Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: sherby on July 13, 2013, 03:48:04 PM

Title: DC-DC Converters
Post by: sherby on July 13, 2013, 03:48:04 PM
Is there any DC-DC Converter for step up, ie low to high voltage to convert 9v to 12v?
I know about 7805 and lm317, but they convert from high to low.
Thanks for the help!'


also i came across LM2622, is there any guide on using it?
Title: Re: DC-DC Converters
Post by: billhowl on July 13, 2013, 05:39:19 PM
DC-DC Converter for step up is called boost converter
One of it is LM2577
(http://74.82.171.210/images12/N105.jpg)
http://www.ebay.com/sch/i.html?_ipg=200&_sacat=0&_from=R40&_nkw=lm2577&_sop=15 (http://www.ebay.com/sch/i.html?_ipg=200&_sacat=0&_from=R40&_nkw=lm2577&_sop=15)
Title: Re: DC-DC Converters
Post by: sherby on July 13, 2013, 05:54:17 PM
Thanks for the reply, also i had a question regarding current.
If the i/p is 9V 1A, so i am guessing with the pot i can change outpt to desired(this case 12v), then what would be the current at the o/p?

will it just be calculated from power conservation P=VI, so 9*1=12*outcurent
?
Title: Re: DC-DC Converters
Post by: billhowl on July 13, 2013, 06:28:22 PM
The Boost converter (http://en.wikipedia.org/wiki/Boost_converter) had efficiency about 80% to 90%

calculated from power conservation P=VI, so 9*1=12*outcurent * 0.8
Title: Re: DC-DC Converters
Post by: sherby on July 13, 2013, 07:22:13 PM
Thanks you guys for all the help!  :)
Title: Re: DC-DC Converters
Post by: jwatte on July 14, 2013, 02:04:05 PM
FWIW, Pololu.com has a nice selection of step-up, step-down, and even step-up-down converters for use on robots. Some of them have up to 95% efficiency under the right conditions.