non stepper motor controlling bridge problem

[reko]

Hey everyone well Audio Guru u helped alot in the sensors topic i would like to ask again for help on a certain subject i found all of u guys making a hell of a discusion about well

I was planning on controlling a dc motor with brushes and commutator to work with atmel at89c2051 mcu (Using pulse width modulation) well i got everything from the tutorial u linked here about the pwg through a bridge to control motor and btw the code there is simple i am a computer science student so i know about it the problem here is that i planned to use the l293d which is equipped with spike-protecting diodes and rated 600 mA per channel but the only bridge i managed to get is a l293B which isn't equipped with the diode and also rated 1A per channel that could be a problem so my question is (Is it possible to use that bridge with a dc non-stepper motor or what?)

P.S:Audio guru u really helped last time i hope u do this time

 

[audioguru2]

the only bridge i managed to get is a l293B which isn't equipped with the diode and also rated 1A per channel that could be a problem so my question is (Is it possible to use that bridge with a dc non-stepper motor or what?

Its datasheet shows where to connect external diodes and how it is used with DC motors having brushes and a commutator.
If your motor draws more than 1A when starting, working hard or is stalled, then the IC will make lots of smoke.

 

[reko]

thanks man but what diode should i use can i use the ln4004 ??

here's the schematic for the circuit as u can see the bridge is l293D which is unavailable as i said before and there's no hope i will find it

View attachment 39815

 

[audioguru2]

A 1N4004 is a rectifier diode for 50Hz or 60Hz and is very slow. PWM at high frequencies needs faster diodes. I don't have a list of fast diodes. I need one also.

 

[reko]

what about ln4448 diode i guess it's fast enough (What is in mind??)

 

[audioguru2]

what about ln4448 diode i guess it's fast enough

Its max current is only 300mA. Is your motor that small?

 

[hotwaterwizard2]

Would it be possible to use this IC to drive large Transistors like a 2N3055 so the circuit can handle Large loads?

http://www.cse.cuhk.edu.hk/~khwong/ceg3430/mrobot7.pdf

View attachment 39818

 

[hotwaterwizard2]

Search Results

L293B and L293E
http://www.st.com/stonline/books/pdf/docs/1328.pdf


L293D
ST Datasheet
http://www.st.com/stonline/books/pdf/docs/1330.pdf

TI Datasheet
http://focus.ti.com/lit/ds/symlink/l293d.pdf

App Notes
http://msgroups.tech.northwestern.edu/dc/dc99/docs/l293eapp1.pdf
http://www.st.com/stonline/products/literature/an/1675.pdf


Other Info
http://www.cse.cuhk.edu.hk/~khwong/ceg3430/mrobot7.pdf

http://www.dprg.org/projects/1998-04a/

http://www.seattlerobotics.org/encoder/may98/steppers.html

http://www.cs.uiowa.edu/~jones/step/circuits.html

http://www.stanford.edu/~pjc30943/school/ME218%20labs/KrisPaulSal%20-%20Lab%208%20Report.doc

http://www.me.umn.edu/courses/me2011/robot/technotes/L293/L293.html

 

[reko]

thanks guys i found the l293D whixh is 600mA output and my motor is 500 mA so i guess it's almost okey to use that bridge directly