Recent content by stephen163

I don't think that explanation is particularly useful. It's a lot more complicated than that. The voltage is between the forward conductor and the return conductors. To a good approximation, no voltage along the conductor is necessary. The signal propagates as a wave and maxwell's equations that...

But my question is WHY does voltage propagate down the line. I know transmission line theory quite well, I know it takes time to propagate and I know there is a distributed L and C in the transmission line model. What I'm stuck on it why the voltage, i.e., the charge between the 2 conductors...

The point is there is no potential difference between one end of the conductor and the other. The potential difference is between the conductors, and even if the 2 conductors were not connected at the load, a wave would still travel down the line. Thnk about a HV transmission system. 2...

Using the telegrapher equations and the distributed element model can explain the CHANGE in the phase and amplitude of V and I as it travels down a line, but it doesn't tell me how the wave propagates. A lot of people resort to saying things like 'the voltage charges up the capacitor and then it...

In a transmission line, what makes the current flow? I understand that the line is excited by an AC voltage at one end. This sets up a changing electric field between the conductors and therefore a changing magnetic field. However, there is no voltage along the line, so what makes the current...

I believe Newton's cradle is a misleading analogy. The situation may be complicated at a quantum level, but on a macroscopic level, I don't see how it's any more complicated than a sea of electrons drifting together under the influence of an applied electric field. The electric field travels at...

The point I don't accept - and this is a point that is paraded as fact on many websites and textbooks, is that speed of light propagation of electricity is somehow just the same as Newton's cradle. If you think about it, an electron at any point in a wire will experience the same electric...

When some people try to explain current flow in a circuit, their explanation troubles me. They say that electrons 'push against each other' and this is responsible for the close to speed of light propagation even when the electrons themselves are moving very slow. My view is that though...

Obviously, DC won't radiate. A transmission line which is excited by a series alternating voltage and one end shorted would behave like an antenna - why wouldn't it? After all, it isn't a transmission line any more, it is a simple circuit.

Yes, it would radiate like an antenna. You can make a transmission line behave like this by putting the voltage source in series. Exciting the 2 conductors in differential mode will allow it to behave like a TEM transmission line. Superconducting power lines with very low resistance should then...

I am talking about a SINGLE wire. A transmission line requires 2 or more conductors. Imagine a single wire with no return path for current. If you have a battery and a closed loop for current flow, it is easy to understand that there is a constant electric field within the conductor acting...

If you connected a DC or AC source to the end of an single, infinitely long, straight wire suspended in free space (separated from anything), would propagation occur along the line?

I'm looking at using different types of material (e.g., nanochrystalline, amorphous, electrical steel) with different geometries and air gaps. I also want to assess the coupling at different frequencies (in the kHz range), so it becomes a more involved problem than just working out the...

I want to model a toroidal transformer with a given permeability and saturation flux density. Specifically, I want to model a split core toroid clipped onto a power line, to simulate coupling, so it is really a one turn secondary and a primary of arbitrary turns. Any software packages out...

I need to obtain a toroid for inductive coupling to medium voltage power lines. The frequencies to be coupled are between 10 kHz and 900 kHz. Bear in mind that at power frequency (50 Hz), the current will be high (up to 100 Amps). Anyone have any idea on a magnetic material that can achieve...