A DC motor is any of a class of rotary electrical motors that converts direct current electrical energy into mechanical energy. The most common types rely on the forces produced by magnetic fields. Nearly all types of DC motors have some internal mechanism, either electromechanical or electronic, to periodically change the direction of current in part of the motor.
DC motors were the first form of motor widely used, as they could be powered from existing direct-current lighting power distribution systems. A DC motor's speed can be controlled over a wide range, using either a variable supply voltage or by changing the strength of current in its field windings. Small DC motors are used in tools, toys, and appliances. The universal motor can operate on direct current but is a lightweight brushed motor used for portable power tools and appliances. Larger DC motors are currently used in propulsion of electric vehicles, elevator and hoists, and in drives for steel rolling mills. The advent of power electronics has made replacement of DC motors with AC motors possible in many applications.
Homework Statement
Hi, well my task is to construct a DC motor. With 25w rotational mechanical output power. It cannot draw more then 5A current, and has to have 3 or more poles in rotation. The motor must be brushed/commutated. There is a max of 30v D.C. input. The motor needs to be built and...
I am trying to drive a 5V DC motor using a MCU output. The motor is run directly off the +5V line which is down-converted from 18V using a TPS5430 Step-down converter.
The MCU coding is basically that when the inputs are in the correct state, the output to the FET turns on for a number of...
Hi, I am attempting at making a simple device that will run on dc power that just spins a item i place vertically in the air. I am trying to do it without having to by any of the parts being i could just buy a new one for around 250 bucks.
My first question is how to you determine the...
I am attempting to build a wind turbine, as many have successfully. I have read that a permanent magnet dc motor out of a treadmill will serve well as the generator for the turbine. I'm not very electrically savvy, but I'm attempting to learn. I have posted pictures of the motor, and the...
DC motor question:
Do the permanent magnets make a motor more efficient as opposed to using coils for the field magnets? Are the permanent magnets responsible for half of the force in which propels the shaft?
Do the magnets perform half the work and the electric the other half?
Thanks so...
hi i am new to this forum. i want to use a battery that will run a dc motor, dc motor will run three phase ac generator through mechanical coupling and the three phase ac generator will produce out put, now two phases of the ac generator will b utlilized by the load and 1 phase will recharge the...
Hello,
I have many time thought about AC & DC Motors, but have not yet find out. Example. if a motor of 4HP 48VDC. We give it power 48VDC but 1HP power, so what happens? And what if we connect it directly with solar panels of 48VDC and 4HP power.
So when sunshine is lower how it will...
Sorry for this noob idea but I'd like to know what happens if:
A 2 HP DC electric motor is coupled to a 5kW DC Generator, will the 5kW DC Generator produce a 5kW output? What will happen to these two equipment. Thanks for the Reply!
Hi experts,
is it possible to have a simple 2-directional switch using just 2 12v coil relays (having normally opened and closed contacts)? Is this equivalent to a h-bridge or must a h-bridge be used? The triggering is from a 555 to the relay coils.
I tested my circuit but it does not seem...
Hi Experts,o:)
I am trying to reverse the direction of a spinning dc motor (around 30watts)
but not sure how this should be done.
I have a logic for the switching of the power polarity to the motor but am worried if back emf would be an issue when the motor is spinning and the polarity...
Hi my name is Bruno !
I don't really know about circuit board hardware ect ect
But i have a pretty good knowledge about Dc and Ac , relay , ohm law ect ect ! And I am learning fast !
There is my problem !
I have a Bmw Convertible with a soft top controlled by an electronic box that...
I'm trying to modify a VCR so that the big drum that scans the tape spins slower (for an art project...). It's a brushless DC motor that uses a special VCR-specific IC to control it, I believe. The chip is a sanyo LB11885 (http://www.semiconductor-sanyo.com/ds_e/EN7884A_d.pdf" datasheet). VCR...
Question:
Assume that a 12V permanent magnet DC motor is to be used for moving the robot legs.
It has a stall current of 2 ampere and a no load speed of 3000 r.p.m.
Assumer that the friction at no load spped was so little that it can be neglected .
When the suply is at 11V, the motor is...
Hi,
I am a 24/7 carer for my wife who has Huntingtons disease. This has caused her to loose the ability to hold a cup.
I want to devise a swinging arm with a cup attatched to one end. It will be operated electricaly with a small LEGO motor that has been geared to give plenty of torque...
Hi,
Can anyone help me to figure how to get 12V for the dc motor using 24V supply.
I would like to use a 12V supply but that would mean some changes to the wiring.
Instead of rewiring,I would like to just make do with the 24V supply.
I will need a series resistor (ranging from 1k -...
Dear Sirs/Mdms,
I would like to find out how different is a brushed vs brushless dc motor in terms of size, weight and power .
I can find articles on the net regarding some comparisons between the 2 types. For example, a brushed is less efficient than a brushless motor.
But i cannot...
ELEG -- DC Motor Control Systems Problem
Homework Statement
The voltage equation of a dc motor is written:
ea(t)= Ra*ia(t) + La*[dia(t)/dt] + Kb*wm(t)
where ea(t) is the applied voltage; ia(t) is the armature current; Ra is the armature resistance; La is the armature inductance; Kb is...
I recently started doing research to build one of these (popular?) two-wheeled balancing things. (A segway clone)
I don't know how to calculate the proper size motors (a pair of motors) for this. I know you have to consider the torque and rotational speed required to size the motor.
Desired...
Hi
I need help deciding how to design my DC motor. I know about series wound and shunt wound motors. I want to design a motor for the highest speed at no load. The limitations are 12V and 1A.
I can only use copper wire (0.315mm, 0.2212 Ohm/meter) and shimstock for the electromagnet...
Hello!
Lastly i was designing a toy car moving in both direction foward and backward using relays and switches. I thank everybody who helped me.
Now i want to move to h-bridge. i have read many books about the h-bridge but one problem that i still have is how to chose power FET transistors...
Hi,
Question 1:
can anyone tell me do we need a rheostat or face-plate starter for a 12V dc motor?
I read in the book and it says the starting current for the motor is very high and it might burn out the armature. I was wondering if I could just directly connect the 12V supply to the...
Hi,
Can any expert advice if I can control the DC motor to make it work as a stepper motor?
I am using PLC to control the DC motor clockwise and counterclockwise in steps. Output O:1/0 controlling clockwise and O:1/1 controlling counterclocewise.I will use the timer say 0.5s pulse to...
Hello I have a project in the works that requires a DC motor to turn a somewhat heavy (but with good bearings) gear assembly. The whole thing will be running off of a common computer power supply at 12V. I haven't selected the motor just yet but am leaning toward maybe an old cordless power...
Lets say I want to move a kick stand on a motorcycle by use of a motor. Hooked up to the battery and a button on the handle bar. Is there a way of controlling the motor so it will automatically shut off when the kick stand has swung down all the way? Also when it has swung back up?
Thanks, Hoovy
Hello Forum , i have a spindle motor from a Hard disk , it's a 3 phases DC brushless motor . This motor has 4 wires , 3 phases and 1 common , how i can know the phases and the common ?
Thanks in advance.
Anita
Hi all,
I've got a problem which is so daft it hurts.
I'm using lithium batteries, and I'm well aware of the dangers, so despite being fine with working on an un-protected cell, I changed to protected ones, and then issues appeared. The current is drawn from a pair of parallel 18650's...
Effect of a pair of slip rings in a DC motor
Hi, I have a question here.
Knowingly that the effect of a slip ring in a DC motor is to reverse the direction of the current in a loop whenever the commutator changes contact from 1 brush to another, so as to ensure the loop to be always...
Hello, I am new to this forum. I hope this can help me with my curious question.
I know that the DC motor can be run by electricity, but also it can create electricity by torque force.
The question I would like to know if this works or not?
One 1.5v DC motor is powered by one...
Hello all.
First off, I am a total newbie and need some help in getting my "project" up and running.
Here goes, I'm trying to get a dolly (weighing around 50lbs. or so) to move at a fairly slow constant speed.
I'm thinking my best option is to find a 12 volt DC motor along w/a speed control...
Homework Statement
Hey, For one of our final lab projects, we have to (less design and more build) an electric DC motor on a 6V DC battery.
Restrictions/Requirements:
No plastic parts can be used
The motor must run for at least 60 seconds
No simple motors allowed
"not-simple" means, it must...
Good day everyone
I'm implementing a speed controller for a DC motor 220 v 2.7 A 1500 rpm.
I've already made and tested the firing circuit and the motor works fine in an open loop.
Now big problem the parameters of the motor are unknown and impossible to find. No time for mechanical...
hi,
sorry my English isn't perfect but please try to understand :
my teacher gave me a project in which i have to use a small dc motor,op amp,and a "servo amplifier" to control the rotation of the shaft of the motor, so can you tell me what is the servo amplifier? and how to use it to control...
Newbee here, hope this is the place for this kind of question.
I want to fab a cart that will carry about 200 lbs. It will be something I will stand behind, holding like a handlebar at waist height with a throttle. Gearing (chain and sprocket is what I'm thinking) would need to give a top...
I have a question. I set up a voltmeter and and ammeter (properly connected in parallel and in series respectively) so that when I input power into a motor in the form of DC current, both the voltmeter and the ammeter read positive values.
Then, I removed the voltage source (i.e. battery)...
Hello, I am designing and eventually constructing a high current DC motor controller to be used in an electric vehicle for a senior design class. Right now I am at the stage of selecting the PWM source for the MOSFET drivers. A team member wants to use dedicated PWM TTL chips, I wish to use a...
How do you use a DC motor to test the work of a flywheel? I'm trying to test the mechanical efficiency of a wobbler oscillating steam-engine. To test the output of the engine I was going to use a DC motor. Included in my calculations do I need to include the efficiency of the DC motor? If so...
In a conventional DC motor 95 percent of the power is supplied to the motor while only 5 percent of the power is supplied to the stator. consider the torque equation. what if you have a motor that has 95percent power supplied to the stator and 5 percent to the motor. the motor will still run but...
Hello,
I have a question regarding calculating the torque output of a DC motor. I can record current and field from a motor drive. I can also record commanded torque. I have time histories for a series of motor commands, and I'm comparing the torque command to a torque that I calculate...
I am trying to relate two concepts, Power and Kinetic Energy, using a small DC motor.
Given the no-load max angular velocity w (rads/s) of the motor and the current drawn (A) at a given voltage (V) the power being used (P) in Watts is:
P = V x A
Given the no-load max angular velocity w...
I am trying to figure out what would be the best way (by best way I mean the cheapest, and simplest effective way) to detect slippage of the wheel. The surface is very low friction, somewhere in the range of 0.05 mu.
Here are my ideas:
Sense current, watch for spikes/troughs
monitor wheel...
I am trying to understand why a DC motor will burn out at low voltages. This idea comes from my dad who is a mechanic. He says that people that always start their car with a half-dead battery tend to burn out their starters and weld parts inside it together from the heat.
Personally I think...
can anyone refer ot my problem: I have a dc motor drive a bracket of 3 kg rotating 180 Anticlockwise
My question Is what is the best velocity and acceleration to achieve fastest speed and minimizing the overturn of the
#1If I set the Velocity higher than the acceleration such as
V= 1800...
Homework Statement
the speed of dc motor is given by N=60(A/p)(V-Ia*Ra)/(Z*phi)
where,
A=no. of parellel paths
P=no of poles
V=voltage applied at dc motor
Ia= armature current
Ra=armeture resistence
Z= total no. of armature conductor
phi=flux per conductor.
but if some how we stop...
OK hey guys,
I am building an electric go kart for a final project, and I'm just trying to get my initial justifications correct, with respect to the classical physics involved.
SPECS: i was the car to be able to reach 60km/h,
The total weight of the car will be approx 200kgs.
the size...
Hi everyone,
I'm new here and I'm electrically stupid. I am working on a mock up of a system designed to pump a variable amount of liquid. I was looking the OEM manual for a small 12v pump and it said that the motor may burn out if run at a voltage lower than 12v.
I understand that the way...
Homework Statement
A dc machine(6W, 120V,1500rpm) is separately excited and delivers rated current at rated terminal voltage.Field winding is connected to 120V supply. Rfw=100\Omega.
a) Determine the value of field current
b) Determine the value of Rfc required.
Homework Equations
Vf=...
If i have a series DC motor and at say X rpm it has a back emf of 11.5v and supply voltage of 12v and i increased the supply voltage (keeping rpm the same) would the back emf stay the same? and if not would the diffrence between back emf and supply increase?
Thank you.
Is it possible/meaningful to use a 12V DC motor to run a 120 amps. Alternator at 2100 rpm ? If yes, what kind of DC Motor should be used (RPM/Watts/HorsePower)