Power peripherals/Bicycle Powered Generator

Documentation of tests/work by ILXO

August 14, 2008

• Switched bike (small kid one) to a larger one to achieve higher rpms
• No belt -- tire is in direct contact with alternator
• ND alternator, serial number -- 4340202037314 -- wish there was some way to find out more about it
  • we don't know what rpms it operates on
• Read output of voltage from B terminal and something sticking out near it - only two terminals that provided any sort of reading. Presumably, this is the right output, and not some regulated value.

Varying rpms
Pedal:Wheel = 42:11

Wheel circumference: 80.11 in
Alternator wheel: 8 in

Test 1:
Measured output: ~1 V
70 pedals/min
theoretical - 2676.4 rpms

Test 2:
Measured output: ~3 V
27 pedals/10 sec
theoretical - 6193.96 rpms

We're assuming either losses in rpm through the transfers. However, adding rubber bands to minimize slippage had little measurable effect. To ensure that the alternator was being run in the correct direction, we flipped our set-up, also with little measurable effect.

Other possibilities may be that the alternator was an RV alternator -- requiring high rpms (up to 8000) -- or, it might even be dead. Uh oh.