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TirthankarMukherjeePIC
01-24-2008, 05:58 PM
when I drive 2 stepper motor .. with ULn2803 ... with sequence

11001100 --- > 1st sequence
01100110
..................
...............


Then every time 4 pins 0f ULN is getting activated ... that means the current through each pin is 500/4 or 125 mA ... ? and when the sequence is

10001000 ----- > 2nd sequence
01000100
....................
.................

then the current through pin is 250 mA ...

I have stepper motor of 12V 500mA ... which one will be the best ....

Or shall I use ULN2003 for each motor .. then using sequence 1 which will give 250 mA to each motor .... or sequence 2 which will give 500mA to each motor ...

What will be the solution to get the maximum torque and speed ...

I dont want to use L297 + L298 ... .. I have some budget problem ...
and L297 is not available here .. Kolkata ..

pratikmahale
01-24-2008, 10:30 PM
ULN 2803 contain eight Darlington transistor and each Darlington load current Capacity of 500mA
So u can use ULN 2803 for 12 v 500mA stepper motor
U can use ULN 2803 in pairs for extra current capacity

read the datasheet of ULN 2803

elecrom
01-25-2008, 04:17 PM
ULN2803 has current rating of 500mA per pin. So It should happily drive ur stepper. Remember, when you give "1" as inuput, o/p is "0", it operates in current sink mode.

TirthankarMukherjeePIC
01-25-2008, 10:49 PM
thanks to both of you

tpsbpl
01-27-2008, 12:56 AM
u can use 8 relay card http://onlinetps.com/shop/index.php?main_page=product_info&cPath=66&products_id=470
it can drive upto 10Amp per channel also l293d http://onlinetps.com/shop/index.php?main_page=product_info&cPath=80_144&products_id=497 or u can also use BD139 http://onlinetps.com/shop/index.php?main_page=product_info&cPath=93&products_id=338 it can delevr 4 Amp small in size