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superchiku
04-06-2008, 10:09 PM
where can i get a 6V battery pack (NiMH ) and also charger in india???

jitun
04-07-2008, 12:04 AM
i will suggest you to use Li-Ion instead of NiMH.

http://www.robokits.co.in/products/?p=productsList&iCategory=6&sName=Power

and for charger use any free battery charger IC sample. Use LT1512 for simplicity or else you can use the better charger ICs fron Intersil (ISL6251). Ask for free sample of these and make a charger yourself. It will cost less.

superchiku
04-07-2008, 12:17 AM
well , i need exactly 6 v to power the servos , the li-ion batteries have a voltage more than that and plzz can u give the schematic of the charger

jitun
04-07-2008, 12:40 AM
you can (and should) use a voltage regulator(LM7806 for 6v) if your need stabilized supply.

And the schematic for battery charger is in the datasheet of the charger IC. Even a more simple charger IC with simpler circuit is from TI "BQ2057". look at its datasheet it has the schematic. Order a free sample of this IC. Use any wall mount adapter for the supply.

PS- For more varity LI-Ion battery packs look for
http://www.rajamanetelectric.com/battery_packs.html
don't mail then and wait for a reply. Call them for inquiry.

Btw you have to make pcb for this.I can help you in making PCBs if you wish.
I am from CET 8th sem.

superchiku
04-07-2008, 01:35 AM
i know how to make pcb's thanks for the help i just need to know abt the batteries

and also have u made any battery monitoring circuit bfore like with DS2478 , if yes then can u share how u did it?

jitun
04-12-2008, 12:12 AM
Use the BQ2057 from Texas Instruments for charging of Li-Ion cells. The circuit is too simple with charge status output(Charging or charged) and following all the specifications for Li-Ion battery charging.It even has optional input for battery temperature. Its a 8 pin IC so takes very less space. Try it.

superchiku
04-12-2008, 12:31 AM
well i ordered the bq2057 but their pins are so small and different
can u tell me how i solder them

jitun
04-12-2008, 12:59 AM
Today evening i received three pieces of these ICs. Btw which package u have ordered. I feel its easy to handle SOIC. SOIC is not that small to solder(I even had success with SOT23 package). If you can make a good PCB then you can solder the IC on it. And please use a pointed soldering iron. The soldering of SMD component will be easy.

superchiku
04-12-2008, 01:46 AM
where to get the pinted soldering iron in bbsr

jitun
04-12-2008, 01:57 AM
I got mine from kolkata. However i had seen the exact one at Khatri hardware store, Cuttack road. It cost around Rs300. Electronic house doesn't have the pointed Soldering irons.

superchiku
04-12-2008, 02:02 AM
electronic house is truly monopolising everything , we need other shops where we can get these parts instead of relying on electronics house

debu
04-12-2008, 09:42 AM
@superchiku: I don't recommend driving a servo directy via a 6v battery. The battery will give 6v only at its peak charge,and upto its rated current, after a while it will drop. If the supply is regulated with a 7806, then even if the voltage drops a little, you will get a steady 6v supply.

Regards,

Debu :)

superchiku
04-12-2008, 12:49 PM
well what ur saying is right , but u see that almost nothing is available here in bbsr so i was looking for these following things from the internet and not from any foreign site, from an indian site

1.molex connectors 3 pin and 2 2 pin housing
2.12v battery pack and charger
3.breakaway header pins
4.wire crimps

jitun
04-12-2008, 08:28 PM
Btw what battery u have decided to use and from where u got it?

superchiku
04-12-2008, 08:33 PM
i have no choice i have to use that triindia 8.4 volt battery to drive evry thing servos , motors, circuit 2100 mah