MultiWii

Hello,
can we use brushed motors for quad without speed controls?
if Yes, would you pls help me how?
if No, why?
im sorry for my bad English
thanks,

Yes you can, but not directly,
You still need a brushed controller. If the PWM output in the Multiwii software is modified you can drive
directly a Mosfet(s).

But its easiest to use brushed controler.

Rob

Hi,
Yes, there is a code for this here:
http://code.google.com/p/multiwii/downloads/list

You just have to buy some mosfets to command the brushed motors.
(never use this code with brushless ESCs !)

hmmm thats pretty cool. you could make a really cheap tri / quad with this and old brushed motors. im thinking of the brushed motors extracted from used electric toothbrushes.

Hi,
thanks a lot for kindly answers,
could you pls give me a link for buying mosfets?

Hi guys, any update for the brushed multiwii copter ?

Hi guys,

I made a tiny hexa copter with brushed motors and used the above mentioned software. My prloblem: whenever I apply a voltage, the motors 5 and 6 start without any command from a rc. I can't find the bug in the software. Who can help me out? I am using an arduino pro mini.

Best regards and thanks a lot
Karl

karlik wrote:Hi guys,

I made a tiny hexa copter with brushed motors and used the above mentioned software. My prloblem: whenever I apply a voltage, the motors 5 and 6 start without any command from a rc. I can't find the bug in the software. Who can help me out? I am using an arduino pro mini.

Best regards and thanks a lot
Karl

Hi,
This code wad made for a quad only.
The 5 and 6 motors are driven differently on a pro mini.
It would be however possible to modify this also for a brush config.

is there a diagram on how to connect the fets to the FC?

Hello everyone, I'm new to electronic, so i have a stupid question: what if I replace the mofset with a regular transistor? The bandwidth of transistor seem ok, the maximum current is ok too?

If by 'regular' you mean bipolar junction transistor (BJT), they can certainly be used a switches, albeit less efficient ones. The turn-off time is inherently slower, the voltage drop (collector-emitter vs source-drain) is usually larger, controlling is done by current rather than voltage for MOSFETs, so the driving circuit is different. Additional great and special feature of MOSFETs is that they can be used in parallel, allowing one more flexibility in designing power stage. Can't do that with BJTs. Overall it is just easier and more effective to use MOSFETs, but if you want to design around BJTs it should be possible. However, if you are asking that question it probably means that you are facing a long and steep learning curve either way... no offense