Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Stepper motor full stepping

Status
Not open for further replies.

trelement

Newbie level 1
Joined
Feb 14, 2009
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,292
74194 bipolar stepper motor driver

Hey Everyone.

I'm trying to get more torque from my unipolar stepper motor.
I'm using a circuit similar to this
https://www.elecfree.com/electronic...08/03/basic-stepper-motor-driver-by-74194.GIF

Except I'm just using the 74LS194, 555 timer (not the same resistances for the frequency), and a ULN2003 transistor array.

What I want to do is change it from single stepping to power stepping ( 2 coils charged up per time )
Its a 6 wire motor, black and brown pair 1; orange yellow pair 2.
I tried putting pin 3 and pin 5 high and 4 and 6 as low.
But the motor goes back and forth.
I tried pin 3 and 4 high, 5 and 6 low; but no movement at all.

How would I make this do power stepping with this shift register.

If I cant do this, if I turn this into a bipolar motor ( ignoring the centre taps) and step it in full mode; roughly how much torque would I get versus single stepping a unipolar?

Thanks in Advance!
 

svhb

Full Member level 5
Joined
Mar 7, 2006
Messages
276
Helped
48
Reputation
96
Reaction score
30
Trophy points
1,308
Activity points
3,026
As I can rmember, the vector will be on 45 degrees with the same force in x and y direction, so I think it is about 1.4 times the torque.

Consider the inductance of the winding, if you drive the windings with a constant voltage, the current will rise according the inductance of the windings (V = LdI/dt). At higher stepping frequences, you do not reach the nominal current anymore, and you loose a lot of torque. When you put the two unipolar windings in series, you get a higher inducance. You can use a chopper circuit to have enough current at higher steprates (sinde the initial voltage is much higher, the slope of the current will also).

Stefaan
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top