Hello to all Physics Educators and everyone else on this list,
I'm helping my son to build the pop bottle electrostatic motor that William
Beaty illustrates in one of his web pages. I'm not a physicist or a Physics
teacher, just a concern father and an amateur scientist so my son and I have
a few questions that have arouse with this proyect that you can help me to
answer.
First of all, we built the motor using an acrylic sheet for the base and we
use aluminum soda cans for the stators and only use a pet bottle and
aluminun foil for the rotor. after we made the motor we tried to make it run
with the TV screen trick. We use a perfectly good working B/W 14" TV but it
didnt work. we try everything and got to the conclusion that TV wasn't
generating any static charge at all.
Then we tried with my big 21" color TV and it work right from the first
time. Now the problem is to get this big TV to the school the day of the
science fair (Feb 26) end get it back home safe and sound.
Ok, enough background, now the questions:
1. Can someone explain (in plain english) how the TV screen generates static
charge and why the small B/W TV didnt work?
2. How can we measure or estimate the voltage we're getting from the TV? I
have a micronta multitester but only goes up to 1000 DC V. How the longitude
of the sparks relates to voltage?
3. Our motor spins to about 100 RPM. Is this fast or slow considering what I
told you about the design and the power source?
4. Stators are placed about half an inch away from the rotor bottle, brush
tips are separated about 1/10 of an inch from rotor. Sometimes sparks jump
directly from stators to the rotor's closer aluminum foil sector.
Theoretically, will the motor performance will improve if we increase the
distance of the stators to the rotor?
I hope you can comment on all questions. Forgive me if Im not using all the
appropiate terms. English is not my first language.