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Electrolytic capacitors spacing & voltage

Started by Primus720, April 24, 2018, 10:22:58 PM

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Primus720

Hi crew. I am currently trying to build a Leviathan delay [wamp faux echo]. At this state, I'm about to order parts, and ran into a bump.

The Leviathan delay needs a few electrolytic capacitors. I need a 10uF, 47uF, 100uF, the PDF says 16v min. On the website (Tayda) I find mixed sizes and voltage.

10uF  5x11mm 25v
47uF  5x11mm 50v
100uF  6x11mm 50v

Would it be okay to use these components on this pcb?

sonnyboy27

yes. You can always use a capacitor that's rated for a higher voltage than is called for.

They may be a bit bigger than the 16V ones so I'd solder them in last. You can always leave some lead space so you can bend them over other flat parts (like resistors and such) if you need some more room.

PariahBrothermann

They'll be just fine  :D.. Generally it's a good plan to at least double the voltage e.g. 9v = 18v plus. That way you reduce the risk of damage. Mixing voltages isn't an issue, as your circuit shouldn't get anywhere near the 25v, 100v, etc. See it as a maximum, like headroom. Hope that makes sense? Size doesn't matter ( I keep telling myself!  ::) ) .... Best of luck with your build. The leviathan is a great delay.

ahiddentableau

The only thing you have to worry about when using bigger caps than is required is that they'll fit in whatever kind of enclosure you plan to use.  As a general rule, 11mm high caps will fit in anything 1590B depth or bigger.  So the Tayda caps will almost certainly be fine.

madbean

Are there any size specs for the caps? 100uF @ 50v could actually be quite large. While an 11mm will certainly fit in a 1590BB for height, the actually width of the caps could be too large for the space allotted on the PCB.

It's probably not a big concern with the Leviathan because the 100uF has a lot of space around it. But, if you are planning on purchasing more than you need for future builds....

For reference, I use Lelon low profile electrolytic caps in most of my builds. The 100uF are 8mm diameter but I generally design my boards to accommodate that size. And, they are only 5mm tall!:
https://www.mouser.com/ProductDetail/140-SS101M1E0805P

https://www.mouser.com/Lelon/Passive-Components/Capacitors/Aluminum-Electrolytic-Capacitors/Aluminum-Electrolytic-Capacitors-Leaded/_/N-75hqw?P=1z0x0woZ1z0zl3mZ1yx4awy

Primus720

#5
Great, that's good to know. Thanks for the help/advice guys.

On another note, I am unable to find some of the ceramic caps. Can I use MLCC (leaded) instead? And, it is possible to mix MLCC and ceramic caps on the same build?
Similar, Can I use Poly Film box with Mylar on this build?

Here the link to the 5pF ceramic cap I am looking into:
https://www.mouser.com/ProductDetail/810-FG18C0G1H050CNT6

I've attached 3 pic for easy reference to the build

m-Kresol

Quote from: Primus720 on April 27, 2018, 05:15:11 AM
Great, that's good to know. Thanks for the help/advice guys.

On another note, I am unable to find some of the ceramic caps. Can I use MLCC (leaded) instead? And, it is possible to mix MLCC and ceramic caps on the same build?
Similar, Can I use Poly Film box with Mylar on this build?

Here the link to the 5pF ceramic cap I am looking into:
https://www.mouser.com/ProductDetail/810-FG18C0G1H050CNT6

I've attached 3 pic for easy reference to the build

You can basically mix whatever you want with our builds. Our DC bias voltage is so low that you will never run into any piezoeffects (humming/ringing) of X7R or C0G MLCC caps and we don't have frequencies > 100 kHz so drop in capacity for polyester/mylar will not be an issue either. The MLCC you chose should be fine (I didn't check lead spacing, you should)

Basically, what you need to watch is lead spacing to fit the pads on the pcb and component size. The tayda greenies get large very fast, so I would stick to box caps. The dielectric type (PP, Polyester, polycarbonate, etc.) is not important for us.

Quote from: PariahBrothermann on April 25, 2018, 09:33:43 AM
They'll be just fine  :D.. Generally it's a good plan to at least double the voltage e.g. 9v = 18v plus.
that's a good idea. in some cases, where size is critical, it's enough to add 1/3 of the operational voltage as safety margin.
I build pedals to hide my lousy playing.

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