I plan to build a simple Arduino robot, with spare components I have from previous projects.
I already have these components:
a very "basic" 24V DC motor
a G2 high-power motor driver 18v25 from Pololu (which indicates "operating voltage: 6.5 V to 30 V (absolute maximum)")
an electric battery with 40V nominal voltage (max voltage: 45V, min voltage: 25V)
As of now, I can power the motor driver using my laboratory power supply (with a wire), but as it would be a robot, I will need to power it with the battery.
What component should I put between the battery and the driver? My questioning is because of the difference in nominal voltage between motor and battery. I guess I cannot simply plug the 40V battery on the "30V max" driver.
Sorry for the dumbness of the question :-S
Thanks!
Check the web page for the Pololu motor driver. They have excellent instructions and wiring diagrams.
I guess I cannot simply plug the 40V battery on the "30V max" driver.
It is impractical to use that battery with that high power motor driver and that motor. Choose lower voltage battery, or a higher voltage motor driver (and probably, a higher voltage motor).
Look into DC-DC Buck Converters. They're 95+% kind of efficient.
What that costs goes up with Output Amps. You want at least twice max what you need continuous (3x is better) since running near max will burn it out pretty soon. I have 6V - 24V IN to 5V OUT 3A max converters that ran less than $2.50 each for 5, shipped! But I wouldn't want to run one past 1A just to let it loaf along content for years. You want his big brother.