Quote:
Originally posted by s_alaniz
Quentin,
Ours is the circuit from the "DC Motor Current to an Analog Input" discussion under "Motors" in the post just before your PDF. We chose that chip because it allowed us to calibrate our wire and design for a simple 5V output. We used two chips in opposite polarity per motor and diode "OR'd" the output so we got a positive reading for forward or reverse currents (I'll have to draw up our final version which proved very useful in checking our motor performance). We used a 3 year old copy of IVEX software to design our circuit, which proved to be clunky. I think it might have been just as easy to use dry transfers or even hand draw it. The Maxim 4172 Chips were
only avalable in surface mount and I thought that might be troublesome, but I showed the guys how to solder them on and they didn't have any trouble. I avoided doing a double sided board, but we were not pressed for space, maybe I'll show them that next year. I also wanted to be able to change our design if needed and even etch a new board. We actually got it right on the first attempt. Just for fun, we're etching our team logo to make "collector" buttons.
Did express PBC give you the design software AND etch the boards for $59? That would be a pretty good deal if you're sure you have a working design.
Best of Luck!
Steve Alaniz
"You're saying we can look forward to robots demanding higher salaries and behaving badly." - Sally Forth
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That sounds like a very good learning experience you went through. It is good to bring the students through a real design process and best if they actually do it themselves....that's why I like what you did.
Yes,
www.expresspcb.com "gives away" the design software, except it isn't software like any other out there....it is really almost a paint program with footprints availible.
You can download it for FREE and look at it yourself.
Actually, it isn't all that bad....but the output goes ONLY to ExpressPCB....it isn't gerber or anything graphical that any other company can understand.
It also does NOT accept any schematic or netlist input....it is very basic....but at $59.00 for three boards, it is a great deal and I highly recommend them.
Check them out at:
Express PCB website
-Quentin
PS: I do not WORK for them, but I DO recommend and use them.
