Electronics > Beginners
My purchase list for my new lab -- budget $1000+, thoughts?
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AnyNameWillDo:

--- Quote from: bitseeker on July 31, 2018, 08:55:43 pm ---Speaking of component sources and speed, lately Arrow has been doing free overnight shipping. Their site search needs replacing, but otherwise, if they have it in stock then there's practically no waiting anymore. Pretty cool.

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I had forgotten about Arrow -- I may need to give them another shot. I had tried to find components there, but found their search feature to be virtually unusable (definitely needs replacing, as you say).
Jwillis:

--- Quote from: ez24 on July 30, 2018, 07:27:24 pm ---
--- Quote from: AnyNameWillDo on July 30, 2018, 06:39:23 pm ---
.. it says 20 AWG has a max transmission of like 1.3 amps.


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When I hear "transmission",  I think of 100s of feet.  Keep in mind that the current rating of good breadboards is 2 amps.  Even at 1 meter, the voltage drop at 2a is very small.  Try the calculator.

I had no trouble running 5a through 18 inch leads.  FYI the AN8008 leads could not.

If you going to run higher amps then a thicker wire might be more useful.   When I made up my leads, I made a lot of 16 ga with alligator clips.  Like someone else said, I have never used them.  Mini grabbers with 18 ga is what I use.

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The maximum Amps for power transmission uses the 700 circular mils per amp rule. 5 amps over 20 gauge is only 8.5% the fusible rating for 20 gauge wire which is around 58.5 amps over 10 seconds. This is set as a standard for safety reasons and longevity of the wire shielding .Its not to say that you can't put more amps through a piece of wire . Wire is generally under rated so 10 amps is around 17% the fusible rating for 20 gauge wire.It will get warm but you could also risk shortening the life of the plastic shielding.
Length of the wire isn't really regarded as a factor for lengths under 100 ft. Most banana cables are between 12inches to 24 inches . I doubt  you'll find any 100ft banana cables.
tooki:

--- Quote from: AnyNameWillDo on July 31, 2018, 08:38:32 pm ---Meanwhile DigiKey has any part imaginable but there are so many variants of each piece that choosing among them is tricky.
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You’ll get better at it with time. Part of it is learning how to read datasheets. (As someone who worked as a professional technical writer for years, I think I’m qualified to say that most datasheets suck in some way or another.) The datasheets (either explicitly, or by comparing several) will reveal the differences between component versions. This is something I find excruciatingly irritating and time-consuming, insofar as datasheets aren’t even remotely consistent in their presentation (even within a manufacturer!), sometimes hiding even critical differences as casual comments in the text, rather than in the spec tables. So you have to become expert at reading extremely carefully, and often at reading between the lines (e.g. if it says one version of it does X, then assume the others don’t). And sometimes, honestly, there’s no obvious way to know. (For example, I found that most resistor datasheets didn’t provide any indication of why you should choose this particular resistor model over the other 5 from the same manufacturer that have seemingly identical specs.)

Sometimes the difference is just how it’s shipped, like if it’s loose or taped for things like capacitors or transistors, or in tubes or not for DIP ICs. Resistors, for example, come both loose, taped (and rolled on a reel) and taped (and folded into a box) — and thus, if you’re ordering just 20 pieces, it’s irrelevant whether they cut them from a rolled tape or a boxed tape — it only matters if you want to buy the whole package. Sometimes the manufacturer has tweaked something inconsequential in the packaging (for example, to reflect a change in the company name, or if a product received an additional certification, despite needing no change in the product itself), but this also results in a new order code, and Digi-Key will have both, until the old stock has sold out.

The other thing is getting experienced with using the Digi-Key search, so you can narrow down to just the package type you want (by which I mean the format of the component, like DIP or surface-mount), as well as selecting normally-stocked only (eliminates tons of parts that are special-order only and irrelevant to the hobbyist due to large minimum quantities and lead time), and in-stock only if you need it now. (In addition to actual component parameters.) The quality of the search tool is, IMHO, a huge differentiator between vendors. Digi-Key and Mouser do pretty well, whereas others (like Conrad and Reichelt in Germany) are just awful. And either way, it takes practice using a given system.



--- Quote from: AnyNameWillDo on July 31, 2018, 08:38:32 pm ---tooki is going to kill me (I can see him going |O  :palm: :horse: :rant: :wtf: already) but I also tossed in some alligator clips. I know, I know, I know -- they suck and all, I just want to experience the suckage for myself and then better appreciate the minigrabbers. ;D Otherwise the mystery is going to eat at me.

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Eh, I mean, you might use them eventually. I think they used to be a lot more important, back when electronics used much larger components, without PCBs, spaced far apart. Today’s stuff is just so much smaller that the alligators are just too bulky and aren’t designed for grabbing small things.
AnyNameWillDo:
I'm getting a little more used to DigiKey and like it a lot.

And yeah the inconsistency in the data sheets is one of the main reasons I find them so painful. Like when I have 6 variants of something and I open all their sheets and each one is several pages in different formats, so I have to try to map and cross-reference which aspects are identical and which aren't, and so on.

However, DigiKey has a nice comparison tool that lets you hide common traits which I think is very helpful and at least provides some degree of cutting through the lack of standardization otherwise.
rdl:
That's exactly it. Even the minigrabbers are starting to seem big and clunky. I've been putting one or two of the smd size on my recent Mouser orders.


--- Quote from: tooki on August 02, 2018, 01:28:50 pm ---... I think they used to be a lot more important, back when electronics used much larger components, without PCBs, spaced far apart. Today’s stuff is just so much smaller that the alligators are just too bulky and aren’t designed for grabbing small things.

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