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View Full Version : PMINMO 297/298 boards


irving2008
16-08-2009, 04:06 PM
Just a thread to show these boards, and my build. Not the latest technology but cheap parts and cheap to assemble

Boards available from Phil Moore, more info here (http://pminmo.com/PMinMOwiki/index.php5?title=L297-8) and buy from here (http://pminmo.com/forsale/blankpcbswcart.html)

Parts sourced from Farnell except L297/L298 and the main heatsink which were from Cricklewood Electronics as they were cheaper and I was passing. The main heatsink was one piece, chopped into 3 with a hacksaw and tidied up with a facemill on the Warco (cutting chips at last!)

First, a pic of the stepper driver board:
irving2008
16-08-2009, 04:14 PM
Phil likes using SMD chip capacitors on his boards.

Here is a technique for holding the capacitor against the board while soldering, using a device constructed from a clothes peg and some coat hanger wire (nothing Heath Robinson here...)
irving2008
16-08-2009, 04:26 PM
Here is a view of the completed driver and breakout boards without heatsinks
irving2008
16-08-2009, 04:30 PM
Final view fitted with heatsinks.

The large heatsink was bought a a bigger item, cut into 3 using a hacksaw then tidied up on my Warco (cutting chips at last) with a facemill.

At 36V and 1.5A the heatsinks are needed else both the L298 and the L317 regulator get too hot...
audioandy
16-08-2009, 09:07 PM
Looks nice and neat Irving excellent job :clap:
Ross77
17-08-2009, 09:50 PM
Ditto. Id be well chuffed if I could solder like that..

What are they like in use? Do the motors Buzz, hum etc.?
irving2008
17-08-2009, 09:57 PM
Ditto. Id be well chuffed if I could solder like that..

What are they like in use? Do the motors Buzz, hum etc.?only tried unloaded so far, but quiet as a mouse... faint whine if you listen hard...

soldering's easy - I did my time hand-building pre-production boards, many many moons ago!
Ross77
20-08-2009, 09:02 PM
only tried unloaded so far, but quiet as a mouse... faint whine if you listen hard...

Happy days... Is that in full or half step?

When I tested my board,(simlar to PMINMO) at 1/2 step they squeeled like little piggys. (probably didnt help as the pulse came from me tapping a wire at o.5v onto the pin :whistling:) havent got around to trying it with the pulser you designed.

BTW. is that + 0r - edge output? I beleive the L297 requires a - edge.?