My memory is a bit foggy on this subject, but isn't Samsung one of the big battery suppliers?
On 9/15/06, Cory Papenfuss <[EMAIL PROTECTED]> wrote: > > >There have been complaints about lack of AA battery power, and many felt > > >abandoned by Pentax engineers. But in fact, I don't think they have a > > >choice. K10D requires much higher voltage to run. > > > > Nope. Voltage is a non-issue these days because single-chip switching > > power supplies are small, cheap and have such amazing efficiency that > > they can be used to step up voltage almost anywhere. (In fact, I > > wouldn't be surprised if they weren't already used in the ist series > > of DSLR's) Current draw and having a battery with sufficient energy > > density are the two real issues. I'd have been happy if they'd just > > built the K10D around CRV3 rechargeables with an AA option. Still, it > > looks as if the battery grip may have sufficient space for a four-AA > > battery option. Keeping my fingers crossed. > > > > > Thanks for that comment so I didn't have to make it... :) > Switching converters are simple and efficient to do anymore. Like you > said, I'd be very surprised if the existing cameras didn't already use > them... since off-the-shelf CPUs are 3.3v, etc. Linear regulators are out > of the question for that sort of thing. > > That said, many of the high-power devices are probably not > regulated. Things like the AF motor don't need regulation so much... > they'll just run slightly slower/faster if the batteries are different. > Things like the flash recharge circuit and backlight driver already have > converters to get to the high voltages required. Having designed a number > of these types of circuits, I can say that one of the main troubles is > *peak* power requirements, not average. Peak requirements are what all > the devices need to be sized for.... average just the heat sinks. > > The SR system probably takes a pretty sizeable peak power, as well > as requiring a lot of EMF (voltage) to manipulate the currents in the SR > coils quickly. Not a lot of average power, but lots of instantaneous > power. Also, the DDR memory touted and the fast sensor readout/refresh > take lots of peak power. > > It's still somewhat unfortunate. NiMH does have a lower energy > density per *mass*, but actually fairly comparable per *volume*. > http://tinyurl.com/jjl84 > > My guess is that Samsung talked 'em into it to keep the > design/production costs down. > > -Cory > -- > > ************************************************************************* > * Cory Papenfuss, Ph.D., PPSEL-IA * > * Electrical Engineering * > * Virginia Polytechnic Institute and State University * > ************************************************************************* > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
