We are endlessly fascinated by the largest, most powerful, or smallest and most infinitesimal of anything. Here we look at two extremes in electric propulsion.
The Prodigious
American Superconductor produces superconducting wires, and from those, winds a very large motor, that if not the biggest thing to power ships, is the most powerful for its size, and the most powerful to be used in a Navy ship.
American Superconductor's 49,000 hp motor compared to largest, but less powerful, naval motor.
The company promotes the following benefits for its 36.5 MW (49,000 horsepower) HTS (high temperature superconductor) motor: high power density (compared to traditional copper-wound motors), high partial load efficiency, low noise, harmonic-free voltage, low synchronous reactance, cyclic load insensitivity, and low maintenance.
The Petite
Lad, living in St. Petersburg, Russia, has constructed the diametrical opposite of the HTS. His micro radio-controlled, electrically-powered model airplane weighs but 0.225 GRAMS – motor, R/C system, and battery. In an R/C forum, readers were blown away by this accomplishment, needless to say, and the general hub-bub prompted this response from Lad.
Lad's 225 mg airplane.
“Thank you all for the congratulations.
“I cut 8.5 mAh Li-poly rebuilt up to 273 mg in halves in argon and sealed it with alu foil.
The battery was cut 6 days ago – no capacity reduction over time so far.
In the picture you’ll see the argon box. (Editor’s note:This is Lad’s inert-gas-filled miniature clean room, to prevent fires from even this minuscule motivator. Li cells don’t take kindly to being punctured.)
“Motor
“2 Magnets D 1mm L 0.5mm, rebuilt
2 Coils: wires D 0.02 , windings 220 , 72 ohms
Gear-box 1 : 6.7
“static thrust with prop d 25 x 15 0.14 gr
current 24 mA”
The video cries out to be seen full screen, since the airplane is a brief flash in the lighter portions of the room.