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esaj

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Just saw your office/desk posts.

I have similar issues here, albeit of a smaller scale. The problem I have is you collect so many completely different things that it is hard to get everything correctly shelved/sorted/stored. Screws, wires, tape, kapton tape, double sided tape, tie wraps, filament (lots of filament!), power tools, screwdrivers, all kinds of sockets and wrenches, knifes, scissors, raspberry pi's, arduinos, small electronic components, bigger electronics components, proto boards, bread boards, soldering tips, and then there is all my drone stuff such as receivers, antennas, built drones, drone parts, spare motors, frames, etc etc etc. And then there are the bigger components I need such as GPS modules, DC stepdown converters, accelerometers (all the adafruit and other stuff). I'm pretty sure I still forgot half of it.

It just becomes impossible to categorise. I end up just buying storage with small boxes inside and dump stuff that is the same in the same small box. 

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49 minutes ago, ir_fuel said:

Just saw your office/desk posts.

I have similar issues here, albeit of a smaller scale. The problem I have is you collect so many completely different things that it is hard to get everything correctly shelved/sorted/stored. Screws, wires, tape, kapton tape, double sided tape, tie wraps, filament (lots of filament!), power tools, screwdrivers, all kinds of sockets and wrenches, knifes, scissors, raspberry pi's, arduinos, small electronic components, bigger electronics components, proto boards, bread boards, soldering tips, and then there is all my drone stuff such as receivers, antennas, built drones, drone parts, spare motors, frames, etc etc etc. And then there are the bigger components I need such as GPS modules, DC stepdown converters, accelerometers (all the adafruit and other stuff). I'm pretty sure I still forgot half of it.

It just becomes impossible to categorise. I end up just buying storage with small boxes inside and dump stuff that is the same in the same small box. 

Most of the components sit in large TME-bags with their original smaller antistatic bags, and the big bags just have a piece of painters tape with a marking like "Op amps and comparators", "Voltage regulators", "SMD inductors" or "Zener diodes". The bags are then put in a large box that sits under one of the tables:

qLz6NIH.jpg

Of course I then have to sort everything to the bags when a new order arrives, and also update an inventory I keep in a spreadsheet, so I don't have to dig through the bags to know what I have. When I need something more specific ("I need an MCP6001 and and an MCP6L91 op amp"), I first dig for and locate the bag  ("Op amps and comparators"), then still have to dig through tens of smaller bags to locate the correct ones. "High volume" stuff like basic passives (resistors, caps) I keep in their original small bags, sorted by value in another box, and fill in the sample books next to the soldering station as needed. A friend of mine swears his way of just using a box with the passives in original bags sorted in order is faster than sample books, but I still prefer the books. This "system" mostly works for small stuff like electronics components, but not for much else.

There are also big parts bins with mostly stuff ordered from China, but also lots of cardboard boxes on the shelves for bigger stuff, wire reels and such, plus some smaller plastic boxes with compartments and printed labels for some bigger stuff/more often needed connectors and such, but yeah, organizing and labeling everything is sometimes a nightmare :P I don't dare to think what a mess it would be should I somehow manage to lose the entire inventory file and would have to go through everything again, as I've also collected most of the key values from datasheets and datasheet links on the inventory sheets for the parts... :wacko:

Edited by esaj
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Moved to a better fitting topic

 

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On 6/8/2019 at 6:44 PM, esaj said:

It's probably the most complex board I've ever designed, with over 100 individual components and over 400 soldering pads. Not "big" in commercial scale, but personally, a sort of a record. I actually have to solder a number of these by hand, so there's that too  :P 

So impressive!:thumbup: 

 

On 6/8/2019 at 6:44 PM, esaj said:

I kind of wish this project would have come a bit sooner, had we started talking about it month or two before, I wouldn't have signed my job contract yet, and could have worked on this full time. 

Your knowledge is simply amazing! Curious- how do you bid on such a lengthy, laborious  project?  

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5 hours ago, Rehab1 said:

So impressive!:thumbup: 

Thanks, although I doubt it's anywhere near as good as a seasoned professional would have made, and likely my design wouldn't pass the certification tests for EMI/EMC:

Electromagnetic compatibility (EMC) is the branch of electrical engineering concerned with the unintentional generation, propagation and reception of electromagnetic energy which may cause unwanted effects such as electromagnetic interference (EMI) or even physical damage in operational equipment. Also, it is the ability of an equipment or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment. The goal of EMC is the correct operation of different equipment in a common electromagnetic environment.

EMC pursues three main classes of issue. Emission is the generation of electromagnetic energy, whether deliberate or accidental, by some source and its release into the environment. EMC studies the unwanted emissions and the countermeasures which may be taken in order to reduce unwanted emissions. The second class, susceptibility, is the tendency of electrical equipment, referred to as the victim, to malfunction or break down in the presence of unwanted emissions, which are known as Radio frequency interference (RFI). Immunity is the opposite of susceptibility, being the ability of equipment to function correctly in the presence of RFI, with the discipline of "hardening" equipment being known equally as susceptibility or immunity. A third class studied is coupling, which is the mechanism by which emitted interference reaches the victim.

Interference mitigation and hence electromagnetic compatibility may be achieved by addressing any or all of these issues, i.e., quieting the sources of interference, inhibiting coupling paths and/or hardening the potential victims. In practice, many of the engineering techniques used, such as grounding and shielding, apply to all three issues.

https://en.wikipedia.org/wiki/Electromagnetic_compatibility

Never even given much thought to such things before :P  All I can say is WIFI, cellphones and Bluetooth still work in the vicinity of the board, so at least it's not radiating that much in those bands as to drown out the high frequency signals  :D  But the allowed levels for certification are far below what would actually be needed to "jam" normal wireless communications, so it could still be radiating at levels multiple times above the limit across different frequency bands. Conducted noise is relatively easy to get rid of, but radiated noise is a much more difficult problem.

At least for the prototyping stage it's enough that it works, even if it radiates/conducts interference more than the standards allow. If a standard-compliant version is needed at some point (I'm not that familiar with the regulations, this application might be exempt), then I'll probably have to pass, as I don't have the equipment to measure such things myself (they cost some serious $$$ compared to my hobbyist stuff), and it takes time and becomes very expensive also to retry the compliance testing over and over until everything's working as it should... from what I've gathered, for example FCC certification tests for simple "unintentional radiators" start at cheapest from somewhere like a couple of thousands, if there's wireless communication going on ("intentional radiator" at certain bandwidth), the prices start from over 10k for each try, and that's just for North America (I think USA + Canada), Europe has its own standards and compliance tests, same probably for Australia, (individual?) Asian countries etc. Getting something certified all across the world can become pretty expensive, even if everything passes on the first go. Private labs that can do the tests and have "anechoic" chambers needed for more accurate measurements take about $1000 per hour, and even pros might need a couple of tries before they pass there, but I guess they usually test it through those before going to the actual agencies giving the certifications, as it's still cheaper when you can be sure that it'll pass on the actual certification tests.

 

5 hours ago, Rehab1 said:

Your knowledge is simply amazing! Curious- how do you bid on such a lengthy, laborious  project?  

In this case, I just gave a fixed number, that's probably 10 times lower than a professional company would have billed (for the same amount of hours, then again, professionals could have probably done it in much less hours). I didn't really know how much time it would take, but I suspected that I'd be looking at least way over 100 hours, and like said, I don't need to make a living out of this (at least for now), the project itself was/is interesting and the "customer" is an old acquaintance. If it was something that resembles more like "working" ;), the price would have been wholly different...

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29 minutes ago, esaj said:

for example FCC certification tests for simple "unintentional radiators" start at cheapest from somewhere like a couple of thousands, if there's wireless communication going on ("intentional radiator" at certain bandwidth), the prices start from over 10k for each try,

So expensive! I can see the rationale behind the tests where large Fortune 500 corporations would easily be able to absorb the costs. Unfortunately a small firm (or hobbyist) would be unable to justify that large of expenditure.

I suppose if your device (still not sure what your working on) meets all of your customer’s standards then the next step would be for the client to take the equipment to an EMI/EMC testing facility for the proper certification at his/her expense. 

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