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L293D problems

Hi,

I was wondering if anybody elts was having slight over heating problems with the motor driver chip.

It realy heats up !!!!!!!!!!!!! Is this normal?

Thanks

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How about using darlington driver ic uln2804.it provides high current gain to drive motors n little combination for flipping of polarity as shown below..might this will help to drive loads..as l293d is incapable do this job.

 stepper control configuration

Pololu had some info about the FA-130 motor and it's use at higher voltages. Basically they can burn out more quickly at voltages greater than 3 volts, which both the L293 and 754410 require at least 4.5 to operate. A little good news is that both drivers lose a little voltage across the output transistors, so the motor sees about a volt less than the supply. What Pololu recommends is replacing the FA-130 motors with an RM3 motor from Solarbotics that runs at a much lower current at a higher voltage. You can get the motor from either store above, and it appears that Active Robots (Standard Motor 3) might have it close by, not sure which would be cheaper when combined with shipping.
hmmm, should have red that thing about the motors first, it is way to late to change motors... might get a pair for when mine break. For the chip I think getting the IT one will help. Thanks for all the help.

are you sure it's too late to change motors/ the rm3 is a drop-in replacement for the fa-130. you don't really have to change anything, aside from feeding the rm3 4-9v instead of 1.5-3v. you might want to look into it.

sorry for the stupid typing, my ctrl, shift, and alt keys stopped working for some mysterious reason.

Dan

it is a bit late but i could change them, it will need quite alot of work because as you can see they are at the heart of the thing. http://letsmakerobots.com/node/2643 but if i realy need to i will.
redezined the robot so now i have acces to the motors, will order new ones. thanks for telling me, the motors could have burnt out i would have had no idea !!!

Looking at the specs for those motors, 220mA for no-load, 660mA normally, and stall of 2.2A, I would say that the TI chip is a much better choce for the motors. It is actually designed to carry that load. (basically, it has a lower resistance, so it generates less heat for the same amount of current it carries.)

-Fergs

What motors are you using? The L293 is only designed to move about 100mA per channel... that's pretty much nothing. The TI SN754410 can carry up to 1A per channel, and is pin-for-pin compatible with the L293, you can just swap it out. I've run a 5-6lb robot at top speed for hours without the chip getting overly hot.

Digikey sells them for under $2, acroname also has the chip plus some other information: http://acroname.com/robotics/parts/R6-754410.html

-Fergs

100mA??  Sheesh ... looks like I'm going to have to can the L293D for my bot, too.

Specs can often get fuzzy in memory. The ST Micro datasheet for the L293D shows 600 mA per channel with a 1.2 A peak, not 100 mA. The Texas Instruments L293D datasheet also shows 600mA with a 1.2 A peak.

The specs for the SN754410 are a little better at 1.1 A and a 2A peak, but both chips are used effectively.