Unipolar Stepper Motor Controller using UCN5804

[MP]

I was looking at the following project:
http://www.electronics-lab.com/projects/motor_light/004/index.html

and in comparing the data sheet with the project schematic, it appears that there is an error. Pins 2 and 7 of the chip are internally grounded. Therefore resistors 1 and 2 are in the wrong place. You will need resistance between your supply voltage and these pins of the chip. If you follow this schematic, you will surely let the smoke out of your chip (or power source), and we wouldn't want to do that. ;)
The small board layout is ok, since it does not add a trace for this.
Has anyone built this circuit? Would like to know how it went.

MP

[mixos]

Sure we would like to know how you went with this project :D

Can you please make the corrections on schematic and post it here? I would be really greatfull if you could do this..

[MP]

In further investigation, it looks as though the data sheet diagram for internal circuitry is not quite right. Where it shows ground, must have some resistance built in that the manufacturer is not showing. If you look at the example circuit given in the data sheet, it also shows the power supply connected directly to these pins (internal ground).
I have attached the data sheet for others to comment.
My original question: Has anyone else used this chip for their steppers? I would like to verify these discrepancies before actually building something on the workbench. I have in the past used other methods for stepper control. This seems like a very easy solution for small 6 wire stepper motors.
MP

UCN5804B.pdf

[caloi]

hi!!!

just would like to ask you guys, what are good replacements for ucn5804b chip.
that chip is not available here and i believe that product was discontinued.

[MP]

You can purchase them at:
Futurlec electronics:
http://www.futurlec.com/Others/UCN5804Bpr.shtml

American Micro Semi:
http://store.americanmicrosemiconductor.com/ucn5804b.html?gclid=CKSGlr7VzoMCFShCDgod8FAG8A

Farnell in One:
http://ie.farnell.com/jsp/endecaSearch/searchPage2.jsp?Ntt=ucn5804b&Nty=1&N=401&Ntk=gensearch

Hope it is helpful.

MP