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Topic: L293D overheated but not burned !! what's the solution ? (Read 6159 times) previous topic - next topic

oric_dan


OK, to answer the original question "L293D overheated but not burned !! what's the solution "

Don't touch it if it is to hot !

I've seen smoke come from a few chips, but only ever seen one chip actually "catch fire", and it was an L293D. The plastic end of the chip literally popped off, and flames literally erupted. It's still one of my favorite memories, ;-).

jack wp

#31
Jul 26, 2013, 09:45 pm Last Edit: Jul 26, 2013, 09:47 pm by jackwp Reason: 1
@oric,
I remember once about 40 years ago, using TTL , I wired something wrong, and as I leaned over to check the wiring, it EXPLODED, one piece of the IC shot by my head. I was thankful that it did not hit my eye. LOL

So - don't touch it, Don't even get close.

I see some people will pigiback these ICs for more current. I never tried it.
Good luck, Jack

oric_dan


I see some people will pigiback these ICs for more current. I never tried it.

I always thought these guys were being a little bit silly,
http://acroname.com/robotics/info/ideas/stacking/stacking.html

jack wp

oric,
Yea, what they say there is a bit  unbelievable, I think stacking would not double the power ability, but maybe add around 40%.
Do you know of an ic that does not have such a heat problem (afordable) ?
Good luck, Jack

firashelou


@oric_dan:

OP has a lot of threads going on at the moment, and they all come to a certain point where he seems to just gather some stuff together and is trying to make it work without understanding a bit.
So he asks questions but always without enough information.
There is an other thread where he asked about controlling a > 1 A motor for his model car and the next day he started this thread.

He has told he does read datasheets but doesn't understand all of it.
I guess English isn't his first language too, complicating things.
But i've never seen him asking questions about things he doesn't understand in datasheets.
He does ask after buying parts, putting them together and gets stuck after that.
If it takes over 3 days to understand, he just gives up to start over with an other approach or part for the same project.

It is very hard to help OP because of all of this, and i really tried.


actully starting from a higher level made me learn a lot :) and with ur help guys i am getting better everyday and understanding more about this world :)
Aiming for the unreachable !

oric_dan


oric,
Yea, what they say there is a bit  unbelievable, I think stacking would not double the power ability, but maybe add around 40%.
Do you know of an ic that does not have such a heat problem (afordable) ?

There are a lot of MOSFET h-bridges that do a lot better, both integrated chips and descrete arrangements. Pololu has some pretty good boards.
http://www.pololu.com/catalog/category/11

oric_dan


actully starting from a higher level made me learn a lot :) and with ur help guys i am getting better everyday and understanding more about this world :)

Do you know how much current your motors actually draw?

firashelou



actully starting from a higher level made me learn a lot :) and with ur help guys i am getting better everyday and understanding more about this world :)

Do you know how much current your motors actually draw?

not but i know the voltage 12V
it was an old RC car, the set of battery used in it is 700mA and 12V
but the circuit has 2 motors, first for traction and second for steering so ...
Aiming for the unreachable !

firashelou

hey guys,
i am thinking about put a piece of metal like the one i have on the motor, for heat sink, wired to pins for heat sink and putting the chip in the sidepods so i can gain more cooling from the small air entering the sidepods when i am up with the speed
what do you think about this solution which you were talking about in a couple of posts ?
Aiming for the unreachable !

MAS3

A real sidepod is made to direct an airflow.
Such airflow cannot exist if there is only an entry, there has to be some exit too.
Is this the case with your model car ?

The heat conduction doesn't have much up with wiring.
It needs a surface to be mechanical connected with, and the surface of the pins that touches the heat sink should be as large as possible.
So be sure those center pins of your l293d make a tight and as large as possible mechanical connection to your heat sinking material.
Have a look at "blink without delay".
Did you connect the grounds ?
Je kunt hier ook in het Nederlands terecht: http://arduino.cc/forum/index.php/board,77.0.html

firashelou

#40
Jul 27, 2013, 09:49 pm Last Edit: Jul 28, 2013, 04:07 pm by firashelou Reason: 1
it has an exit yes
but it's better than leaving the chip inside the car, a + better than 0,
so about the piece of metal for heat sink, it should be connected with a wire to the pins ?

there are some pictures
Aiming for the unreachable !

oric_dan




actully starting from a higher level made me learn a lot :) and with ur help guys i am getting better everyday and understanding more about this world :)

Do you know how much current your motors actually draw?

not but i know the voltage 12V
it was an old RC car, the set of battery used in it is 700mA and 12V
but the circuit has 2 motors, first for traction and second for steering so ...


If you don't have a DMM, you should go out and buy one, and find out what the motor current is, especially under load.

firashelou





actully starting from a higher level made me learn a lot :) and with ur help guys i am getting better everyday and understanding more about this world :)

Do you know how much current your motors actually draw?

not but i know the voltage 12V
it was an old RC car, the set of battery used in it is 700mA and 12V
but the circuit has 2 motors, first for traction and second for steering so ...


If you don't have a DMM, you should go out and buy one, and find out what the motor current is, especially under load.


lol i have 3 !! my head is so busy that i missed this one !! lol i am laughing right now like a crazy on my stupid mistake !!
Aiming for the unreachable !

alnath

Firashelou, when you post photos, could you please resize them to about 900px wide ?
Easier to see them  ;)

firashelou

#44
Jul 28, 2013, 02:25 am Last Edit: Jul 28, 2013, 04:11 pm by firashelou Reason: 1

Firashelou, when you post photos, could you please resize them to about 900px wide ?
Easier to see them  ;)


ok i will no problem :) but a solution 2 can be the right click open in a new tab :P
Aiming for the unreachable !

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