help required in driving Bipolar stepper using uC in Proteus simulator,

[shohaib1]

you provided a scematic of NPN's, but do i always have to use in Darlington form,
can i not use as single form, not in darlington configuration??

---------- Post added at 14:13 ---------- Previous post was at 14:09 ----------

and next
i got a L298n IC,
now any suggestions, from where should i start??
i have read briefly its data sheet, but still of no use....... and now i have started gooogling l298 circuits

 

[john blue]

yes. but darlington provides move power to the motor

---------- Post added at 14:54 ---------- Previous post was at 14:53 ----------

read the datasheet but focus of the application section, most of the datasheet has this but some unfortunately not

 

[alexan_e]

The Darlington configuration is when the emitter of the first transistor drives the base of the second transistor , like the picture below, my configuration is not Darlington.
In every transistor the emitter has a voltage difference of about 0.7V with the base , since we are driving with 5v the output at the emitter of the upper transistor of the half bridge would be 4.3v so i use the driving transistor to feed the base with 0 or 12V so that the output is 11.3V.
When the driving NPN is not conducting the 500 ohm resistor is working as a pull up resistor and gives 12v to the base, when the driving NPN is on then the current flows through the resistor and the voltage drop creates a voltage of almost 0.
If you are using a 5v power supply then you can drive the upper transistor without the driver.

Alex

 

[john blue]