Brushless Sensorless ESC Question ?
12-29-2006, 07:52 AM
#1
Brushless Sensorless ESC Question ?
I have a 25 amp ESC made by Ultrafly that says it is brushless and sensorless that i was wanting to use with my E-Flight Park 450 motor, i know the motor is brushless, but i dont know if it is sensorless or what sensorless even means ? i have this combo all rigged up in a plane but im afraid to test it out til i know for sure it will work without burning them up...help please? [sm=spinnyeyes.gif]
12-29-2006, 10:22 AM
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RE: Brushless Sensorless ESC Question ?
The sensorless just means that you have to manually program in the information rather than it auto-detecting the number of battery cells, type of cells (LiPo or NiMh), low voltage cut-off, etc..it does not have a sensor that auto-detects that information. At least as far as I understand it 
You should be able to hook up the motor without any problems.
You should be able to hook up the motor without any problems.
12-29-2006, 11:23 AM
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RE: Brushless Sensorless ESC Question ?
No, that's not what "sensorless" means with regard to brushless ESCs.
In a sensored brushless motor, small Hall effect sensors are spaced evenly around the perimeter of the rotating can. These sensors detect the rotational position of the can, and the ESC uses this information to determine when to energize the different windings in the motor. The brushless motors inside many CD-ROM drives are of this type.
In our R/C-type sensorless brushless motors, there are no sensors to tell the ESC the position of the can, but the ESC still requires this information. So the ESC energizes only 2 of the 3 phases at any given instant in time. During the moments when a phase is not energized, the ESC uses it to determine the position of the can (a coil of wire in a moving magnetic field produces a small current, which is detected by the ESC). No sensors are required.
That's the difference between sensored and sensorsless brushless motors.
The vast majority of brushless motors and ESCs for R/C use are sensorsless. In fact, I don't know of any sensored R/C motors, although there may be some out there.
Your setup should work fine.
- Jeff
In a sensored brushless motor, small Hall effect sensors are spaced evenly around the perimeter of the rotating can. These sensors detect the rotational position of the can, and the ESC uses this information to determine when to energize the different windings in the motor. The brushless motors inside many CD-ROM drives are of this type.
In our R/C-type sensorless brushless motors, there are no sensors to tell the ESC the position of the can, but the ESC still requires this information. So the ESC energizes only 2 of the 3 phases at any given instant in time. During the moments when a phase is not energized, the ESC uses it to determine the position of the can (a coil of wire in a moving magnetic field produces a small current, which is detected by the ESC). No sensors are required.
That's the difference between sensored and sensorsless brushless motors.
The vast majority of brushless motors and ESCs for R/C use are sensorsless. In fact, I don't know of any sensored R/C motors, although there may be some out there.
Your setup should work fine.
- Jeff
