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Claimed "1/4 watt" through-hole resistors from Amazon seller "Eamasawa"

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Siwastaja:
Simon is fundamentally right, you should primarily look at specs, and let the manufacturer choose the best internal materials and construction techniques to achieve the specs; it shouldn't matter.

This being said, it really does not hurt to understand what goes into manufacturing of parts, because the spec sheets may fail to capture some important or difficult-to-put-in-numbers parameters.

I have observed that many engineers, especially of older generations, do tend to rely too much on their intuitive generalization based on the "types" or "construction techniques" of the parts, and rules of thumb thereof. "Use a high-ESR capacitor at regulator output for stability." vs. almost all modern regulator ICs from the last 20 years are stable with zero ESR. The problem is, this unofficial data gets old; while spec sheets don't lie (except when they do lie!).

But it would be stupid not to augment your design process with such experience, just keep the main focus on the actual data instead of generalizations and always be ready to challenge your own generalizations.

Simon:
I read all chip datasheets very carefully especially regulators. Some say don't put more that "x µF" some say make sure the ESR is over this or under this. Of course it depends on what you are designing for. I usually have to work with -46 to +85-125 depending on location so what the thing is made of really falls out in the wash of the search. I spent 2 days picking inductors and capacitors for a switch mode regulator, but I will just use descriptive codes for resistors like 1kR_0805_1%_100ppm_-55/+125C and let the assembly deal with that. For bread boarding it really does not matter.

Simon:
I have not too long ago heard completely contradictory views on tantalum's cause there is a mix of what modern parts do and what older people remember them as being some decades ago. I avoid them anyway based on price.

SilverSolder:

Making a cost optimized product that still works well is a worthy engineering challenge.   Choosing components that do the job well and reliably, while not costing much, probably requires "bending the rules" a little - the trick is to bend, rather than break them!  I would guess it takes quite a bit of testing to end up with a good compromise.

floobydust:

--- Quote from: Simon on September 19, 2020, 09:12:57 am ---I have not too long ago heard completely contradictory views on tantalum's cause there is a mix of what modern parts do and what older people remember them as being some decades ago. I avoid them anyway based on price.

--- End quote ---

It's not older people remembering what the parts were like decades ago- it's knowledge that electronic components have many parameters that aren't on the datasheets.
Example is voltage derating tantalums, how much noise they have, their lifetime compared to ceramic capacitors which age as well.
Example is 1/4W resistor voltage coefficient of resistance, difference between alloys on the leads, how much power they are good for in real life.

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