Good hobbyist source for ultracapacitors?

P

Paul Ciszek

Guest
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?

--
Please reply to: | "One of the hardest parts of my job is to
pciszek at panix dot com | connect Iraq to the War on Terror."
Autoreply is disabled | -- G. W. Bush, 9/7/2006
 
Paul Ciszek wrote:

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?
Click to expand...
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
 
On Mon, 21 May 2007 19:18:00 +0000 (UTC), the renowned
nospam@nospam.com (Paul Ciszek) wrote:

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?
Click to expand...
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
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Paul Ciszek (nospam@nospam.com) writes:
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
Click to expand...
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.
 
On Mon, 21 May 2007 19:18:00 +0000 (UTC), nospam@nospam.com (Paul
Ciszek) wrote:

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?
Click to expand...
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
 
On May 21, 12:18 pm, nos...@nospam.com (Paul Ciszek) wrote:
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
Click to expand...
has 1F 5.5 v caps for $3.50
 
In article <1179881039.845973.146630@o5g2000hsb.googlegroups.com>,
Tolstoy <kellrobinson@billburg.com> wrote:
On May 21, 12:18 pm, nos...@nospam.com (Paul Ciszek) wrote:
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
Click to expand...
Thanks. I finally found some on Digikey as well, searching on "capacitor"
instead of "supercapacitor" or "ultracapacitor".

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.


--
Please reply to: | "One of the hardest parts of my job is to
pciszek at panix dot com | connect Iraq to the War on Terror."
Autoreply is disabled | -- G. W. Bush, 9/7/2006
 
nospam@nospam.com (Paul Ciszek) wrote in
news:f3232m$f25$1@reader2.panix.com:

Thanks. I finally found some on Digikey as well, searching on
"capacitor" instead of "supercapacitor" or "ultracapacitor".
Click to expand...
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?
Click to expand...
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.
Click to expand...
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.
 
Paul Ciszek wrote:

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

Graham
 
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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