What do you mean by logic chip? How can that help?
- I would put electrolytic capacitors at least at the input of the supply voltages. Since dim-channels work in PWM.
A flying calculation would put at least 1000uF for each power supply, they should be with greater capacity on the lower voltages as the currents increase compared to what you reported in the previous posts.
Why do I need cap, what would they do?
On the relay card they have 2 100uF caps on the input power. Different types what it looks like. Don’t know why? But I guess I have to have some caps.
- I don’t know what you need the D37, D2, D4 diodes for or put those suppressors or put nothing.
The relay card have that on the 5v power input. Don’t know if it is needed.
I imagine I need that if any reverse current feeds + to the minus side so it doesn’t get back to the PSU.
- I’m looking at the GND plan under the mosfets and I can’t understand how it’s done.
I do not like.
I just copied the N-Drive Shield because that looked professional. I don’t know if it’s supposed to be done that way, but a big copper plane under and over, solder mask removed, so you can fill it with solder to have more mass to cool down the Mosfet, or put a heatsink, I don’t know why “Freetronics” have done it that way? Maybe someone else can answer that?
- Switch footprint pads do not have the welding mask layer. If you look at the 3d view, the pads are covered with the welding mask and in this
I used the footprint in the end of this thred : DPDT/SPDT footprints anyone?
How do I change the footprint with solder mask?
Also should I change the return current path? I can’t visualize how the current would flow. I have put visas on several places. But I don’t known if that is enough. It feels like it would be simpler to draw cables from inputs to each Chanel. But that feels like a workaround.
By the way wrote this in bead with iPhone, so have to review it, maybe change some things.