InKits Nextion case power wiring

Ken Simmons

I'm using the 3.5" Nextion case from InKits ( and have a couple of questions/concerns on the power wiring. The only schematic I've found doesn't show all the pieces that are included like the fuse and the extra switch. I've tried to create a schematic from the pictures available. The problem there is that I'm coming up with a strange configuration. Specifically, the fuse appears to be after both switches. I also don't see a diode, either in series or as a crowbar. The wiring of the power connector is difficult to see in all the pictures so the diode could be there, but that would put it before the fuse.

I've also seen pictures of a small circuit board that contains the crowbar diode. I didn't receive a board like that, but I believe those pictures were from earlier versions of the case.

I know there are many posts about power protection, but I couldn't seem to find any for this particular case and wiring setup. It can include a battery and a switch configuration for charging the battery, but you can't simply connect power to a LiOn or LiPo battery for charging without risking safety.

Any suggestions or clarification would be appreciated.

Justin Phillips K5AXL

I think their power schematic is more a suggestion or how Sunil did it. If you have no need of a battery connection you can leave that out. The power schematic they provided does depict dc barrel power going to the 3 way rocker switch first, then to the fuse. I'm no EE, so I don't know if there any technical advantage to putting the main switch before or after the fuse, but I wired mine the way their schematic/pics show it, just left the batter connection off. I was thinking of putting the case fan on the second position, so I can power on with or without the fan running.

They have a download available with lots of pictures and a couple schematics to help explain their intended wiring.

Scroll all the way down for the Nextion case files.