HighHopes wrote:ahhhh..... github. i been avoiding you for years cause i tend not to work in teams so i do all my revision control myself. but ya, i can see its usefulness.
lets say i wanted to make a change to the schematic you posted in github. you ok if i do that? i don't know how to do this yet in github.. will need to watch some tutorials or something i guess. but, as of this moment, here's how i see it. lets say i downloaded your entire zip folder. then i open my kicad, and decide to make a change. i do that, save it. zip entirety of the folder then upload to github (following tutorial methods so repository will do revision history properly). that sounds something close to the correct method?
Great, I was hoping to get you onboard.
You can skip the tutorials for now. Save them for when you destroy your repository and you need to figure out how to fix it.
About git, its not about zips, you pull entire directories from the remote (online) repository.
A good way to publicly collaborate would be this:
1) Install git on your computer
2) sign up on github.com
3) Once logged in, go to https://github.com/paltatech/current_sensor
and fork the repository. There is a fork button around there. It will create a copy of my repository in your github account.
4) Now you can select a directory on your pc, open inside a terminal and run "git clone https://github.com/highhopes/current_sensor.git
(assuming your username is highhopes)
Now you have a copy of the repository (current files and all its history) in your pc. Steps 1-4 are needed only once. I prefer command line because its very few commands to learn, I don't like GUIs with many buttons, I already have CADs.
5) perform the changes as you wish. To upload to YOUR repository, open the terminal inside the working directory and run these 3 commands
git add .
(there is a ".". This adds files to be commited)
git commit -m'Describe your changes'
git push origin master
Now your changes are in the cloud.
6) If you want me to include your changes in my repository, go to https://github.com/highhopes/current_sensor
and create a pull request. It will invite me to pull your commit(s) from your repository.
Its good to make as many step 5) as possible, specially in software when you misplace a stupid colon and the whole thing falls apart and you struggle to find at which point in the history is the error.
This is how it looks like with many people contribute to a project
https://github.com/KiCad/kicad-source-m ... its/master
This is how a lone wolf like us uses git version control
https://github.com/paltatech/VESC-contr ... its/master
HighHopes wrote:anyway.. haven't read enough about the AMC1303 chip yet but i was thinking the schematic you have is shunt resistance referenced to ISOGND (V- is connected to ISOGND). this would be for like measuring the current in IGBT emitter to ground path which is not what we want. we want to measure the phase current in the AC output which is not really referenced to anything, its truly differential (or should be) because this shunt is in the inverter AC output. easy enough... just don't connect ISOGND to V-. but the chip has a power supply which is referenced to ISOGND so now you have a floating measurement (which really is differential) which is good but can the chip do that? or does it have to have V- connected to ISOGND to achieve the datasheet performance. that's what i was thinking when i open your schematic and did first browse through. otherwise, looks good. and i like the voltage divider at the buffer output... gives you some interface option to different voltage level in a pinch. for me, i'll be using a DSP with 3.3V analog in.
also, there's bound to be some voltage transients on the shunt. reading AMC1303 datasheet makes me think it self protects but need to confirm by reading more.
The schematic is intended to be used as a bidirectional current sensor, you can put the shunt in series with the phases and it will measure positive and negative currents. The working principle is a bit odd and I didn't care enough to fully comprehend it, but I know its bidirectional because I tried swapping + with - in a dc bus voltage sensor because of a wiring error, and it worked okay measuring -80v.
This is the circuit I played with.
https://eyrie.io/board/88ebffa8546c4bd0 ... pped=false
ISOGND is called that way because its a kicad built in symbol, quick to place. There could be a better choice of worlds out there, its a reference rather than a ground.
I have to upload some changes, I added a buffer to reconstruct the 20MHz digital signal. If there is long wiring between the adc and the filter, that square wave can get distorted, so a buffer would return it to pristine condition.