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
yes, it does heat up quite
yes, it does heat up quite fast. If I well remember, Frits had a couple of those burned. You could try placing a heat sink on it, or some sort of fan, or some dissipative paste.
will try to get my hands on
will try to get my hands on a small fan but a heat sink would help a lot.
wouldnt bu any chance know how to make one or where to get something like that?
A heatsink is just a piece
A heatsink is just a piece of metal with a lot of surface area.
Just had a heatsink idea
How about getting a short piece of copper tubing (about the length of the chip). Then try to flatten one side, to get good contact on the top of the chip only (not the pins). Then perhaps drill a couple small holes near the center of the tube and on either side, and with very fine wire, twist it on the chip with the middle pins only (the 4 ground pins, 2 on each side). You can put some thermal grease on top of the chip to help some, but most of the dissipation will be through the ground pins to your copper heatsink.
the copper tubing sounds
the copper tubing sounds like a good idea, but the wire bit will need more patients than i have, might use 2 bits of copper, one flat and one still round so that air can pass through it, will connect them to the chip with some sort of thermo past or something in that line.
Thanks for the idea !!
What motors are you using?
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
I am using 2 FA-130 type
I am using 2 FA-130 type motor with a torque of 3V, dont know if that helps?
If the TI SN754410 can handle the motors without overheating might get that one.
Thanks
Looking at the specs for
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
Motor exchange
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
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
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
100mA?? Sheesh … looks
100mA?? Sheesh … looks like I’m going to have to can the L293D for my bot, too.
it is a bit late but i could
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.
but if i realy need to i will.
Check the datasheet
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.
would brass tubing work?
would brass tubing work? and maybe JB weld to attach it to the chip?
Yes it will work, but not as
Yes it will work, but not as good as copper. Copper best, aluminum next, brass ok, but better than nothing.
found a heatsink in a old
redezined the robot so now i
Alternate driver ic
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.
