PURPOSE: To demonstrate a how a person can pedal a simple DC generator and transform mechanical energy into electrical energy capable of delivering up to a kilowatt of power directly to a resistive load.
DESCRIPTION: A permanent magnet synchronous DC motor has a roller attached to the axle. The motor is used as a generator and is mounted so the axle roller is pressed by a spring force against the tire wheel of an exercise bicycle. The output of the generator is connected to a bank of four parallel 250 Watt lamps and switches. As the bicycle is pedaled the load is increased sequentially from no load to 1 kilowatt by throwing the switch to each 250 Watt lamp.
http://www.youtube.com/watch?v=DN61UNxcqlE
The motor is made by Pacific Scientific model PWM3614-5349-7-1, 120 Volts DC, 11.2 Amp, 1.5 HP, 4800 rpm. It was purchased for $40.00 in 1999 from a Surplus Electronics Parts Catalogs. A list of these suppliers can be found here:
http://physics.brown.edu/physics/userpages/staff/Gerald_Zani/catalogs.htm
The roller attached to the axle was purchased from Mcmaster-Carr. www.mcmaster.com
This type of motor is commonly found in a consumer treadmill. So if you're lucky enought to find a discarded treadmill you can strip the motor and make this demo.
EQUIPMENT: Bicycle is stored in the slanty room in 066. The parallel lamps are stored on top of the E&M cabinet