K4-09: BICYCLE GENERATOR - LIGHT BULBs VS CFLs

K4-09

Compare brightness and power requirements of regular tungsten filament light bulbs and compact fluorescent lamps.

Pedaling the bicycle generates 110 VAC, which can be used to light an array of four 110 volt 60 watt incandescent light bulbs. The sum, totaling 240 watts when fully lit, can be verified using the voltmeter mounted on the bicycle. Alternatively, switch in the array of 15 watt CFLs (compact fluorescent lamps) and use the bicycle generator to light them. These CFLs are equivalent in light output to the 60 watt incandescent bulbs. It is easy to notice that the same amount of light created by the standard light bulbs can be created relatively easily using CFLs. The upper two photographs above show Krishna pumping the bicycle generator to light the incandescent bulbs (top photograph) and the CFL bulbs (second photograph); the lower two photographs show the arrays of lamps plugged into the 110 VAC outlet in front of the bicycle. The third photograph shows the incandescent bulbs and the last one shows the CFLs being activated. The student volunteer for riding the bicycle will testify as to the increased effort required to light the incandescents over the CFLs. This is a dramatic demonstration and can be used very effectively in class.

K4, FS1