Because you do not run your car 24 hours a day, 7 days a week, for months and years. Local experience with battery charger peltons is that brushes wear in about 3 - 4 months with the internal charge regulator (which cuts off induction current at full battery charge and causes the turbine to spin at nearly VJet) and 8 - 10 months with resistive field currrent control and constant turbine speed.
Max Le lundi 17 octobre 2005 à 15:54 -0700, davis ron a écrit : > That is the same thing I was thinking after > reading Oso's comment. I have only had alternator > failure a couple of times over 30 plus years of > driving. Wny would they wear out so much faster when > used with microhydro? > > --- Radu Babau <[EMAIL PROTECTED]> wrote: > > > Hello Oso, > > > > > > You are saying that: > > > > > Most alternators are rated at 6000 rpm, so it > > should produce the full > > > 70 amps. You do need to subtract the excitation > > current from that, so > > > I would not count on anything above 65 amps. > > > > > > Spinning it at that speed, the brushes are not > > going to last very > > > long, 6-8 weeks would be my guess. If you cut the > > speed to about 3000 > > > rpm, the alternator should still produce 50-55 > > amps and the brushes > > > will last a little longer, say 12-16 weeks. > > > > I am wondering about this 12-16 weeks brushes life > > time. Some of us have > > cars which we mostly ride in the city, 90% of their > > life time, on which the > > normal motor speed is something from 1000-3000 > > rpm's. Usually there is > > something like 1.5 ratio between the alternator and > > motor shaft. Other > > people are mostly using their cars to run on > > highways, which means 2000-5000 > > rpm motor speed. In both cases the life time of a > > alternator (including > > brushes) is at least 5 years, even more. It is that > > kind of equipment that > > you only change once during a normal car lifetime. > > > > Am I wrong ? Am I right ? > > > > > > Radu > > > > > > > > > > > > > > __________________________________ > Yahoo! Mail - PC Magazine Editors' Choice 2005 > http://mail.yahoo.com > > > > > > Does your company feature in the microhydro business directory at > http://microhydropower.net/directory ? If not, please register free of charge > and be exposed to the microhydro community world wide! > > NOTE: The advertisements in this email are added by Yahoogroups who provides > us with free email group services. The microhydro-group does not endorse > products or support the advertisements in any way. > > More information on micro hydropower at http://microhydropower.net > > To unsubscribe: send empty message to [EMAIL PROTECTED] > Yahoo! Groups Links > > > > > > > > > > ------------------------ Yahoo! Groups Sponsor --------------------~--> Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/FGYolB/TM --------------------------------------------------------------------~-> Does your company feature in the microhydro business directory at http://microhydropower.net/directory ? If not, please register free of charge and be exposed to the microhydro community world wide! NOTE: The advertisements in this email are added by Yahoogroups who provides us with free email group services. The microhydro-group does not endorse products or support the advertisements in any way. More information on micro hydropower at http://microhydropower.net To unsubscribe: send empty message to [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/microhydro/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
