[COMPLETED] Laser Cut Prototyping mini-GB

[scottc]

Wow, what a beautiful keyboard!

[Muirium]

"Neutral" is just the return path for mains current, the necessary counterpart to "live". It's not the same as ground / earth at all. Earth is meant for safety while neutral can float around at a voltage all its own, depending on the exact amount of live current.

So, don't touch neutral, folks. It's not as certain a bad as live, but no guarantees!

[Jmneuv]

Here it's common in older houses' wall sockets to bridge the ground connector to neutral for lack of a proper ground. Can't say i'm a fan of that.

[Vierax]

Thanks, Vierax. You're probably right about the third prong being connected to nothing. I've installed a few wall switch dimmers and a ceiling light and in each case, there were only two wires to connect. No ground and no neutral. I will look into RCDs. All receptacles are GFCI but I don't know if that addresses the issue or if they're even effective without the ground and/or neutral. I'm having some other electrical work done soon (220V run) and will ask the electrician.

If you rent your home, you can negotiate with the owner about the bill of this electrical norm update – In some countries, he must do some diagnostics before rend an habitation so he might be outlaw, do a research about your legislation.
It can be a huge cost if the wiring is obsolete but it's the price of your security and the advantage for the owner is that this update can be a major argument for the next renter (and of course an argument to raise the price).

If you own it, well… save money for your life, your family and your friends (kb and caps can ever wait )

Sorry for the Out Of Topic, guys

Muirium > Totally agreed : neutral is as dangerous as phase especially with AC !

[mtl]

Clearly there is a lot for me to learn about AC power systems. Here's an article I found particularly enlightening.

The building was constructed in the 1950's and I believe is grandfathered out of the NEC requirements for groundING of wall receptacles. But I will ask the electrician. Fun fact: My power distribution panel is just a few in/cm from the kitchen sink (!) but passed inspection b/c of the date of construction.

So to revisit the wiring issue, there is apparently one hot and one groundED neutral but no ground, so that would mean the fancy GFCI outlet "protection" is just for show. It's a condo so there's no landlord or coop to shift the responsibility to, at least for the wiring inside my unit. For the 240V run, the electrician is wiring in a differently-phased hot, but that will still leave the circuit without a ground line.

And back to the keyboard, it seems that either (a) the building electrical supply and the keyboard are floating above/below ground and by contacting it, I am grounding the circuit and receiving a shock, or (b) I am building up static charge from the atmosphere and by contacting the grounded keyboard, it is helpfully relieving me of the built-up charge. Either way, I think the problem is not the keyboard, except for the fact that an insulated enclosure would avoid the problem.

[mtl]

mtl your board are really nice

Thank you. It looks like I need to invest in a can of spray air and do some crumb maintenance.

[mtl]

I made some improvements to the case design I used in this GB to address various issues with the build, and also started documenting a few things on the wiki. Although I don't presume anyone will want to recreate this design exactly, maybe some aspects of it or things learned along the way could be of use in other keyboards.

The updated case design is attached to this post, mainly because the wiki only allows images and PDFs to be uploaded. Details on the changes are here. Most of the changes are straightforward enough that I'm fairly confident they haven't created any new issues, but I can't be completely sure.