@jstarne1... Thank you.. But the problem is Sabertooth is not available in India and I can't afford to import it.. So I am looking for some inexpensive dual motor driver... But I was wondering if I can add any external heat sink to the driver... Is it possible? If so, how?

I am using the following motors...

http://robokits.co.in/shop/index.php?main_page=product_info&cPath=2&products_id=186

So any other inexpensive motor driver replacement for it?

The motors have an amperage of 7.5 Amps max and the motor driver can deliver up to 20 Amps... But it doesn't have a heat sink.. Can the motor driver be used without heat sink as we have an the motors amperage is only 7.5 Amps?

@pranav there's not a practical way to attach a heat sink to the regulators because they soldered them face down to the PCB . that being said you could just use a small fan like a 80mm PC cooling fan over it should work. Since the motors are only rated at 7 amp stall this controller should he fine if there is any truth to the specifications posted.

Im not sure if you can get these in India either, but have you looked into Robo Claw or SyRen? both of these motor drivers are similar to the sabertooth and are available in different amp ratings.

Thank a lot for your valuable suggestions guys... But unfortunately both the above mentioned motor drivers are unavailable in India...

Personally I would use this motor driver if I were you. I use a few Pololu Motor Drivers in my robot and am very happy with them:

Dual VNH3SP30 Motor Driver Carrier MD03A www.pololu.com/catalog/product/707

It's a little compact and powerful driver that's capable of continuous 9 amp and max 30 amp. Highly protected. Supply voltage can be between 5.5 and 16 vdc. It's pricy at about $50 USD but will worth it. It has no heat sink but you may not need one and can always add one. Here's a statement taken from the description of this Motor Driver:

The motor drivers have maximum current ratings of 30 A continuous. However, the chips by themselves will overheat at lower currents (see table above for typical values). The actual current you can deliver will depend on how well you can keep the motor drivers cool. The carrier printed circuit board is designed to draw heat out of the motor driver chips, but performance can be improved by adding a heat sink. In our tests, we were able to deliver short durations (on the order of milliseconds) of 30 A and several seconds of 20 A without overheating. At 6 A, the chip gets just barely noticeably warm to the touch. For high-current installations, the motor and power supply wires should also be soldered directly instead of going through the supplied terminal blocks, which are rated for up to 15 A

Good luck and have fun, Dave Schulpius

@dschulpius.. Thanks.. that's a good option for me.. I'll try to get one...

Outstanding! Let us know if you get one and if it works for you.