Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Need help on circuit for driving stepper motor from a PIC

Status
Not open for further replies.

knight1

New Member
I had written a simple instruction for stepper motor and downloaded it into PIC16F84 but now i got a problem on driving the stepper motor...a unipolar stepper...it require 24V and 500mA...how could i get this output for my motor??? need help...from newbie...
 
Last edited:
Have a look at , simply disconnect link J1, and connect 24V to the top of the four diodes. This presumes your motor is actually 24V 500mA, and you're not over driving it and require current limiting.
 
nice info...but as my PIC16F84 output 25mA from it's i/o ...a question is does it enought supply for base current for this BC337 transistor?? or i need to search for 1 that accept 25mA for the base??? I kinda lost here...thanxx...
 
knight1 said:
nice info...but as my PIC16F84 output 25mA from it's i/o ...a question is does it enought supply for base current for this BC337 transistor?? or i need to search for 1 that accept 25mA for the base??? I kinda lost here...thanxx...

It's fine! - the current is set by the resistors feeding the bases.
 
so means i just change the resistor will do??anyway i got this transistor MPS2222...so think i can use it as well...is that ok??since the Vcb=50Vdc...i not so total understand bout datasheet..soli for that....
 
knight1 said:
so means i just change the resistor will do??anyway i got this transistor MPS2222...so think i can use it as well...is that ok??since the Vcb=50Vdc...i not so total understand bout datasheet..soli for that....

There shouldn't be any need to change the resistor, and the MPS2222 looks fine.
 
assuming the lowest Hfe=50 and 5V input... in theory and skipping some voltage drop
Ib=(5-0.7)/470=9.1mA
Ic=iB*HFe=9.1mA*50=457mA

A bit weak. Now using 20mA at the transistor base,
Ic=Ib*Hfe=20mA*50=1 Amp

Wich resistor?
E=R*I
R=E/I= 4.3/20mA = 215Ohm => 200-220 ohm standard sould do the job.
 
Last edited:
now i got it...anyway, thanx for the advice..i try out 1st...Thank You once again....
 
Last edited:
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top