An engine or motor is a machine designed to convert one form of energy into mechanical energy. Heat engines convert heat into work via various thermodynamic processes. The internal combustion engine is perhaps the most common example of a heat engine, in which heat from the combustion of a fuel causes rapid pressurisation of the gaseous combustion products in the combustion chamber, causing them to expand and drive a piston, which turns a crankshaft. Electric motors convert electrical energy into mechanical motion, pneumatic motors use compressed air, and clockwork motors in wind-up toys use elastic energy. In biological systems, molecular motors, like myosins in muscles, use chemical energy to create forces and ultimately motion.
I was wondering about , have there been or are there any systems that would use a large capacitance rotary capacitor/s as a mechanism for soft start of larger AC motors and also they would serve as power factor correction devices? The idea is basically simple, say one has a 3 phase motor and we...
Hi, it's probably a frequent question, but I can't seem to wrap my hear around. I'm trying to understand how I reach that value, not just how to get the value.
I'm designing a vehicle with 4 wheels. It'll climb a surface with a slope theta (in degrees).
This is the FBD that I've come up with of...
i don't get how a dc motor will overspeed when you don't give the field windings power
cause you need flux to make the motor move so how will taking away the flux make the motor go super fast
Hello,
I am after some help to try and understand SVM implementation is a micro that controls a motor.
As I understand it one of the advantages of using space vector modulation over sinusoidal PWM modulation in motor control is that it can control the phase voltages such that the line-to-line...
i'm simulating a small dc motor that is driven by volt = 1.54v, current = 250 milli amps, so that gives me 0.385 watts supplied to the motor
next i attached a 4mm thick circular acrylic disc as a flywheel. so in this simulation i spin up the acrylic disc as a flywheel
my acrylic disc is 12cm...
(a) When the cab is carrying its maximum capacity, at what rate must the motor deliver energy to get the cab up to cruising speed?
My shot was finding the acceleration,
a=1.5/2 = 0.75m/s2
Displacement of elevator
Vf2 = vi2 + 2aΔx
Δx = 1.5m
Force of elevator (Since it accelerates...
Hello everyone,
I see videos showing the output torque can be increased by using gears and this is usually demonstrated with DC motors (simple DC motors can be removed from toys). I understand the general logic:
* The DC rotates in a high speed.
* The gear system reduces the output speed.
* If...
So while thinking about motors this suddenly struck me,
So as the universal series wound motor is spinning there is always some arcing going on around the place where the brushes contact the copper segments that slide past them, I assume this is at least partly because as each coil pair of the...
Hello
So i was curious to know, what kind of tests you guys would run on a setup, for an AC drive and motor, to see if the controlling works properly?
kind regards
few questions
1) is it true that for a 50 or 60hz induction motor maximum torque is achieved from 0hz up to design hz and if an VFD is used and frequency is increased above 50 or 60hz like 100hz the rpm will increase but the available torque will decrease?
Is the reason behind this the fact...
Why we use such connection between 4 and 5 terminals? Why the transformer isn't connected via 2 and 4 terminals from CB, the voltage will still be 380V because it's between two phases? In such situation the terminals 5 and 6 will stay unused, why not on this way?
I was curious in regards to a homopolar motor where the energy imparted into the rotor comes from if the energy input is say 10v at 1000 amps and there is 10v 1000amps output. Aswell if the effect of the magnetic field produces a different power on the rim of the disk vs the input from the...
Want to know how to get the actual power the pump needs.
I can measure the flow rate by the flow meter and count the revolutions of the pump.
But selecting the proper motor for the pump would be a problem.
So I want to know how to determine the power of the rotary lobe pump and generate the...
I have my field windings on the bench and it has a heavy and light wire wound in pareral there are three wires off the field windings . It looks like to me after testing switch with ohm metter positive turns on motor but when switch is in on position green wire off switch is not connected to...
Hello my dear physicists,
I'm trying to model the varied generated (needed)Torque to rotate a washing machine Drum during a Washing Process
so i assumed that the Model has as Input the target vilocity and as an Output the new needed torque to rotate the Drum(to be as a input for the motor...
I have a "262 Lionel Line" O gauge train, from the early 1930's. It has sentimental value, my Father-In-Law (RIP) got it as a gift when he was about age 10. I've set it up each Christmas, a short track around the tree. But it is difficult to control, the gearing is high (it goes fast), so...
I'm using a servo to lift a pen. The pen and a bit of mechanism weights 35g.
The servo I use to bring the pen up and down claims to have a torsional moment of 1.5kg/cm. Sometimes they call it torque in the specs. But surely that does not mean they are claiming that if I hung a 1.5kg weight a 1...
Hi,
The picture below shows a DC generator. The magnetic field is uniform. As the coil rotates clockwise, the right side of coil is moving downward and the left side of coil moves upward. Using Fleming's right hand rule, one can deduce the direction of conventional current in both sides of...
Hello everyone,
I currently bought a Z axis table for my laser engraver. I am trying to hook the stepper motor up separately. I currently have a 12v transformer, a capacitor, 2 push button switches and one 3 way switch along with the stepper motor. Is there any way I can wire the stepper to the...
Assuming we have a 3 phase motor I've always wondered why is it that the rotor spins rather than just being compleltly pulled towards the direction of the phase or the electromagnet? What causes that angular movement?
Hi,
The shown below, Figure 1, is an interaction of magnetic fields of stator and rotor of a squirrel cage induction motor.
I believe the current is coming out of the squirrel cage bar on the left and entering on the right as is shown below, Figure 2. I have assumed that the bars highlighted in...
So I'm a college student currently doing A-Level Physics, I am attempting to build a type 4 double arm barn door tracker and although it has been a complicated project, I believe I've got all the planning done, however, I have a 2Rpm motor, a PWM motor controller, 2 9v batteries, an M8 threaded...
This is a wonderful area of active research. Early in my EE career, I was interested in trying to use IC-scale nerve interfaces to bypass spinal cord injuries, but the science of interfacing electronics to nerve cells for long-term use was not developed enough. Even today, it is a problematic...
Homework Equations:
E=V-IaRa
n2 = (n1×E2)/E1
If = V/Rf
V×Ia
T∝ΦIa
E∝ΦN
i)
V = 500v, N1 = 600RPM, It = 45A, Rf = 220Ω, Ra = 0.3Ω
It = Ia + If
If = V/Rf = 500/220 = 2.273A
Ia = It - If = 45 - 2.273 = 42.727A
Now: T∝ΦIa and if the flux per pole is constant then T∝Ia
So Ia when the Torque falls...
When an alternating current motor first turns on, what causes an alternating current motor to pull locked rotor amps for approximately one second after first turning on as opposed to just pulling the same amount of amps the entire time?
What causes the amperage on an AC motor to drop after...
Summary: Hello; i am trying to work my way thru some motor sizing calculations on a semi-simple example so that i can more easily do it in the future. Could i get some guidance?
Hello:
I am trying to develop a good system for sizing motors (generally steppers). In the past i just guesstimated...
Hi everyone, I want to rotate this (see attached image) platform at a speed of 20 RPM. To this end, I have to calculate the torque and power of a motor required. I have done preliminary calculations, however the numbers I'm getting doesn't seem right. For example, I'm getting that the torque...
Summary: Non - ideal pulley question, should be easy but has got me good
Hey guys, looking for some help on this pulley question. It involves torque, and works with Newton's 2nd law in conjunction with a non-ideal pulley.
Text of question:
" When the motor in the figure below lowers the m =...
Homework Statement: what kind of electric motor with reducer is needed?
Homework Equations: what kind of electric motor with reducer is needed?
what kind of electric motor with reducer is needed?
speed 55mm/s
<moved to EE forum>
Hello!
I'm currently in the process of making a moving cosplay prop, and as a perfectionist, I'd like it to move exactly like the original. Kind of like in this animation:
https://www.deviantart.com/ace-wong/art/RWBY-Qrow-s-Weapon-Animation-606779918
The problem I've stumbled upon, is how to...
https://www.physicsforums.com/attachments/250022
For the part (a), set the tension of the string that pulls the elevator be ##T_1## and the tension that pushes the counterweight be ##T_2##. Then we have the following equations:
$$T_1−1200g=1200 \cdot 1.5$$
$$1000g−T_2=1000 \cdot (−1.5)$$
where...
Hi.
I am new here.
I have a question on how to speed control a DC motor running a pump. The pump is a seawater cooling pump cooling a large V8 motor.
Therefore I need to control the RPM, based on the temp of the V8 Motor.
Any ideas?
Greetings
This query is regarding a 5 wire induction motor without a wiring diagram from a washing machine, one permanent capacitor, no centrifugal switch. here its 240v 50hz
I would appreciate someone explaining how to actually figure out the connections after measuring the resistance of the...
hi,
I'm working on a rotational system, and my goal is to rotate a 500kg(1100lbs) load to 90° in 1.5 seconds. Inertia of load makes system hard to accelerate and decelerate. I designed a gear system but still motor needs too much torque.
Is there any possible method to decrease motor torque...
I don't have a debugger yet, but my company is getting one...
In the mean time, I've been un/commenting out parts of Mbed's code. Their Hello World program is available from this website, and it can be used directly in their online IDE by clicking "Import Program"...
First some basic figures which are very rounded as I'm interested in the approach to the problem rather than accuracy of the answer at this stage:
The field current will be 500/220 = 2.2727 Amps, and so power is a fixed loss at 1136.36 Watts
The armature current is 45 - 2.2727 = 42.72 Amps. At...
What are the negative effects (if any) of running a compound DC motor with the series field open? I’m troubleshooting a 100hp recoiler motor on a metal slitter machine that constantly blows line and load fuses. It is on a DC drive. The drive has been replaced and the motor has been rewound.
The...
Summary: How do you determine the armature current during the braking time?
For a simple permanent magnet DC motor with a known resistance and inductance in series with the armature, I would like to know how to determine the armature current if there was an electronic motor drive controlling...
So I've attached my graph and found that the windage/friction losses occur roughly around 230Watts. I just don't know how i further explain the magnetising current I0. I know I0 = input current on no load. So do i assumed from P = √3 x VL x IL x CosФ that CosФ=230/√3*220*6.8= 0.0849 or...
I’ve been trying to design a counterbalance system using a constant torque motor spring assembly. The spring I’m looking at has 25.4kg cm torque on the shaft from the output drum.
So if I put a 100mm diameter cable drum on this shaft I should be able to counterbalance 5kg over the given...
Hi everyone!
My name is Cristian and I would like to ask you for advice. I am trying to build a shredder for solid recycled plastics (particularly PP and PE) and I am seeking and motor to rotate the shaft of this device.
Specifically, I require a motor with a 75 RPM speed and over 20 Nm torque...
Hey all!
I am working on my first ebike build and posted a question about friction drives earlier. Now, I have decided to go with a Mid-drive. I made calculations and found out the torque and rpm required for the build. But I am having difficulty find the right motor and gear ratio. I am trying...
Summary: For the same mass of copper wire, would more turns or greater thickness create a stronger magnetic field from a coil?
So I am attempting to make a brush less DC motor, and I am wondering whether the coils would create a greater magnetic force if there are more turns or if the wire is...
What is better to feed a 500w asynchronous motor, an asynchronous or synchronous aerogenerator of 1kw? Why is a asynchronous/synchronous aereogenerator better in this case? Thanks you
My plan is to use the compressor at work as a free ride to and from work. I want to install an air tank (a rated one, not an improvised one) onto a bicycle and then run an air motor to turn the wheel (with whatever gears etc needed to make it work). I will probably be using an air tool, such as...
The motor is required to operate at its resonance frequency and I am looking to add a thin-walled (0.010") copper tube inside the stator bore to add some damping. The current motor air-gap is 0.015". If I install a copper tube in the stator bore bonded to the stator and leave a 0.005" air-gap...
When an electric motor first starts running, the motor will draw approximately 5X the normal amp draw of the motor for approximately the first half second that the motor runs. The amps that an electric motor draws for about half a second that are about 5X the normal amp draw of the motor are...
Randomly popped in my mind when trying to design microvalves and no idea where to post this... Lip motorboating is when you exhale with your mouth closed, causing your lips to flap like a horse and make a fart sound. My question is not what causes the sound but what causes the lip vibration. Any...
I have drone motor with propellers attached to the top of ring flywheels rim at the edge and the flywheel is 18 inches in diameter and weigh's 2kg.
The drone motor with propellers rpm 5200 and thrust 900 grams.
What rpm will the flywheel be rotating at.