The voltage drop across the motor and the current tell you the power going into the motor, not the efficiency. Some of that power is being used to move the vehicle, but how much?
George Tylinski wrote: >Thermal measurements can be very difficult because it occurs in 3 modes; >conduction, convection, and radiation. You will never capture all the >thermal paths out of the motor. > >On the other hand, if you can accurately measure the voltage drop across >the motor and the current through it, you are done. Of course it's >fluctuating wildly all the time, so some averaging would be required >over a "typical" trip. > >- GT > >>-----Original Message----- >>From: Mark Dodrill [mailto:[EMAIL PROTECTED]] >>Sent: Friday, September 27, 2002 4:59 PM >>To: EV List >>Subject: How much power am I losing? >> >> >>Since my Optima YT's are rolling along just fine (about 1k >>miles on them now), I want to turn my attention to increasing >>overall efficiency, to reduce my Amp/Hrs per mile. I'll be >>looking into front end alignment, LRR tires, etc, but I >>suspect my motor is where I'm losing the most. >> >>Since it is a 6.7" ADC (a bit small for my car), I suspect >>that I'm having a lot of electricity turned into heating up >>the motor instead of having the motor run faster (since I'm >>at the upper end of the power/torque it will do). I'm >>wondering how I can measure this loss. If I were to measure >>the air temp going into the motor and the temp leaving the >>motor, with a fan of a fixed CFM blowing air through the >>motor (in a sealed manner), can I use that information to >>figure out how many BTUs or Watts of heat are being generated? >> >>Any ideas on how to proceed on quantifying this would be appreciated. >> >>Mark Dodrill >> > > >
