The speed tag has no wiki summary.
1
vote
4answers
150 views
which RPM measurement method is suitable?
I have a PMDC motor which is electronically controlled for speed. And it is a closed loop system. A proximity sensor is there to measure the speed of the motor and there are 12 bolts attached to the ...
2
votes
1answer
60 views
Program speed with and without JTAG debugger
I have some custom boards with an ARM processor (marvell78100, armv5 compliant), some SDRAM and some Flash. I'm trying to investigate timings problem with the SDRAM, since it seems the layout was not ...
0
votes
1answer
262 views
Feedback for DC Motor Speed Control using PID
I'm working on a project in which I have to control the speed of a DC motor using an analog PID(using op-amps). The input will be provided with a potentiometer. The issue is that I can't figure out ...
4
votes
1answer
99 views
AVR assembly: Most fastest way to increment two combined bytes
What could be the fastest way to increment two combined bytes in assembler (assuming I'm working on a 8-bit CPU)? Currently I'm doing this:
...
3
votes
3answers
108 views
How to syncronize two motors with one pot?
I am trying to synchronize two dc motors with their own controllers. The controllers are name brand and use a 10k pot to control the speed. I have a duel 10k pot and would like to be able to "trim" ...
2
votes
1answer
113 views
Optiflow based Odometry speed sensing
Am planning to build a odometry speed sensor based on optiflow to measure the speed of the conveyor. I am using ADNS-5020-E from a old mouse of mine and managed to get the X and Y coordinates by ...
1
vote
0answers
210 views
high torque and high rpm dc motors
I am making an electric 4x4 car, will it make a difference in overall speed if:
Case1: all 4 motors are high torque and relatively low rpm
Case2: 2 high torque relatively low rpm and 2 high rpm ...
7
votes
1answer
1k views
How can I measure back-EMF to infer the speed of a DC motor?
I'm interested in measuring the back-EMF of a motor to determine a motor's speed because it's cheap and requires no additional mechanical parts. How can I measure the back-EMF when I'm driving the ...
2
votes
1answer
228 views
Why does BLDC Motor Spin Slower with Same Duty Cycle at Higher Frequencies?
I have an OTS BLDC motor controller as well as one that I just made myself and both seem to be dramatically slower at higher frequencies. When I look at how much current is being drawn it makes ...
1
vote
4answers
362 views
Can I reduce rpm further of a gear motor by using PWM?
I am working on a project where I need to move the object from one point to another in a dead slow speed , The object doesnt weight more than 5 pounds .
I found a DC gear motor with has a RPM of 0.5 ...
13
votes
3answers
330 views
What is a good approach to detecting distance and speed in model railroads?
Up front I must admit to little hands-on knowledge of modern microcontrollers and their software - I know power engineering and big motors much better (45 years of it).
Now, my question:
Trying to ...
1
vote
1answer
1k views
What is the difference between 1-phase and 3-phase motors?
I've read the wiki page on AC motors, but it's still unclear to me as to how they work. I'm looking at motors for a project and need them to be able to have their speed controlled by a light dimmer ...
0
votes
1answer
368 views
Speed of electricity (signal propagation?) through copper for communications delay
I would like to be be able to calculate the delay for communications
data within TCP/IP networking through cat5e networking cable.
That is a pretty vague ...
5
votes
1answer
218 views
What limits the modulation of digital signals?
I am trying to understand why there are different speed on different frequency bands. I see that e.g. ZigBee can do 250kb/s for both 2.4GHz and 868/915MHz, but ...
1
vote
1answer
381 views
How do I calculate necessary mosfet turn on/turn off time?
I'm trying to measure capacitance of C1 using this design:
Everything works from 3.3V.
The mosfets is my addition to it - i want to discharge the capacitor after each half-cycle. Everything works ...
5
votes
3answers
5k views
How are current and voltage related to torque and speed of a brushless motor?
I know that electric vehicles have different performances depending on battery and motor, but it's not clear how electrical and mechanical units are related.
Can anybody please help?
Will a 100V ...
3
votes
4answers
561 views
Conveyor belt speed monitoring
I am new to all this so forgive the dumb rating.
I need to monitor the speed of a few conveyor belts, the belts are around 10ft to 50ft long and 3ft wide and has anything from heavy boxes to thin ...
3
votes
3answers
999 views
i'm trying to make a small blower motor variable speed but can't
I have a small blower motor 120 v, 1.87 amps, and I want to make it variable speed. I hooked up a dimmer switch for a light bulb but it did not work very well. I went to a electronics store and they ...
-3
votes
1answer
1k views
What is the fastest 32gb micro sd card around? [closed]
I've been looking around but I'm having trouble understanding the class speed system. What is the difference between, for example, Class 10 and UHS Speed Class 1? Are SDXC cards faster than SDHC?
3
votes
2answers
113 views
What gives some flash memory a higher speed rating than other flash memory?
What gives some SD/MMC cards a much higher speed class rating than other SD/MMC cards?
Why are some solid-state "disks" (SSDs) much faster than other SSDs?
I'm hoping that I can take at least some ...
3
votes
2answers
1k views
AC fan speed control
I use this fan to cool my room, but sometimes it is too fast and I have to frequenctly turn it on and off to keep normal temperature. Maybe it is possible to reduce the speed by connecting a resistor ...
4
votes
1answer
675 views
How to calculate signal propagation speed through vias?
There is a need to have a group of signals arrive simultaneously to their respective destinations, given that they start their journey at the same time.
However, due to physical constraints it is not ...
4
votes
2answers
501 views
How do I modify a DC electric generator to get the same power at a lower speed?
This will be a theoretical question.
Suppose that I have a DC generator, and I'm getting 300VA power from it when it rotates at 2000rpm.
I want to make it run at a lower speed of about 700rpm, and I ...
4
votes
1answer
296 views
Important characteristics of high speed diodes
I am wondering if an application requires high speed diodes, what charactristic I should look for in datasheets?
For example, between 1N4448 and 1N914 and 1N3595 who is the winner?
My guess will be ...
0
votes
2answers
767 views
How to design DC Motor speed control, using PID
I am looking to control the speed of a DC Motor using PID, it is speed control. I understand how the PID works, but i have a few questions. Like,how would I find my gains for each of the PID, what ...
2
votes
3answers
433 views
Motor controller software design
I have to design a PID controller for a differential drive robot.
The hardware board consists of a AVR atmega168 running at 16mhz.
Driven by two 24v scooter motors with 256 CPR encoders
The motors ...
4
votes
2answers
2k views
Determine MOSFET switching speed
How can I determine the switching speed of a MOSFET, with given Qg (gate charge), Vgs (G-S junction voltage) and gate resistor ?
How should I determine the required value of the gate resistor?
6
votes
4answers
624 views
Different Adder Implementations
I'm putting together an ALU, that I want to synthesize on an FPGA. The carry-look-ahead adder is the one many choose to use as opposed to the ripple-carry adder. However, a thought crossed my mind. ...
3
votes
2answers
223 views
How to get 3D speed vectors?
I want to make a device that measures absolute small scale 3D speed. Small scale as in 10-150cm movements, and absolute as relative to ground and not relative to the device (the device will turn, ...
0
votes
6answers
2k views
Rotary encoders to ensure 2 wheel robot goes straight!
I have successfully counted the rotary encoders on the wheel of my robot so this is not a problem.
My problem is what to do with this number.
Basically, the bigger problem is that I need my robot to ...
7
votes
2answers
626 views
What determines the speed of a homopolar motor?
What determines the speed of rotation of a homopolar motor?
3
votes
1answer
486 views
angle calculations
I am using a Freescale 3 axis accelerometer to build a model that flies and would like to log and calculate angles during a flight. My model can both hover and move up to 40kph as well as rotate on ...
3
votes
2answers
905 views
What is used to control AC motor speed?
This is a AC 220v 60W 0.2A fan I recently bought to replace my old bathroom vent that gave up some time ago. The problem is that the new one doesn't come with a built in speed controller like the old ...
3
votes
2answers
337 views
Slowing down a motor - Mousebot
I put together the a Herbie the Mousebot the other day and he is FAST! Too fast to demonstrate in a small area.
Have a look a this video to see just how he zips around.
Documentation: Mousebot
So ...
