This would be for a car application, 8-10V when cranking, 12.5V not running, and 13.5ish when running.
I have a sensor that i need to provide a stable 12V with any of those input voltages.
Anybody got any ideas?
i tried a radio-shack 12V TO220 package regulator, but it wants at least 14v input.. it works, but not very well.
At what maximum current output value?
You could use a switching boost regulator to boost to say 15vdc, feeding a switching buck regulator adjusted down to +12dc output.
Lefty
You would need a sepic or buck/boost switching power supply. Search for them on ebay. They have modules that can power up to 2 Amps.
this one looks like it will fit the bill.
too bad it's in china. anyone know where to get one of these in the states?
It's probably actually easier to boost to 16-24V, and then regulate back down to 12V, especially if you don't need a lot of current.
Digi-Key has literally hundreds of different voltage converters that will do the trick.
Try an LM2585 perhaps?
Or a ready-made module for about $5. Something like http://search.digikey.com/us/en/products/VBSD1-S12-S12-SIP/102-1365-ND/989820
Higher-end parts with wider input range: http://search.digikey.com/us/en/products/VWRBS2-D12-S12-SIP/102-1511-ND/1558906