http://autos.groups.yahoo.com/group/ULEA/ Ultra Light Electric Assist Fri, 22 Jan 2010 01:47:34 GMT jgtetz76 http://autos.groups.yahoo.com/group/ULEA/message/975 http://autos.groups.yahoo.com/group/ULEA/message/975 ... No its super critical to have the current limiter on a 100 watt or any watt system. It makes the system idiot proof. If the operator engages the motor at Wed, 20 Jan 2010 15:17:40 GMT Hugh Currin http://autos.groups.yahoo.com/group/ULEA/message/974 http://autos.groups.yahoo.com/group/ULEA/message/974 John: Such a current control may not be worth the added complexity at a few hundred watts but may be nice to have. Probably have to build one and try it to Wed, 20 Jan 2010 15:01:50 GMT Hugh Currin http://autos.groups.yahoo.com/group/ULEA/message/973 http://autos.groups.yahoo.com/group/ULEA/message/973 John: That is encouraging. It's hard to tell from Kelly's web site or manual just what their controller does. They do mention "current loop" once which would Wed, 20 Jan 2010 03:10:12 GMT jgtetz76 http://autos.groups.yahoo.com/group/ULEA/message/972 http://autos.groups.yahoo.com/group/ULEA/message/972 ... .....Just checking. And now I understand a bit more what your after. All these problems with high power. I have none of these - just push the button and Mon, 18 Jan 2010 21:57:06 GMT John Hopkins http://autos.groups.yahoo.com/group/ULEA/message/971 http://autos.groups.yahoo.com/group/ULEA/message/971 I'm not really qualified to respond, *but* based on my reading at endless sphere and other places, my understanding is that some of the higher-end, sensored Mon, 18 Jan 2010 15:46:59 GMT Hugh Currin http://autos.groups.yahoo.com/group/ULEA/message/970 http://autos.groups.yahoo.com/group/ULEA/message/970 John: I've seen your write up on current limiting and modifications to a servo tester. It makes sense, the torque without this protection is enough to break an Mon, 18 Jan 2010 02:20:05 GMT jgtetz76 http://autos.groups.yahoo.com/group/ULEA/message/969 http://autos.groups.yahoo.com/group/ULEA/message/969 ... Hugh It looks like you havent read my write up on current limiting. Its in the Files section. Current limiting is definitely the way to go. It idiot proffs Sat, 16 Jan 2010 21:16:17 GMT Hugh Currin http://autos.groups.yahoo.com/group/ULEA/message/968 http://autos.groups.yahoo.com/group/ULEA/message/968 Power People: I just uploaded a file to the ULEA file section. It is motor-select.pdf. It describes the analysis I've tried to do in selecting a motor. It also Sun, 20 Dec 2009 17:22:49 GMT John Johnston III http://autos.groups.yahoo.com/group/ULEA/message/967 http://autos.groups.yahoo.com/group/ULEA/message/967 FYI. http://senseable.mit.edu/copenhagenwheel/ - John Mon, 09 Nov 2009 17:52:08 GMT leitralad http://autos.groups.yahoo.com/group/ULEA/message/966 http://autos.groups.yahoo.com/group/ULEA/message/966 Shaft speed squared may be true at full power, but I'd like to see evidence whether it is strictly true when throttled. The eddy current and hystersis loses Mon, 09 Nov 2009 12:23:25 GMT mileshellon http://autos.groups.yahoo.com/group/ULEA/message/965 http://autos.groups.yahoo.com/group/ULEA/message/965 Comparable with hysteresis losses would make them a significant portion then.... Eddy current losses are proportional to shaft speed squared. Miles Mon, 09 Nov 2009 01:17:59 GMT C POLLARD http://autos.groups.yahoo.com/group/ULEA/message/964 http://autos.groups.yahoo.com/group/ULEA/message/964 ... * Then just use the high temp value or the one for the current you normally run at. ... * I don't agree that eddy current losses are a significant portion Mon, 09 Nov 2009 00:26:08 GMT leitralad http://autos.groups.yahoo.com/group/ULEA/message/963 http://autos.groups.yahoo.com/group/ULEA/message/963 ScorpionCalc and the other programs that predict motor performance use three motor characteristics, Rm, Io and Kv, that are assumed to remain constant Mon, 02 Nov 2009 05:29:51 GMT jgtetz76 http://autos.groups.yahoo.com/group/ULEA/message/962 http://autos.groups.yahoo.com/group/ULEA/message/962 Ok maybe this will go thru. been trying for the last couple of days ... I need IC for touring but electric seems the best solution for commuting and around Mon, 02 Nov 2009 05:17:04 GMT jgtetz76 http://autos.groups.yahoo.com/group/ULEA/message/961 http://autos.groups.yahoo.com/group/ULEA/message/961 This is a test. John Tetz