Voltage regulator help

[Phantom]

So. I have a small lipo battery, its voltage goes from 4.2v fully charged and keeps going down i dunno how far, past 1v.

I want to have ~3v for a bunch of LED's, so i figure a 3.3v voltage regulator would work best for what i need.

but i was looking around online and they all have a 'Primary Input Voltage' see here. Since my battery dosnt supply a constant voltage, can the input voltage be lower or higher than that value? whats the minimum voltage it needs to operate properly?

or would there be an even better option than a voltage regulator that i don't know about?

[FOOKz™]

primary input voltage is what you supply your regulator... its also the absolute minimum the regulator will work at. (because its a range of voltages).

Mostly all voltage regulators need a higher input voltage than what they put out. If the input voltage dips below a certain threshold the regulator will turn off and not put out any voltage (in most cases).

I say just stick with a 3.3v and recharge if necessary.




Also LiPO batteries WILL EXPLODE/LEAK if you discharge all of it's power... and you're saying that it hits 1v ??? wow man be careful.

[frenulem - No.5417]

wouldn't a diode drop the voltage enough when it's fully charged?

[FOOKz™]

wouldn't a diode drop the voltage enough when it's fully charged?

Most silicon diodes drop an approximation of 0.6v to 0.7v Regardless of input voltage.

So to use diodes to regulate voltage is like saying a resistor is a voltage regulator.

EDIT: i was thinking about what you probably meant was a zener diode. Yeah you can use one of those but you will need a resistor in series to help it handle larger voltage drops.

[hyper999]

surely if you use a regulator in this situation you will only get a very short amount of time before the output from the battery drops below what you need to run the regulator?

I would just run the leds straight off the battery (with appropriate current limiting resistors of course) with out a regulator...