I have a LiPo supplying nominal 3,7V -- 4,07 at the moment, possibly fully charged.
I also have a gyro sensor that ask for 3,3 V - and I'd hate to fry it.
I really, really cannot understand the law of Ohm, so I am asking, can any one tell me what to throw in there?
Thanks :)
(Oh, and any tips on brown out detection would be appreciated; I'd hate to discharge my LiPo, but am trying to keep this simple, becaue that is my style ;) - Any smart tips on making sure it will not go too low?)
Since the output varies, I would go with a regulator. Like a LD1117V33 for example, you want to couple it with a 10μF capacitor though, to keep it stable and nice.
What I do is hook up the battery to a 10k pot. Add your measure thingie and adjust the pot until you get your 3.3v. Now disconnect everything and use the ohm setting on the multimeter to measure each side of the pot. These are the values of the resistors you will need to build your resistor bridge.
Since the gyroscope doesn’t use much current you should have no problem finding an ultra low dropout voltage regulator, but I think they are typically surface mount devices. This will allow you to regulate to 3.3v from anything around 3.4v and above. It could be simpler to use two lipos in series and a regular regulator if smd is a problem.
Isn’t a voltage divider linear so that when the battery voltage goes down so does the divider output? I think that a regulator or a zener diode is a better solution.
