Pre-Made DC-DC Converters...Question?

XFactor · Post by **XFactor** » Tue Mar 07, 2006 7:44 am

Ok so i looked around and found this page:
http://www.build-it-electronics.com/page2.htm

Can anyone tell me if any of those converters will work with a battery with an output voltage of 7.4v?

Post by **marshallh** » Tue Mar 07, 2006 10:24 am

I doubt any of those can handle the current that the N64 requires.

Have you tried the TI converters?

joevennix · Post by **joevennix** » Tue Mar 07, 2006 12:02 pm

I used a 7.2V battery with a TI converter and it worked great! I'd highly recommend them, plus they're FREE.

XFactor · Post by **XFactor** » Tue Mar 07, 2006 2:08 pm

Thanks Marshall for clarifying that.

joevennix...how did you use the TI converter? did you build your own board? if so, how and where can i find a guide that tells me how to do it?

daguuy · Post by **daguuy** » Tue Mar 07, 2006 3:47 pm

it's just a doohicky with 3 pins: input, ground, and output. you put a 100uf cap between the output and ground. it's that simple

XFactor · Post by **XFactor** » Tue Mar 07, 2006 4:05 pm

Ok i just need clarification because i have seen many diagrams that i cannot possibly decrypt (i am not really educated as to converters)...

I need to buy this converter (per Timmeh's instructions for a 7.4v battery):
http://focus.ti.com/docs/prod/folders/p ... 65131.html

It will most likly run off of one of these two batteries:
http://www.batteryspace.com/index.asp?P ... rodID=2326
or
http://www.batteryspace.com/index.asp?P ... rodID=2312

I am more leaning toward the first since it conserves considerable space. I would then buy a 100uf cap and a board to house it.

So after all that crap is allocated, this would be the ideal configuration:
input:7.4v> v[board]v output:3.3v>
{battery}--------[TI converter}{100uf cap]---------N64

daguuy, can you confirm this is all i need? This converter has been the one thing i cannot get a clear answer on from pretty much everyone else here.

daguuy · Post by **daguuy** » Tue Mar 07, 2006 4:13 pm

i have no idea how to use that dc-dc convertor. i don't know if you need a special kind of dc-dc (buck boost or whatever it's called) with lithium batteries because i don't know much about those so i can't help you there. if you don't need a special dc-dc convetor with litium batteries or use NiMH batteries, just get a free sample of the one in the free dc-dc convertor thread and i'll show you how to hook it up (it shows you how in the datasheet) .

timmeh87 · Post by **timmeh87** » Tue Mar 07, 2006 5:07 pm

that converter will make the voltage of one lithium cell (or several in parallel) high enough for the 12V line in the 64 and for the screen. it will not supply your 3.3v line. youd also need a separate on for that. and its really complicated to put together... you have been warned.

you might instead want to go with batteries in series with a the easier-to-use step down converter

XFactor · Post by **XFactor** » Tue Mar 07, 2006 6:07 pm

I ordered the converter I supplied the above link for maybe an hour ago. It will come Thursday.

Now as for the other converter, this I honestly never knew about

. I have been looking all over the internet just to get a guide in order to build the first one, because the circuit diagrams are hard to follow for someone who has never delt with capacitors or regulators to this extent. I'm sure once an adequate guide is found, the build should be simple (granted no hardcore calculations need to be done

).

I have no issue with buying the parts for these converters, but i suppose concentrating my energies on the first (the one i just ordered) would be the best solution. I have seen diagrams for caps set above 9.6v, but i am going to run a 7.4v (so i assume the diagrams for the 9.6 are invalid).

Any guides or suggestions as to what i'd need to make the first converter would be immensely appreciated.