Sean
If I am not using the DVI encoder can I go lower? Is there a way to
disable the DVI encoder to save power other than removing it?
My plan is to use a buck-boost regulator from single cell lithium
batteries and set the output voltage to the lowest possible voltage I
can get away with.
Thanks,
Sean
We did some quick tests. It seems it's possible to do normal jobs with
3.6 V.
The reason we wanna go below 3.8 V is that there are lots of 3.6 or
3.7 V
batteries. We attached a DC power supply to the power jack and
supplied 3.6 V
to the beagle board. With that, we were able to boot the board all the
way in
to debian+X.
> The only place you can put the voltage is via the power jack. 3.8V will not
> cause any damage to the board. Technically you could go lower than that, but
> the DVI would not work. Doen't go below the specification for the
> TWL4030/TPS65950. You can disable the DVI device via SW which will result in
> a reduction of 100mA. If you lower the voltage to a point that the DVI isn't
> working, I can't guarantee what the current consumption would be. We have
> powered the whole board with DVI running from a USB Lithium pack for I think
> a couple of hours. Removing the SD card will also save power, around 50mA.
>
> Gerald
>
> On Tue, Nov 11, 2008 at 3:59 PM, Sean D'Epagnier <geckosena...@gmail.com>wrote:
>> > On Tue, Nov 11, 2008 at 2:44 PM, Gerald Coley <ger...@beagleboard.org>
>
>
> > Is there a risk of damage below 3.8v? I am tempted to try running a
> > little lower. Is it best to input the 3.8v at the 5v power jack? Is
> > there a better place to power the board from to reduce power
> > consumption.
>
> > If I am not using the DVI encoder can I go lower? Is there a way to
> > disable the DVI encoder to save power other than removing it?
>
> > My plan is to use a buck-boost regulator from single cell lithium
> > batteries and set the output voltage to the lowest possible voltage I
> > can get away with.
>
> > Thanks,
> > Sean
>
> > wrote:
> > > You can run from 3.8V but I would not go below that. The onboard
> > regulator
> > > provides power to the DVI encoder, so you need to have enough to keep it
> > in
> > > regulation. One note, the monitor ID may not work as it requires 5V to
> > read
> > > the ID. If you don't need this, it should be OK. Make sure it is well
> > > regulated.
>
> > > Gerald
>
> > > On Tue, Nov 11, 2008 at 3:21 PM, Sean D'Epagnier <geckosena...@gmail.com
>
> > > wrote:
>
> > >> Can't you save even more power by powering from less than 5v? I heard
> > >> talk of 3.8v. If you figure out how to do this I want to know so I
> > >> can do it as well.
>
> > >> Sean
>
Thanks.
On Nov 3 2008, 1:16 pm, Koen Kooi <koen.k...@gmail.com> wrote:
> Hi,
>
> Philip was asking about powerconsumption, so I put a fluke 87 meter in
> between the +5V and beagle. The results after some quick tests:
>
> uboot 2008.1orc2:
> ~290mA at uboot prompt
>
> 2.6.27-omap1:
> ~350mA at X desktop
> ~400mA using 100% cpu at 600MHz
>
> 2.6.27 omap-pm-next:
> ~275mA at X desktop
>
> Powertopreports with with 2.6.27 omap-pm-next:
>
> I am new to this. In order that I get this right, could you please
> send me the step by step commands to get the pm kernel and patches? I
> am using debian on my beagleboard. Will this work with the debian
> build?
It won't
regards,
Koen