EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: watchmaker on November 15, 2023, 05:26:31 pm
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As a very small payback, here is how I am storing transistors.
They are in vials that fit standard testube racks. Labeled on top and grouped by type. No searching of drawers.
Regards,
Dewey[attach=1]
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Neat! :D
Though I see one problem with expensive parts or use in professional(1) context: ESD. Perhaps pouring out the parts on an ESD mat before use is a good idea.
Glass is not dissipative, so any charges accumulating on parts will stay there. Glass is also the second material for which the triboelectric effect (https://en.wikipedia.org/wiki/Triboelectric_effect) has been discovered and a classic element of electrostatic demonstrations. I do not know, if the effect is present while rubbing against epoxy. If it is, you see the problem. :)
Obviously your idea is still much better than any other non-ESD-stafe container, because it’s “mechanically” much more convenient. :D
(1) For hobbyist uses losing one in a thousand cheap parts may not even be noticed, there are greater dangers to components than the container, and the consequences are usually a bit of head scratching and more soldering.
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Neat! :D
Though I see one problem with expensive parts or use in professional(1) context: ESD. Perhaps pouring out the parts on an ESD mat before use is a good idea.
Glass is not dissipative, so any charges accumulating on parts will stay there. Glass is also the second material for which the triboelectric effect (https://en.wikipedia.org/wiki/Triboelectric_effect) has been discovered and a classic element of electrostatic demonstrations. I do not know, if the effect is present while rubbing against epoxy. If it is, you see the problem. :)
Obviously your idea is still much better than any other non-ESD-stafe container, because it’s “mechanically” much more convenient. :D
(1) For hobbyist uses losing one in a thousand cheap parts may not even be noticed, there are greater dangers to components than the container, and the consequences are usually a bit of head scratching and more soldering.
The vials are plastic. While I had not thought about ESD, I do use an anti ESD mat and a ground strap.
I may have been naive, but I saw many assortments put up in plastic boxes. And the grab bag these came from was made up of baggies. I will check a couple numbers to see if they test ok.
Thanks,
Dewey
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So as not to be a tease, I looked at ebay where I had purchased my case of vials. The racks are on Amazon.
There are smaller lots. I bought my case 15 years ago because I was selling several thousand micro drills (never again!! Too old to have my wife leave me!).
Something like this: But ensure the vials are 15 or 16 mm in diameter. Smaller becomes too small for the transistors, larger will not fit the rack. And as cautioned above, do not use glass.
https://www.ebay.com/itm/165917768416 (https://www.ebay.com/itm/165917768416)
I thought about trying to distribute some of mine, but see above.
Regards,
Dewey
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I want to be clear, that I do not want to criticize your idea or suggest its unsuitability. In terms of ESD it’s no worse than any other solution, which does not care about static charges. And that covers majority of what hobbyists use. It’s just important to be aware of shortcomings. :D
Answering your question, which — please — should not be taken as discouraging you from using the vials or being too scared of the problem: depends.
Many hobbyists are unaware or wouldn’t spend money on ESD safe equipment. So yes, you will see a lot of poorly stored components. Does it matter? In my opinion, in non-professional context it matters little. Avoid if possible, but chances of encountering problems are low.
“Plastic” is an extremely wide group of materials. The sole properties shared are the ease of shaping at industrial level and consisting of polymers. In that group are materials, which are either safe by themselves or may have surface treated to be safe. Dissipative/conductive, antistatic and shielding bags are a common example — components often come in these.
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Not frightened, just took it as sage advice. Besides, buying used "NOS" devices is a crapshoot. We have no idea how they were handled. For this reason I will not buy ICs (have not yet) unless they come with a return privilege. Even buying components in factory packaging can be a gamble.
OTOH, not sure there is a disadvantage to polycarbonate vials over plastic storage boxes or plastic bin compartments. Quick spot checks revealed no damaged MosFets.
I will also add that NOS components should not be used in critical applications. Good for learning and mockups, but not for final circuits. NOS parts are like buying oil on ebay. A professional only uses oil purchased directly from a distributor and charges the cost against the work. I doubt any professional would use NOS components, even sealed in plastic.
This thread is a very good place for your cautionary post. It is beginners who are trying to build a stock of parts. It is a good time to learn ESD prevention. Especially handle MosFets with care. Have not yet blown one, but I use the strap and mat. And I never wear synthetics in the learning lab.
I did mishandle an HP3457 main board, but I think that was more a space issue than ESD. So I expanded my space. Price of education. SO now I have a front panel nicely milled for a replacement LCD display w/ backlight and need to decide where I go from here. Sits in a corner giggling at me.
It all comes down to price. Never bet more than you can afford to lose. If I can buy at a price where a dozen components out of 50 or 60 are likely to be good, then it makes sense. The issue is many sellers think they are sitting on gold and do not realize it is nothing more than sand (Si). They can sit on it.
In Maryland in the 1980s there was an auction of 200 cars in a field. Very sought after models, Roadmasters, Dusenbergs, etc. Owner had been offered prices over the previous 30 years but always responded "They will be worth something someday". They were: $25 each. Trees through the engine compartments.