Duet 3 Mini 5+ Driver 0 VS filter capacitors

[ReXT3D]

Hello,

Ever since I acquired the Mini 5+ I was wondering why there are only four 100uF VS filter capacitors for the five TMC drivers. The schematic confirms that Driver 0 does not have the 100uF low ESR capacitor that the remaining drivers 1 through 4 have.

Thank you.

[Nurgelrot]

@rext3d They needed that space for the Duet logo

[dc42]

@nurgelrot the main purpose of those capacitors is to absorb the back EMF of the motors when they are commanded to decelerate. We calculated that 400uF was enough for 5 drivers. Each driver is close to at least one capacitor. In addition, each driver has two 0.1uF capacitors close to it; so it's less important that the 100uF electrolytic capacitors have low ESR.

[ReXT3D]

Thank you for the explanation @dc42.

[oliof]

@dc42 are you saying the Mini has protection to avoid driver blowout as shown in ? (That's M84 during a very fast linear move blowing out the drivers)

PS: this is neither RRF nor a duet board.