\nPCB trace width: 8 mils, 1 oz., 0.6 A – 1.0 A current max
\nPCB trace width: 12 mils, 1 oz., 0.9 A – 1.4 A current max
\nPCB trace width: 16 mils, 1 oz., 1.1 A – 1.7 A current max<\/p>\n
50 lines \/ inch with a total spacing of 20 mils can carry 1.0 A.<\/p>\n
Kapton polyimide ribbon with copper cladding is sold as Pyralux.
\nAnother possibility is to use ribbon cables glued down to form an array–called Premo-Flex and Etched Polyimide. 1 ft cables are $1\/cable on ebay.<\/p>\n
SATA ribbon cables–AWM20624 80C 60V FFC 24 Pin 0.5mm Pitch, conductor is 0.05 mm x 0.32 mm, carries 1.1A, 0.2 mm thick, 100x 23cm for $15 (ebay)<\/p>\n
Drivers for linear motors:<\/strong> Some designs only require coils energized in one direction. These designs can use n controllers to control n x n coils, using an array of half H-bridges:<\/p>\n C: coil The coils are activated in turn, each with a duty cycle of 1\/X, where X is the number of rounds needed to activate all the coils in a highest cycle driving case. This depends on the type of mover used–the number of coils needed to drive it and their arrangement. It also depends on whether one or more movers is utilized.<\/p>\n One or more high and low side pair are activated to turn on coil(s), then additional sets in turn to complete a duty cycle. The driving current can be higher as the heat generated depends primarily on the total active time x current.<\/p>\n Testing linear motor designs:<\/strong><\/p>\n 6\/7\/14 long linear coils<\/strong> I made a single coil of 10 turns using varnished wire from an inductor, 34 gauge (~0.16 mm wide). The wire was laid down on a piece of tape, and then covered with a layer of tape. Each 10 turn arm is 3 mm wide, and they are about 4 mm apart to match the magnet pair. The coil arms are slightly too far apart–by about 0.5 mm.<\/p>\n I ran 0.35 – 1.4 A through the coil and the magnet moved: At 1.4 A, the magnet could pull 2.5 g. The pull test was done on a sled of teflon tape using known weights. Test 2: A single coil of with one turn was made using varnished wire from an inductor. The wire was laid down on a piece of tape, and then covered with a layer of tape. The loops are 7 mm apart to match the magnet pair.<\/p>\n At 1.35 A, the magnet moved, but just barely.<\/p>\n
\nMost linear motor designs require an H-bridge controller for each coil.<\/p>\n+V
\n__
\n|||
\nMMM
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\nCCC--M-|
\nCCC--M-|-V
\nCCC--M-|<\/code><\/p>\n
\nM: Mosfet<\/p>\n
\nUseful references:<\/strong>
\nLinear Electric Machines, Drives, and MAGLEVs Handbook by Ion Boldea chapter 18<\/a><\/p>\n
\nI made up a test coil for a Filho et al., 1999<\/a>, Filho et al., 1999(b)<\/a> style planar motor:<\/p>\n![\"10](\"pics\/coil3_6-7-14.jpg\")
\n![\"10](\"pics\/coil4_6-7-14.jpg\")
<\/p>\n
\nCoil video 1<\/a><\/p>\n
\nCoil video 2<\/a><\/p>\n