Re: Electronics gurus please help

vajk,

The most important PCB layout consideration for power circuits is
ground and power supply distribution. If you like, send me your
circuit diagram and board layout and I will critique it for you. Best
would be a .dxf or .dwg format. Use the mariss92705@... e-mail
address.

Mariss

--- In CAD_CAM_EDM_DRO@y..., Vajk Fekete <vajk.fekete@o...> wrote:
> hi,
>
> i am building a stepper driver for my homemade mill, that i am
going to use with EMC.
>
> i have salvaged some steppers (60ozin, 6 wire), and also the driver
chip from old printers.
> the driver is a sla7026, 3A max chopper, unipolar.
>
> question1: is a chopper unipolar driver much worse than a chopper
bipolar drive?
>
> question2: a bit longer, and i badly need advice here:
>
> i have built an axis drive on veroboard, with rather long wires,
etc, and it worked ok.
> then i made a rather simple pcb, built a sigle axis on that, and
after correcting some errors, it works ok.
> then i made a final design for the pcb, built one axis, and it does
not work. built another, and the with same symptoms it is not working.
>
> so experts: at a chopping frequency a couple 10Khz, could the pcb
layout have this much influence? i checked all the components, all
the connections, spent about 2 days on it, so i am 98% that the
> working and not working circuit only differs in the shape of the
traces.
>
> i am no EE, but have some electronics building experience, more
from the digital world. and i do not have a scope, so cannot check if
the timer is working ok or not.
>
> any ideas are welcome,
>
> thanks,
>
> vajk