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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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1answer
42 views

What is the maximum torque and at what rpm a 250W, 36V BLDC motor can produce [on hold]

I am an EV enthusiast, I am working on designing a BLDC motor. My motor is a mid driven inrunner BLDC motor. The thing that is troubling me is torque, I need to design my motor in such a way that I ...
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45 views

110v A/C motor swap to DC 12V Brushless? [on hold]

I have a 20+ year old Alpine Air ozone purifier running 24 hours a day since the day I got it. The replacement motors are quite expensive and harder to obtain as the unit ages. Brushless motors seem ...
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2answers
72 views

Cheap alternative to limit inrush current (eg. relay bypassing a fixed resistor or MOSFET)

I'm editing the question because several (great) answers focus on the fact that the LTC3780 module (inside ajustable my power supply) can handle the inrush current (maybe, maybe not). I'm glad to know,...
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2answers
47 views

SVPWM: Does setting modulation index to 0 still consumes power?

I've implemeneted a 3rd harmonic injection SVPWM (Space Vector PWM) scheme and it performs quite well. One peculiarity i have noticed was, when i set the modulation index to 0, the motor stops as ...
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4answers
246 views

Brushless motor design with additional separation layer at the air gap

As a thought experiment, I was thinking about how to actuate an passive impeller inside a tube from outside, contactless. Imagine a tube equipped with an impeller inside it. The impeller is mounted in ...
8
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1answer
230 views

Inferring back emf from oscilloscope

I have this stepper motor with unknown back EMF / RPM. There are 200 steps/rev (i.e. 1.8deg step angle), and 8mH "phase inductance", but I'm not sure if that's enough to calculate back EMF. I hooked ...
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0answers
21 views

BEMF and zero crossing point detection

I am trying to control a BLDC motor without sensors using BEMF method and zero crossing detection. I managed to detect the zero crossing point but I am not sure if it is correct. I read that the hall ...
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1answer
44 views

Cooling fan analysis [closed]

Current value specification is 0.75+_10% for brushless DC motor.but my bldc motor draws 0.6amps as running current.what effect will occur if draws lower current as o.6amps instead of 0.675amps ...
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2answers
50 views

Bulk Capacitor for Motor Driver

I'm creating a motor driver for a BLDC motor. I was wondering how we can calculate or choose what capacitance we need for our purposes. We're using the motor driver for a chain drive /transmission ...
2
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0answers
59 views

HIP4086 Driver Failing After Connecting to BLDC Motor

Update: A Renesas Tech pointed me to the documentation for the HIP4080, which is basically a two leg version of the HIP4086, but with much more thorough documentation. I now have three working ...
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1answer
38 views

How to calculate torque of a 4-pole BDC hobby motor

I have a hobby motor that claims to be a 2200KV motor. This particular one is a 4-pole motor. Using a drill, I spun the motor at 1312 RPM. On an oscilloscope I see 1.3V peak-to-peak waveform between ...
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1answer
44 views

What is the function of series inductors on the motor phases of a commercial brushless EC/BLDC motor controller?

While designing my own BLDC controller I got curious about how the big boys do it and opened up a commercially available one (Maxpos 50/5). Most things were quite straightforward, except a 11.3uH ...
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0answers
26 views

BLDC bemf shape

I am trying to detect the zero crossing point of the BEMF voltage in order to control the motor sensorless. The following picture shows the ideal shape of BEMF and in many application notes or ...
1
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1answer
86 views

12v DC brushless PWM fan burnt out via Arduino Uno

I’m working on a project where I want to control the speed of a fan using a microprocessor. I read several posts about using an Arduino Uno to control the PWM function on a 4 pin fan you find in PCs, ...
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2answers
40 views

Determine efficiency, voltage, current from motor characteristic curves

I would to identify efficiency, voltage, current for a particular Brush less DC motor in our lab given characteristic curves. Electrical specifications are The operating conditions are ...
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3answers
154 views

bldc motor, esc and battery draw, nominal vs peak

I want to better understand how Electronic Speed Controllers (ESC) work for BLDC motors. Specifically, I am trying to understand battery current draw. Question 1: When an ESC is rated at 200 amps ...
3
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2answers
90 views

How to measure DC motor (used as generator) efficiency using homebrew methods?

Background I'll be making a "micro thermal power station" in the single-digit watt range at home (one-off, educational project. Bear with me). A heat source, likely ethanol, will cause a stirling ...
0
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1answer
82 views

Why P and N channel MOSFET is quite hot during braking of 3PH BLDC motor?

IRF4905 datasheetIRF 3205 Datasheeet I am working on a 24-volt BLDC 3ph drive application. I have made this design with a basic understanding of p and n channel MOSFET. In this design, MOSFET gate ...
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1answer
69 views

Dynamic voltage divider

I'm trying to build an ESC (electronic speed controller) for three phase brushless motor. I found some intresting circuits but I am trying to build something very easy to do, with mosfet and pc817 and ...
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0answers
40 views

BLDC startup algorithm

How do real world algorithms for sensorless BLDC motors handle startup under load? Right now I run phase 1 for a few milliseconds to get the rotor in a known position, the I run open loop for a ...
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3answers
46 views

bldc regenerative braking, braking torque

I'm trying to figure out the braking torque calculation for a BLDC simulation. Now if I'm looking at a datasheet I know the torque at a given rpm at acceleration. If I brake with regenerative breaking ...
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1answer
26 views

calculation of torque constant based on bldc datasheet, getting different torque constants

I'm trying to get the torque constant of a bldc. Based on this: how to read datasheet I just divide the torque at any given point with the current. I tried out that method with different values and ...
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2answers
66 views

Mosfet Driver - High Side Output Problem

I've been trying to make a 3 phase inverter to drive a BLDC motor. Mosfets : IRF3205 Driver : IR2101 Supply voltage for FETs and drivers : 12V BLDC : https://media.digikey.com/pdf/Data%20Sheets/...
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2answers
47 views

A2212-15t 930kv brushless motor voltage limit

So here's the thing, I am planing on buying those brushless motors (a2212-15t 930kv motor) and I was planning to use it with 5 li-ion battery. I was gonna do this until I saw the line saying: No of ...
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2answers
41 views

BLDC Motor max load

Hi i have a BLDC moter https://www.banggood.com/350W-48V-DC-Brushless-Motor-Geared-Ebike-Tricycle-Kit-Engine-Electric-Scooter-p-1419702.html?akmClientCountry=NL&rmmds=cart_middle_products&...
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3answers
53 views

How to make sense of speed vs Torque curves in speed control mode

I am operating my motor in closed loop speed control mode using motor controller. Toque vs speed curves gives us a relation between them which is one-one correspondence. But in a closed loop speed ...
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6answers
1k views

What's the output of a record cartridge playing an out-of-speed record

I'm very interested in vinyl records and analog music, and the belt of my turntable got loose. Upon such situation it piqued my curiosity, what is the output signal at the end of the arm cartridge ...
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2answers
110 views

Motor is consuming less than rated current and more than rated power

I have a brushless DC motor of following specs. I am using a roboteq controller to operated the motor. While running the motor i have collected the few params and here are the plots. power curve - ...
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0answers
37 views

Regenerative energy Dissipator for BLDC motor

I want to design a circuit to dissipate the reverse energy from BLDC motor, can I use PWM control technique in voltage sense circuit in order to switch on the power circuit? In detail : In my ...
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0answers
40 views

How does recuperation works in BLDC?

Using BLDC wheels is common on electric transport. A wheel is a multiphase motor, where each phase(coil) is separated from power source(battery) with some kind of transistor, driven by PWM-like signal....
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2answers
113 views

MOSFETs blowing up on BLDC motor controller upon battery connection

I'm trying to build a sensors motor controller for a 500 watt bicycle hub motor. The problem I am having with it is when I connect power (4500 mAh 12s lipo) I usually destroy a transistor or two ...
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0answers
28 views

BLDC acceleration curve

I am currently working on an solar powered RC-cart that is being driven by an BLDC. By working on this project I was searching for a way to calculate the acceleration time of the cart. Is there a ...
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0answers
45 views

mutual inductance of BLDC motor

I want to use BLDC motor for charging the E-rickshaw for that I need to find the parameters of the motor. I have measured the Resistance and self-inductance of the motor but I am facing difficulties ...
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0answers
22 views

Motor-side of BLAC supply goes into overvoltage when regenrative braking using an LM5060

I am currently using an LM5060 for protection of the motor supply on my BLAC motor driver. Everything works well until I decelerate the motor quickly, this makes the supply voltage peak above the OVP ...
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1answer
35 views

3 Phase PMSM Motor Current Measurement: Figuring out the 2 negative terminal currents with 1 positive current measurement

I am trying to implement F.O.C for a PMSM machine with a custom made inverter board. The H-bridges are from Infineon (IFX007T) and they provide current sensing capabilities. The problem is, i need the ...
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1answer
94 views

Why is back emf of bldc trapezoidal?

I am trying to understand why would the back emf in bldc be trapezoidal. Lets consider a simple motor with two stator coils placed opposite to each other. Lets say a bar magnet is kept as a rotor. If ...
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1answer
34 views

PWM phase voltage and current measurement for power consumption calculation for a BLDC MOTOR

I have been trying to log both voltage and current from the battery of an electric two wheeler for finding out efficiency at inverter, battery level.
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0answers
124 views

I have designed and 3D printed a new motor that was based on a video i saw earlier, however motor keeps stuttering and wont turn, what went wrong?

Figure 1 Figure2 I started by doing 150 turns on each coil making sure they were winded in the same direction, then connected the starting point of each coil together and took each phase winding to ...
2
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1answer
56 views

Powering 36V motor with 48V LiPo battery through a motor controller [closed]

I am planning to use 36V BLDC motors from a hoverboard, (this one) with this motor controller. The controller mentioned can handle up to 50V, 60A continuous. I would appreciate it if someone can ...
1
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1answer
54 views

How to power an electric motor

I would like to attempt to assemble an outrunner BLDC motor from scratch. Its working principle seems ridiculously simple and I'm up for the challenge. There is one thing that I would like to clear up ...
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1answer
83 views

BLDC controller MOSFET heating problem

I am using schematic to controll a bldc motor without sensors. As gate drivers I am using IR2101 and also I added some diodes in anti-parallel with gate resistors (not shown in the schematic) I am ...
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0answers
37 views

BLDC hoverboard motor with no specifications

I have this kind of motor but I can not find any electrical specifications about it. All I know is that is a 36V,250W BLDC motor. How can I determine the number of poles, the coil resistance/...
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2answers
2k views

Why do BLDC motor (1 kW) controllers have so many MOSFETs?

I have a 1 kW three-phase BLDC motor from China, and I was developing the controller myself. At 48 Vdc, the maximum current should be about 25 Amps and a peak current of 50 Amps for short durations. ...
0
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1answer
43 views

Sensorless speed control and startup of BLDC

Regarding the sensorless speed control of a BLDC, I have some doubt about what may happen in two scenarios when the rotor's position is unknown: 1) the start-up from zero and 2) with an initial ...
0
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1answer
63 views

How to control 4 motors which are conected to a flight controller using Raspberry Pi?

I just started a project to make a drone without a radio controller. I want to control 4 brushless motors connected to a flight controller KK 2.1.5 using Rpi 3 B+. Obviously, the motors are first ...
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0answers
90 views

Formula for RPM and its relation with slot stator

I want to clarify a formula regarding RPM. The formula \$\mathrm{RPM} = 120f/p\$ where \$f\$= frequency and \$p\$= # of poles. But what if the motor has different slots, for example, a 24 slot stator ...
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2answers
46 views

BLDC Motor Drive control

I am using a 310VDC, 4pole BLDC motor with hall sensor feedback for my application. My objective to run the BLDC motor at 7500 rpm. My motor rated speed is 8500rpm. I am able to run motor at 7500 ...
0
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1answer
90 views

Why does shorting the phases of a BLDC motor cause it to lock?

Normally a motor can be locked by shorting its phases. When the motor is not connected and we short all the the three phase terminals (tie them together) and try to rotate the shaft it offers lot of ...
3
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1answer
80 views

What is causing these switching transients on a 3 phase motor driver?

One time I built a 3 phase motor driver, which works quite well in the original configuration. Recently, I changed the physical layout to this rectangular form factor, and now it has quite large ...
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0answers
48 views

Identification of BLDC Motor

I would to know if make sense to obtain the current of the BLDC motor, using the BLDC motor torque measurement. In particular, i'm able to measure the torque of a BLDC motor but not the current that ...