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11

Your example is an ethernet interface, in which the connection to the magnetics isn't directly shown. But the input TPIN pair and the output TPOUT pair are connected to transformers (the "ethernet magnetics") which send or receive pulses down the twisted pair cable to the other ethernet devices. ENC28J60 Datasheet (italic references are to the datasheet) ...

4

Here's another dodgy water analogy. simulate this circuit – Schematic created using CircuitLab Figure 1. Water tank and pipe analogies. The capacitor is like a water tanks where charge is the equivalent of water. The more water you put into the tank the higher the level will be in the tank and the higher the pressure at the outlet. The more charge ...

3

Because the datasheet says so on page 7. For C30, in the text on page 7 on the right you'll find: Each VDD and VSS pin pair should have a 0.1uF ceramic bypass capacitor (not shown in the schematic) For C33 and L3, A look in the schematic tell us it's purpose shown with additional remarks: (Note that L3 is not an inductor, but a ferite bead!) These ...

3

If the intent is simply to provide smoothing on the incoming pulses, then you do NOT want coupling (transformer action) between each winding. There is nothing to be gained from coupling the windings on a common core, and quite a lot to be lost (e.g. edges from one input creating spikes doubling the voltage on another; possibly destroying its driver). ...

2

Are Lp and Ls only due to leakage flux or they generally represent self inductances of both the coils? If yes, what about the rest of the flux, won't that induce emf? Lp and Ls are leakage inductances due to imperfect coupling between the primary and secondary. Lm is the prime mover when it comes to flux because it is the magnetization inductance: - ...

2

Why is it driven with rectified mains which equals to 375 VDC? It isn't, the rectified mains is alternately switched onto the primary of the flyback transformer (in order to store energy) then it is disconnected thus allowing most of that stored energy to be transferred to the secondary winding. U1 does that switching: - the duty cycle does in fact, like ...

2

If you want to see what the graph would look like, you need to plot some more points. You picked only 3 obvious values. We know that as the frequency increases from 0 to the resonant frequency, the magnitude of the impedance goes from infinity to 0. As the frequency increases through resonance the magnitude of the impedance goes back to infinity. To get an ...

1

Consider winding L1 and L2 on the same core and including X and Y capacitors which essentially form an EMI filter. You have two optimization goals. You'd want the components as close as possible to the switches in order to minimize parasitics that will affect switching waveforms, while making sure magnetic field produced by the inductors is small and ...

1

The way I would think of this is that the 25uF capacitor and associated 1N4148 diode form an analog of the output voltage on the mains side of the transformer. I think there's something wrong with where the zener diode and/or 3.9K resistor goes- it should inhibit the base drive of the BJT to regulate the voltage. Edit:- The red LED effectively goes on ...

1

L3 and C33 Further to the above answers note that your schematic shows an inductance of 10uH which is almost certainly wrong. As others have commented, L3 should be a ferrite bead. These are described by their impedance at a certain frequency and not their inductance. Typically they have near zero resistance to DC current but high impedance at the ...

1

I know two papers in the academic literature (IEEE) regarding measurement of Q factors in your frequency range, maybe they can help you. Both use mica or porcelain capacitors in the resonance circuit to obtain the lowest possible capacitor ESR. Zulauf and Rivas-Davila, Single-Turn Air-Core coils for High-Frequency Inductive Wireless Power Transfer The ...

1

A coil 1 uH and 30 mOhm should be measurable with a vector analyzer, at least between 1 to 10 MHz, check this image of the specs of a E5061B where I marked in orange the area that should be interesting for you: You can find the rest of the specs here here. Are you sure you did a correct de-embedding?

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RLC in whatever arrangement is a linear load. The load you describe has nonlinearities.

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As inductance falls due to the saturation of the core, with a voltage source supplying the stimulus, the rate of change of current increases proportionately. Given that Faraday’s law of induction is: - $$V = L\dfrac{di}{dt}$$ The induced voltage remains largely the same. This of course assumes that the voltage supply is capable of delivering the high ...

1

The most important property of an inductor used in an inverter circuit is the current allowed to run through it. A tiny axial inductor may have the same inductance as a radial one but most likely it has a much smaller maximum current. The inductance needed depends on the voltage spread you want to achieve. I recommend to stick to the datasheet of the ...

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Only certain meters like Keithley micro-ohmmeters that use DC pulses to measure low resistances have been affected in my experience. Meters that use DC are not affected by inductance.

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