Yes, the main function of a low FSR cap in parallel with a
high impedance power source is to be a kind of intermediate
low impedance element, to supply high peak current demand
when it is necessary.  The main reason here is to allow a
high current =with= high voltage for a brief moment, what
is very difficult to acquire from a solar cell, for example.
Wagner.

Sean Breheny wrote:
>
> Hi John,
>
> At 05:40 PM 3/8/99 -0600, you wrote:
> [SNIP]
> >|Won't you actually achieve max. power transfer to the cap when the product
> >|of the voltage across it and the current thru it is maximum? This won't
> >|occur when you first hook it up because the voltage across the cap is
> >|initially zero,so the power transfered is initially zero.
> >
> [SNIP]
> >Suppose, however, that you have a device powered by a "9 volt"
> >battery which needs to drive a 100-ohm solenoid for 100ms with
> >at least 60mA.  If you have a 4,700uF cap in parallel with the
> >battery it will be able to supply that demand while dropping
> >less than two volts even if the battery is not in good shape and
> >has an internal resistance of 100 ohms (in which case connecting
> >a 100ohm load without the cap would cause the voltage to drop by
> >half, failing to meet the 60mA requirement).
> >
>
> I see,I misunderstood the original post,then,I should have followed the
> thread more closely. I thought that the original post was talking about
> simply using a battery to charge a cap,nothing else,and was saying that the
> power delivered to the cap was greatest when the cap was discharged
> completely.
>
> Thanks,
>
> Sean
>
> |
> | Sean Breheny
> | Amateur Radio Callsign: KA3YXM
> | Electrical Engineering Student
> \--------------=----------------
> Save lives, please look at http://www.all.org
> Personal page: http://www.people.cornell.edu/pages/shb7
> mailto:shb7@cornell.edu ICQ #: 3329174

--
--------------------------------------------------------
Wagner Lipnharski - UST Research Inc. - Orlando, Florida
Forum and microcontroller web site:   http:/www.ustr.net
Microcontrollers Survey:  http://www.ustr.net/tellme.htm