Search ebay for "LM2596 buck converter". Variable output up to 3A, 10 for $10 from China. I'm running my setup from a 12V car battery through these. There are buck/boost converters to be had on ebay too, they're a bit more expensive but still probably cheaper than you can make them yourself.
On 13 November 2013 15:03, <[email protected]> wrote: > I agreed there are better solutions available and that is really what I am > asking... what are those better solutions? For what I am looking to do is > having everything needed to run the BBB off battery for as cheap as > possible. We are designing a hardware setup for students to use and they > have to be able to buy all the components for as cheap as possible. The > problem with Lipo (from what I have seen) is that the chargers are the > expensive part. > > Here is where I am at right now. Need at least 9V for running motors as > well as the BBB. > 3-cell Lipo = $9 from > HobbyKing<http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=32951> > Lipo charger = $12 from > HobbyKing<http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=41636> > Lipo charger power supply = $8 from > Amazon<http://www.amazon.com/Adapter-Power-Supply-LCD-Monitor/dp/B003TUMDWG/ref=sr_1_11?s=electronics&ie=UTF8&qid=1383430607&sr=1-11&keywords=12v+4a+power+supply> > Voltage Reg, diode, caps, wires etc. = $3 from DigitKey > > This might be the best solution. But my thought was students might already > have AA battery chargers at home. > > Thoughts? > > Also, can you point me to a better circuit design that doesn't use the > 7805? > > -Rowland > > > On Monday, November 11, 2013 4:22:39 PM UTC-5, Dieter Wirz wrote: >> >> Ron is perfectly right! >> And where do you get cheap rechargeable batteries? >> LIPO prices are going down >> alcaline prices are going up >> >> Do you really want to invest time and money in last millennium >> alcaline technology? >> >> 7805? If you connect 9v to an 7805 about 40% of the power is converted >> to heat. There are much better solutions available. >> >> BTW @Ron: What buck/boost regulators are you using. Maybe you can >> provide some hints to the community... I have the ADP1111 sitting on >> my Desktop, but I did not find the time to solder something >> together..... >> > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
