# PWM Motor Control Plans



## KVBarkley (Jan 9, 2009)

My Aristo Basic Train Engineer has been getting flaky. The other day my Aristo 040 slowed to a crawl no matter how many times, or how long I pressed the "go faster" button I could not get it faster. (I have not yet really figured out what kind of button pushing it wants!) I know it is the BTE, since when I hooked the track directly to the wall wart connector, the train promptly zipped around and derailed. 8^) I am not sure whether it is an RF or DC problem.


Anyway, I was wondering if any one knew of a PWM type power supply design. I think I can build that up a little faster than troubleshooting the BTE.


While a high power NMOS switching device would be good -- (I work as an RF engineer manufacturing High Power RF Tranistors. We make the used-to-be Motorola MRF150 (for any of you Hams) , which would be more than big enough for this supply - and I can get it really cheap, heh heh.) -- I am thinking that a high side PMOS switch is a better topography.


Are there any circuits out there already?


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## George Schreyer (Jan 16, 2009)

LMD18200


BTW, if you are working at Moto RF devices, you MIGHT be building parts I designed at TRW Semi over 20 years ago.


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## altterrain (Jan 2, 2008)

You can use a Meanwell 6 amp unit - http://cgi.ebay.com/24V-DC-6A-145W-Regulated-Switching-Power-Supply_W0QQitemZ110364144816QQihZ001QQ 

with one of these to control it - http://www.bakatronics.com/shop/item.aspx?itemid=444 

I have one of set up for temp layouts. 

-Brian


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## Del Tapparo (Jan 4, 2008)

While not really intended for "Trackside" use, my Basic RailBoss R/C board would be a suitable replacement for the Aristo Basic TE. You would have to provide your own housing for it, and supply a cheap hobby radio, but it wouild be good for 5 amps instead of 2.5 amps, and also have the capability of automated station stops!


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## KVBarkley (Jan 9, 2009)

Thanks everyone, 

George: Gary Lopes is my Boss! 

I was thinking something like this with some reversing logic: 
http://www.solorb.com/elect/pwm/pwm0/


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## KVBarkley (Jan 9, 2009)

Oh, and George, that LMD18200 looks perfect - it even has current limiting built in 
$14 at digikey.


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## George Schreyer (Jan 16, 2009)

I haven't seen Gary in years, say hello for me


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