Read about dc motor | 36 Discussions | Page 1

  1. K

    DC Compound Motor Help

    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...
  2. M

    Two Different Designs of DC Motors

    Hello, I have two designs of DC motors. Which one is more efficient? I believe what is in question is the location of the communicator. Whether it should be closer to the out piece of the shaft turning the gears? Or should it be further away towards the end? Does this make a difference...
  3. T

    Using a generator to charge 2 batteries

    My project is to create a circuit for a stroller that can store the mechanical work into electrical while moving around and with the push of a switch, use the electrically stored energy to assist the movement of the stroller. I’ve tried capacitors but it ended up not being enough voltage and I...
  4. K

    Choosing the right ESC for a Brushless motor

    Hello everyone. I have a RC helicopter (WLtoys V912) that recently had a crash. The main board was damaged and replaced and I got it working again but there is a problem. The main brushless motor is not as powerful as before and I have to apply 75% throttle to keep hovering above the ground. It...
  5. E

    Slowly Rotating Device For a Camera Pan Timelapse

    Hello all! I just discovered PF as I have been searching about a project I have been pondering for a day. The idea is to have a device that I can set my 3lb camera and have the device rotate left-to-right && || right-to-left over the duration of 2 hours for use in a sunset/cloud timelapse...
  6. J

    Torque on a DC motor spinning a wheel horizontally

    I need a 12v DC with appropriate torque. In my design, the axle of the motor would be pointed straight in the air and I want to affix a wheel to it and have the wheel spin flat, sort of like a pottery wheel sort of design. I know what the wheel is made of, its dimensions and approximate weight...
  7. nashikin58

    How to avoid a clash of magnetic charge and electric charge

    Hi, now I'm working on a project which involves a dc motor and high voltage. I'm developing a machine consists of a motor to rotate a platform disc and high voltage will be applied during the rotation. The problem is when I supply a positive high voltage at motor shaft during rotation, the motor...
  8. S

    Engineering Electrical Machine - Shunt DC Motor Problem

    Hi guys, can someone please have a look at the following problem that I am struggling with; An 8.25 kW shunt DC motor is supplied with a terminal DC voltage of 300 V. The armature resistance of the motor Ra is 0.25 ohms, and the field resistance Rf is 40 ohms. The field winding consists of 1500...
  9. D

    What generator/DC motor do I need for my wind turbine

    I am making a small wind turbine for my A-level RMT and wondering what kind of generator I need to charge a 12volt battery. The turbine is a vertical axis savonius turbine that will probably be about a meter high and half a meter wide. I know I can use permanent magnet dc motors and someone...
  10. D

    BLDC motor as generator to power eddy current brakes

    Hi everyone - here's a concept that I'd like a few opinions on: As part of a project, I'm looking at using a brushless DC motor mounted on a high-speed vehicle as a generator. Once the vehicle hits its top speed, the batteries should disconnect from the motor and the vehicle's own velocity will...
  11. kostoglotov

    Which data set should I trust more?

    Homework Statement Control systems subject. Have a DC motor setup on a difference op-amp, then with gain, and the axel moves a wiper on a pot used for feedback. I understand the concepts reasonably well enough to complete the assignment. I'm using MATLAB scripts to approximate parameters...
  12. Cocoleia

    Conservation of Power in the armature circuit of a DC motor

    Homework Statement I am asked in a lab report to explain the conservation of power in the armature circuit of the DC motor. Homework Equations This is the data I have acquired: The Attempt at a Solution I have been reading around, and I have learned somewhat about the Armature Copper Loss...
  13. H

    Four carbon brushes for a DC Motor- what are they for?

    Hi in every theoretical explanation of any kind of DC motor there's always a split ring commutator and two brushes like in the following pic then when it comes to my motorbike/car starter motor rebuild the real thing in practice is different- see the following pic with four carbon brushes- two...
  14. Manoj Sahu

    Why DC series motor should not be started without load?

    Today a professor of mine who teaches Electrical machines told us that a DC series motor should not be started without load. I wonder why is that so. Please provide a detailed explanation of this PF members. Thank you very much in advance.
  15. J

    Engineering Separately excited DC motor

    Homework Statement A 180V separately excited DC motor has an armature resistance of 1.2ohm. When the note runs at 1200rpm,t he armature current is 10A. 1) Assuming that motor torque is constant at all speeds,d determine the mechanical torque and power developed in the motor. 2)Find the speed of...
  16. E

    Engineering Electrical Machines DC Shunt Motor

    An 8.25 kW shunt DC motor is supplied with a terminal DC voltage of 300 V. The armature resistance of the motor Ra is 0.25 , and the field resistance Rf is 40 . The field winding consists of 1500 turns. An adjustable resistance Radj is connected in series to the field winding. Radj may be...
  17. C

    Using a DC Motor as a Generator

    So I'm working on a senior design project and was trying to use a DC motor to charge a battery. The point is to allow for quick use to charge a phone or a laptop in circumstances where you need a quick charge. We have lead-acid batteries connected in series and parallel to give us: 14,000mAh...
  18. H

    DC Motor for Miniature Car

    Hello all, I'm building a miniature vehicle and plan on using a DC motor that supposedly spins at 12800 rpm (1340 rad/s) for the engine. However, I'm a little confused as to what the car's acceleration would be. The DC motor on its own would instantaneously have an angular velocity of 1340...
  19. cyril joel

    Dc motor

    Hello i am abeginer i have to connect a 12v dc motor can i connect it to two 9v batteries in series meabs a total output of 18V.
  20. marellasunny

    Linear actuator limit switch replacement/repair

    Linear actuator spec.: 400mm stroke, 6000N, 2 limit switches, 5mm/sec, 12V DC supply, BIBUS IP65 casing. One of the limit switches of my LA (Linear Actuator) seems to have burned out. This happened because I accidentally plugged the LA leads into the AC mains socket (my LA is rated to run at...
  21. Narayanan KR

    A motor design to defy Lenz' law?

    1. The two rotors (purple, green) are electricaly isolated but mechanically fit to rotate along same axis 2. The motor action on the left side rotor will move the armature set, this will produce currents in right side rotor that will pass via a variable load. 3. do you see the magnetic feilds...
  22. J

    I Power Output Given Certain Torque

    Hi, I have a problem that I've been trying to figure out for a while but cannot seem to get on my own. I'm trying to figure out how much power will be generated in a motor given a certain amount of torque. The problem is, to find the amount of power output , I also need to know the rotational...
  23. C

    Looking for the right DC motor

    Hello forum. I'm looking for a DC motor for a little project. I don't have a lot of experience with different types of motors, though I'm fairly confident I don't want a servo motor or a stepper motor. I have a disk of non-uniform weight distribution. I want to mount the disk vertically (motor...
  24. O

    How does a DC motor work?

    How can this DC motor work without a commutator. Should it not turn no more than once and then stop because on one side the rotor is attracted to the magnet? An answer I can think of is that the rotor is repelled on one side and attracted on the other by the same force which neutralize each...
  25. R

    Calculating the speed taking into account the weight of a person

    I need to buy a DC motor for an electric skateboard project. I need to calculate the speed at which it can travel with a person on top. I can calculate the speed at which the skateboard can go but is does not account for the weight of a person as that will surely decrease the speed. What formula...
  26. K

    Need Help Selecting a Motor

    Hello, I am working on a design, and I am having trouble selecting a motor. I will be able to supply 1.2 A and 12VDC, and I need the motor to be able to move a load of 0.5 lbs at 500 rpm. So far, I tried calculating torque (based on F=ma and T=Fr, r=1.06 in in this case). Then I used HP=...
  27. D

    Maximum voltage and current values for building a DC motor

    Hello, I am building a large DC motor for a Go-kart. I have a question: How would I know how much voltage and current (the maximum values I can use) I need to make the DC motor work and spin? I'm guessing the armature size and the winded wire's length depends on how much voltage and current...
  28. D

    Building a large DC motor

    Hello, I would like to start building a simple DC motor Go-kart, but I would like to build my own DC motor for it. A simple one that can make the car move. I know how DC motors work and I understand the physics of it, but i'm not sure about some things: - Are all DC motors (large or small) the...
  29. D

    Predicting DC generator response

    I am creating a scale model wind turbine using a DC motor as a generator and would like to predict the motor response analytically. Generally speaking, the flow will spin the rotor (as in the turbine's), which will spin the motor, and then there will be what I'm calling the motor response, and...
  30. C

    Mechanism that only rotates when driven from one side

    I have a geared DC motor taken from a hand drill. When I manually turn the internal motor, the drill bit rotates. This can be done in both directions. However If I try and turn the drill bit it does not rotate. What is the mechanism called that achieves this? My friend says it is a sprag...
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