5v dc from 1.5v battery
throwaway18 said:
To make use of all the available energy in a dry-cell battery you need to use them down to 1.1V per cell.
You can use a switching regulator.
Hmm. if remember rigth standard 'emty' dry/akaline battery is 0.9 Volt/cell -> 3.6 Volt for 4 cell-pack.
For 5 Volt logic-supply You need switched voltage converter going in buck-mode with fresh battery and smothly going to boost mode with half to empty batterys. or you in same situation as old digital camera needs new batterys in short time and 'used' replaced battery have more than half capacity remains + user cannot use NiMH-batterys in your power hungry equipment (1.2 V/cell * 4 = 4.8 Volt)...
Other way, use boost switcher to make 8-10 Volt from batterys 3.6 - 6.4 Volt and next step using buck switcher to make wanted 5.0 Volt. (if you want high power and high quality loadspeakers/ear-phone drivers without clipping in high level - you want more than 5 Volt to feed this drivers...)
or design your equipment for 3.3 Volt logic...
for more easy design - use 6 cell battery pack and make buck switcher power supply can handle from 9.6 Volt (fresh alkaline batterys) to 5.4 Volt (empty battery as 0.9 Volt/cell) and also make possible to use NiMh-batteries.
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Is hard but possible to find few app-notes to bulid switches can work both in buck and boost mode depend if input voltage is higher or lower compare to output voltage - look on Maxim, Linear technology, National semiconductor etc. appnote library.
(I look long ago for simular problem as unstable 12 Volt car-batterys (6.5 Volt with start engine to near 16 Volt charging voltage in cold weather) to stable 12 Volt for example feed computers and harddisk.)