Hi all
I've an alarm unit that's powered by a standard 3.7V DC mobile phone battery.
I want to use a 12V battery pack to extend the life of the alarm unit.
What's the easiest way to convert the 12V supply to 3.7V supply for the alarm.
I could use the standard cigarrette lighter plug ins for USB power conversion, but I imagine there would be alot of energy wasted in doing this. Am I correct in saying this?? If someone has a solution to my problem, it would be a great help
Hi,
National Semiconductors web side: "simple switcher" ie., but such other vendors as PI, LT(linear Technology, TI, ST, Micrel, On Semi...
Simplest simple switcher are maybe the easiest to design_online:
**broken link removed**
But other producers have good tools "PI Expert Design Software" too: PI (Power Integration): **broken link removed**
K.
Hi Slammer,
Nice thing, but efficiency of ca. 62% isnt a peak & it will be not compensated w. some better price ($ 0.80... 0.90) if you have a battery often to change :-(
K.
Added after 5 minutes:
Hi Trackerman,
USB isnt supplyed (as I know) at 3.7V: http://www.datatranslation.com/phpkb/question.php?ID=235
"What is the specified USB port supply voltage range?
The High Power USB port must be between 4.75 and 5.25 volts. The Econ modules have been tested from 4.65 to 5.5 volts without any problem. The DT9812 series will usually use less then 400mA of the 500mA current specification. *Created: 12/20/04"
K.