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.
Hello,
I'm trying to size a motor for an application that I'm working on.
The application involves winding paper with two motors. One motor will unwind and the other motor will rewind. However, I'm trying to figure out what the motor power rating should be. Here's the worst case scenario...
This isn't a homework question because nobody assigned it to me. It is a theoretical question however.
I understand that in a balanced 3-phase system with a constant load, instantaneous power is constant. Not "pretty constant" but a flat line. This suggests to me (warning: amateur) that...
Sir what would be the life of permanent magnet motor which runs by the repulsion of north pols. Is magnets energy wasted during this repulsion process or not. Because it continuously work on repulsion of two north pols.
Homework Statement
I try to derive the expression of ω with respect to t,
but the problem is the armature current Ia or the flux is unknown. I don't know how to solve it.
Anyone could give me ideas? Thanks a lotHomework Equations
τ=J(ω/t)
Vs=IaRa+Ea
T=KEøIa
Ea=KEøω
Hello guys,
I have to make a short circuit calculation for school but I am a bit lost.. I have a copy off the IEC61363 and internet connection as my help lines.
Homework Statement
The network consists of a generator feeding to switchboard A with a cable in between, on the same...
I am building a two coil DC motor as a project. I have two neodymium magnets, an aluminium split ring, and alligator clips acting as brushes, connected to a 9v battery. For some reason it is not working and I cannot figure out why. Can anyone think of something I may be doing wrong. I can post...
Hello Wizards!
I'm trying to use a stepper motor as a wind powered generator.
I connected some resistors to one coil of the motor, and turned the motor with a drill,
while reading the voltages.
The power ( watts ) number I came up with seems too high.
Am I missing something...
Hi I am trying to calculate the efficiency of my DC motor. I know that efficiency is:
Power Out / Power In * 100
I have been told by my teacher that Power In is calculated by the following formula,
Power In = Power * Time
And Power Out is;
Power Out = Mass * Gravity * Height...
Homework Statement
I can not understand this question: "Describe the characteristics of a three-phase induction motor?"
Does it mean speed,torque,etc?
Thanks
Homework Equations
The Attempt at a Solution
how would you calculate the resistance required for a resistor which is in series with a generator (DC motor in reverse) to achieve a certain torque from the generator?
Eg, there's a torque of 30kN acting on a 100kW generator while it moves at 50RPM.
The is the same mechanism as electric...
I want to design a bidirectional DC motor ,
so use four transistors in the H bridge circuit.
I can understand the first circuit,
but for the second, I can't understand why input signal ,
eg: A, is connected to the same side of transistors?
What is the differences, which one I should...
Hi, I am working on a project that needs some rotation around a central axis. I was looking over at some Servos but I don't know how to calculate the torque required by the servo.
I was thinking of doing a simple free body diagram, but as I was drawing it I realized the forces are on the Z axis...
I am working on a timelaps project so I need my motor to move very slowley, the motor I am using has a max voltage of 24V and a stall current of 1 Amp
The motor I want to use is on this link:
http://www.dynamicperception.com/EZ-Swap-DC-Motor-p/dp-dcm.htm
This motor will need to lift...
Hi I am trying to work out the torque required to rotate an object from 0 to 1RPM in 1 second (1 second accelerate to 1RMP) , its working in time laps so very small movement is required.
The diameter of the gear is 30mm and the diameter of the shaft is 10mm, the object on top weights 20kg...
Specifically, this is all to do with rotor size of brushless DC motors and how it plays a part in calculating angular velocity / volts / amps / torque.
There is no single equation to be solved here.
Any relating information or equations..., any and all, please jump in.
I've been looking at all...
Hi!
I'm stuck on a very basic problem while trying to design a product. Basically, I need to know how to calculate the gear ratios, pitch, motor specs etc for two rack and pinion mechanisms- one horizontal and one vertical. The pinion moves along the rack in both situations.
Mass to be moved-...
Hi All
I am asking this question as a mechanical engineer, so please bare this in mind if you have the time to post a reply...
I have a basic DIY type cement mixer that has given up today. It is a AC 230V model with the most basic of drive setups (pulley and drive belt attached to the...
Hello,
i'm unsure of how to complete the final part of this question;
Homework Statement
A motor is designed to operate at 118V and draws a current of 12A when it first starts up. At it's normal operating speed, the motor draws a current of 2A. Compute:
a) the resistance of the...
hi guys! i was wondering if the solid magnet part of a brushed dc motor needs to be strong in order to make a strong motor? I'm designing a motor from scratch and wondering if i should use an existing ferrite magnet that is somewhat strong or should I design a electromagnet that is stronger...
Homework Statement
i need to calculate the power used up to carry a vehicle with 433mm diameter wheels,mass of 163kg up a slope of 3%. The horizontal distance of the slope is 2.9km. The surface of the slope is asphalt with rolling resistance of 0.22
From the following motor specs...
Hi,
I am making a Simulink model for the drive cycle of a hybrid bus. My bus is using a gas turbine engine to power a generator which then charges the batteries.
I have a motor model which I have attached a screenshot of, and I know I can use this as a generator also. I just have no idea...
Hi.
Having measured an induction motor on no load and obtained a torque figure, I have noticed that when load is increased, the torque continues to decrease. How it this possible as I am observing a reduction in rotor speed and increase in rotor currents and current drawn from supply?
Hi,
Does anyone know or could help me understand the reasoning for the amount of slip within an induction motor decreasing with frequency under the same load conditions? I.e. For no external load, the slip is higher at 50Hz than at 20Hz etc? Thanks
Hi, I am currently simulating a 3 phase induction motor system. One of the tests that I have run is to keep the motor parameters (reactance, resistance etc.) constant, and then change the frequency of the supply (50, 40, 30 Hz etc.) before measuring input parameters (current and power drawn...
Hello everyone, I'm a bit confused about the power drawn by a motor. Since back emf reduces current when the motor is rotating at high speed, is it true that back emf reduces the power required at high speed? THX :D
A 3-phase induction motor in our factory had unequal phase currents. One of the currents was nearly normal while the other two were about twice the usual value. Somebody said that prolonged running causes increase in resistance of stator winding, and this results in increased current. But this...
hi! so I'm in secondary two, and so far in my syllabus we have covered up to work done. now this is my homework, and I'm not sure whether my answer is accurate, could you help me with this?
(I haven't learned the equations yet)
I have measured some properties of four sewing machine motors for domestic use. They are all universal motors (series motors) for the public grid voltage in Europe. The four motors are:
a) Singer 66K motor. Motor seems to be produced about 1930 in UK.
b) Singer 201K motor. Motor seems to be...
Hi,
When a load is applied to the rotor of an induction motor, the rotor speed decreases and as a result, the induced currents in the rotor and the torque produced increases due to the relative speed difference between the rotor and the rotating field within the stator. My question is...
Hello guys, i have a problem in determining a thickness of a plate. i have a motor (m = 17 kg) attached to a plate. the design can be seen in the attachment. i need to know the dimension of "t".
Can someone give me tips? I want to know the gravity effects on the electric motor's rpm. Is there or not? If there is effects on electric motor, how would it differ?
Hi,
I'm new here and had a question relating to my senior design project in mechanical engineering. My project ends up involving a small DC electric motor, which needs to be able to be reversed and it would be nice to be able to have some speed variability.
I'm aware of speed controllers and I...
Hi, I have a single phase ac motor system currently working at 2980rpm, 5.6 amp, 50 hz, 240v, efficiency 87% giving approx 1 horse power.
Can I have a similar powered dc motor run off a 12 volt car battery. Can this be achieved inexpensively?
Could I use an inverter for original system...
I'm looking for a DC Motor to power a small 50lb robotic platform with maximum speed of 10mi/hr.
What should I be looking for?
I've made some basic assumptions of 8" or 12" diameter wheels and so the rpm rating should 420 rpm and 300rpm respectively to attain 10mph. I plan to use at least two...
Homework Statement
The coil of a DC motor has a resistance of 2.0 ohms. The motor is runned by a battery of 12 V and an internal resistance of 0.5 ohms.
a) Calculate the current at the moment the motor is started
b) Calculate the current when the motor is running at 600 RPM , when there is...
I have built a conveyor system but still need to power it. It is not a conveyor belt, but rather a trolley of sorts for moving materials up to the second floor. It runs parallel to stairs for about 17 or 18 feet in my garage at an angle of apx 38°. It needs to be able to move at least 500 lbs...
Homework Statement
This crane lifts a 125 kg heavey motor. What is the member forces of BF and BD?
Use 10 m/s^2 as accleration of gravity.
https://dl.dropboxusercontent.com/u/11241083/problemtruss.png
Homework Equations
F=ma
Sum Fx=0
Sum Fy=0
Sum M=0
The Attempt at a...
hey friends
i am new to the forum so greetings to all
i have a problem and need some help
i will brief the problem in two lines:
i need a motor to turn a wheel of inertia I, by means of sprockets and chains, the motor should reach
1280 rpm after 6 rounds so the wheel reach a given normal...
I have :
Cylinder : 958,000 lbs
Motor 200 HP
required RPM : 5
time : 60 seconds
Torque: 18,757 lbs-ft
What to find ?
Time required by the motor to reach that torque
Doubt :
Is there a chart or a graph that gives this value ?
is there any eqaution / formula that helps finding...
If in the DC motor specs doc says that it can handle + - 16 Volts maximum and 3A of peak current but the nominal voltage is 6 V and the continuous current is 1A...
it means that it is safe if you feed it with 3A during the time of start up?
Supposedly it is only meant to be at the start...
HI,
please help me... I am thirsty for any insights to my problem.
I have a motor:
Output: 60W
VOLT:12V DC
AMP: 7.5A
RPM:1800
TORQUE: 3.5kgcm
I have a motor reducer:
for converting rotation movement of motor to up and down motion(for lifting heavy load)
look like this...
I have a Geared DC Motor rated 12V, 0.6A, 180RPM, 3kg.cm, 66% Efficiency. I measured the impedance of the disconnected motor at 45 Ohm.
I want to use it with a with a simple 12V 1A DC Power Supply in a Field Current Control Circuit to be able to dial in variable speeds.
Will the circuit in...
People of physics forum
i have come here to ask for help.
i am trying to model a armature controlled dc motor with no load but and opposite force in the form of frictional damping
the expression i have raised and am assuming it to be right is
ωout/Vin = k/(L(s)+R)(I(s)+C)+ kt.k...
I bought a Savox servo motor (http://www.savoxusa.com/Savox_SB2272MG_Digital_Servo_p/savsb2272mg.htm)
I'm planning on using the motor to generate a pitching motion sinusoidally from 0 to 60 degrees back to 0 and so on...
Do you guys think this motor is precise enough to generate the...
hey,
So I am working on this project where I am trying to come up with a motor set up to drive two wheels of a trolley. The entire trolley weighs 650 kgs and i require a motor with a torque of about 400Nm. I want to set it up in such a way that i want to be able to apply very little force to...
I am looking for a DC Motor with the given specifications:
Power: 2HP
Torque: 400 Nm
Voltage: 12V/24V
Current: 120 A
Number of Drive Wheels: 2
Diameter of drive wheels: .435m
Gear Reduction set up: Worm drive arrangement
Total weight being driven: 650kgs
Speed at motor: 1500rpm...