Hello all,
I am using BLDC micromotor from Saeshin
it RPM range is 500 to 35000
torque = 4Ncm
I am using 1KHz PWM waveform with variable duty cycle from microcontroller and giving to motor driver IC
L6205 and at the OUT pins of the L6205 motor is connected
Can you tell me the relation between PWM and RPM. suppose I want to generate 5000 RPM then what setting in RPM I should do?
Regards

 

A BLDC motor is essentially a synchronous motor, so it depends on the pole count of the motor, which will give you the electrical revolutions per mechanical for each revolution.
Does the motor have any form of electronic commutation? or post a link to the motor.
Max.

 

Higher frequency will produce higher RPM in a similar industrial motor.

 

A BLDC motor is essentially a synchronous motor, so it depends on the pole count of the motor, which will give you the electrical revolutions per mechanical for each revolution.
Does the motor have any form of electronic commutation? or post a link to the motor.
Max.

Hello,
here is the link for the motor
http://saeshin.en.ec21.com/Strong_E-type_Motor_Series--324317_2619598.html

 

They are certainly very high rpm motors, up to 50krpm.
I would expect those to be 2 pole motors, if so for e.g. at 50hz the rpm would be 3krpm.
RPM= (50/Pole Pairs) x 60. (50/1) x 60 = 3000rpm.
Max.

 

They are certainly very high rpm motors, up to 50krpm.
I would expect those to be 2 pole motors, if so for e.g. at 50hz the rpm would be 3krpm.
RPM= (50/Pole Pairs) x 60. (50/1) x 60 = 3000rpm.
Max.

Hi,
but I am using 1KHz pulse with duty cycle of 30% ON and 70% OFF which gives me 5500 RPM
how I should relate this? what is the relation between RPM-voltage-PWM?
what if I give 50% duty cycle?
regards

 

One way to tell the pole count of a P.M. motor is to short all three stator wires and as you spin the shaft, count the number of 'bumps' felt, this number is the pole count.
I suggest going to sites such as Picmicro that have rafts of app notes and explanations of controlling both AC sinusoidal and BLDC motors, both motors are virtually identical but the way they are controlled are quite different.
One e.g. http://www.microchip.com/pagehandler/en-us/technology/motorcontrol/motor-types/pmsm.html
http://www.microchip.com/pagehandler/en-us/technology/motorcontrol/motor-types/bldc.html
Also see A-M-C, one of the major manuf. sites for example drives and engineering notes.
Increasing the DC supply will increase the torque capability of the motor.
As a general P.S. voltage should be at least 10% above motor rated voltage for PWM drives.
Max.