I have a device that is currently powered from a "wall wart" power supply (@15V). It's basically four strings of high brightness LED's. Each string is controlled by a constant current buck LED driver - everything works OK.
I've been asked about the feasibility of making an add-on module to let the device be powered by battery, while retaining the ability to plug it into the wall wart supply when possible.
Rather than do a major redesign to a buck-boost or something like that, I thought a quick and easy solution would be to design a power pack with batteries and a boost converter that would just output 15V. This has the added advantage of letting me use alkaline, NiCD, NiMH or Li-Ion cells but still get the same Vout.
On the one hand, this seems like it should be no problem, since our wall-wart is already doing a buck conversion - so I don't see issues mixing various switching regulators. On the other hand, I figured I'd ask before I start working on some designs in case there's something I am missing.
So, is there any issue using a boost converter to feed into a buck converter, other than the efficiency loss? Anything special I ought to look out for? Or does anyone have any creative suggestions on this problem?