Appreciate your concern but if transistors were as unreliable as you suggest then our new cars are really death traps. Safety is the major reason I built this replacement. I have read of many owner driving on the freeway and their engines cut off due to a failed RPM relay. Lucky no one has suffered as a result. Try pulling of the DC beltway during rush hour..... --- In dmcnews@xxxxxxxxxxxxxxx, "David Teitelbaum" <jtrealty@...> wrote: > > I would suggest you test all possible failure modes. This is a key > safety item and it MUST "fail safe". I applaude your efforts to > improve the Delorean but you may be allowing yourself too much > potential liability exposure. The current RPM relay available from the > vendors has a low failure rate and it only seems to "fail safe". I > have never heard of an instance of a properly wired car where the RPM > relay failed in a constant run state. Even if you are not planning on > making any money on this you certainly don't want to lose money > either! Just defending yourself in a lawsuit can be costly even if you > win! Maybe a double-redundant circuit could make it less likely to > fail "ON". A relay (mechanical) element has certain inherent safety > advantages. That's why it has to be constantly energized, it opens the > circuit if loses signal (fail safe). A shorted power transistor can > make the pump run constantly (even if the motor should stop with the > key on). Just substituting a power transistor will reduce the power > requirements but that's not all that the relay does! > David Teitelbaum > vin 10757 > > > --- In dmcnews@xxxxxxxxxxxxxxx, "tho323" <tho323@> wrote: > > > > I have been beta testing a new, re-engineered RPM Relay design, and > > wanted to share my thoughts about it. I have posted a full review at my > > blog (link below), and here are some key excerpts: > > > > > [moderator snip] > ------------------------------------ To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnewsYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/