From: Chris Tromley >Not liking the efficiency hit, but still an interesting idea.
Like any hybrid, you lose efficiency at the peak; but regain it during other modes of operation. If you spend enough time in these other modes, then your overall efficiency improves. I'm no expert, but I suspect a chain's efficiency is very high only at full load. At light load, it has so many moving parts (all of them with sleeve bearings) that I suspect its efficiency becomes quite low. It is possible to design electric motors and generators to have a very wide efficiency band. PM motors have high peak efficiency, but low light-load efficiency because they run at "full field" all the time. A wound-field motor loses a bit at full load (a couple percent due to field power), but gains at light load. A wound field DC or AC synchronous motor/generator might therefore be the best option. Brainstorming... I've always wondered if a human-spring hybrid might have merit. Springs don't store much energy, but can be an extremely efficient way to store small amounts of power and get virtually all of it back. Wind up the spring going downhill, and use the stored energy to go back up. :-) -- Excellence does not require perfection. -- Henry James -- Lee A. Hart http://www.sunrise-ev.com/controllers.htm now includes the GE EV-1 _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
