Questions tagged [coil]

A coil is an electrical conductor such as a wire in the shape of a coil, spiral or helix. Coils are used in applications where electric currents interact with magnetic fields, in devices such as inductors, electromagnets, transformers, and sensor coils.

An electromagnetic coil is a device comprising two distinct elements: a conductor and a core. The conductor is most commonly made from solid copper wire, which is wrapped around a core. Each time the wire is looped around the core, it is called a turn. Multiple turns are considered to be a coil.

The most common use of an electromagnetic coil is that of an inductor that stores energy within its magnetic field. Considered a passive electrical component, an inductor has no gain and cannot control the directional flow of the energy. The way an inductor harnesses energy is by the electric current passing through its body.

700 questions
5
votes
1 answer

Calculate coil impedance, inductance and resistance

The voltage over a coil is u(t)=100⋅sin(100t+pi/3) V and current through it i(t)=20⋅sin(100t). First off let's calculate the impedance, I'm quite sure I'm correct on this one. This is where I get stuck because now I need to calculate resistance…
Gripen
  • 167
  • 9
2
votes
4 answers

Where to have an electromagnetic coil made?

I have an antique clock that I am trying to get up and running. I'm told that it needs a new coil, as power is getting to the coil, but not through it. I'm struggling to find anyone to make a new coil/repair the old one as it too small a job for the…
2
votes
2 answers

Driving electromagnetic coil "out of spec"

I'm designing automatic watering system for my garden. I've bought these bistable electromagnetic valves. But specs are somewhat confusing: voltage range is 3.6-6 V, current consumption is 200-300 mA, coil resistance is approx 9 Ohms. I've measured…
Drobot Viktor
  • 257
  • 1
  • 7
1
vote
2 answers

How to drive riding lawn mower ignition coil?

I have a ignition coil I scavenged from a dead lawn mower and would like to play around with it. The problem though is it is not like a standard car ignition coil and I have no idea how to drive it. It seems like a magnet in the engine spins…
Nate
  • 11
  • 2
1
vote
2 answers

Coil inductance measurement

I want to obtain the inductance value from a coil. To do so i'm using a basic RL circuit as follows. The function generator has a 50 Ω internal resistance and the coil resistance is 87 Ω. The coil has a small sticker with it's value (6,24 mH)…
PJC
  • 25
  • 7
1
vote
1 answer

Magnetic coil failure

I got some very small coil (OD<1cm). They are made of copper wires at 46AWG. By applying a changing voltage(sine wave), I can get a very small magnetic field (such I could attract some small magnets). The matter is the coil fail very easily. I have…
MW_hk
  • 255
  • 1
  • 5
  • 13
0
votes
3 answers

Isolating concentric coils

Due to space constraint, I wanted to set up two coils over each other. (So one coil is wound on a spool, then I want to wind the other coil over it (not necessarily touching it.)) However as it will cause them to effect each other (as it behaves…
Sherby
  • 2,356
  • 6
  • 27
  • 46
0
votes
4 answers

Is it possible to store energy in an air coil?

I just want to know if an air coil can store energy. Does it necessarily need to have a core material and air gap to store energy?
exolune
  • 59
  • 2
0
votes
1 answer

Practical inductor result can I get in PCB layout

I have a physical coil inductor of 1 mm width and 10 cm length. It has 10 spiral wound turns. Its inductance is 1.05 uH. Can I get the same result from a PCB layout?
Vishnu
  • 1
0
votes
0 answers

Coil magnetic field strength is much lower than calculated value

I wound my own coil (air-core) using 22AWG enameled magnet wire. The diameter is 3cm and the length is 1cm. I wound 36 loops which resulted in 3 layers of wire on the spool. I am pulsing current too quickly to use my ammeter so I measured the…
0
votes
1 answer

How do I build a 2 mH inductor coil (with air gap) from a microwave oven transformer?

I am converting the voltage on a kiln from AC to DC. The kiln (48 A, 240 V) holds two crucibles for melting colored glass. When I gather glass using a steel pipe for glassblowing, I receive a strong shock if I am simultaneously grounded. I theorize…
0
votes
1 answer

what exactly is this component and what the marking on it means?

my car stereo (audi rns-e) showed a blank white screen, took it apart and the outer part of this component was rattling around. i want to replace it to see if it was the problem, but i dont really know what this actually is. looks like a coil or…
konrad
  • 1
0
votes
1 answer

What inductors are used to reduce coil whine?

I was wondering about this after two years of heavy coil whine from a pS4Pro power supply. It looks like the worst designed PSU ever made, and I'm aware some modern ATX PSUs have reduced coil whine to close to zero by using inductors. What kind of…
noiztmaker
  • 23
  • 4
0
votes
0 answers

How to pass high current through photo interrupter sensor

I am currently trying to build a coil gun that uses a high current to create a strong electromagnetic attraction. I'm using a photointerrupter sensor to detect when the projectile begins to leave the coil and want to use it as a switch. If nothing…
Marco T
  • 3
  • 2
0
votes
0 answers

LVIT: w/ coil "spoiler": how much impact on inductance and Q

I've been reading about a linear displacement sensor known as a Linear Variable Inductance Transducer (LVIT). This uses a movable conductive shield over a coil to modify the inductance. The shield is referred to as a "spoiler". Note the spoiler…
Burt_Harris
  • 398
  • 2
  • 14
1
2