The effect of phantom grounds on projected images

[@jefforgeron5249]

Thanks! I have a diy projector that was having a similar problem with image shifting when a TEC cooler was switched on. I redid all my grounds properly to a single point, and the problem went away. Again thanks!

[@ScannerMAX]

AHA great. If you search the internet for "William Benner Projector Connections" you will no doubt run across a link to the article I wrote years ago. I put a re-print of the article in my book about Laser Scanners as well.

[@-elektryx-5248]

So out of curiosity. If they cause crosstalk when connected to each other, and work perfectly when both grounds are lifted, why do they have a ground wire at all and are there any circumstances where you need to connect the ground? I'm just about to read your article, so i assume the answer will be in there anyway... Great video, thanks!

[@ScannerMAX]

Great question. Our own servo driver has a "ground" (central) pin on the command signal, but in the manual we tell people not to use it... We have it there only for legacy (i.e. historical) reasons. I think there are very rare circumstances when it would make sense to use it...