So I have been doing a TON of reading recently about sensored motors and sensored VESCs, VS. sensorless motors and sensorless VESCs. What are the advantages and what do they even do?!?!? I’m new and please don’t tell me “go read more”! Trust me I have
Sensored gives a smoother startup, but a lower top speed. The VESC can use sensors at startup and disable them at a certain RPM.
The sensors are disabled? Also, what kind of sensors are they (what do they measure or prevent), and where can they be found besides a VESC?
There aren’t any in the vesc. They are in the motor. The sensors get turned off after startup so they don’t limit speed.
Their called Hall Sensors. From what I understand they measure the mangetic field around them and output a voltage based the fields strength. I think in this case they are used so the VESC can determine where the motors magnets are, and electrify the right parts of the stator to reduce cogging. However I dont know why they would reduce top speed.
I’m pretty sure the boosted boards remote uses them as well. The throttle wheel has two magnets on it, one on either end and a hall sensor attached to center throttle position. When the wheel gets turned the hall sensor measures an increase or decrease in magnetic field strength since the magnet attached to the wheel is now further from the center, and sends that value to the reciever.
So it’s best to get sensored and have the vesc un sensor them?
Yes you are right, the hall sensors output a voltage based on the position of the stator with respect to the magnets (they measure the electromagnetic induced current). The VESC can then more accurately command the motor to the correct RPM.
The reason this limits the top speed is that this process takes time and it’s probably not as fast as when the motor is going at top speed so to keep accurate tabs the VESC slows it down to whatever speed it can manage.
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There is a hybrid mode you can run that is sensored at low RPMs to reduce cogging and have a smoother startup and non sensored after a certain RPM where it is no longer needed.
You can find plenty of info by googling rc sensored vs sensorless motors and on the VESC how to threads
IF you can figure out the order of the wires. I’m still stumped.
anyone know how much more efficient sensors are in foc or have done real comparisons?
According to rew on vedders site they do little for efficiency
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basically an unsensored motor will chirp for a bit if you try to accelerate from a stand still on flat ground, but after literally one second it will go. during your actual cruising you will notice no difference between sensors and no sensors.