Browsing All Posts filed under »Dimensioning«

The braking problem – energy analysis

September 26, 2008


I’ve been just talking about regenerative braking for too long. It’s time to define the requirements. When trying to dimension ultracapacitors or batteries for regen braking, we have to take into account the energy and power of the braking in it’s worst case: from top speed down to zero, and in the shortest time possible. […]

Redoing the highway math

May 29, 2008


I haven’t had the time or the patience to repeat the roll-down test again. However, I found an old picture file I took out of the Web a few years ago that has all the measures of my car, and, most importantly, it has a perfect frontal area projection! 🙂 With a little help from […]

Sensible A-class physics

April 24, 2008


“Portuguese drivers in the greater Lisbon area last monday were surprised by a strange scenario: a crazy dude with a camera and tripod in the backseat of the car, going back and forth on the same road, over and over again, accelerating to 80 kph and then letting the car stop by itself. He spent […]

Motor requirements

January 16, 2008


Since I’m trying to develop an electric motor, it would be nice if we knew the target specs, right? 😉 I’m taking the engineering approach and calculating the motor specs in order to guarantee a transparent transition for the vehicle’s driver after the conversion.