Questions tagged [speed]
Speed is a scalar quantity referring to the rate at which an object changes position (but is not position-sensitive).
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Need a support to find out "how fast the MOSFETs (Sie882DF) can switch"
I am using Power MOSFET from Vishay part number Sie882DF to operate at linear region, Following are the steps I have followed to determine the switching speed,
Datasheet electrical spec:
Sie882DF ...
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Using blind vias for fanouts in GND and power planes
I am designing high density board with high pins count BGA, and hundreds of decoupling capacitors, in that what are the recommendations for using blind vias for fanouts to connect power and GND planes....
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Is it safe to replace a 120ns Flash memory with a 90ns part?
Here is an old PLC board with a pair of AM29F200AB-120SI SOP-44 256kB 5V flash chips. One is unable to retain data, after nearly three decades in service.
These are very challenging to find today, ...
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Phase velocity expression
We have a \$\beta l\$ expression which is represented as phase velocity.
I know \$\omega_o=2\pi f\$.
What is the exact expression for phase velocity used in here?
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Can you design a DC motor with any arbitrary torque speed curve?
Title pretty much says it all. I have a low-rpm (30-160) and moderate-torque (2 N-m) application. These characteristics are pretty easy to hit with an off-the-shelf dc motor + gearbox. But let's say I ...
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BLDC torque and speed control
Actually I drive a DC motor in speed and torque at the same time. I would like to know if there is a solution to do the same with a BLDC. The motor is 50W max.
I can make a custom PCB to use a BLDC ...
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Need help figuring out how to organise a system to run a stepper motor at low speed without Steps-skipping
TL;DR : How to prevent step-skipping with a NEMA gearbox motor at low speed.
Edit: following @glen_geek comment, removing the load on the system seems to remove the problem, hinting at inertia and ...
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How much lower than the ideal torqe curve is the actual torque of a PMSM running at overspeed?
VFD-controlled PMSM's are said to produce constant maximum torque up to the rated speed. Above the rated speed the VFD performs defluxing and produces constant power. This should then mean that at 200%...
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Synchronous motor: intuitive explanation of f = 120/PN
In synchronous motors, let f be the frequence, P the number of poles and N the number of tours per second:
$$f = \frac{120}{PN}$$
I don't understand this relation at all. In my opinion, the more ...
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Slowing down 3-speed ceiling fan
I have a 120 V, 60 Hz, 3-speed ceiling fan. The capacitor is a 4-wire one with the following value for capacitor E183963 CBB61:
5 μF +/-5% 250 VAC = Yellow
5 μF +/-5% 250 VAC = Purple
4.5 μF +/-5% 280 ...
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DC motor spins faster in reverse
Due to certain circumstances I need to run my brushed DC motor in reverse (positive to black wire, negative to red wire).
What I noticed is that when set up this way running at no load requires 1.5A. ...
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Ethernet speed issue
We have made a customized harness cable for Ethernet communication as shown in the attached image. Here we are facing an issue with communication speed.
Whenever we use the below cable, we get only 10 ...
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Mimimum time required for an NMOS transistor to operate as a switch?
How do I calculate the minimum time required for an NMOS transistor to work properly as a switch i.e. in the triode region?
When the time period is very narrow, the switch might not turn on and our ...
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Why does this DC motor increase in current and then decrease as the speed increases?
Well, the general answer to this is that as the motor needs to overcome the inertia from its state of rest, it requires high starting torque and aka high current is consumed to do that work.
On the ...
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Adding variable speed control to 3-speed bldc pool pump motor
I have several 1.5 hp 240 V bldc pool pump motors I've repaired and salvaged from work with plans to re-purpose them on certain projects, an upgraded high torque motor for my mini lathe being a good ...
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Electrical torque and electrical power of a generator?
Having the electrical torque and the angular speed of a synchronous generator, can I calculate its electrical power output as the product between the electrical torque and its angular speed w (Pe=Tew) ...
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Maximum speed Nema-34 stepper motor can handle
I've got used 34HS8801 NEMA34 stepper motor which I am experimenting with. Unfortunately, dtasheet doesn't provide driving voltage, nor does it provide maximum RPMs.
Now, I would like to see how fast ...
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What is happening when a motor is set to a "high" speed?
When looking at different electrical devices like a blender, vacuum cleaner, fan, or drill, it's common for these devices to have different speed settings like "low" or "high" or ...
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Can you control BLDC motor speed with PWM?
I wanted to control the speed of a very fast and noisy brushless dc cooling fan. The fan I have is a 3 pin 12v 6.3w 120mm fan by Delta Electronics. From what I've learned from the internet is that the ...
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STM32F334 Nucleo-64 ADC speed
I have a problem with my ADC speed. I'd like to have a speed over 1 MSPS but I get only 60 KSPS. I use a very basic code that uses ADC interrupt to stock the value into a table and when the full data ...
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Quick state feedback controller question
If two estimators where used in a state feedback system, one with error dynamics poles at -10 and -9 and another one at -80 and -90.
Which system will give you a better overall performance?
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How to judge my achievable design frequency on FPGA?
I am coding a design from scratch in VHDL. The FPGA target is a Cyclone V. My design resource occupancy is around 30 % of Logic.
I able to reach a frequency of around 80 MHz. The worst paths are ...
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Measure ball speed with sensor inside
I came across a product which is a ball with a small Bluetooth sensor placed inside. This sensor, coupled with an app, can measure ball speed, height and length of throw. I wonder how this is possible,...
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How are real-time speed and torque of a brushless DC motor computed?
Let's suppose I need to work with a three-phase brushless DC motor. The DC motor has only three wires to control its 3 phases, there is no other wires (no Hall effect sensor return for example). ...
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Exciting the rotor and stator of a slip ring induction motor at different frequencies, will it develope torque?
I came across this question as I was preparing for an exam, I am unable to understand the theory behind it.
The textbook says the motor can run a 600 and 2400 rpm but gives no explanation. Could ...
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What is the effect on speed and power when we connect three motors on a single shaft? [closed]
Rolls Royce used three 750R (YASA) motors in their aircraft "Ionbird." All motors are mounted on the same propeller shaft.
What is the effect on the overall speed and power of the motors?
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High frequency BLDC control for parallel speed and position control. Looking for thoughts
I was not able to find a similar topic but am kind of stuck with my problem.
What am I doing?
I am trying to control the speed of a BLDC Motor very precisely but have to control the position of the ...
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DC motor coupled to a DC generator
Consider a separately excited DC motor which is coupled to a shunt dc generator (under no load condition) and acts as a prime mover. If we set the speed of the DC motor to some certain value (for ...
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Replacing a 3-phase speed-varying drum switch with a VFD?
I am working on a stock feeder / power feeder (used with woodworking equipment). It has an 8-position drum switch to control both fwd/reverse direction as well as vary the speed. The ON positions of ...
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Controlling the speed of a single phase 4-pole induction motor
I have a Crompton Greaves single phase induction motor that powers my drill press (image below). I believe it’s rated at 1/2HP. I wanted to control the speed of this motor so that I can use the drill ...
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Speed of compound wound dc motor
This is homework.
Given a 500W, 200V compound wound motor with constant shunt field and a series field that varies with armature current, how do we calculate the change in motor speed.
I know the ...
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Engineering basic question: speed of a device designed in FPGA [closed]
I am studying FPGA by myself, sorry if it is a stupid question for you.
I am going to design a block in FPGA ( vivado/vhdl). This block will transmit data. I need to reach for this block, for example ...
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Tachometer frequency problem
I have an NPN tachometer sensor. I want to measure the rotation speed of a three phase motor, but the output frequency of the tachometer changes. For example, if the actual value of the motor ...
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Throttling of Electronic Speed Controller with 6S lipo
Thanks for having look at this.
I had an turnigy 150A ESC and 2000KV bldc motor. I calibrated ESC and it happened perfectly.
I connected 3S lipo to ESC and increased the throttle from 1100uS to 2000uS....
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Single phase motor does not stop
I have a circuit that controls sine phase motor with three triacs.
When I turn it on it works properly, I can regulate the speed, but when I turn it off the motor does not stop, it still spins but not ...
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Display the speed of a Dc motor [closed]
I have an industrial rotating machine (huge dimensions) working with a DC motor, there is a button that changes its speed but the value of this speed is not displayed.
is there a circuit that measures ...
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Can I lower speed on 1/4 HP PSC fan motor by lowering the input voltage without harming motor?
I have pics of the motor label. This motor now has three speed settings: low, medium and high. I have pictures of the control as well.
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Not sure about the way to compute the voltage across a DC motor driven by a NPN BJT
Long story short, I wanted to make my own H-bridge but I was out of p-channel MOSFETS so I tried to design one with BJTs instead, but before doing just that I simply wanted to try to run an average 3-...
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How to get fine DC brush motor speed regulation?
I want to get a fine speed regulation of Pittman DC 24 V brushed motor with 10,000 RPM for a hobby project. The voltage I will use is battery 12 V DC, so does that mean the speed will be 5,000 RPM?
I ...
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Why the speed and current will decrease when I change the connection delta to star on ac motor?but reduce motor voltage will have opposite result?
On the 3phase motor, The motor has been accelerated to a stable operating speed, then I reduce the line voltage -> speed decrease -> slip increase -> current increase -> the power will ...
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Alternating current frequency
An introductory discussion of alternating current in a primer I was taking left me thinking. We don't see a light bulb flicker because the alternating happens at 50-60 Hz. If it takes 1.28 seconds for ...
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Expected SDRAM access speeds?
I would like to get an idea of how fast SDRAM accesses should be.
If I have a 32-bit ARM based processor running at 500MHz accessing an SDR sdram device clocked at 166MHz, what sort of read/write ...
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What is the value of this resistor?
I am trying to fix a rotary tool's AC powered DC motor controller, there is a resistor that has been burned out, I want to replace it for a new one, my question is how do I find the value of the ...
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Are we controlling the speed or torque when we press the accelerator pedal in an electric car?
In this video, at 16:23, the presenter says that when we press the accelerator pedal in an electric car, we are "commanding torque and not speed". I'm confused here, aren't we making the car ...
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Can I reduce this AC motor speed?
I spent yesterday opening this fan unit and researching...
I'm looking to reduce the speed by about 25-40%, at the lowest speed setting only.
Please have a look at the photo and let me know what ...
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What type of oscilloscope can be used to troubleshoot 100BASE-T1 automotive ethernet?
I would like to implement the 100Mbps single pair automotive ethernet specified in 802.3bw, otherwise known as 100BASE-T1. I was told that in order to troubleshoot and test on this standard, the ...
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Momentary button for voltage boost circuit design
I am just starting to dabble in electrical engineering and circuit design, so forgive my ignorant questions. I am trying to get started building a very simple experiment with my son and I'm not sure ...
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Single phase capacitor start induction motor TRIAC speed control and centrifugal switch replacement
I have a machine tool with a 1 HP reversible motor. I am looking at implementing speed control by using a zero crossing detector and phase angle controlling circuit. I am planning on using a micro ...
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Convert Hair Dryer to Variable Speed
I am using a hair dryer to increase oxygen/air levels in a torch assembly for a forge for metal work. I need to be able to increase/decrease the fan motor speed smoothly and more precisely than the ...
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Altering PWM on four pin fans using only transistors
I have some high RPM 4 pin Tacho PWM fans, they run at 6000RPM and 56.5 DB at 100% duty cycle the noise is enough to drive you insane - there are seven of them total running off of a SAS backplane, ...
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