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LTSpice high voltage capacitors
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bitrex
Feb 4, 2016, 11:16:46 AM2/4/16
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LTSpice seems to have a discouraging lack of "high voltage" (> 100V)
electrolytic capacitors in its standard library.
Is there a third party library that's good to use?
Does it matter much for simulation purposes? Thanks.
electrolytic capacitors in its standard library.
Is there a third party library that's good to use?
Does it matter much for simulation purposes? Thanks.
Jim Thompson
Feb 4, 2016, 11:20:40 AM2/4/16
to
included capacitance variations with applied voltage.
For simulation purposes a capacitor is a capacitor is a capacitor...
...Jim Thompson
--
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I love to cook with wine. Sometimes I even put it in the food.
bitrex
Feb 4, 2016, 11:37:59 AM2/4/16
to
On 02/04/2016 11:20 AM, Jim Thompson wrote:
> On Thu, 4 Feb 2016 11:16:41 -0500, bitrex
> <bit...@de.lete.earthlink.net> wrote:
>
>> LTSpice seems to have a discouraging lack of "high voltage" (> 100V)
>> electrolytic capacitors in its standard library.
>>
>> Is there a third party library that's good to use?
>>
>> Does it matter much for simulation purposes? Thanks.
>
> No. The only time voltage on a cap would matter would be if the model
> included capacitance variations with applied voltage.
>
> For simulation purposes a capacitor is a capacitor is a capacitor...
>
> ...Jim Thompson
>
And I would guess that all things being equal, a higher voltage eletro
> On Thu, 4 Feb 2016 11:16:41 -0500, bitrex
> <bit...@de.lete.earthlink.net> wrote:
>
>> LTSpice seems to have a discouraging lack of "high voltage" (> 100V)
>> electrolytic capacitors in its standard library.
>>
>> Is there a third party library that's good to use?
>>
>> Does it matter much for simulation purposes? Thanks.
>
> No. The only time voltage on a cap would matter would be if the model
> included capacitance variations with applied voltage.
>
> For simulation purposes a capacitor is a capacitor is a capacitor...
>
> ...Jim Thompson
>
capacitor is going to have higher ESR for the same value, just because
the dielectric is going to be physically thicker and more loss is going
to be incurred polarizing it.
Don't know exactly, not like, a capacitor expert...
John Larkin
Feb 4, 2016, 11:47:03 AM2/4/16
to
>
>Don't know exactly, not like, a capacitor expert...
diodes.
Look up the typical ESR (and ESL if it matters) on a candidate cap and
force those values in Spice, internal to the cap or with external
parts.
--
John Larkin Highland Technology, Inc
lunatic fringe electronics
Jim Thompson
Feb 4, 2016, 11:51:28 AM2/4/16
to
nominal Spice capacitor is ideal.
Tim Williams
Feb 4, 2016, 7:38:18 PM2/4/16
to
"bitrex" <bit...@de.lete.earthlink.net> wrote in message
news:B7Lsy.278309$b8.5...@fx29.iad...
itself is a darn sight near ideal, compared to the dissipation factor of an
ugly old 'lytic!).
ESR is entirely due to electrolyte. Which is also why it varies so much at
low temperature -- ion mobility.
HV caps use thicker foil (with coarser etching and deeper anodization), so
the spiral has to be a little thicker for a given C*V rating, and will have
slightly fewer turns; so you should expect the ESR to be higher (less
electrolyte cross section), but not really by much.
Speaking of C*V rating, electrolytics are almost constant in C*V, with
respect to the rated values of C and V. Which is not the same as C*V^2,
which is energy. So they get quite a bit more energy-dense at high voltage
ratings, so if you ever needed to store just a huge wad of energy, on
relatively short notice, high voltage (up to 500V) is the way to go!
Tim
--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com
news:B7Lsy.278309$b8.5...@fx29.iad...
> And I would guess that all things being equal, a higher voltage eletro
> capacitor is going to have higher ESR for the same value, just because the
> dielectric is going to be physically thicker and more loss is going to be
> incurred polarizing it.
>
> Don't know exactly, not like, a capacitor expert...
Not by much. Certainly the dielectric isn't the problem (the dielectric
> capacitor is going to have higher ESR for the same value, just because the
> dielectric is going to be physically thicker and more loss is going to be
> incurred polarizing it.
>
> Don't know exactly, not like, a capacitor expert...
itself is a darn sight near ideal, compared to the dissipation factor of an
ugly old 'lytic!).
ESR is entirely due to electrolyte. Which is also why it varies so much at
low temperature -- ion mobility.
HV caps use thicker foil (with coarser etching and deeper anodization), so
the spiral has to be a little thicker for a given C*V rating, and will have
slightly fewer turns; so you should expect the ESR to be higher (less
electrolyte cross section), but not really by much.
Speaking of C*V rating, electrolytics are almost constant in C*V, with
respect to the rated values of C and V. Which is not the same as C*V^2,
which is energy. So they get quite a bit more energy-dense at high voltage
ratings, so if you ever needed to store just a huge wad of energy, on
relatively short notice, high voltage (up to 500V) is the way to go!
Tim
--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com
M Philbrook
Feb 4, 2016, 9:42:54 PM2/4/16
to
In article <JPKsy.320151$QG6.2...@fx31.iad>,
bit...@de.lete.earthlink.net says...
Why would you worry about that?
Jamie
bit...@de.lete.earthlink.net says...
Jamie
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