PWM Motor Controller/Amplifier
PWM Motor Controller/Amplifier
(OP)
I'm working on an application where I need to intercept an existing PWM signal (~120Hz, 0-12.0V) - which is limited to 20A max current - and output an identical signal with a capacity of up to 60A. The signal controls a single brushless DC motor but my application will add another (identical) motor in parallel with the first (and possibly 2 more motors).
Based on my limited understanding (never worked with any kind of transistors) and what I've been able to gather researching online, I thought N-channel MOSFET's might be just the thing and I've come up with the attached circuit that I believe will meet my needs.
I'm considering using a pair of IXYS HiPerFET IXFE48N50Q in parallel to give plenty of overhead. Am I on the right track with the circuit design? If so, are the IXYS units a good fit (if a little expensive)?
Link to IXYS specs: ht tp://searc h.digikey. com/script s/DkSearch /dksus.dll ?Detail&am p;name=IXF E48N50Q-ND
Appreciate any insight/feedback.
Based on my limited understanding (never worked with any kind of transistors) and what I've been able to gather researching online, I thought N-channel MOSFET's might be just the thing and I've come up with the attached circuit that I believe will meet my needs.
I'm considering using a pair of IXYS HiPerFET IXFE48N50Q in parallel to give plenty of overhead. Am I on the right track with the circuit design? If so, are the IXYS units a good fit (if a little expensive)?
Link to IXYS specs: ht
Appreciate any insight/feedback.
Mikah B.
www.allanglesdesign.com





RE: PWM Motor Controller/Amplifier
TTFN
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RE: PWM Motor Controller/Amplifier
Is the concept sound or are we barking up the wrong tree? There are other more "brute force" simple solutions, but this seems like it could be elegant and cost-effective for our need.
Mikah B.
www.allanglesdesign.com
RE: PWM Motor Controller/Amplifier
TTFN
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Chinese prisoner wins Nobel Peace Prize
RE: PWM Motor Controller/Amplifier
You're right, it is a fair amount of current. The FET I spec'd is rated for 41A max continuous drain. I expect the system to consume about 30A during normal continuous operation which is why I chose a pair of FET's in parallel. My thought was that by running two FET's in saturation but well below their capacity, I could avoid excessive heat buildup. Demand could spike as high as 60A for short periods of time (4-8 seconds).
Mikah B.
www.allanglesdesign.com
RE: PWM Motor Controller/Amplifier
Dan - Owner

http://www.Hi-TecDesigns.com
RE: PWM Motor Controller/Amplifier
Mikah B.
www.allanglesdesign.com
RE: PWM Motor Controller/Amplifier
Dan - Owner

http://www.Hi-TecDesigns.com
RE: PWM Motor Controller/Amplifier
Again, you should get an EE to do this.
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
Chinese prisoner wins Nobel Peace Prize
RE: PWM Motor Controller/Amplifier
IRstuff: Like I said, I will get an EE to look at it if the concept has merit. I just want to have my homework well and truly in order first.
Mikah B.
www.allanglesdesign.com