Good hobbyist source for ultracapacitors?

P

Paul Ciszek

Jan 1, 1970
0
I am googling around for ultracapcitors/supercapacitors, and most pages
want to sell me a prefab "power module" or "request a quote". Where is
the best place to order unit quantities of ultracapacitors of various
sizes for prototyping and general farting around with?

E

Eeyore

Jan 1, 1970
0
Paul said:
I am googling around for ultracapcitors/supercapacitors, and most pages
want to sell me a prefab "power module" or "request a quote". Where is
the best place to order unit quantities of ultracapacitors of various
sizes for prototyping and general farting around with?

You need to go to component distributors. Most google seaches for ultracaps will
return results for outfits selling upgrades for in car entertainment systems.

Graham

S

Spehro Pefhany

Jan 1, 1970
0
On Mon, 21 May 2007 19:18:00 +0000 (UTC), the renowned
I am googling around for ultracapcitors/supercapacitors, and most pages
want to sell me a prefab "power module" or "request a quote". Where is
the best place to order unit quantities of ultracapacitors of various
sizes for prototyping and general farting around with?

If you want the kind used for memory backup, try Mouser, Digikey etc.
Maybe Jameco or some of the surplus places could have some too.

If you're looking for the kind that have more oomph, you'll probably
have more trouble unless you get lucky with surplus.

Best regards,
Spehro Pefhany

M

Michael Black

Jan 1, 1970
0
Paul said:
I am googling around for ultracapcitors/supercapacitors, and most pages
want to sell me a prefab "power module" or "request a quote". Where is
the best place to order unit quantities of ultracapacitors of various
sizes for prototyping and general farting around with?
VCRs, tv sets, likely some digitally tuned AM/FM tuners or stereo receivers
to keep the memory alive while the unit is off. Perhaps some other
consumer electronic equipment that likewise has settings you want to
keep when off.

I know I've found them in VCRs and tv sets.

B

Brendan Gillatt

Jan 1, 1970
0
I am googling around for ultracapcitors/supercapacitors, and most pages
want to sell me a prefab "power module" or "request a quote". Where is
the best place to order unit quantities of ultracapacitors of various
sizes for prototyping and general farting around with?

If you're in the US, Solarbotics.com do some nice ones: 1Farad at
2.5volts.

If, like me, you're in the UK, try Total Robotics:
http://www.totalrobots.com/acatalog/Total_Robots_Capacitors_28.html
Brendan Gillatt
www.brendangillatt.co.uk
GPG: 0x6E265E61

T

Tolstoy

Jan 1, 1970
0
I am googling around for ultracapcitors/supercapacitors, and most pages
want to sell me a prefab "power module" or "request a quote". Where is
the best place to order unit quantities of ultracapacitors of various
sizes for prototyping and general farting around with?
www.allelectronics.com
has 1F 5.5 v caps for $3.50 P Paul Ciszek Jan 1, 1970 0 www.allelectronics.com has 1F 5.5 v caps for$3.50

Thanks. I finally found some on Digikey as well, searching on "capacitor"

Does anyone know how much "excess" you need on the voltage rating? If
I have a PV module that might provide 12V peak and a load that can run
at significantly less than that (voltage regulators, etc.) then what
voltage rating do I need on the ultracapacitor?

I am thinking I need about a Farad with a voltage rating of at least
15V; nothing seems to exist in that range. However, at least one
manufacturer says that you can string their ultracapacitors in series
to get higher voltages (at a lower capacitance, of course). If I were
using the ones Tolstoy describes, I would have to put three in series
to get a voltage rating of 16.5V and a capacitance of 1/3 of a Farad,
then put three of those strings in parallel to get 1 Farad.

Does anyone know if it is better to put them in series first or in
parallel first? i.e.,

|-C-C-C-| |-C-| |-C-| |-C-|
--|-C-C-C-|-- vs. --|-C-|-|-C-|-|-C-|--
|-C-C-C-| |-C-| |-C-| |-C-|

I am thinking that the latter is more likely to yield uniform voltage
across all of the caps. Either one is a nuisance.

L

Lostgallifreyan

Jan 1, 1970
0
[email protected] (Paul Ciszek) wrote in
Thanks. I finally found some on Digikey as well, searching on
"capacitor" instead of "supercapacitor" or "ultracapacitor".

I left off posting here till I knew whether you meant these, or the big
oomphy things used in car sound systems...

Electric Double Layer caps, GoldCaps (Panasonic brand). I also had trouble
once finding some on Digikey till I knew what type they were called by. Now
they group those with the aerogel, super and ultra all in one link it's
easier.
Does anyone know how much "excess" you need on the voltage rating? If
I have a PV module that might provide 12V peak and a load that can run
at significantly less than that (voltage regulators, etc.) then what
voltage rating do I need on the ultracapacitor?

Regulate before the caps. I think you probably meant that but if not,
you'll need to. Some kind of wide-ranging input DC-DC power converter..
I am thinking I need about a Farad with a voltage rating of at least
15V; nothing seems to exist in that range. However, at least one
manufacturer says that you can string their ultracapacitors in series
to get higher voltages (at a lower capacitance, of course). If I were
using the ones Tolstoy describes, I would have to put three in series
to get a voltage rating of 16.5V and a capacitance of 1/3 of a Farad,
then put three of those strings in parallel to get 1 Farad.

Does anyone know if it is better to put them in series first or in
parallel first? i.e.,

|-C-C-C-| |-C-| |-C-| |-C-|
--|-C-C-C-|-- vs. --|-C-|-|-C-|-|-C-|--
|-C-C-C-| |-C-| |-C-| |-C-|

I am thinking that the latter is more likely to yield uniform voltage
across all of the caps. Either one is a nuisance.

Either will do, but I'd favour the second. I've used the 1F and 0.33F
2.5V types in parallel with a laser diode with no problems, the diode
maintains a safe voltage of around 2.4, so you can operate close to limit.
If you're wanting the full voltage, you might want to use the second
network you drew, and across each set, a resistance. The value will have to
be chosen by trial and error, I think, but each should be equal, to make
sure the voltage is equally divided across the network. I think there is
some internal DC leakage with these caps, and if it's unequal, you might
get some capacitors seeing more voltage than others. If you omit the
resistors, the connections in your second layout will be better, as they'll
help to average out differences.

E

Eeyore

Jan 1, 1970
0
Paul said:
Does anyone know how much "excess" you need on the voltage rating? If
I have a PV module that might provide 12V peak and a load that can run
at significantly less than that (voltage regulators, etc.) then what
voltage rating do I need on the ultracapacitor?

The cap's voltage rating needs at least to equal the peak voltage output.

Graham

L

legg

Jan 1, 1970
0
Mouser stocks Powerstor Aerogel Supercaps from Cooper-Bussman, with
less than 100mOhm esr.

Maxwell Technologies sells small quantities of supercaps in 'D' cell
body sizes under the BCap or Boostcap trade name. These offer
interestingly simple mechanical possibilities for retrofit.

RL

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