Preferred LiFePO4 USB charger/regulator IC

On 11/15/2013 4:10 AM, Clifford Heath wrote:
> On 15/11/13 19:30, mike wrote:
>> On 11/14/2013 10:57 PM, Clifford Heath wrote:
>>> Not a concern at this level - it's a ham radio device (fox transmitter
>>> and sniffer receivers).
>
>> I'd be interested in learning more about the device.
>> Back in the early '60's we had transmitter hunts on 6 meters.
>
> Great fun, yeah?
>
Way cool.
Come a long way in 50 years ;-)
Now all you need is a radio controlled drone to carry
the receiver and the camera and some defensive weapons
to take out the competition.

On 15/11/13 23:33, mike wrote:
> Now all you need is a radio controlled drone to carry
> the receiver and the camera and some defensive weapons
> to take out the competition.

Hah, good idea. It would need to be quick and have good duration.
Sometimes the fox is 40km away.

Actually one team hunts all bands on equipment that converts first to 
21.4MHz. It turns out that's inside a ham band, so we could legally 
transmit on their IF and see how good their shielding is :)

We had a balloon hunt at this year's competition, without anyone being 
told prior. There's an animation on youtube:
<http://www.youtube.com/watch?v=lJnpUvikUac>

Clifford Heath.

Den mandag den 11. november 2013 19.47.01 UTC+1 skrev edward....@gmail.com:
> > > We are using 800mAHr on 3.3V, so around 2.7 WattHour.
> 
> > 
> 
> > > People are leaving essential info on posting, which is really draining my mind reading power, especially over the net.
> 
> 
> 
> > He's stating the size of his load.  He hasn't expressed any preference
> 
> > for how long the battery needs to last --so, no claims as to how long
> 
> > it will take to *charge*, etc.  I.e., your (below) battery mmay give him
> 
> > an hour or two of runtime.  It may give *you* TEN hours, depending on
> 
> > *your* load!
> 
> > 
> 
> 
> 
> Hence, my joke about reading his mind over the net.  We need to know the size and type of battery involved, as well as load.  For example, you can pull half a watt out of a 3V 200mAHr coin cell at 5mA.  But at 50mA (typical 32 bitter), it would not last more than one-tenth of a watt.  So, it's better to spec the battery several time more than your load.
> 
> 
> 
> We looked at all kinds of batteries, including LiFePO4, but end up going back 
>to NiMH.  We can get 800mAHr (3 x AAA) for $2 and 400mAHr (3 x AAAA) for >
>$1.5.  Nothing Li* for less than $10.

http://www.hobbyking.com/hobbyking/store/uh_listCategoriesAndProducts.asp?cwhl=XX&idCategory=86&v=&sortlist=P&LiPoConfig=1&CatSortOrder=asc


-Lasse