Actually DDR2 uses less volatge than either DDR and SDR memory. This is one reason why laptops quickly used DDR2 (even DDR2 400 when DDR400 elraedy existed) because they are of less power consumption (at a given speed of course).
2006/9/15, Cory Papenfuss <[EMAIL PROTECTED]>: > > >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 > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > -- Thibault Massart aka Thibouille ---------------------- *ist-D,Z1,SuperA,KX,MX, P30t and KR-10x ;) ... -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
