mōtiv tutorial complete development of a transducer motor in under 30 minutes dan wiggins and mark...

MōTIV TutorialMōTIV TutorialComplete development of a transducer motor in under 30 minutes

Dan Wiggins and Mark Beach, DYNE AnalyticsCopyright © 2013 Dan Wiggins. All Rights Reserved. For ALMA and instructional use only!

• Typical starting point• MAYBE box use? 15L/47 Hz• Sketchy, at best!• Use the TS Parameter Wizard

Nominal Size 6.5 InchesCone Material AluminumCone Shape Curvilinear/constant radiusCone Finish & Color Black anodized matteDustcap Concave, end of former mountDustcap Material Black anodized aluminumSurround Material Natural Butyl RubberSurround Shape S Roll Basket Material Aluminum, 35mm ID, 4mm thickVoice Coil Diameter 25.4mm (1 inch)Voice Coil Wire CopperSpider Material CONEX40Magnetic Shielding NoTerminal Sizes Positive: 0.25” Negative: 0.187”

Re 6.5 OhmsLe at 1 kHz 0.26 mHFs 45Qts .36Qms 3.6Vas 22 litersSd 126 cm²SPL/w/m 89 dB @ 1W, 1mXmax (BL) 4mm one way minimumXmax (Mechanical) 10mm one way minimumPower Handling 50W RMS

What do we want?What do we want?

Copyright © 2013 Dan Wiggins. All Rights Reserved. For ALMA and instructional use only!

Set up the voice coilSet up the voice coil• VCID as needed• Copper wire as needed• Low Le = few layers• Set Winding length assuming 6mm top

plate• Set former – power dissipation• Proper DCR, Le looks promising!


Set up the motorSet up the motor• Typical clearances for voice coil• Use existing magnets• Is Xmech OK?• Typical materials• Turn off Le for now – speed!• Turn off Load Lines – speed!• Simulate the results – OK?


Application DefinitionApplication Definition• Ignore environment for now• Define driver• No need for filters now• We know the Mms of the

VC; add extra mass to get us where we need to be


Run and ResultsRun and Results• VC offset issue?• Low BL – bigger

magnet?• Pole saturated a lot –

make the ID smaller?• Consider inductance

rings• Xmax low – longer VC!


VC and BL tweaksVC and BL tweaks• Duplicate to concept 2• Pole ID – smaller for

more flux flow • Magnet – DMEGC 3614

of Y30BH• Adjust steel for different

size of magnet• Pole extension – get VC

offset to zero• VC longer – add 2mm,

adjust wire diameter to keep DCR


Run and ResultsRun and Results• Compare against concept

1• Good Xmax• Good T/S parameters• THD is down – good!• Still some saturation –

good!• Box alignment looks

flatter• We’ve nailed out the

basics


Inductance Inductance optimizationoptimization

• Make it flat!• Consider effect of aluminum

basket• Lower ring – closer to VC is good!

o Start with aluminumo 1mm thick ringo Close to VC

• Activate Load Lines – check!• Activate Le calculations

o Use relevant frequencies


Run and ResultsRun and Results• Le looks good – can

we go thinner?• Fairly symmetric• Is the 250 Hz line

OK?• Check load line –

bump up power to peak 100W


Save and documentSave and document• Add appropriate notes to file

for your own records• Dump out into a nice HTML

file – anyone can read• Maybe see if you can refine

other topologies?o Underhungo XBL™


Compare different Compare different topologiestopologies

• Took about 5 minutes per motor

• Quick comparison of different models

• Overhung – big power handling, simple, normal

• Underhung – lower THD, thicker top plate, same magnet mass, Le issues

• XBL – lower THD, top plate between OH/UH, more stroke, same magnet mass, better Le


Questions and wrapupQuestions and wrapup

THANK YOU!THANK YOU!


mōtiv tutorial complete development of a transducer motor in under 30 minutes dan wiggins and mark...

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