New answers tagged

0

They only specify maximum power/amps etc. and I need to now nominal values for it. 'Nominal' values aren't particularly useful. The important parameters are Kv (velocity constant) or Kt (torque constant), internal resistance, no-load current, maximum rpm and maximum operating temperature. The data provided covers most of this. What torque does it have ...


0

how can I increase speed and decrease torque keeping watts same. Please explain for dc and bldc motor. Brushed or brushless DC makes no difference, the principle is the same. When the rotor/armature is spinning the motor acts as a generator, producing a voltage proportional to rpm (Faraday's Law). This voltage opposes the supply voltage. The difference ...


0

The speed of a d.c. motor is given by $$ N = \frac { V - I_a.R_a}{kφ} $$ where 'V' is the applied voltage, 'Ia' the armature current, 'Ra' the armature resistance, 'k' a constant based on the number of poles, the number of conductors and number of parallel paths in the armature and 'φ' the flux per pole. That speed could be either increased or decreased ...


0

Optocoupler doesn't provide any help if the other signals aren't galvanically isolated. You have to make all the signals the same way - all isolated or not isolated. It depends how the driver and the electronics are made, if they have isolation already embedded.


0

The output will be relative to the Control Signal ground (GND1). This is probably the same ground you have for all the other outputs from the BOB. You can check this by using a multimeter to measure between the alarm output and GND1, you should see approximately 0V or 5V depending on the alarm state. Once verified by a multimeter, you should have no ...


0

Apparently, I just didn't look hard enough. I couldn't find any half bridge drivers that operate below 4.5V, but there are high side integrated gate drivers that do (such as the MIC5018).


1

When BLDC motors off, do they affect my normal riding... Yes. The attraction between the magnets and the steel core fo the windings will cause "reluctance torque" that will be like a small amount of braking. If the coils are connected together through the ESC, there can be generator action that could be used to charge the batteries, but that would add to ...


1

For a fan load that requires only 135 watts, a single phase induction motor with a variable AC voltage would be least expensive alternative for continuously adjustable speed control. A split-phase, capacitor-run motor would be fine. A shaded-pole motor would also be ok. A split-phase capacitor-start motor would not work, because the capacitor might not ...


-1

You can deduce the speed of the motor from the back EMF that it generates. This eliminates the need for a separate tachometer. We have used this technique on numerous gimbaled systems. This may be what they're referring to in OP's marketing quote.


9

It means the poster doesn't know the difference between an induction machine and a synchronous machine, nor do they know the range of DC brushless motors out there. Having waxed cynical: the term "Brushless DC motor" is imprecise. The best-fitting explanation for what people usually mean is that it's a brushless motor that's got a magnetic design that ...


1

Your first diagram is incomplete. Motors with that arrangement of poles tend to include an iron flux return ring round the outside, which is usually used as the motor case. The very first electrical machines did use a horseshoe magnet arrangement. This is one of Edison's, and it's from here Put 'vintage electrical generator' into your search engine.


1

That question depends a lot on the control architecture, and that is a design choice. But it should be safe to assume that you would have some "lower level" controller directly controlling the motor (due to simpler systems being more reliable and a PID controller being able to correct small model/system errors). The MPC will probably generate the reference ...


0

PWM frequency has nothing to do with MPC update rate. Neither the velocity controller has the same sampling time of PWM cycle. You can choose a PWM cycle that suits physical parameters of the motor - e.g. inductance and/or max. frequency of the AC voltage output in case you use BLDC or PMSM. The speed controller sample time is determined upon the ...


0

The unequal numbers are chosen to minimize ripple. The rotating field is generated in the stator, hence mechanical rotation depends on the stator


1

What you haven't mentioned is what you will do with the extra power. As you plan to increase the current capability, you will increase the available torque. (Assuming, of course, the motor can take the extra heating). This will improve acceleration or hill climbing ability (assuming a road vehicle) but won't by itself allow any higher speed. If that is ...


2

I was wondering if I could upgrade my current bldc motor controller (three phase motor) to a higher wattage/output power by doing the following modifications: Probably - but it depends to some extent on the application and how sophisticated the controller is. I could attempt a point by point response but essentially they are broadly covered below for 3X ...


0

You can measure the output of the controller with the two single phase wattmeter method, so if you've got a three channel power analyzer you can set it up so that one is measuring the input (assuming that you have a single phase AC, or DC supply), and two the output of the controller, and some analyzers, like the Yokogawa one I have, have the efficiency ...


0

To determine efficiency, you need to load the controller appropriately and then measure the input and output power or the losses. Neither of those is easy to do accurately. Wattmeters that can measure the power accurately may be quite expensive. You may find it easier to enclose the controller in an insulated box and measure the temperature rise of air ...


1

Benjamin Vedder's "VESC" project which is open source will allow you to do anything you want. You can find older versions and the latest version online. VESC allows sensorless or sensor based operation, dynamic braking, FOC control, and much much more. Current VESC 6 project page Older 2016 VESC V4 site which may be enough. You can buy commercial ESC's ...


1

The DRV10975 already is a BLDC sensorless speed controller. You should avoid this product, if you want to control the torque. What you need is a current controller, PWM controlled bridge and then a feedback information about the current and speed. You have to limit the torque if the motor reaches max. speed. This is a classic cascaded loop: simulate this ...


Top 50 recent answers are included