Agree with Charles- from personal experience!<br>Don't use the L293 for low voltage (<12V) systems! You'll lose too much voltage to heat the device. Best bet is probably to make your own h-bridge - it's not that hard...<br>
Hanno<br><br><div class="gmail_quote">2009/3/25 Charles Manning <span dir="ltr"><<a href="mailto:cdhmanning@gmail.com">cdhmanning@gmail.com</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I would not put the L298 high on the list because it is a common collector device, just like the L293.<br>
<br>
The internal configuration of these devices means that the output
voltage does not swing all the way to the rail and you lose approx 1.5 to 2 volts in the driver chip. This turns into heat, but also means that
your motor does not get driven as hard as it should meaning that it does not get enough Weetbix to win that Sumo competition. That is perhaps
not too much of an issue when you're using 12V or more input, but
obviously throwing away 1.5V or so is bad news for low voltage systems.<br>
<br>Many modern HBridge designs are "rail to rail" and do not suffer this problem.<div><div></div><div class="h5"><br><br><br><br><div class="gmail_quote">On Wed, Mar 25, 2009 at 3:54 PM, Andrew Errington <span dir="ltr"><<a href="mailto:a.errington@lancaster.ac.uk" target="_blank">a.errington@lancaster.ac.uk</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">I actually like this design:<br>
<br>
<a href="http://www.mcmanis.com/chuck/Robotics/tutorial/h-bridge/bjt-circuit.html" target="_blank">http://www.mcmanis.com/chuck/Robotics/tutorial/h-bridge/bjt-circuit.html</a><br>
<br>
Because the opto circuit is very elegant (it combines optical isolation<br>
with 'smoke-free' logic). I've never built one as I was not able to find<br>
a fast enough opto-isolator to do high-frequency PWM. It may be that<br>
that is a non-issue however.<br>
<br>
Good luck with whatever design you choose.<br>
<br>
Andrew<br>
<br>
<br>
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