Guru
Joined: 21/06/2018
Location: AustraliaPosts: 1156
| Posted: 02:16pm 06 Jun 2024 |
Dex I am afraid that what looks like a simple solution to you, I cannot see how it will work in practice without causing other issues. I suggest you try to actually come up with a schematic to do this and you may then see the problem. Maybe I might then have a better understanding of your suggestion and why it might or could work. The elegant way the inverter switched on and off from a single switch took a lot of planning and understanding of the inner workings of the Nano code.
You know I don't have the energy or time right now to explain why someones simple sounding suggestion of how the issue might be fixed when I'm not sure they fully understand all the balls in motion and why the contactor stays in after the existing switch is turned off until after the SPWM has ramped back to zero and then the contactor opens. If you short the 5V line to ground whilst the inverter is running and full current is flowing I cant see any solution that does not undo that basic function and protection and there are a lot of FETs to replace if they dont take well to a crowbar on the logic supply.
Why is the second switch such an issue? If you want to stop the inverter set the run/stop switch to stop. If you want to turn off the inverter after it is stopped turn the on off switch to off. if you want a simple start to the inverter turn the run stop switch to run and then turn the on off switch to on. Or leave the run/stop switch in the stop position and after turning the inverter on then switch it to run. The only nono is to set the on/off switch to off before stopping the inverter first, put an ejector switch with red cover over the on off switch.
I have devoted an enormous amount of all my spare time to get to this point since I sent your boards to you in February? I am now being relied on to provide a solution to this 11th hour glitch that will work. You see before I came to the forum no one used just an on off switch, they had a push button pre-charge and then when they guessed the caps were charged they threw the main switch to either a bang or then operated a run switch to either a bang or welcome hum. When I first suggested the solenoid solution I was bagged endlessly but in my usual fashion I ignored the "help" and criticism and went ahead and proved it could work well, then some others slowly adopted it.
This is not the end story just the end of a chapter. I have a need to provide a working solution to all the members that want to build this type of inverter and have reliable power and have placed their trust and faith and money in a Wiseguy solution. At some point in all projects you need to stop farting about and draw a line at an acceptable solution that works and then breathe a bit and start thinking about the next chapter otherwise it will never end.
I can assure you my brain cells are already forming a plan of how to make much better single switch solution for Rev8 and it will benefit from all that we have learned from this episode. I am prepared to help you maybe have a single switch solution but I have racked my brain and as the solution got more and more complicated I gave up and re thought out from first principles a working solution for the Rev7 everyone is about to receive and applicable to the Rev6 you have and is (I hope) compatible with existing software - I cant see any gotchas yet.
I am also still churning over ideas for a single switch solution before the boards are returned to me and shipped out, but at least now I do have a fall back solution with 2 switches that I am sure will work fine in the absence of a single switch and is relatively easy to implement.
Edited 2024-06-07 00:35 by wiseguy