Coil Definition and 864 Threads

Homework Statement In a lab I passed a magnet through a coil and measured the voltage. I need/want to know why when moving a magnet through a coil you induce a current. I don't necessarily need a direct answer - I more just want to know if my argument holds and where to look if I'm...

Hi there. I have a current I running throught a tesla spiral coil, and I have to compute the magnetic field at the center of it. The tesla coil has N turns, and an inner radius a, and outer radius b. This is the tesla spiral coil: The courrent enters through the outer cable, and goes out...

In engine, there is valve and the valve spring. If you have ever look at the valve spring before, then you will notice that one end has its coil closer together than the other end. So a valve spring is a kind of progressive spring. In almost all engine repair manual I read, the instruction is...

Homework Statement A glass cylinder of radius R, length l, and density \rho has a 10-turn coil of wire wrapped lengthwise, as seen in the figure . The cylinder is placed on a ramp tilted at angle \theta with the edge of the coil parallel to the ramp. A uniform magnetic field of strength B...

I'm getting ready for my Christmas break project and I've settled on building a Tesla coil. I was looking at this << link deleted by Moderators >> but I'm still not really certain about what the components do and why they're needed. I kind of understand what a capacitor and transformer is but...

Hello, I've just bought a HV Spark Coil from this site: http://www.rmcybernetics.com/shop/high-voltage/hv-spark-coil/prod_4.html And I was wondering if anyone could help me on how I could power it? I'm really poor on money at the moment since I've just spent it on this item, so if anyone...

hello everybody i'm a student to mechanical engineering and I'm in my last year of my studies. in this year i supose to make a project and in part of my project i need to know how to design a coil that will gives me 0.5 tesla inside the core of the coil. unfortunatly, after a lot of searches...

Hi, When coil is excited with ac because of varying nature of current ,flux of varying nature will be developed in coil and because of varying flux emf will induce in coil. what will happen if coil is excited with dc? intially cureent will increase from zero to maximum and is...

I have a situation that a magnet is placed near to a coil. Especially in pumps and the pump is working based on the stroke mechanisam. The coil is powerd up by a DC source of 12volts and the piston(which having magnet on it) is attracted by this coil called as stroke. The distance between the...

Hello, I was thinking about this and I'm still not sure. I have a long coil (which has uniform magnetic field inside) and a piece of ferromagnetic. Coil is connected to some power source and is positioned perpendicular to surface of the Earth. If I put that piece of ferromagnetic metal...

Hi, i am developing a home-made generator but i am having some trouble with coil design. Going on Faraday's induction formula : V = N A (2 pi RPM/60) B a 50 turn coil with a radius of 20mm going at 20,000 RPM should give me 80 volts or so, in practice i am getting much less than...

Hi everyone i am building a 1.8KW tesla tower and i have a problem i couldn't make the primery part round because the wire was too strong, does that effect my design and will it work ? [PLAIN]http://im13.gulfup.com/2011-11-01/1320190449301.jpg

I'm an old digital guy working on a little analog oscillator project so I'm a bit in over my head. The objective is to detect alloy deviations in samples of aluminum scrap: a very simple go/no-go detector I've cobbled together an inductive meter design using a dual op-amp sine wave...

Homework Statement A single-turn circular loop of radius R = 0.235 m is coaxial with a long 1780 turn solenoid of radius 0.0435 m and length 0.850 m, as seen in the figure below. The variable resistor is changed so that the solenoid current decreases linearly from 6.12 A to 1.46 A in 0.230...

I want to model a coil circuit with induced EMF. I want to verify that my model is correct in a circuit. That the voltage developed across the load is calculated correctly. From the equivalent circuit, you can see the current depend on the jX_L and it acts as a low pass filter in the complete...

I'm looking at redesigning a hydraulic solenoid valve with the aim of reducing the package size. The solenoid coil is by far the largest component of the device, with about 4000 coils arrayed in about 90 layers stacked on top of each other. I'm wondering if I can reduce the size by removing some...

A professor the other day used an induction coil power a crt tube like the one at the link below. http://chemteacher.chemeddl.org/services/chemteacher/index.php?option=com_content&view=article&id=99 I understand the general idea of both induction coils and crts, but what confuses me is...

...and need some help with a bit of engineering. I've got 5 2200μF capacitors @ 400V (I'm familiar with high voltage + current, just not inductors, and have the appropriate safety gear) in parallel with about .05Ω ESR a piece. These are running into a GE C150 SCR, which can surge up to 1200...

If we know the inductance of an iron-cored coil to be 200mH, and we remove the iron core such that the core is now air, how exactly can we determine what the new inductance is with just this information? I played around with the equation for inductance, however, I could not seem to get it...

I was wondering whether an induction hob cooker would work in reverse if a hot pan is placed on the coil - so would this generate a current? I would assume not as the heat induction pan wouldn't be able to create a magnetic field in the coil?

[Solved] Estimate induced emf in the coil Homework Statement Consider a single-loop coil whose magnetic flux is given by this image: Estimate the induced emf in the coil at times near t = 0.3s, t = 0.4s and t = 0.5s This is for algebra-based physics. Homework Equations emf = -N*(change in...

Howdy folks, I'm having trouble finding a spec for bends in wound wire i.e. a coil. For example if you take the coil, say 150mm long and roll it on a flat surface and it deflects from the table in places (wiggles), how does one possibly determine what is an acceptable bend and what isn't? It...

Hi everyone, I am currently doing some experimentation with electromagnetic coils, I realize I will need a waveform amplifier for the testing using my rsr32 function generator. Could someone point me in the direction of a decently priced one?

Hi, I am trying to control a voice coil motor's force, which is directly proportional to the current through its coil. The direction of the force needs to be reversed, so I thought an H-bridge would be a good way to do it. I have read a lot about H-bridges but I am still confused about a few...

"multiplying equations" - spiral coil heat transfer Hi, I was wondering if anyone could explain to me what is meant in this article by "Multiplying equations 8 & 9". I have both equation 8 and equation 9 however I cannot seem to work out how to get equation 10...not sure if it's something...

Hi, What if the inductor coil is wound one way rather than the other. Then the circular flow of current will be clockwise in one case and anticlockwise in the other. And if the inductor is connected to an ac source, then the current will vary. Now in both the orientations, the variation...

considering this relay http://my.element14.com/durakool/dm84-2012-35-5024/power-relay-dpdt-2co-24vac-8a-pc/dp/1557207" what does contact DC voltage meant? and to energize / activate the coil i need a 24v current to do the job?

Homework Statement A coil of wire consisting of 40 rectangular loops, with width 16 cm and height 30 cm, is placed in a constant magnetic field given by B = 0.055Tx + 0.210T.z The coil is hinged to a fixed thin rod along the y-axis (along segment da in the figure) and is originally located in...

Homework Statement suppose we have a coil sitting on a desk (with radius =1), and then a spark passes by the side of it, in such a way that the magnetic flux through the coil is maximized. The coil is attached to a full wave rectifier which is connected to a very large capacitor. There is an...

I'm doing a lab write-up for physics 2. The experiment is about the title, a bar magnet being dropped through a solenoid. I have to explain four graphs that plot the change in emf (y axis) vs. time (x) axis. There are incoming and outgoing peaks on these graphs. I have to tie these results...

hi gang, Just building a seismometer I have 2 x 2.5cm disc rare Earth magnets spaced far enough apart for a coil of wire to move between them. Would you expect there to be any difference in induced voltage into a coil between 2 magnets when the magnets are orientated to attract or repel ...

Hey guys, Im trying to design a electric gear shiftier for a motor bike. Basically I require about 200N of force to change gear with a 10mm throw (in both directions). I would like to use a tube neodymium magnet. (23mm diameter 25mm high with a 5mm hole throw the centre with a N48 grade) What I...

Hey guys, Im trying to design a electric gear shiftier for a motor bike. Basically I require about 200N of force to change gear with a 10mm throw (in both directions). I would like to use a tube neodymium magnet. (23mm diameter 25mm high with a 5mm hole throw the centre with a N48 grade) What...

Hello PFs, I need to build some Helmholtz coils, and I was wondering if anybody here had suggestions on what to make the actual rims that hold the wire in a coil are generally made out of? So far its been suggested that I use bicycle rims, but even that creates a question--aluminum or steel...

It's pretty straightforward. I built a circuit to energize a coil and connected a diode in parallel to make sure the discharge won't harm the transistor. The diode is in working order, I've tested it with a multimeter and found that it has a high resistor value when forward-biased and it doesn't...

Homework Statement A solid disk of mass M and radius R is on a vertical shaft. The shaft is attached to a coil spring which exerts a linear restoring torque of magnitude C\theta, where theta is the angle measured from the static equilibrium position and C is constant. Neglect the mass of the...

How can we calculate the flux in a coil which carries a current? I am having trouble determining the field at any point inside the coil other than the center? Any help is appreciated...

I'm feeding the current in pulses via 50v 6800 mfd capacitor. Will it destroy the ignition coil instantly, or will just overheat it? It won't be for automotive use but for general high voltage experiments. As long as instant destruction is a remote possibility, it's easy enough to mitigate...

According to Faraday's laws... change in magnetic flux linking a coil induces current in the coil.., but for conduction of electrons ...there must be an electric field ! how is the electric field induced in the coil??

Homework Statement A rectangular coil with N = 2,000 turns that has a resistance of 7.90 Ohms is coplanar with a long wire which carries a current which depends on time according to I0 *exp(-t/tau), where I0 = 6.50 A and tau = 4.30 s. The rectangular loop has a width of W = 2.00 cm and length L...

So I've never gotten a straight answer as to how you calculate the resistance of a coil (or cap for that matter). I hesitate to use the term "impedance" because I've been told too many times to count that impedance is the total resistance of a circuit. My professors dance around the topic from...

Homework Statement What is the induced magentic field inside the coil? Attached image shows the coil and direction of rotation. Homework Equations Right hand rule of some sort. The Attempt at a Solution Not sure what hand rule to use to find the induced field in the coil. What...

Hi! I'm a new face here and have an easy question. I know how to calculate induced current when magnet moves through coil (it's E=BLv) but how do you calculate how much a magnet will decelerate when it goes through the coil? Will it decelarate at all? I have one of those mechanically-powered...

Homework Statement A 40 turn square coil has an area 11.0 cm2 and is rotated with an angular speed of 110.0 rads in a uniform 1.00 T magnetic field. The axis of the coil is perpendicular to the field at all times. (i.) What is the frequency of the sinusoidal voltage induced across its...

greetings, what is the difference between a wire and a coil with respect to magnetic field or in electronics?

Hi all, I'm studying computer aided design at university but i have to complete an electronics module. My knowledge is extremely basic and my lecturer 'does not have the time to go through basic physics' so i need a little help. I have been asked to... 'Design a coil which has a given...

I have to desgin an experiment for physics and and my research question is going to be: How does the cross-sectional area of the solenoid’s coil affect the strength of its magnetic field? This is my hypothesis, my question is if you think the reasoning is valid. I believe I should find it is...

I am making a coil gun for my physics project and I am wondering if it is better to use a thick wire or a thin wire for the coiling process. (both are magnetic wire) Also, when I coil it, am I supposed to make only one layer of coil as opposed to several layers? Thanks in advance.

Is anyone familiar with the Tesla magnatic fueless generator and the associated Tesla coil set up, I have some basic engineering questions before making the coil eg. can three 200V 1uf capacitors in series be used instead of one 600V 1uf capacitor (which is difficult and expensive to purchase)?

I'm wrestling with the notion that a small coil of wire in a planar flat spiral can be a real tuned antenna. The fact that the coil is only three turns and about the diameter of a quarter further irritates my ability to understand how such a simple thing can be viewed as a real antenna. The...