[ref http://electric-vehicle-discussion-list.413529.n4.nabble.com/Series-motor-overspeed-protection-tp4679797.html ]
The evdl member must be new as their email is incorrectly set to send out their text as a html attachment (no one can easily read your posts). As our beloved evdl.org sys admin would say, ***Please change your email settings to only send as plain ASCII text (not html, nor as an attachment). I pulled down the html attachment and paste it for all to read: - I recently bought an EV conversion that uses an ADC 9 inch series wound motor and a Curtis controller. The original owner wanted to add a motor speed sensor and a way to shut down the controller if the speed was too high (as in someone reving it in neutral), but that hasn't been done. It seems pretty easy to add a speed sensor and a circuit that will over ride the "throttle" pot and kill power to the motor, but I'm wondering how fast it needs to react. I'd like to average the speed over a few pulses from the speed sensor (to reduce the impact of noise) but still shut off fast enough to save the motor. Any ideas? Bill - Bill, because you did not subscribe to the evdl with your name (which means your posts do not easily state who we are talking to), *Please always include your name (the same point of reference) in each post you make. Please tell us more details of your conversion: make, model, year, and how you are driving it (on flat roads & highways, or up in mountains at lower speeds, etc.). The converter than made my former S-10 Blazer conversion EV [ http://brucedp.150m.com/blazer/ ] warned me to be careful of over rev'ing the AdvancedDC 9" motor they used. Except for when I was proofing/testing a new-prototype for a startup controller company (Auburn C600), I never had to really spend much effort to worry about over rev'ing the motor. It is only during some mountain-climbing driving when that proto-controller went full on (fried) that I had to pull the red-knob kill-power switch, and I easily pulled-over coasting to a stop. A tow home eventually got the proto-controller issue resolved (they replaced it). At one time, I had a converter check the motor brushes and he found with all the 'anywhere everywhere' long trip driving I had done, the brushes were fine and still had years to go before they needed replacing. He did not report any damage like over speeding, etc. So I can feel safe in saying that I drove that Blazer EV for 15+ years and never had a e-motor over-speed issue during daily/normal driving. If the previous owner put the fear of God in you, perhaps if you do not have a kill-power switch, you ought to install one. It came in handy more than that one instance. For EVLN EV-newswire posts use: http://evdl.org/evln/ {brucedp.150m.com} -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Series-motor-overspeed-protection-tp4679797p4679802.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)