Raspberry PI LED Light Show KiCad circuit - User Submissions #3

Raspberry PI LED Light Show KiCad circuit - User Submissions #3
In this user submission, I go over the schematic and PCB of a Raspberry PI zero HAT. It powers 8 LED strips and is used to sync music with the lights for a custom "light show".
-- User Submissions --
View the video here: • Circuit Design Review ...
Submit files here: www.microtype....
microtype.io/
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[@aarondcmedia9585]

Good to see your videos back. Nice tip about testing wrt UL processes.

[@MicroTypeEngineering]

Thanks!

[@TomLeg]

Very useful video. Can't imagine why it has so few views, and so very few likes! .... It's like engineering school for DIYers.

[@jonjmz]

You talked a little about going through the UL process for a few products. I think a video about who they are and the benefits as well as what the process is like would be really cool. Or maybe a general "certifications" video. Keep up the great work.

[@carlosdiaz4535]

That would be a great video.

[@MicroTypeEngineering]

Great suggestion!

[@davidandrews8566]

Another very informative video. I found your design considerations particularly useful. Thank you

[@MicroTypeEngineering]

Glad it was helpful!

[@yosoyjose]

this kind of contend is sparse, very helpful, thanks from Colombia

[@MicroTypeEngineering]

You're very welcome!

[@toastrecon]

So interesting. Thanks!

[@hommepomme4750]

I love your videos ! thank you for bringing this content to us, I think these videos are important because there is not a lot of content that can bridge the gap between the maker community and actual electrical engineering. I don't understand why there is so many videos on how to connect your Arduino to your shitty overheating L298N and close to nothing on how to take your passion to the next level and actually adhere to engineering practices and learn how to do things right.

[@MicroTypeEngineering]

Hah! Yes, that's what I'm trying to do! You're welcome.

[@10e999]

Great video ! Quick question for @20:24 "> There's gonna be a voltage drop here. The ticker the trace, the less apparent that will be." Why ? In DC the current will follow the path of least resistance. I don't understand how ticker trace will help.

[@suncrafterspielt9479]

thicker trace means less resistance

[@10e999]

@@suncrafterspielt9479 Why, from a physics stand point?

[@suncrafterspielt9479]

The resistance of a thin wire is greater than the resistance of a thick wire because a thin wire has fewer electrons to carry the current

[@10e999]

@@suncrafterspielt9479 Thanks for your answer. Never too late for the fundemental. For those interested, the resistance of a wire can be define by R = pL/A where p = resistivity of the wire L = length A = Cross section area

[@suncrafterspielt9479]

Yess :D Thanks ... have been waiting for that

[@suncrafterspielt9479]

Isnt the diode shorted out by the +5V nets? (10:13)

[@MicroTypeEngineering]

Lol.. Yeah, just noticed that. I think the PCB net was fine, but yeah, the 5V node to the right should be removed on the schematic

[@Muny]

I'm not sure I agree with your logic on when the fuse is supposed to trip. I think the idea you conveyed was that every load on the 12V rail would have to be drawing their worst-case currents for it to trip. But this doesn't make any sense. The fuse is to protect against something like a short on one of the LED strips. If there was no fuse then the supply would be shorted (the result of which of course depends on how the supply behaves here, where the short is, etc). You would spec the fuse such that with everything drawing its maximum rated current, the fuse does not trip. That makes it so it doesn't trip under expected conditions.

[@MicroTypeEngineering]

100% valid, I don't think I explained my reasoning very well. Let's use this board as an example, and lets say that each one of the 8 LED outputs has a 500mA fuse, and a 2A input fuse. The realistically only place we have a dead short is on one of the outputs (of course, if you drop metal on the PCB, it could short anywhere, but you'd have bigger things to worry about if that happened!) If a dead short happens on an LED, the 500mA fuse will blow 100% of the time before the 2A input fuse, thus, making it redundant. Of course, as I showed, there are other uses for an input fuse, but it really shouldn't ever be directly needed for over current events.

[@frankbose544]

i just sent my design in hope he reviews it