- #1
Stormclad
- 1
- 0
Homework Statement
I want to know the affect of stator design on bicycle dynamo performance using magnetic circuits, and power output. The bicycle dynamo is a single phase AC generator with permanent magnets on its rotor (mounted on hubshell) and a lundell type armature(mounted on bike axle). At 30rpm, the dynamo is expected give out 2.4W at 3V. Load is 15ohm.
Homework Equations
I've tried using Faraday' law, Voltage generated=-N(change in flux & area)over time, but I keep getting larger results than expected.
My attempt at applying:
Faraday's Law:
Total B of the magnet is: 4000mT, so for this voltage estimation I am assuming perfect coupling of field through the stators
The coil has a cross area of 483.05mm^2 and 320 turns.
There are 28 poles, so I assume the coil experiences a field change 14 times per second at 30rpm.
So Voltage generated = -(320)(4000mT)(483.05mm^2*14) = 8.65V
How do you factor in the 15 ohm load into the basic equation?
The Attempt at a Solution
Aside from the attempt in the previous section, I'm stuck. Would appreciate links or recommendations of reference if some reading is in order.
Thank you,
Derek
Last edited: