Question about 1N5408 diode on TMC2209 circuit board

[Graham Cowie]

I'm looking to build the TMC2209 base autofocusser using the circuit board TMC-2209-08.
With the 1N5408 diode I was wondering about the reson for the spoec chosen as it is rated for 3A, 1000V reverse voltage. I'm just trying to understand why this particular diode as it seems overrated for the voltages that it will be operating at. Also I was wondering about fitting it in the circuit baord as the spec say the diode length is 7.2m - 9.5mm but the hole spacing on the board is ~7.2mm which seems closer to the spacing for smaller diodes. would this be fitted in a more vertical orientation.

I'll add that I'm trying to learn electronics and coding and this is a great project to fit in with it and I appreciate that this is being provided for the community. Just the only question that springs to mind. Many

Thanks, G

[brownrb]

Hi Graham

Its okay to question.
my own choices for things are just that, my own.

The TMC2209 is an advanced project. There is a lot to configure, and it is pure luck if it works correctly 1st time,

You can use a smaller 2A diode if required. Such as the HER208
I recall measuring current for a drv8825 board, lcd display, temperature probe at around 600mA
(around late 2014 I think). No idea what it is now.

Yes, the pin holes are incorrect for IN5408

The IN5408 is pretty much the same diode I use for all my projects. Once buying all these packs of components (x5, 10 or 20 pcs in a pack) I tend to reuse them. Some projects require more than 1A or 2A - it depends on what is connected. mySQM+ a classic case as it has a hug e number of things dangling off it.

Regards
Robert

[Graham Cowie]

Thanks for that Robert. I've put it in vertically for now and it looks good. There is a lot of tall stuff on the board with the 470uF cap and the cooler on the stepper driver.

I've been playing around with the TMC 2209 outside of the board and it does seem to be a temperamental beast, so I'm expecting to spend a lot of time troubleshooting the autofocusser. Which is absolutely fine :) This is the ideal crossing point between wanting to learn electronics, coding and as a bonus I get a snazzy autofocusser at the end of it.

If all else fails, I can build one of the easier versions, which I probably will anyway.

Thanks again for your help Robert and maintaining this fantastic project and the excellent documentation.

[brownrb]

The TMC2225 and TMC2209 are supported, from BIGTREE only, no help is available for other TMC types or other Manufacturer.

They really do not fit an existing PCB like the DRV8825 because of the extra pins involved.

Regards
Robert