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Questions tagged [brushless-dc-motor]

A brushless DC electric motor is a DC motor type that uses an electronic inverter/switching circuit to energize the motor coils in a sequence (based on the detected rotor position) in order to rotate the motor.

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0answers
673 views

Regenerative braking circuit for a BLDC Motor

I am trying to design a regenerative braking circuit for clamping the voltage when it is increased due to BLDC Motor acting as a generator. Simulation wise I am getting the exact result. But when I ...
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1answer
250 views

Hard and Soft Chopping

I am controlling my BLDC (Brushless DC motor) controller with PWM technique by changing the duty cycle to reduce the power(current) in phase winding. what is hard and soft chopping in PWM based ...
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1answer
466 views

STM32405 ADC on Update Event of Timer 1 or 8

I'm not sure what I should be asking for because some of the terminology is confusing to me, but what I'm trying to do is use the two motor timers (TIM1 and TIM8) on the STM32F405 to sample BEMF on a ...
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1answer
134 views

BLDC motor's frequency

I have a 3-phase motor. I want to find out the frequency of the motor so that I can supply the required PWM frequency for the motor. My motor specification: 360 Watts (36v and 10A) rated max 30 ...
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0answers
221 views

Sensorless FOC position observer error

I am designing my own FOC (field oriented control) system, and I am trying to implement sensorless control. I have successfully implemented sensored FOC with my system on two different motors using ...
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2answers
183 views

Why should half-bridge driver have resistance in series with VCC?

I am using the three of the RT9624A half bridge driver as part of a 3-phase motor control circuit. Everything was working well in testing until I got to about 80% duty cycle and one of the drivers ...
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1answer
115 views

How this flying copter actually work [closed]

The link below shows a drone copter without any swash plate mechanism only using two bldc motors which accelerate and deccelerate per cycle creating lateral force and moment. How does it work? I want ...
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65 views

Design of ESC for bldc motor having encoder

Is it possible to vary the speed of propeller or BLDC motor from maximum value to minimum value per cycle of rotation. I mean blade accelerated per half cycle and deaccelerated per next half cycle. ...
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2answers
447 views

Why BLDC are DC motors as basically they work on ac by using inverter? Can I directly give AC supply to BLDC motor?

What I have heard is BLDC is workhorse in industry even laptop fans they work on BLDC but why they are called DC motor as eventually they use inverter to get ac as input? Can I directly give AC supply ...
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2answers
640 views

Why does my BLDC motor change behavior at high speed?

Background I've recorded torque vs speed performance of a small sub 50 gram hobby BLDC motor, the KDE 2304XF-2350. I power the motor at different fixed voltages to the ESC (electronic commutator) ...
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1answer
350 views

Low side current sensing

I’m making a BLDC motor controller application. The motor control IC (Allegro A4931) uses low side current sensing (R7,R8,R9) for controlling the motor. Unfortunately the motor IC does not output a ...
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2answers
632 views

DC motor characteristic lines

For a university project, we need to use electric motors. (This is not our area of expertise, we are aerospace engineers, not electric engineers.) We have already selected a suitable motor based on ...
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1answer
154 views

How do i determine max voltage for a custom BLDC [closed]

I would like to know the process that you would go through to determine the voltage rating on a BLDC. I imagine that it has something to do with how the coils are wrapped and the how many coils there ...
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1answer
554 views

How to empirically tune DQ current PI controllers in BLDC/PMSM motor for vector control?

I need to experimentally set the \$k_p\$ and \$k_i\$ parameters of PI controllers for the DQ-axes of a vector controlled BLDC motor. I have been looking for papers and application notes proposing ...
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0answers
50 views

BLDC BEMF unequal power-on stage length for different phases

i'm driving BLDC using sensorless method. The driving algorithm is woking fine, but on the bemf oscilogram i can see, that the power-on stage length is little bit different for each of the 3 phases. I'...
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1answer
59 views

Need help with understanding PMDC Motors

I'm running out of places - and people - who have enough understanding of the questions I am asking. Please help! I'm building a crab/shrimp pot puller. I've seen the regular production models and a ...
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89 views

Issue with RPi and BLDC controller board

I'm having some trouble figuring out what I'm doing wrong so hopefully someone can spot my error and help set me straight. These are my motor and the board with everything labeled. Then below that is ...
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1answer
1k views

Speed measurement of brushless dc motor with hall sensors with STM32

I have difficulties understanding and finding a solution to find the speed of a BLDC motor. Here is the specs: 3 Phase BLDC with 3x Hall sensors in 120 degrees, 2 pole-pair The image below shows the ...
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0answers
75 views

Waterproof PCB pump driving stage

We are having issues with a small 12V DC pump which is used in a number of test systems in the field. The pump is powered by a standard DC power supply and integrates a small PCB driving stage, with ...
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2answers
2k views

Controlling BLDC motor with Raspberry Pi

I'm trying to figure out how to control the speed of a 400-watt, 3000RPM, 48V BLDC with Hall sensors with a Raspberry Pi 3. I've been able to find information where people will us an ESC like this ...
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0answers
58 views

Why not detecting zero crossing of the back EMFs in BLDC by software?

I am reading about the state-of-the-art approaches to detect the zero crossing of the back (trapezoidal) EMFs on a 3-phase BLDC for sensorless control. Even digitally implemented, they use various ...
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2answers
2k views

Function of gate resistor

I've been studying some ESC (electronic speed control) circuits for BLDC motor control and something always catch my attention. In many of these schematics there's often a resistor connecting the ...
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0answers
238 views

BLDC phase voltage wave form

I am measuring the phase voltage of a BLDC motor as shown in the figure below. As the motor doesn't have neutral point, a virtual neutral point(VN) is created by the resistor network and three-phase ...
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4answers
139 views

Which type of DC electric motor is the best suited for driving a mechanical clock?

I want to drive a clock mechanism with a motor. In order to get acceptable accuracy I need a motor that can deliver a certain rpm very precisely, is low on vibrations, noise and power consumption, and ...
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0answers
209 views

Low frequency PWM Brushless DC Motor Speed Control

I am programming a L293D motor driver with a BLDC motor to spin at speeds of 60-300 RPM. It is for a hybrid drone/car where I want the motors to spin slowly while having the necessary torque to drive. ...
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1answer
2k views

What's the meaning of current rating of BLDC motor and it's relation to a phase peak and RMS current? [closed]

Considering battery powered BLDC motor having rated voltage and current specs, what is exact meaning of the rated "current"? Since BLDC motor is NOT powered by a DC current (enjoy the twisted logic of ...
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2answers
241 views

Why does my in-wheel BLDC motor have sinusoidal back emf (line to line) when rotated by external system?

I have an in-wheel BLDC motor with 46 poles (permanent magnet) on the rotor and 51 slots in the stator. When I used an external machine to rotate my in-wheel BLDC motor, then measuring across two ...
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2answers
325 views

why in-wheel BLDC motor have more pole than normal BLDC motor?

I am using a In-wheel BLDC Motor having poles 46 but another normal BLDC motor have less pole as 8 pole. I have searched about other In-wheel BLDC motor and it also have 42 poles.
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159 views

My BLDC motor is stuttering and I have no idea why

I'm driving 2 BLDC motors with two ESCs, the motors and the ESCs are powered by an external LiPo battery and the Arduino is powered via usb. The motors work with pulses between 1000 and 2000 ...
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0answers
400 views

Meaning of motor constants for three-phase PMSM

When looking at three-phase permanent magnet synchronous (brushless) motors, \$K_T\$ and \$K_V\$ numbers are often specified. Also, controllers for these motors typically specify maximum currents. ...
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2answers
382 views

brushless vs brushed motor [closed]

I'm currently making a radio controlled fighting robot and have pulled apart some drills which have a brushed RS550S DC motor (0.5Nm 18V 60A so 1080W) and a gearbox attached. Right now I'm looking at ...
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2answers
333 views

Can I use this BLDC controller for RC motor for friction drive eBike?

I want to build an eBike for myself. I've read a lot on the subject of converting Bikes to eBikes and I think the best approach would be to build a so called friction drive, wherein a small RC BLDC ...
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1answer
220 views

Motor regeneration Circuit Issues

I've been trying to get a motor regen power dissipation circuit working that I pulled from here. The circuit works as provided but when I attempt to modify the load resistor, the mosfet is not longer ...
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3answers
3k views

How do single phase BLDC motors start in proper direction?

There are descriptions on internet of the single phase BLDC motors which are powered by Vdc (such as PC cooling fans 12V). Interestingly pictures shown describing outrunner type with equal number of ...
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0answers
303 views

Relationship between brushless coil inductance and back EMF as a function of phase angle

In general, does the inductance across the coils of a brushless motor have the same waveform as the back EMF? That is, if back EMF is sinusoidal, should I expect the inductance to be sinusoidal [with ...
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0answers
261 views

BEMF polarity is backwards

Please take a look at this waveform of a 3 phase, BLDC motor: Check out that rising and THEN falling slope...Pretty nice. Now, take a look at what I'm getting on my motors sensorless resistor ...
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1answer
385 views

FOC current control autotuning PI Controller for BLDC Motors

I try to understand, how the guys from odrive tuned the current control PI parameters for Field Oriented Control: https://github.com/madcowswe/ODrive/blob/master/Firmware/MotorControl/low_level.c In ...
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0answers
131 views

High side current sensing in BLDC motor?

I want to measure DC current flow through the 48 V battery in bldc motor (through Inverter circuit). Are INA 282, INA 169 work properly or not? Since my battery motor specification is 48 V, 5 Amp, 250 ...
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0answers
83 views

Using a 670Kv outrunner motor, how can I calculate a way to get variable low speed and high torque?

I have an E-flite Power 46, 670Kv outrunner motor (Kv is the shorthand for RPM/volts, it has 3.9A idle current, 40A maximum continuous current, 14.4-19.2 voltage range, 925 watt maximum) but I wish to ...
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3answers
509 views

Can an Induction motor be called a BLDC motor if operated from a DC supply?

A BLDC motor is a Permanent Magnet Synchronous Motor which is powered by a DC supply via an inverter stage. Since the motor is externally commutated by the inverter and the supply is DC, it is called "...
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1answer
502 views

Is there possibility to “short” and lock a BLDC motor as on the DC brush motor

As we know, you can mechanically lock a DC brush motor by short the two terminals with relative strength. Now, in my design I wanted to use BLDC for reduced noise, but can I do something similar for ...
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2answers
957 views

What is the main reason for using speed feedback in a motor positioning control system?

This question is not to solve a particular problem but rather one of principle to understand the main reason a designer would want to include speed feedback in a motor controlled positioning system. ...
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1answer
404 views

Floppy / Brushless DC motor speed regulation [closed]

I have a non working TEAC FD-235f 161-U, which is a rather rare (nowadays) 3-1/2" Amiga floppy drive. A cap had leaked over the PCB and eaten away at the traces. I jumper wired the broken traces and ...
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0answers
140 views

SPACE VECTOR MODULATION(SVM) for BLDC motor

I want to run a 4 pole bldc motor(12V) using SVM in open loop. microcontroller: Infineon IDE: Keil Microvision. I have successfully generated the Space vector which starts rotating as shown in the ...
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2answers
189 views

Designing from low-voltage 3-phase motor driver for more powerfull BLDC motor

I am starting to work on undergraduate project to build electric skateboard. Main thing I will foucus on, will be ESC (electric speed controler) made for a motor 190KV (motor spec.). I got micro-...
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0answers
147 views

Overcoming cogging/ripple torque in gimbal motor

So I'm trying to figure out how to spin a camera on a brushless gimbal motor. I am feeding each of the terminals a sinusoidal pwm signal from a via 3 half bridges on the SN754410. Each of the pwm ...
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1answer
134 views

controling bldc motor with atmega32 [closed]

is it possible to control the speed of a bldc motor using a direct connection to ATMEGA32 microcontroller? Or there should be an interface since motors need more voltages than the microcontroller (...
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2answers
99 views

Wire gauge on Drones different?

How is it a 12 volt 40 amp wire in a car has to be approximately 16mm thick but a drone can use 3.5mm thick cable for 12 volt 120 amps. What is the difference? They both have the same amount of power?...
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1answer
179 views

What are the functions of the diodes in this BLDC controller circuit?

I'm trying to understand the function of the diodes in this snippet of an automotive BLDC controller. I believe that D102 is for over-voltage protection, and reverse polarity protection. Also, I ...
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1answer
193 views

OpAmp for FOC current sensing on a BLDC/PMSM

How critical is this pull-up resistor to Vdd for current sensing in a Field Oriented Control of a BLDC or PMSM? Right now, I don't have that pull up...I'm running the shunt resistor voltage straight ...