so about the piece of metal for heat sink, it should be connected with a wire to the pins ?
Quote from: firashelou on Jul 27, 2013, 09:49 pmso about the piece of metal for heat sink, it should be connected with a wire to the pins ?No, that will not work. Ideally, those pins (Gnd - 4, 5, 12, 13) should be soldered to a "ground plane", with the underside of the IC laying right on the copper of the "ground plane". That's how the heat gets drawn out - mechanical, physical contact.Barring that, any heatsinking will have, at best, only marginal effect.I would not anticipate any marked result from clamping a piece of metal atop the IC.The L293 is a #%@& IC that people expect too much from.> > > Why is this being discussed in "Microcontrollers"?
can you please show me an example on how to do it by posting a picture ?
i wasn't sure were to ask this question so i chose microcontrollers isn't it ?
Quote from: firashelou on Jul 28, 2013, 10:39 pmcan you please show me an example on how to do it by posting a picture ?I have attached ST's datasheet (PDF).If you look at page 4 of 7 ("4/7") they depict [see "Figure 2"] the sort of board surface required.Quote from: firashelou on Jul 28, 2013, 10:39 pmi wasn't sure were to ask this question so i chose microcontrollers isn't it ?I'm not "The Boss", but a L293D is a "four channel driver".
> > > Why is this being discussed in "Microcontrollers"?
I'm sorry but I don't have a CAD package to render you an orthogonal view of the situation and it is beyond my artistic ability to draw it for you.But, here's a link to Unitrode's datasheet, where they present (see Figure 10) the ideal ground plane vs. the IC outline. http://www.zagrosrobotics.com/files/L293.pdfA prototyper of any accomplishment could splay, or "un-bend", all of the pins [except the Gnd pins] out straight from the IC body and solder the Gnd leads to a piece of copper-clad board and then "dead-bug" (etc) all of the other connections from there.
Quote from: Runaway Pancake on Jul 28, 2013, 08:05 pm> > > Why is this being discussed in "Microcontrollers"?yes, I was wondering too ... should be in general electronics, I guess
I will put in my last 2 cents worth.There is no one answer as to how to take away all the heat. There are many things that could be done to reduce the heat, such as: use a better IC, solder it onto a copper clad board, reduce the duty cycle, blow air across it, glue a heat sink on top of the IC, and the list goes on and on. I think we have about exhausted discussions on this little IC. Jack
Here is one heatsink http://www.circuitspecialists.com/33hs016.htmlAnd a google for "heatsink glue adhesive" finds several glues.Good Luck, Jack
soldered pins : 1, 2, 3, 4,6,7,8soldered just to the "PCB" : 9, 16