dc motor driver

[t_sanoop]

hi,

i am doing a robotic project . i am using a dc motor which is having high power...i used uln2003 driver ic to connect to the motor.but i found the ic is getting heated....i had shorted 3 pins of ic inorder to get high current capacity.....if any of you know any current sink ic which is having 1-3Amp current capcity....hoping that i will get reply from you...


thanking you
sanoop

 

[Jabir]

hai sanoop

Is it a stepper motor ?
Why are u using darlinton ics ?

I think the correct option is the h-bridge ics
L293 or L298.

 

[docel]

L298s are right for the current. Heatsink the 298, about 4"x4"

 

[philba]

Heat is going to be your enemy here. You should get a tight handle on the current draw of the motor.

The L293 won't deliver the current you need. the L298 will do it though the limit appears to be 3A - right at your limit. that's a little troublesome. neither package (multiwatt or powerso) are super easy to prototype with. with 3A of current, the L298 will dissipate a very large amount of heat Vsat at 2A is 4.9V - that's 9.8W. Take it up to 3A and it's going to around 15W. I suspect you can get by with passive cooling (heatsink) for 1A draw but 2 or 3A draw will probably need forced air.

alternatively, you could build an h-bridge with mosfets. Mosfets with a reasonably low Rds will give you significantly lower heat dissipation. For example, mosfets with an Rds of .1 ohms will dissipate about a watt each at 3A. It would probably get by with a smallish heatsink. Plenty of plans on the web.

Phil

 

[bibinjohn]

use L293D for normal DC motors. If it is greater than 600ma go for L298
refer page67 of
MY EXPERIENCE IN AUTONOMOUS ROBOTICS
you can get it from yahoo group-booksbybibin
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