14 votes

Inductor as insulator?

If an inductor were subjected to a very high frequency, would it be possible for it to behave close to an insulator Yes. Inductors are used widely in RF circuits to block RF signals while allowing DC ...
The Photon's user avatar
  • 129k
7 votes

Inductor as insulator?

Reactance isn't resistivity, but yes, this is a common technique. The term is "RF choke".
John Doty's user avatar
  • 3,894
7 votes

How do buck regulator modules with integrated inductors manage to be so small?

There are some hints in TI patents such as this one. Looks like most of the volume of the converter is the inductor. They need a certain volume of ferrite and more space for the copper winding to ...
Spehro Pefhany's user avatar
7 votes
Accepted

How do buck regulator modules with integrated inductors manage to be so small?

They just used a small one. The Coilcraft XGL4025-331MEC is a 330nH inductor with a 4mm x 4mm footprint and 2.5mm height, for example. It can handle 20A with a 40°C temperature rise. Its inductance ...
Jonathan S.'s user avatar
  • 17.8k
5 votes

Why use a loopstick rather than a choke for MW radio frequency reception?

That coil serves two purposes: antenna and resonator (the resonator may require an associated capacitor). A choke is a terrible antenna, but may have lighter weight than a loopstick's ferrite. Andy's ...
glen_geek's user avatar
  • 25.4k
5 votes

Multiple resonance frequencies of common-mode choke

From the datasheet: they show a pair of two-layer windings. It's not clear how exactly they wired it for the test -- exact pinning, orientation, and even nearby materials, are critical at such ...
Tim Williams's user avatar
  • 32.1k
5 votes

Multiple resonance frequencies of common-mode choke

The model is just a model, and a simple one, maybe good up to the first resonating frequency, enough to maybe characterize the performance up to the rated frequency it is still useful. In real world, ...
Justme's user avatar
  • 144k
5 votes
Accepted

Inductor as insulator?

Looking for imaginative explanations Your question is interesting and thought provoking. So I suggest we forget for a moment the traditional boring textbook explanations and try to answer it with only ...
Circuit fantasist's user avatar
4 votes

Inductor as insulator?

An inductor gives "inertia" to current. When a voltage is applied across an inductor, current gradually starts flowing. When you want it to stop flowing, you have to apply the opposite ...
user253751's user avatar
  • 12.4k
4 votes
Accepted

Inductor saturation vs RMS current

"Saturation current" is defined as the DC current that causes the inductance to drop by some percentage X%. So for every value of X% there is a "saturation current" specification. ...
bobflux's user avatar
  • 75.8k
3 votes

Multiple resonance frequencies of common-mode choke

Transistor models becoming less resembling subcircuits and more like fitted approximations, models of magnetics follow suit. Wurth's model of 744830017132 does not show high-frequency peaks of the ...
V.V.T's user avatar
  • 4,114
2 votes

Parallel resistor across inductor practical model - switching converter

The equations apply for a minimum of 100kHz frequency, and frequency is in Hz, so Rvar2 would be a minimum of about 84Ω. At that low a frequency the reactance of the 1.5uH inductance is <1Ω. If you ...
Spehro Pefhany's user avatar
2 votes
Accepted

Why do loopsticks and chokes receive RFs equally well?

That "long wire" is electrically short, and almost all the field around it is electric. Additionally, you aren't measuring radiation, you're in the near field where electric and magnetic ...
Tim Williams's user avatar
  • 32.1k
2 votes
Accepted

Why use a loopstick rather than a choke for MW radio frequency reception?

why do medium wave (AM) radios use a ferrite rod rather than a choke to tune into radio stations? For long/medium wave reception what "we" want is a diameter that is as large as is possible....
Andy aka's user avatar
  • 453k
2 votes
Accepted

PCB layout for inductors

Distance affects the coupling coefficient between inductors. Most generally, one can consider all inductors coupled, that coupling given by a matrix of coupling factors, from each one to every other. ...
Tim Williams's user avatar
  • 32.1k
1 vote

Inductor as insulator?

IRL, an inductor will have a self resonant frequency SRF. From DC to, say, one decade below the SRF its impedance will rise pretty much in proportion to frequency. From one decade above, impedance is ...
greybeard's user avatar
  • 1,778
1 vote

Cause of Current Spikes at Zero Crossing in LC Circuit Connected to 50Hz Mains

The question then is: What could be causing these large current spikes at the zero crossing? It looks like inductor core saturation. A full specification of the inductor is needed to confirm this. ...
Andy aka's user avatar
  • 453k
1 vote
Accepted

Ferrite bead parameters clarifications required

135.6dBµV is approx. 6.026V. It is not a factor, it is a unit. It is surely not a typo: 135dB is a massively larger factor than the 5.91 impedance ratio in question. They are not discussing any ...
Tim Williams's user avatar
  • 32.1k
1 vote
Accepted

Would the induced current depend on the number of turns?

Voltage is induced; current only flows if there is a load on the secondary and that is not clear from your picture. The device marked "G" could be a galvanometer and that does measure ...
Andy aka's user avatar
  • 453k
1 vote
Accepted

What type of galvanometer is in this picture?

That appears to be an astatic galvanometer in the drawing of Faraday's demonstration of the law of induction. In an astatic galvanometer, there's a support (the two "posts") from which a ...
JRE's user avatar
  • 71k
1 vote

Where does the negative inductor current go during CCM at no load in synchronous converters?

True. What you get is a bi-directional converter, the power is transferred from higher to lower potential regarding the duty cycle setpoint. In a no load condition you'll get a kind of reactive power -...
Marko Buršič's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible