buying stuff from mouser, shipping fees are crazy high

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marcn
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Post by marcn »

Try it 8-)
As you mentioned 10uf in ceramic is hard to come by and if you find it its gonna be pretty big. That's reason enough to go electrolytic.
In case you're worried about 'sound' these sit in your psu path and all they do is store a charge so that the supply to your IC's or transistors is constant.
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mlatu
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Post by mlatu »

Ah, so it's their size why you would avoid them, I haven't had my hand on many capacitors so I don't know how big they're gonna be.

In the picture they all look the same to me XD

https://i.ebayimg.com/images/g/y90AAOSw ... s-l300.jpg
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cygmu
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Post by cygmu »

mlatu wrote:Huh, as you probably can imagine I didn't see that tiny plus sign.

I'm still curious about what would happen if I used an unpolarized cap there.
You can always replace a polarized capacitor with an unpolarized one. The polarization is a restriction on use rather than being advantageous in any way.

The issue with such a replacement is that you will inevitably be using a different type of capacitor (film or ceramic in place of electrolytic or tantalum, say) and different caps have different characteristics.

It is not at all true that ceramic caps are "close to ideal". Regular ceramics, with dielectrics characterised as things like X7R, have some decidedly non-ideal properties. The main one is that their capacitance varies with the voltage across them. In the audio path, this leads to distortion: as the signal (and therefore voltage) varies, the capacitance varies so the way in which the signal is transmitted varies.

For power supply decoupling, where the voltage is steady, it means that you may not be getting the capacitance you expect: a 10uF ceramic with 12V across it could appear as a 4uF capacitor, for example.

The exception to this is C0G ceramics, whose properties are really excellent in almost every respect. They are very common in small values, and essentially unavailable in larger values.

The big caps at the power input of a module should probably be electrolytic, not because of the polarisation but just because they are among the best caps for the purpose at the value you need. The smaller decoupling caps near ICs can be regular ceramic, e.g. 100nF, because even if they behave as 10nF caps when voltage is applied, they will still do the job. For caps in the audio path, C0G or film are good.

Well, that's my understanding anyway.
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mlatu
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Post by mlatu »

Hm, allright, I was refering to some chart comparing various capacitor types' impedences at increasing frequencies.

http://www.iequalscdvdt.com/esr.html


I have to admit I didn't read the text, yet. :doh: I probably should.



You said:
For power supply decoupling, where the voltage is steady, it means that you may not be getting the capacitance you expect: a 10uF ceramic with 12V across it could appear as a 4uF capacitor, for example.
Is that example cap rated for around double the voltage?
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cygmu
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Post by cygmu »

mlatu wrote:
For power supply decoupling, where the voltage is steady, it means that you may not be getting the capacitance you expect: a 10uF ceramic with 12V across it could appear as a 4uF capacitor, for example.
Is that example cap rated for around double the voltage?
Yes, the surprising finding in this report
https://www.maximintegrated.com/en/app- ... vp/id/5527
was that the derating of capacitance with bias voltage does not depend as much as you might expect on the voltage rating of the cap. The package size seemed to matter more -- smaller package caps behaved worse. This might mean that through hole parts are among the better ones, because they will tend to be large, though that might not be universal.
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mlatu
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Post by mlatu »

This is ridiculous.

Like selling a tank that decreases in size if you increase the diameter of the hose you want to fill it with... I know it's not a good analogy, and I guess there are usecases where it doesn't matter. Or perhaps where this is even beneficial.

I guess I'll try both, film and ceramic and try to see where I can get away with using the cheaper ceramic ones.
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cygmu
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Post by cygmu »

You will almost certainly get away with using any kind of capacitor in the decoupling role anyway. I imagine there is no precise way to calculate what is needed in a module without knowing what the rest of the system is, so people use 10uF or 22uF as a rough “good enough” attempt to smooth out power transients.

This thread has made me a bit nostalgic for the days when my Mouser orders were below the free shipping threshold and I had to combine them or wait or find other sources. Doesn’t seem to happen now...
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Re:

Post by dummy0 »

zorglub76 wrote: Thu Aug 30, 2018 5:52 am I know that pain. Here, in Serbia, I'm paying 30EUR for shipping, and if my order is over 50EUR, taxes kick in (customs, VAT, DHL services etc.), which add up to almost 130EUR for a 51EUR order.

Anyway, I now mostly buy from Arrow and Farnell, which have free shipping. Also, Arrow has most of the things that you can find on Mouser or DigiKey. I've seen a banner on Arrow's site saying that there's an option to get them pay all the customs expenses, but I haven't checked this. The only downside of Arrow is that you'll get huge amount of boxes and bags and antistatic bags and paper and similar junk for just a single multiturn trimpot (happened to me).
Hey zorglub,

Which shipping service were you using? I need some components from mouser, and International priority is too expensive. I need some advice bc I' m from Serbia too and wouldn't like paying 60eur for a 30eur order :despair:
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solar1
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Re: buying stuff from mouser, shipping fees are crazy high

Post by solar1 »

i had a salesperson from Mouser tell me the high cost for shipping one tiny part is because they figured out a minimum shipping/handling cost in a attempt to cover their handing of so many millions of orders...that way it spreads the cost out over many customers. (heaven forbid, they would cut into their profit margins ...why should they pay for the part picker when it can be passed on to the customer? :)

I know im being a bit snarky, but it's rough for an old guy on a fixed income to pay $8+ for a tiny transistor!
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Post by jorg »

mlatu wrote: Thu Aug 30, 2018 8:01 am Hm, I was certain digikey only sells to companies.. perhaps because they wanted to set up some sort of account when we ordered a couple of parts at work.

Well, thanks for enlightening me.

I'll be spending a couple of sleepless nights comparing prices now :D
I've been buying from them since I was a teen in the 1970s. They're very friendly to hobbyists.
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joem
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Re: buying stuff from mouser, shipping fees are crazy high

Post by joem »

solar1 wrote: Tue Nov 02, 2021 12:03 pm i had a salesperson from Mouser tell me the high cost for shipping one tiny part is because they figured out a minimum shipping/handling cost in a attempt to cover their handing of so many millions of orders...that way it spreads the cost out over many customers. (heaven forbid, they would cut into their profit margins ...why should they pay for the part picker when it can be passed on to the customer? :)
You're paying for their employees one way or another. There's no money they can use to pay the shipping people that doesn't come from the customer. I would much rather have the possibility of ordering single pieces and paying a bit more for handling than not even having the possibility of single piece orders.
solar1 wrote: Tue Nov 02, 2021 12:03 pm I know im being a bit snarky, but it's rough for an old guy on a fixed income to pay $8+ for a tiny transistor!
A bit of snark in response: Maybe you shouldn't be ordering just one transistor at a time. It's only $8 per transistor if you're ordering single quantities. :)
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solar1
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Re: buying stuff from mouser, shipping fees are crazy high

Post by solar1 »

i realize we all pay one way or another. this only happened once in doing a emergency repair for a long term customer whom was fine with the cost, i was not. Please rest easy. it will be alright.

i buy from mouser quite often, try to relax. i was only trying to make a point.
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EATyourGUITAR
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Re: buying stuff from mouser, shipping fees are crazy high

Post by EATyourGUITAR »

At work I recently dropped mouser for master electronics. I also started using arrow and AVNET. It depends what you buy and how much you buy. If you are spending $10,000 you can have a team of people in sales and engineering working for you free to find substitutions, call the manufacturer, read datasheets etc.. very happy with the switch. I use allied electronics to browse for components by price or most popular just to get part numbers. But the price from allied has always been poop. I also use factorymation and a few other vendors but this is for industrial electrical so not really relevant here. Master electronics has Panasonic caps in stock. Check them out.
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d.simon
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Re: buying stuff from mouser, shipping fees are crazy high

Post by d.simon »

One time I ordered so much from mouser they had to split the order into 2 separate ones. about 800 line items at $2200. I was imagining some warehouse guy saying WTF???

They way I was able to do that was with a script I wrote for managing projects and BOMs. A funny side effect is when there's a bug in the script - so I might get some extra or unknown parts if I don't go over the final order with some care.

...I started with an interest in synths and I'm here now with a new hobby of BOMs and parts/inventory management. :hihi:

I used to organize the parts like general inventory until I realized I'm mostly buying for specific projects. So I bag them in kit format...and if multiple projects use the same part I organize that alphabetically by project name. So the highest project on the list (that isn't finished) will contain the part.

Unless its resistors or caps - those are kept separately organized (alphanumerically) by my own customer id. (and NOT by value)

The customer ID is key for me - a custom ID that can be tagged onto the labels. But before I used that I could still organize by a mouser line item ID.

For projects...there's two levels of sorting - by project name, and then by customer ID. My customer Id's are of the format jn19_XTAL_700 - where jn19 would be my own order tag (June 2019) followed by a general category (XTAL, R.T, R.805, C.T, etc - R.T = Resistor through hole) followed by my own line item number for that order (an absolute number from 1 to X of the entire order - not based on category)

all those are located on spreadsheets too besides the physical goods.
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EATyourGUITAR
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Re: buying stuff from mouser, shipping fees are crazy high

Post by EATyourGUITAR »

Funny I get flagged as a bot on mouser but your bot gets through.
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d.simon
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Re: buying stuff from mouser, shipping fees are crazy high

Post by d.simon »

EATyourGUITAR wrote: Mon Nov 08, 2021 1:09 pm Funny I get flagged as a bot on mouser but your bot gets through.
It doesn't crawl the system...mostly I enter the mouser numbers on the separate project bom spreadsheets by hand (or from an edited BOM I get from the internets).
so the only thing that could be detected as a bot would be the order upload...which I do with Mouser's BOM spreadsheet importer.

Before order upload I manually iterate the script through the order making sure to combine compatible components across projects...so I don't get a bunch of different brand's of 1k 5% resistors for example.

Once the order is uploaded I review it and adjust quantities (like with resistors to get the qty discounts)
Its a slightly iterative process - For example if some parts are backordered I look for alternates .

I do recall some sort of bot detection one or two times.
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EATyourGUITAR
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Re: buying stuff from mouser, shipping fees are crazy high

Post by EATyourGUITAR »

I had to long press with the mouse on an anti-bot button.
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zorglub76
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Re: buying stuff from mouser, shipping fees are crazy high

Post by zorglub76 »

dummy0 wrote: Tue Nov 02, 2021 11:36 am Hey zorglub,

Which shipping service were you using? I need some components from mouser, and International priority is too expensive. I need some advice bc I' m from Serbia too and wouldn't like paying 60eur for a 30eur order :despair:
Sorry, I haven't been using MW for some time...
I'm still not using Mouser, unless it's the only way to get some parts. I usually wait for months and then order everything I need from them.
I mostly use LCSC now (~$10 shipping), and sometimes TME (15eur shipping)
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