New answers tagged brushless-dc-motor
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After some research i found the solution. thus, i will answer my own question
Some motor spec use \$ke= Vrms/rpm \$(because when calculating the Ke they used the VRMS volatge and not the peak voltage) so in my example the \$Vrms=40*0.8/sqrt(2)\$
but most motor manufactures use \$Ke= Vpeak/rpm\$ so in my example \$Vpeak=40*0.8\$
and in order to calculate ...
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If you'd take time to read a bit more through the datasheet, you'll find that two pages below, in the Current Sense Amplifiers section, this text appears:
The DRV8305 provides three bidirectional low-side current shunt amplifiers. These can be used to sense the current flowing through each half-bridge. If individual half-bridge sensing is not required, a ...
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I suggest using a logic level n-MOSFET for driving the high side MOSFET.
Notice the freewheeling diode which is mandatory when driving an inductive load like a motor.
simulate this circuit – Schematic created using CircuitLab
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You can put all the batteries in series and the supercapacitor parallel to them. That way you will get more current and the supercapacitor will always be charging.
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Steady state motor speed is proportional to the voltage applied. When the PWM frequency is high, due to the inductance of the motor, the 'effective' motor voltage is controlled directly by the duty cycle (% of the supply voltage).
To find the speed voltage relationship, measure the steady state speed in rpm and divide it by the supply voltage. The constant ...
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simulate this circuit – Schematic created using CircuitLab
There's a couple issues that I see. One being that your Mosfet is only rated for 13V higher than your rail. With that amount of current plus an inductive load, you are likely to see voltage spikes well above that. The second being that your mosfet is going to turn on very slow due to the large ...
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Please do not show a positive voltage supply as Vee, and show it at the top of the schematic. Both of those actions suggest it is a negative voltage wrt ground.
The output of the 3144 is an open-collector NPN transistor, so you have built a wired-OR gate (inverted output).
If you want an AND gate, you can add pullup resistors to each output (eg. 10K to Vcc) ...
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Your Hall sensors appear to be of the usual output-low-when active and hopefully open-collector/open-drain configuration. Thus in your shown circuit, the LED will light when either activates and sinks current.
Your literal request is for the functionality of an "AND" gate but with active low inputs and the outputs, or in simple terms, an AND gate ...
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I'm not sure but for my understanding, BLDC motor has trapezoidal b-EMF. If your motor has sinusoidal b-EMF waveform then it's probably a PMSM with distributed stator windings. Then the saliency is up to measurment.
For your question, I think one possibility is that your motor actually has an IPM rotor. Then you can measure the Ld and Lq. Normally Lq is ...
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I assume the motor is going through a reduction gear of some kind, or you would need a stepper motor. The ESCs for model vehicles sense the voltage generated by the motor windings (back EMF(a fancy term for voltage in the electrical trade)) to determine commutation time & direction for the coils. The motor only has 3 wires (no Hall sensors). If your ESC ...
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A perminant magnet synchronous machine (PMSM) must be excited with an AC current for torque to be developed.
A Brush less DC (BLDC) PMSM has a backEMF profile which is trapizoidal in shape to maximise the peak torque but also to simplify the drive algorithm as they can be excited with a simple quasi square wave controller.
A Brush less AC (BLAC) machine has ...
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This will depend primarily on the controller. The BLDC controller's job is to adjust the coil current direction based on rotor position. There are three common ways the rotor position is determined, in order from most common to least common:
Sensorless back-EMF voltage control: detects the voltage caused by the spinning rotor. It usually only works well at ...
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The more poles a brushless motor has, the smoother it will spin at low RPM with a trapezoid/square wave drive. But if you just use a sinusoidal drive then it doesn't really matter. Of course you still need an appropriate rotor feedback mechanism for the RPM you are spinning at. Some are ineffective at low speeds. So it's more about the drive than it is about ...
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The brushless motor can spin at any low speed. Maintaining low speed smooth may require some algorithms, feedback hardware and stuff, but is totally doable. For example with incremental encoder you can use 1/T method (measure time between pulses rather than count them) to sense the speed. With high resolution encoders even that may be not necessary.
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A brushless DC motor can be operated as a stepper motor. Operating stepwise, it can operate as slowly as you want. Smooth operation would be more difficult. Determining that would probably require a simulation with complete characterization of the motor, controller and load.
Of course, the motor cooling would also need to be considered.
If a "typical&...
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I agree. Your time has value. But solutions also have value. I hope you think better of your time than wasting it on dead-end fantasy solutions that aren't going to happen.
The problem with maritime power is that energy requirement is quadratic to speed - that's why boats cruise slower than max speed. So you're talking about a considerable amount of ...
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Without changing the motor there is only so much you can do, since the motor is going to have a power limit over which you risk burning it out.
However you may be able to get enhanced performance in exchange for a shorter lifespan by increasing the battery voltage to some degree.
A solid state voltage booster will probably not be practical, due to the high ...
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With a brushed DC motor, it's relatively easy. One way to express it is that you measure the resistance of the motor, and calculate the stall current. However, as the resistance of brushes varies somewhat with current, you need the resistance at the stall current, so to get that accurately, you end up measuring the stall current anyway. But however you do it,...
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Mechanical output power is determined by torque and speed.
Speed is limited by supply voltage and how much the bearings of the motor are rated for. Torque is limited by how much current the motor coils can take without overheating, which is mostly constant irrespective of speed.
Thus the actual motor power will depend a lot on the actual application: what ...
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what is difference between the two versions?
Before answering this question, note that, to increase motor speed at steady operation, we need to increase the torque. Torque increases when current increases. Current increases when voltage increases (or average voltage value in the case of PWM). So, to control speed, we can choose torque, current, or ...
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Without knowing certain important details about your circuit (motor current? motor phase resistance? operating voltage? overall current draw? actual schematic?) any answer to your question is a guess. That being said, your shunt resistor value is atypically high (2 orders of magnitude higher than the one I just designed into a general purpose FOC driver). ...
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Switching loses, the complementary mosfets are on together, you need to increase dead time between the mosfets that drive the coils.
You can do it with R C and a diode to the gates if it can't be done in the chip.
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If it's an output power rating, it won't be at full speed (which is the unloaded speed) but at rated speed, which varies, but will typically be 80-90% of the unloaded speed.
Decent motors will specify the measurement conditions and show how speed reduces as power increases for a given voltage under increasing load (torque) and current.
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A properly specified BLDC motor (or in fact any motor) will state its mechanical output power. If the motor specification says 500 watts (and it's a reliable specification) then that is the output shaft power. Input power can be a little to a lot more depending on how you drive it and what you are asking the motor to do regards speed and torque.
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reference signal should take values from 0 to 1, but if I take desired speed for example 600 rad/s and have actual value for example 300 rad/s then PI controller output will be much higher than 1.
In a control system, the gains chosen has to be based on required dynamic response characteristics as well as the capability of the control-effector system. Here, ...
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