ABSF WROTE:Actually I wanted to propose using 2x LM2577 to step up the voltage from 7.2V to 12V. But from my experience, using LM2577 at its max current (3A) would make it very, very hot and will shorten its life and the 100uH coil will even melt. And the time left to run your robot would be reduced to 14.4 minutes if the conversion power loss is 20%, provided my calculation is correct.
So I guess a better option is to get a battery with higher voltage e.g. > 11.5V (Expensive) with same A/H rating,
OR get the 12V from a PC ATX PSU. Cytron has a breakout board for this PSU and is very well designed. The +12V has a capacity of 14A (though I know it may not be true) but at least 10A should be there. And you dont have to worry about the +5V for your MCU.
BB-ATXRA - Breakout Board ATX Right Angle
http://cytron.com.my/viewProduct.php?pi ... !yn0flxwc=Allen
Allen, good suggestion on the booster. Never use that before, but want to try it one day.
BTW, the 12V required on MD10C is just for operation, is not for motor power. According to the User's Manual, this driver require minimum 12V to operate, it can either be from power to motor, or from microcontroller or controller. There is jumper to select where you get this minimum voltage from
So if you are using 12V to supply the motor, you can select VIN (Vmotor), and let say you want to drive motor with 6V only, no problem, you can still supply this 12V for driver from controller site or external, but it is very small current (not sure how much, they din state it). So your proposal of boosting the voltage is still applicable
On the other hand, did you get the BB-ATXRA? Went through the article using it, seem to be interesting. Wanted to try it, but I malas to get an ATX power supply from computer shop. Seem to be useful as you said, 3.3V, 5V +-12V, high current. They should put a few fast blow fuse to protect the track
OK, will try one day when I get an ATX power supply. If you have try, share with us