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Forum Index : Electronics : recycling those Aerosharp chokes
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Madness Guru  Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
If you did use the TFB as a shut down it would not stop your fan from working but the fan would come on everytime you shut down the inverter. The Chinese have the LM393 on the EG002 boards and perhaps part of the reason it is there is to avoid this problem. If you lie awake at night trying to figure out how to get an absolute perfect sine wave no matter what load you have on you may end up in the crazy ward at your local hospital. There must be a point where you be an Aussie and say she'll be right mate or is that not in your genes? BTW I am mostly of Deutsch blood but 5th generation Australian. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
That's funny, my one has done it when there is little or no load, it doesn't happen with sudden big loads or the oven or hair dryer, clothes dryer 10in angle grinder, none of them ever have an issue, just twice at around 5am the clocks reset, it never happened during the day.(Now I said that, it bloody will though) Gary would caps help like Oz did? Cheers Caveman Mark Off grid eastern Melb |
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| Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
I have put caps on but they had no effect that I noticed. Is it first light that is triggering it? Although that is a little early just maybe your charge controller turns on at that time. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Its hardly surprising that really nasty reactive or highly non linear loads distort the voltage waveform. Its nothing to really worry about, its only likely to happen with a single very large nasty load. With the usually mixed and distributed household loads the effect should be a lot less. Highly reactive loads, particularly very large motors are going to screw up the careful transformer tuning and very likely bring the wiggles back. Not to worry. There may also be fairly high reactive current flowing throughout the zero crossing, something that will not be there with a purely resistive load. With unipolar drive that could possibly create a discontinuity at the zero crossing. If you did not have that little oscilloscope connected to the inverter, you would probably never suspect all these little dramas anyway.... There may be occasional weird stuff happening, but as long as the inverter and load both keep on doing their respective jobs, its not likely to produce any effects that are really noticeable to other members of the household. Cheers, Tony. |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
Nup pitch black @ Warp, yep, just get it working fine and run it. Move on to next project. Cheers Caveman Mark Off grid eastern Melb |
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| Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
Maek it is not shutting down due to your low voltage setting is it? There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
Nah, that got set back to 47. Both times it happened batt was around 50v. Nothing logged on arduino. Cheers Caveman Mark Off grid eastern Melb |
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Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Mad, my screen name is tinker - I like tinkering and no, it does not keep me awake at night. Part of learning is to know why things happen as they do with these inverters. Now, as to sine wave distortions, here are three I photographed today: First one is running a 2KW shredder motor (idling).  Next one is running my cheap 700W microwave.  Last one is of my induction stove, set to 1KW.  So you see its not just any inductance.... BTW, all appliances ran fine. It will be a while until I can tackle that odd blackout symptom, something else keeping me bust ATM. Klaus |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
I wonder if it would look like that on a proper cro? My little one showed funny things the big one doesn't. Cheers Caveman Mark Off grid eastern Melb |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Remember the little CRO only has eight bits of vertical resolution, which is what puts all those jagged little steps on the waveform. They are not really there. But the larger bends and kinks will be there, but even the grid can look pretty horrible at times and everything still works fine. Cheers, Tony. |
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| BenandAmber Guru Joined: 16/02/2019 Location: United StatesPosts: 961 |
Thanks renewablemark for giving the link to this page I've learned a lot you are so good at picking out what people should read Thanks again be warned i am good parrot but Dumber than a box of rocks |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
I did end up doing that actually. The wave isn't as nice, the ferrites did make it better. Having the steel double core and the double stacked ferrite works the best. They all seem to be a little bit different and the choke needs to be tuned to your own setup. I know Warpspeed said his machine behaved differently when it was connected to the house wiring. Funny this was there is one particular load (only a small one too) in my house that messed with the wave when the ferrite was removed, but with it in place along with the steel core it disappeared. Cheers Caveman Mark Off grid eastern Melb |
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| BenandAmber Guru Joined: 16/02/2019 Location: United StatesPosts: 961 |
Them other guys seem to prefer those silicon steel ones I think poida the great told us newbies to use ferrite for a reason I think it may be more forgiving I'm pretty sure he said he had a few mosfet to blow trying to use those silicon steel ones be warned i am good parrot but Dumber than a box of rocks |
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poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1419 |
Yes, ferrite is best for beginners, building their first inverter, to run at modest outputs. The cores are not expensive, maybe $20 AU for a good sized one. Some people here are very confident of the iron core chokes they made. I'm OK with that. I also know my inverter blew 3 times within 2 weeks when using a iron cored choke and I cured that when I used the ferrite cores. wronger than a phone book full of wrong phone numbers |
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| Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
I suspect yer did not make that choke big enough. Did you read warpspeeds reasons for using *non saturating* chokes? You'll find in the same pages mention that ferrite cores saturate very easily. I suppose using a ferrite *and* an iron (silicon steel flakes!) choke as Mark does is also beneficial. Two chokes take up more room in the inverter enclosure though and when I tried that I could observe very little difference. But ferrite alone? Horrible sine wave form at big loads in my experience. My comments here relate to the EG8010 based inverter. I have not yet progressed past moderate loads with the nano test inverter to see what different type chokes do to it. Klaus |
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| johnmc Senior Member  Joined: 21/01/2011 Location: AustraliaPosts: 282 |
I have only used the ferrite core and it has been running at up to 8 kw at times usually about 3 kw is the norm, the load varies from welder to pumps and all the household appliances. The sine wave to 4kw was ok when I checked it about6 months ago  cheers john johnmc |
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mackoffgrid Guru Joined: 13/03/2017 Location: AustraliaPosts: 460 |
An interesting read BIG inductors - DIY style? : EEVBLOG |
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| BenandAmber Guru Joined: 16/02/2019 Location: United StatesPosts: 961 |
 How's this for a free ferrite choke think it'll work someone told me they tried it can't remember who it was now Two sets of off two old television tubes Super glued together If I ever get a chance one day I'm going to try it be warned i am good parrot but Dumber than a box of rocks |
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| poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1419 |
MY experience with ferrite alone can be seen below. Yellow is AC current. Blue is AC voltage. This time, my Tektronix 2235 makes an appearance, just to show that the Rigol DSO does not lie. The 2235 is showing AC voltage. This is running a load over 2kW.  Here is a video, where you can observe the not-too-bad-to-my-eyes sine wave as I switch in 800W, 1600W and then to full 2kW+ of the heater, then switch back to 1600W, the 800W then "idle" which is also running the household loads of approx 300W. You can hear my switching of the radiator in the background. If you view it at 720p full screen you can observe the Powermate's readouts of power, power factor etc as I switch in and out more and less load. The inverter is a straight forward 12 HY4008 aliexpress board with EG8010 controller, with a 3kW toroid, and a ferrite choke of about 50uH. The same board and toroid combo that failed within hours running one of the aerosharp chokes. In my view, ferrite works fine and does the required job. I have posted already a comparison of ferrite v iron cored chokes for anyone interested in the detail behind my opinion on this matter. wronger than a phone book full of wrong phone numbers |
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| Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
I hear you poida. In my opinion no two inverters described here are the same, especially when it comes to the 'built from scratch' types. My experience of bought inverter modules is limited to the 8KW power jack type. And yes, that one ran for a long time with just the 3-4 turn E65 ferrite core choke. It still would do so but I have replaced the ferrite choke with my home made recycled aerosharp one and that inverter is for sale if I find a buyer (too many inverters here  ).Btw, when I looked back at the picture you posted of your rewound aerosharp choke I am not surprised that it blew your fets. I tried winding it that way once, even tried the original (more turns) winding, none was liked by the inverters I have. If you check my choke pictures you will see I wind them quite differently and also tune the air gaps with spacers to set the saturation current well above the max working current. For those happy with that E65 ferrite choke, I have 3 spare ones here. They are wound with very heavy gauge enameled copper and are 3 turns, 3 1/2 turns, 4 turns. But they might be a bit too heavy to post long distances. Klaus |
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