Soft start switching mod for Gaindel Inverter

[Tim Rotunda]

Waited too long before I realized I shouldn't have gotten this inverter and am no longer able to return it.  I don't need a boat anchor so I built a mod.

This is nothing fancy, its small and as easy as soldering a few wires and clicking a few icons.  I threw the schematic, physical drawing and code on the same Omnigraffle then converted it to PDF, which is attached.  I am not 100% the pasting of the code into the cad file didn't ad something unneeded like auto punctuation or whatever so I also attached the .ino file.

I designed and built for the remote panel below, but I think it will work with the basic one.  There are many ways to design this but I chose to use the least number of parts method.  The Arduino Nano Every cost $5 and is small enough to fit inside the display panel case.  External 12v isn't probably necessary, but I didn't want to rely on the 12v from the inverter sent across the super long cable they provide.  Three wires attach to the remote pcb.  A ground wire, a wire from one side of the power "on" LED and a wire from the right side of the switch as viewed in the pic attached.  That last one is the trigger wire and connects to the Nano on pin D3, via an LED and 10k resistor.  A low current diode would work just as well, but I like pretty lights.  One of the GND pins on the Nano, will go to the right most pin of the RJ plug as shown below.  The yellow wire is attached to the power indicator LED and goes to the Nano Pin A1 and is used to sense power on the LED.  The other three wires are 12v and ground and then EXT IO3+.  Anywhere you pickup the 12v/gnd is fine.

The code is stupid simple.  It simply waits for a logic one from the EXT IO3+, it checks the sense level.  If the sense level indicates the Inverter is powered on, the trigger line is held high for 500ms.  It then goes back around to look at the EXT IO3+.  If it remains high but the power indicator is off, it loops back around again.  If the power on button on the remote is pushed, the inverter will turn on but the code will know better and turn it off again.  When the EXT IO3+ returns to low, the inverter stays off until someone presses the inverter power button.

The only time the Inverter will power up is when EXT IO3+ from the SBMS0 says it can and then only when commanded to by the push of the remote button.  I don't know how reliable the design is but if nothing blows up or changes with the remote, it should work indefinitely.  I suppose it could be made more resultant against failures buy using a pull-up resistor on the trigger and invert the logic from the SBMS, but I don't really have time to mess with it anymore.  If I find that to work better, I will update and share as time allows.

Post any questions.

 

[Dacian Todea]

Thanks for posting. Maybe others will find this easier than the electronic only version that Ross made https://groups.google.com/g/electrodacus/c/M8fe1VRLtYw/m/FokPNKT5AwAJ

You may want to make sure that the Arduino board can handle possible 14V+ if directly supplied from battery depending on what linear regulator they used.

Guessing EXT IO3- is connected to GND.

[Tim Rotunda]

Nothing like a choice.  The older I get, the harder it is to work with tiny parts to say nothing of seeing them so soldering wires is about my limit now.  Amazing what a half a stick of gum sized thing can do.

The Nano Every and most of the Arduino and similar boards generally have a Vin of 7-20'ish volts, so no worries.  I have mine powered for now, a USB cable plugged into a wall wart plugged into the house AC, (not the inverter).  Yes, IO3- is on ground.