capacitor ripple vs endurance & other questions

[PCBONEZ]

Re: capacitor ripple vs endurance & other questions

WOW!! KZE is higher ESR than FM!!!! Is KZG any better? Sorry for not looking at the spec sheets myself, I don't understand how to calculate ESR from a spec sheet.

Yup,

The interesting thing is, if you buy in lots of 10pc or more then many times FM are less expensive than caps with less good ratings.
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Only problem is sometimes FM are big for their uF and so won't fit.

[mockingbird]

Re: capacitor ripple vs endurance & other questions

Ahh.. so impedance is ESR. I was looking for Electrostatic Resistance.

[PCBONEZ]

Re: capacitor ripple vs endurance & other questions

Ahh.. so impedance is ESR. I was looking for Electrostatic Resistance.

Not ~really~ but close enough at 100kHz.

Lets run an example cap through the math so everyone finally gets it:
I chose a 1500uF 6.3v MBZ with ESR = 0.026 Ohms
[Middle of the normal range of caps on mobos and Rubycon gives actual ESR in data sheet vs Impedance.]

Z = Impedance
C = 1500 uF = 0.0015 F
ESR = .026 Ohm [squared = 0.000676 Ohm]
ƒ = 100 kHz = 100,000 Hz [Data sheet standard.]
p = PI = 3.14159
10 nH = 0.00000001 H
-- nH guessed as reasonable based on other reading. Is physical size dependent.
-- Lytics range from 4 nF for an itty bitty to 34 nF for a beer can cap.]

XC= 1 ÷ 2pƒC
2pƒC = 2 x 3.14159 x 100000Hz x 0.0015F = 942.477
XC = 1 ÷ 942.477 = 0.001061
XC = 0.001061

XL = 2pƒL
XL = 2pƒL = 2 x 3.14159 x 100000Hz x 0.00000001H = 0.006283
XL = 0.006283

(XL - XC) = 0.005222
(XL - XC)² = 0.0000273

Z² = ESR² + (XL - XC)² = 0.000676 + 0.0000273 = 0.0007033
Z² = 0.0007033
Z = 0.0265

Z is only 0.0005 different from ESR at 100kHz
That's less than 2% different.
.

[mockingbird]

Re: capacitor ripple vs endurance & other questions

I could never see the chalkboard in math class.

[Toasty]

Re: capacitor ripple vs endurance & other questions

[PCBONEZ]

Re: capacitor ripple vs endurance & other questions

I could never see the chalkboard in math class.

Not ~really~ but close enough at 100kHz.

Lets run an example cap through the math so everyone finally gets it:
I chose a 1500uF 6.3v MBZ with ESR = 0.026 Ohms
[Middle of the normal range of caps on mobos and Rubycon gives actual ESR in data sheet vs Impedance.]

Z = Impedance
C = 1500 uF = 0.0015 F
ESR = .026 Ohm [squared = 0.000676 Ohm]
ƒ = 100 kHz = 100,000 Hz [Data sheet standard.]
p = PI = 3.14159
10 nH = 0.00000001 H
-- nH guessed as reasonable based on other reading. Is physical size dependent.
-- Lytics range from 4 nF for an itty bitty to 34 nF for a beer can cap.]

XC= 1 ÷ 2pƒC
2pƒC = 2 x 3.14159 x 100000Hz x 0.0015F = 942.477
XC = 1 ÷ 942.477 = 0.001061
XC = 0.001061

XL = 2pƒL
XL = 2pƒL = 2 x 3.14159 x 100000Hz x 0.00000001H = 0.006283
XL = 0.006283

(XL - XC) = 0.005222
(XL - XC)² = 0.0000273

Z² = ESR² + (XL - XC)² = 0.000676 + 0.0000273 = 0.0007033
Z² = 0.0007033
Z = 0.0265

Z is only 0.0005 different from ESR at 100kHz
That's less than 2% different.
.

[Toasty]

Re: capacitor ripple vs endurance & other questions



BWAHAHAHAHAHAHAAAA!!!

[GameBooy2020]

Re: capacitor ripple vs endurance & other questions

I managed to find capacitors for all the other values except for the 470uf @ 25V (10x16mm).

I want to use either Nic Components NRSJ, NRSK, sanyo WG, or Rubycon ZLG, but I'm having a hard time finding someone who sells these capacitors. Does anyone know of any good suppliers that carry one of these brands in the specified size above?

[Toasty]

Re: capacitor ripple vs endurance & other questions

Where are you located? Profile location is blank...?

In USA, you ~generally~ won't find them. You may find 1 out of the whole group from a distributor who will only sell them in qty of 1,000 or more.

Use DigiKey, Mouser, Newark, badcaps.net.
Stick with Nichicon, Panasonic, Nippon Chemi-con, Rubycon, Samxon

Great overall selection and you won't pull all your hair out trying to find them...

[GameBooy2020]

Re: capacitor ripple vs endurance & other questions

Where are you located?

I'm located in winter springs, FL

Use DigiKey, Mouser, Newark, badcaps.net.

I've tried searching these places for the brands, but the only place that had the type and size that I needed was mouser (found nichicon hv, but they have none in stock & the lead time is 19 weeks). Guess I'll have to settle for a lower grade capacitor...

[momaka]

Re: capacitor ripple vs endurance & other questions

I managed to find capacitors for all the other values except for the 470uf @ 25V (10x16mm).

Are these for the CapXon KF replacements? If so, you didn't look hard enough .

United Chemicon KZE (ammo pack - cheaper):
661-EKZE250ETD471MJ1

United Chemicon KY:
661-EKY250ELL471MJ1

Nichicon HE:
647-UHE1E471MPD6

These are Mouser part numbers.

[kc8adu]

Re: capacitor ripple vs endurance & other questions

just get them from badcaps.net.problem solved!

[smason]

Re: capacitor ripple vs endurance & other questions

Not ~really~ but close enough at 100kHz.
.

Oh man, I just spewed beer out my nose.

[unitron]

Re: capacitor ripple vs endurance & other questions

The ratings to look at beyond uF and volts are ESR and Ripple.
[Remember going up in volts isn't a problem.]

ESR is isn't really Impedance (Z) - but:
At the 100kHz they use for data sheets Xc and ESL are at values such that *effectively* ESR = Impedance.
The actual equation is:
Z² = ESR² + (XL - XC)²
[Note: (XL - XC) must be corrected to a positive value if it isn't.]
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------SNIP-------

.

If XL-XC <0, then squaring that value will automatically result in a postive number, 'cause a negative number times a negative number is a negative negative (i.e., positive) number.

Now if the formula/equation called for raising it to an odd numbered power, then you would need to be sure to take the absolute value.


regards,
unitron

(who's currently screwing around with a DAC-19M015 out of a Westinghouse SK-19H210S)

[PCBONEZ]

Re: capacitor ripple vs endurance & other questions

XL-XC aren't squared in all equations and the value must not be <0.

[Toasty]

Re: capacitor ripple vs endurance & other questions

Oh, this is tooo funny -

>>(who's currently screwing around with a DAC-19M015 out of a Westinghouse SK-19H210S)<<

Look up "DAC-19M015" in Google and go to the ShopJimmy.com result.

If you don't see it in the small pic, use the enlarge function...

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.

.

Well??

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.

.

Come on.....

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.

.

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Comes with pre-blown cap!!




Send me a dozen, will ya?!?

[Per Hansson]

Re: capacitor ripple vs endurance & other questions

Hahahaha, that was the best one today by far

[unitron]

Re: capacitor ripple vs endurance & other questions

XL-XC aren't squared in all equations and the value must not be <0.

It's been enough years since electronics classes that I don't recall the others that involve both inductive *and* capacitive reactance, and the books aren't ready to hand, but I was only talking about the equation you actually used, which is basically the one for impedence--resistance along the X axis, starting at 0 and moving to the right, XL - XC along the Y Axis, and impedence is the hypotenuse of the resulting triangle, in other words, the Pythagorean Theorem--called for the squaring of XL-XC.


Now that I think about it, staring points and directions don't really matter. You take resistance, put it at a right angle to the difference between inductive reactance and capacitive reactance, and measure the length between the two unconnected line ends, and that's your impedence. Polarity/sign doesn't matter because what you're dealing with are lengths, and there isn't really any such thing as a negative length. Either something has length or it's a one-dimensional point.

[unitron]

Re: capacitor ripple vs endurance & other questions

Oh, this is tooo funny -

>>(who's currently screwing around with a DAC-19M015 out of a Westinghouse SK-19H210S)<<

Look up "DAC-19M015" in Google and go to the ShopJimmy.com result.

If you don't see it in the small pic, use the enlarge function...

.

.

.

Well??

.

.

.

Come on.....

.

.

.

.

Comes with pre-blown cap!!




Send me a dozen, will ya?!?

If you're talking about the one in the upper right hand corner, I've already got one domed just like that, although without the sporty splash of brown.


Discount-Merchant has a picture of one where the caps are actually going to wait until you've gone to the trouble of installing the board and applying power before going bad, but they're currently out of stock.

[PCBONEZ]

Re: capacitor ripple vs endurance & other questions

It's been enough years since electronics classes that I don't recall the others that involve both inductive *and* capacitive reactance, and the books aren't ready to hand, but I was only talking about the equation you actually used, which is basically the one for impedence--resistance along the X axis, starting at 0 and moving to the right, XL - XC along the Y Axis, and impedence is the hypotenuse of the resulting triangle, in other words, the Pythagorean Theorem--called for the squaring of XL-XC.


Now that I think about it, staring points and directions don't really matter. You take resistance, put it at a right angle to the difference between inductive reactance and capacitive reactance, and measure the length between the two unconnected line ends, and that's your impedence. Polarity/sign doesn't matter because what you're dealing with are lengths, and there isn't really any such thing as a negative length. Either something has length or it's a one-dimensional point.

It's not 'my' equation.
You can grab a copy at most any cap manufacturer's site.
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They don't [or didn't used to] teach ESR in school.
The 3 foot tall stack of Navy NEETS training manuals as 2 or 3 sentences about ESR and that's it.
Civilian programs covered it about as well.
It got a casual mention saying it wasn't significant and it wouldn't be included in the equations.
It wasn't significant because they teach DC and jump into RF without covering anything in between.
At DC ESR is zero and at RF it isn't significant compared to Xc.
It's in between DC and RF were ESR matters.
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The reason I explained it that way is so people that aren't math gurus would understand ESR and not trip over the math.
That variable is the difference between XC and XL and which one is greater changes which means negative numbers are possible.
Either [XC-XL] or [XL-XC] work as long as it's + or zero.
The way I deliberately worded it is JUST FINE and deliberately avoided a more complicated discussion that could confuse people.
.