Need Help!- my L297 L6203 doesnt work ??

[lalaabdallah]

Hey everybody,im new member here in this great site,i became so interrested in the cnc field and after Effort of self- i understand how it works with these beautifull machines,idecieded to build my own router cnc 3axes using L297 L6203 chips (4A) for the motor driver ,and with easy interface (itook it from * Geoff Williams, "CNC Robotics: Build Your Own Workshop Bot"

my power is three pc power supply parallel connection In order to ensure 34V 7A
my motor bipolair NEMA23 4wires current per phase (3A 4,2V),impédance 1,4ohm

After i put my DB interface and the driver card under power (5V) i switch on for the 34V , iturned the variable résistance (2,2k) but nothing move i tested the step pin it was fixed on 3,87 V and the direction pin it was variable but around 2,2 V,i tested also the A- A+ ,B- B+ but its 0 volts.

Im not Professional in electronics i'm just Amateur and i need help because i spent money and time to realize my machine ,for more information in test points in my driver card im ready to do.

I feel upset after my Failure but i'm sure the professionals here will helps me

i attached the interface card and the driver card Schemes.

thx

[john_100]

I've just had a quick look at your pcb design and it looks OK
but without the book or any other information I don't know what component values you have used


first with all the L6203 motor driver outputs at 0v ,
check the L6203's enable pin 11 is at +5v ??
If pin 11 is at 0v the L6203 IC's outputs are disabled !

once you have an output from the L6203's
if it does not step ,check you have the enable pin 10 on th L297 at +5v ?

John

[lalaabdallah]

Originally Posted by john_100 I've just had a quick look at your pcb design and it looks OK but without the book or any other information I don't know what component values you have used first with all the L6203 motor driver outputs at 0v , check the L6203's enable pin 11 is at +5v ?? If pin 11 is at 0v the L6203 IC's outputs are disabled ! once you have an output from the L6203's if it does not step ,check you have the enable pin 10 on th L297 at +5v ? John

Hello John

I'm so glad after ur repaly ,and iwould present to you my components values shematic,itry to upload here but something wrong happened ,iwish u give me ur email so ican send it to u ,i'm waiting your replay.

thank you

[john_100]

Hi lalaabdallah ,

with a logic 1 (+5v) on the L297 reset pin20 , control pin 11 and enable
pin 10 the circuit should work

on the L6203 IC's you should have +5v on the enable pin 11 and one of the inputs - IN1 pin5 or IN2 pin7

on the net I've found some other examples of boards using the same IC's

PMinMO.com

Selfmade Stepperdriver L297-L6203

Schematic: http://i20.tinypic.com/2emdkx0.png

PCB: http://i23.tinypic.com/28lg9c8.png


the circuit for the Elektor magazines board is close enough to check your pcb design,
your version has an adjustable reference voltage to set the motor current and an RC network to reset the L297 at switch on

John

at switch on ,the reset circuit in the 2nd diagram holds the L297's reset pin low long enough to reset the chips counter

once the voltdrop across the sensor resistors R6 & R7 exceeds the reference voltage at pin 15
the motor current is cut off until reset by the L297's own internal oscillator or an oscillator connected to the Sync terminal (pin1)