StarDestroyer.Net BBS

gday all, seeing as there is such a variety of peoples here on the board i thought i wouold ask for some help/ advice on a current physics assessment task i have at school

ok, for the assignment i have to build a cheap, efficient electric motor that runs off a 9 volt battery.

I have seen a few designs, but most use round batteries (mainly D and C). If anyone has a design they could let me use or some helpfully info i should keep in mind when actually building one, could you plz give me a heads up. thx all, any help is appreciated

mantakai wrote:gday all, seeing as there is such a variety of peoples here on the board i thought i wouold ask for some help/ advice on a current physics assessment task i have at school

ok, for the assignment i have to build a cheap, efficient electric motor that runs off a 9 volt battery.

I have seen a few designs, but most use round batteries (mainly D and C). If anyone has a design they could let me use or some helpfully info i should keep in mind when actually building one, could you plz give me a heads up. thx all, any help is appreciated

Are you talking the actual motor, or a motor with the appropriate driver circuit? And no, we're not going to just give you the design. There's a very important thing you need to keep in mind when doing your design. How much current does your motor need to operate? Too little current, and it won't work at all. Too much current, and you burn the thing out. The reason we usually use the big 1.5 V cells is because the typical small motor is designed to operate at about 3 VDC with a few milliamps of current. A nine volt battery supplies more juice than the motor really needs. So you'll need some manner of resistor network to cut down the voltage while supplying the appropriate amount of current.

(Ohm's Law: V = IR where V is voltage, I is current, and R is resistance. This formula can be rearranged to solve for current, or resistance, like so:
I = V/R, or R = V/I)

This should be covered in a little more depth in your physics or circuits text.

MAXXXXXXXXX AMPERAGE BABY

Seriously, just build a simple thing out of rolls of copper wires with a few Twisted and hanged as brushers with big ass fixed magnets around. The induced negative voltage should keep if from spinning to fast or eating the battary too fast. For efficiency, the key would probably to minimize mechanical friction I guess.

Just how high level is this suppose to be? 1 week effort or @$$ for the term thing?