ccumulator for a mobile device, a +/- 10% TOLERANCE

[Elvis P.]

Hi Folks!

I want to use an accumulator for a mobile device. the needs 5 V. it would be a good idea to have the charging parts and undervolt indicator in that device too. i would like to do that with an up/down switching supply which is able to supply within a +/- 10% TOLERANCE. does anyone have experience/tipps/advices relating to that topic???

thx in advance for your help
Elvis P.

 

[exata]

power supply

National has all the parts you need and also online simulation/design software at **broken link removed**

 

[shanren]

do you use a li-ion battery or NI-MH?the input voltage will decide what kind of converter you use,and the charing circuit.try w*w.linear.com and w*w.maxim-ic.com.they have lots of converter and charing ciruit.

 

[beuch]

I charge my accumulator with a constant current.

My accumulators support current constant charge.
I use a voltage regulator to provide the constant current. (look in datasheet of all classical regulator).

With this method, the circuit is simple but the charge duration is over 10 hours.

To reduce this duration you can use a fast charger (TI BQ20xx, National LM3647, MAXIM MAX712 ...), but you will pay !

The charge profile of your accumulator depends on the technology Ni-MH, Ni-Cd, Li-Ion. Have a look on battery manufacturer recommandations (SAFT, SANYO).

beuch