5 volts out of 4 rechargeable batteries
October 12, 2010
Hi folks. I'm pretty new tor robotics, and I am hoping to solve the issue of providing 5volts to my cpu and digital circuits. To start with I use 4 1.2volt rechargeable batteries, this provides 4.8 @ 1.2 volts per battery... unless they are freshly charged in which case each battery is now at 1.4volts and 4 of them bump the voltage up to 5.6volts which is a tad too high for my gear.
One idea is to use a low drop 5volt voltage regulator, but what happens when the voltage hits 5.0v, I take it that regulators and low dropout ones need a little bit more voltage than the target voltage to work. Most of the gear I use will work down to 4.5 volts, so having a battery pack with a voltage regulator not working once it hits 5volts would really limit the amount of time my robot will run for.
Another thought was use a diode to drop 0.7 of a volt so instead of 5.6 I get 4.9volts, I am thinking this is a cheap and easy solution.
I am wondering how much power would this diode be consuming.