When do you use low voltage motors vs high voltage versions?

[fly_joy]

What applications do you use low voltage motors for?

I see many motors are available in LV and HV versions like the m-20's, n-20 and now GWS is offering low volatage versions of their motors.

I would think that using fewer cells for the same power would be advantageous, especially for indoor flying where the weight of the cells is a high percentage of the AUW of the plane.

Is there an efficency trade off or other reasons to consider?

thanks,

Larry

[Dave Robelen]

Hello Larry,
Basically I see it as an issue of weight control. The LV versions of the small Mabuchi motors (N20,M20) develop a littles total power than the HV versions, but there is a significant weight savings as you assumed. Not sure about the GWS, they have so many different winds that it would take some investigative work.
Regards, Dave Robelen

[KeithK]

Larry,

Lower voltage for the same watts out requires higher amps, giving shorter flights and perhaps working the cells harder than they like.

Keith

[fly_joy]

Keith and Dave,

Thanks for the replies.

For the same watts input (albeit at a lower voltage and higher current for the LV version) do you get the same power out of LV and HV motors, e.g., an n-20 LV and n-20 HV with the same wattage input?

[Dave Robelen]

Hi Fly_joy,
I am going more on impressions here but I feel I am getting more oomph out of the HV version for similar watts in. I believe the reason is that we are running these little suckers so far beyond their design efficiency point that the HV version simply suffers a little less. There is also the matter of the brushes where pushing the amps too far on either will result in really short life.
Regards, Dave Robelen

[KeithK]

Fly_Joy,

Like Dave said, I think the high voltage versions are more efficient. Without getting into technicalities, amps are what cause losses and heat. But then again, more cells weigh more.

Keith