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1
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2answers
37 views

Circuit Analysis Involving DC Motors

When it comes to simple circuit analysis, there is millions of tutorials on how to analyze a resistor circuit, a RC circuit, or those involving LED the non-ohmic devices. However, I did not find a ...
2
votes
1answer
32 views

What is the state space model for a BLDC motor

I wanted to model a brushless DC motor so that I can add controllers(PID ) to correct the transient state behaviors. I started to model my BLDC and I found some model. Then I used specs from MAXON ...
1
vote
4answers
252 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
votes
1answer
237 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 ...
3
votes
2answers
98 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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0answers
65 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 ...
0
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2answers
42 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&...
0
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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 ...
0
votes
1answer
224 views

How to drive 4-pin fan

I've been attempting to get this 4-pin brushless dc pc fan working for some time now. It has a red (+) black (-) blue (PWM in) and yellow (tachometer out). I only want this fan running at maximum ...
2
votes
1answer
472 views

BLDC (Brushless DC Motor) vs PMSM (Permanent Magnet Synchornous Motor)

The differences between BLDC and PMSM are very small and for what I have seen while reading about it, is not clear to many of us. Most of the articles I have read say that the main difference is that ...
0
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1answer
59 views

Dc motor as torque transducer for BLDC motor

I bought a cheap BLDC motor on some Chinese website and could not find its characteristics. However, I have A28-400 24V amp flow Dc motor with its characteristics. If I'm able to build a test rig to ...
4
votes
2answers
710 views

BLDC Motor Constants: Why is my Kt and Ke different?

I'm new to working with motors. Reading up on BLDC theory, it is repeatedly said that in SI units, the Ke and Kt will be numerically equal. I downloaded the motor spec excel sheet of the T1101 motor ...
0
votes
4answers
2k views

Using a BLDC motor for regenerative braking

I am planning on using a BLDC motor to drive a small go-kart like vehicle. I would like to implement regenerative braking, but am having trouble finding certain details. My main concern is being able ...
2
votes
2answers
578 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 ...
0
votes
4answers
129 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 ...
0
votes
1answer
193 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 ...
0
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0answers
224 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 ...
1
vote
1answer
411 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 ...
0
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2answers
2k views

Speed and Torque control of a BLDC

First off, I have very little knowledge in electrical engineering and my last official contact with the subject was when I was in high school so go easy on me. I am trying to understand if it's ...
1
vote
4answers
1k views

How any one achieve sinusoidal back emf in PMSM and Trapezoidal back EMF in BLDC ? What is the winding differences?

How any one can achieve sinusoidal back emf and trapezoidal back emf in the motor. What is the winding differences in those motors. I have take an In-wheel BLDC exterior motor which is used in e-bike....
0
votes
2answers
406 views

How does line impedance of a BLDC motor relate to the RPM of its rotor?

I am curious about the impedance of the three phase BLDC motor when it is in operation. If the speed of the rotor of a BLDC motor is proportional to the frequency of the three phase current, and the ...
1
vote
2answers
267 views

Mechanical time constant of PMDC Motor in starting and after switching off the supply is same or different?

In my MATLAB/SIMULINK model of the PMDC motor the mechanical time constant has same value in the case starting of motor and after switching off the supply but in experimental setup there is a ...
3
votes
3answers
1k views

Higher KV means lower torque for DC motors?

I'm in the process of trying to build an electric skateboard. On the websites I visited I read that torque and KV are inversely proportional which does seem counter intuitive. So I'm wondering why ...
0
votes
1answer
90 views

Brushed motor VS BLDC [closed]

Our brushed DC motor is rated for 3-4 amps and can be overloaded for 8+ amps. We are currently changing the brushed motor for a brushless (BLDC) motor, rated at 3.5 amps. How much can I overload the ...
0
votes
1answer
166 views

Is there any special kind of DC motor with no mechanical resistance if unpowered? [closed]

Im trying to find a dc motor that does not have any significant mechanical resistance if unpowered. So if i were to spin one up with my finger it would keep spinning. Im not looking for a specific ...
3
votes
1answer
481 views

Can I break my BLDC motor by connecting an ESC in the wrong way?

I've got a brushless DC-motor and an ESC. The ESC has three wires and the motor 8 (of which 5 are for the Hall sensor). The 3 wires of the ESC are not colored or marked, so I just wanted to try some ...
0
votes
1answer
123 views

Can I drive and reverse this motor with an ESC?

I've just ordered this motor, which I want to drive and reverse using my Raspberry Pi. I've successfully used an H-bridge to drive and reverse a brushed DC motor before, but for this motor I think I ...
1
vote
1answer
320 views

H bridge heating issue when driving BLDC

Hi I have been trying to create a custom Brushless DC motor driver circuit using P type and N type transistors (known as H bridge). This is the circuit I designed and prototyped on the breadboard. ...
1
vote
2answers
82 views

Identifying a BLDC and its characteristics

I have some motors to be used in copters, can anyone tell me: a) if they are BLDC b) how could I find what current they would draw and their power ratings? c) what ESC should I use for it
1
vote
1answer
68 views

Chosing the right motor for a vibration platform

The following photo depicts a vibration testbed that uses a motor, springs and some wood. The purpose of this effort is to make a test bed vibrate the attached kinetic energy harvester at the movement ...
0
votes
1answer
2k views

Is the stepper motor DC or AC motor? [closed]

Is the stepper motor DC or AC motor ?
0
votes
1answer
410 views

Relating Hall sensor outputs to absolute rotor position (Which combination corresponds to which angle)

I have a working 6-step BLDC commutation which works based on the Hall effect sensor outputs. I would like to apply the same code to another motor, which doesnt have Hall sensors but an absolute rotor ...
1
vote
0answers
327 views

Stuttering of Gimbal Brushless DC Motor

I am trying make a Gimbal BLDC motor spin slowly (~0.2Hz). For some reason I have problems with the motor stuttering, as shown in this video. At the end of the video I also show PWM signal from the ...
1
vote
5answers
3k views

Why are BLDC motors so expensive? [closed]

My general question is why brushless DC motors seem to be much more expensive than similarly sized brushed permanent magnet motors, especially considering that the construction of the latter is more ...
1
vote
1answer
111 views

What would be a suitable motor controller for this BLDC?

I'm looking at replacing some steppers with a BLDC to get smoother operation and higher speed. The BLDC motor we want to use is this one. It is a small 2-axis robot that requires accurate position ...
0
votes
1answer
646 views

Whats is the angle precision of a 3 phases bldc motor?

I have a small BLDC motor and I would like to use it in a project of mine. Is there any relation between the minimum angle (precision) I can move the motor and its number of poles? How could I ...
2
votes
3answers
818 views

Regenerative Power on DC bus between DC motor and voltage supplier

Currently, I am looking for a back-EMF solution for brushless DC motor drive. My input voltage for motor driver is 48V (which starts at 50V level and starts to decline until 35V as a feature of fuel ...
0
votes
2answers
527 views

Consequences of higher voltage supplied to BLDC motor? [closed]

What happens to a brush-less DC motor if I supply a voltage about 1.25 times greater than the rated voltage?
1
vote
1answer
183 views

Why L6743D MOSFET driver is not working properly?

I've started to build a brushless driver by using some Power MOSFETs and some MOSFET drivers, in order to drive the Power MOSFETs. I have connected the chips as shown in the application circuit (page ...
-1
votes
2answers
4k views

Controlling brushless gimbal motor (BGM2804)

I'm using a standard board for control this type of motor (SimpleBGC), this board uses an atmeg328p e some brushless drivers. I'm writing a simple code for turn left/right with some velocity, but i'm ...
0
votes
2answers
710 views

What kind of DC motor is this and what does the circuit do?

I've had this motor at least for 5 years (salvaged from something) and I remember it working then. However it doesn't work now (5 VDC mobile charger) and so I opened it up expecting to see just the ...
-1
votes
1answer
166 views

Constant RPM Low Speed Motor drive [closed]

What is the best way to drive a motor (DC/Brushless/Stepper) at a constant, yet low RPM? It must have no jitter and no drift over time. I'm aware that some gearing will be required. Basically what ...
3
votes
3answers
4k views

why the supply voltage of dc motor decreases when the motor load increases?

When I plot the supply voltage of a one-cell LiPo battery during the working period, I found that the supply voltage would drop dramatically when the motor is commanded to speed up. I think this is ...
0
votes
1answer
189 views

Designing a brushless DC motor:

I watched a DIY video recently on building a brushless DC motor. Can someone demonstrate for me how to calculate the max torque & max rpm of that motor based on the components that are used in ...
2
votes
2answers
261 views

Should we use a Brushed or Brush-less DC motor to build a solar car?

We are trying to build a small Solar car the car's dimensions (Length :100CM, Width 60CM) the car mass is not going to exceed 2KG The car speed can be up to 2.5 or 3 m/s We`ll be using PV modules ...
2
votes
1answer
1k views

Can you damage DC motor by backdriving it (with disconnected leads)?

We are looking for application where we need sometimes backdrive DC-motor manually. In order to protect motor driver and rest of the electronics we're thinking of electrically disconnecting motor ...
0
votes
1answer
98 views

Help with Motor encoder connection with motorcontroller

I am new to building drones and bots. I started out using motors without encoders with my Roboclaw Motor Controller for my pet project. Here is the controller's link. Connection seemed simple and it ...
0
votes
1answer
579 views

DC Motor with coil inside a rotating magnet. How does it work?

I have seen the following patent online. And I was wandering how that motor works. It seems that the vector of the cross sectional area of the coil is parallel to the vector of the rotation of the ...
1
vote
1answer
1k views

BLDC Motor Maximum Locked Rotor Current

Is there any equation to find the maximum Locked Rotor current using the motor characteristics values? The motor I am interested in is ThinGap 7140. Here is the datasheet: http://www.thingap.com/wp-...
1
vote
1answer
1k views

The Hall sensor in a BLDC - winding magnetic field interference?

I am wondering what is the impact of the magnetic field generated by the BLDC windings being energized on the rotor position measurements with the Hall sensor. I found some unclear explains stating ...