Hi
@Zwy, nice to see you here.
I saw your videos. They are what that finally pushed me to break out my scope and take a look-see.
Thanks, I'm kinda no nonsense when it comes to my videos, no fancy production, just me and some video talking about solar. I created my channel back when I was banned here for a week after telling James off. I used the free time productively.
Unfortunately, I think that my scope is not as good as yours... at capturing the spike(s) riding the sine.
You have 2 channels running so your sample rate will be one half of total sampling rate on each channel. That is why I always used one channel in those videos. I'd have to look at my scope specs and your scope specs but most likely they are close.
I've used scopes for a long time now, about 25 years, forgot about 1/2 of what I used to know. Don't use them as often. Back in the day when diagnosing automotive circuits without all the PCM monitoring we have now, the scope was used quite often. I still use mine often, just not daily. I should use it more to keep in practice.
I have, from the begining, believed that I may have defective units, and was hoping that SS / EG4 would prove me wrong.
In your scope capture you can see the problem with the H bridge switch. That is that glitch at midpoint. It appears this is the culprit from everything I have seen with my scope.
@RCinFLA commented on in one of the threads from way back when I posted some of these videos in the forums and before that I had done some research on how these operate to determine what I was seeing. On AC current, the sine has to reverse due to the AC current. The H bridge has to switch polarity. The trick is to time it right plus be able to keep the positive side from jumping to the negative side.
The other thing I saw with the 6500EX was the DC voltage not holding correctly. If you zoom in on the sine, you will see the DC of the wave riding on top of the sine. What is done from what I've determined is the DC is feed into a high voltage bus with a converter, then switching occurs to break it into sections of increasing and decreasing voltage in order to create the AC sine. That is how I describe it anyway. What you see is a hump in that part of the wave that will ride along the sine. That should not be there.
Another thing I saw on the 6500EX was with high PV input, the sine would get all funky, I'm sure you saw that video.
The LV6548's I have are both rock steady, just like shown in the video. None of those humps riding the sine either.
Just everything about the 6500EX is just so substandard. You don't see any of this behavior or glitches on the LV6548 so it has to be faulty hardware. Firmware isn't going to fix it. I've been pretty quiet about these units after they took mine back but I still see posts like yours coming in and I've decided to tell people they should push for store credit or refund. That is James's problem, he took on these units, spec'd them out and changes were made without any real testing as they pushed to get these out to market. They can live with the consequences, you should not have to.
