from that.
Also confirm your findings about using two chokes. See my post later today, I'm using a different ferrite choke. Klaus
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 07:36am 20 Jul 2018
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Yes Warp, thanks for the help mate, I never would have had a clue how to do that, or the equipment. Hopefully this will be a nice happy machine that will last a long time.
Big Big thanks to Madness, the number of times he has helped me is countless, couldn't have done it without you mate. And Oz, we don't see him much around her lately, but his help was/is always appreciated.Edited by renewableMark 2018-07-21Cheers Caveman Mark Off grid eastern Melb
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 07:41am 20 Jul 2018
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Klaus, you used the smaller of the two chokes from the aerosharp yeah?Cheers Caveman Mark Off grid eastern Melb
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 07:41am 20 Jul 2018
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Marks choke has 12 turns but the gap is much smaller then yours at around 1.1mm.
We first tried 17 turns with some junk wire and it went as straight as an arrow to 70 amps without the slightest sign of saturation. Then my tester that only has 50amp mosfets in it, blew up.
17 x 70 is 1,190 ampere turns. With only 12 turns it will do 100 amps easy, and probably a lot more. The smaller gap actually works very well, that choke had 125uH which is pretty good.
Cheers, Tony.
Ralph2k6 Senior Member Joined: 24/09/2017 Location: AustraliaPosts: 129
Posted: 07:54am 20 Jul 2018
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Looking very nice Mark. Its certainly been quite a journey, thanks for keeping us updated, helps us learn. And those who are knowledgeable can stretch their grey matter a bit with helping out. Have you got a decent enclosure lined up? Ralph
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 08:51am 20 Jul 2018
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G'day Ralph, I'm going to use the aerosharp cases I modified, somewhere back in this lengthy thread they are there. It's a tad embarrassing it's taken me this long and the thread that should be 4 pages is so long, but hey I got there eventually.Cheers Caveman Mark Off grid eastern Melb
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 09:30am 20 Jul 2018
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With your case Mark, fit the heatsink so it is vertical when the case is mounted in its final place. Have a fan blow in air from the bottom, right at the heat sinks.
Maybe another fan to extract the air on top, could be controlled independently.
Try not to have the heat sink sideways. I did that with inverter #1, a converted powerjack which fitted easier into the Aerosharp box this way.
It has 2 fans blowing air in, sideways, and 2 fans exhausting air. In summer they ran just about all the time.
That is why I went for the bigger home made enclosures. The 3 fans for them (1 in, 2 out) rarely come on in Summer and I have yet to hear them running in the Winter. Klaus
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 09:53am 20 Jul 2018
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Thanks Klaus, yeah I have 2x aerosharp cases side by side,( like Mad did) the powerboard with heatsinks will be vertical with a pull push fans top and bottom, the other side is the same with torroid, filters and chokes. 4 fans all up. I had it laid out ok before with just the one choke, might get a bit tight with the extra one now. P40 you can see the case.Edited by renewableMark 2018-07-21Cheers Caveman Mark Off grid eastern Melb
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 10:46am 20 Jul 2018
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Yes the vertical configuration does make a difference, with my inverter you can always feel the warmer air rising out the top at lower power levels. Saves fans having to force the air through as it rises up naturally unless the load increases above 3KW or so then the fans start doing their job. I have the fans coming on at 40 degrees on the heat sink and 50 on the toroid. In the cooler months now the heatsink fans hardly ever come on.
Though I had a major problem the other day with a huge cloud of smoke coming out of the inverter, turned out to be one of the Aerosharp toroid capacitors blew a hole out the side. The inverter was still running, at first I thought it was the toroid but was a simple 5 minute fix to replace the cap.Edited by Madness 2018-07-21There are only 10 types of people in the world: those who understand binary, and those who don't.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 10:32am 31 Aug 2018
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Well the inverter is running nicely, it has been powering the house totally off grid for over a week now. I had to connect mains today though as we have had two solid days of total gloom and we had to run the dishwasher and oven. I need to get up on the roof and fit the rest of the panels.
Funny thing is twice it re started on it's own, both times were around 5 am where no, or little load was present, both times the battery was over 50v, no fault registered on the arduino. only way I knew was the clocks reset.
I have the switch in a shielded wire and it's pretty short. Was thinking about putting caps on the control board like Oz did to my Clockman board. Anyone else had the same issue?Cheers Caveman Mark Off grid eastern Melb
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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