# Tag Info

### Can the frequency of voltage change throughout a circuit?

In a Linear, Time-Invariant (LTI) system, the frequency will not change. An excitation at 2 Hz will lead to effects at 2 Hz throughout the system. Circuits consisting only of linear, time-invariant ...
• 13.7k
Accepted

### Is the resistive component of impedance the same as DC resistance for a given component?

In an ideal world where resistances do not depend on frequency, yes, but in the real world, no. The real part of an impedance at any non-zero frequency (the AC resistance) does not coincide with the ...

### Is the resistive component of impedance the same as DC resistance for a given component?

will the resistance component of that impedance, ZcosΦ, be the same as the resistance when that same component is in a DC circuit with the same voltage, R=V/I? No, probably not in anything other than ...
• 380k

### When do we add a resistor between the inverting and non-inverting terminal of an op-amp

It's called "forcing the noise gain". That resistor effectively reduces the feedback fraction (beta) which reduces the loop gain (beta * Aol), improving stability margins. The closed loop ...
• 4,980

### Can the frequency of voltage change throughout a circuit?

Ideal resistors, inductors, and capacitors are linear components. So via the superposition property of linearity, and therefore superposition of frequencies (like Fourier), no new frequencies will be ...
• 46.4k

### How to measure output impedance of this circuit?

Attach the typical load to the output. Measure the output amplitude. Now decrease the load impedance by (for example) 10%, and measure again. If you need to be able to drive a wide range of load ...
• 121k

### Meaning of "impedance looking into..."?

Impedance is defined as Z=U/I, so to define it you need two nets through which you define a current flowing and across which you define a voltage. "Looking into" is kind of a shorthand to ...
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### Is the resistive component of impedance the same as DC resistance for a given component?

Not always. The real component of impedance just represents real, permanent power loss (not energy removed from the circuit and stored to be eventually released back into the circuit in the future). ...
• 46.4k

### Reduce Resistance and Heat Dissipation in a fuse

Fuse losses are often specified rather than resistance for larger fuses. For example this 200A fuse (with your required 100kA break capacity) has a 32W loss at rated RMS current, so the resistance is ...
• 328k

### When do we add a resistor between the inverting and non-inverting terminal of an op-amp

Generally, the inputs will have some resistance feeding them, so the resistor shown has the effect of simply reducing the input voltage seen by the amp. This has the effect of slowing the amp's output ...
• 1,035
Accepted

### Design challenges with high input impedance amplifier

You are on right track you just need to go one step further, that is make your own instrumentation amplifier out of 3 opamps. 2 of them have high input impedance and 1 is fully differential. The input ...
• 423
1 vote

### Current sensing using transimpedance amplifier

That won't work beyond the GBW of the amplifier and certainly not with NFB at 10GHz. learn Transmission Line Theory and physical impedance characteristics of 3D metal structures like L/C ratios and LC ...
1 vote

### How is the characteristic impedance of a transmission line sensed according to this paper?

When you send a signal into a transmission line, the current initially drawn by the line depends only on the signal voltage and the line's impedance. The line initially appears like a resistor, with ...
• 140k
1 vote

### When do we add a resistor between the inverting and non-inverting terminal of an op-amp

As an example of such use of resistor, I compare it with the use of capacitor for reducing "bandwidth". However, this is a function of the specs of the opamp. NB: sometimes, a capacitor is ...
• 3,916
1 vote
Accepted

### Are T-parameters the same thing as ABCD parameters?

Both T parameters and ABCD parameters allow you to analyse a cascade by simply multiplying matrices for each component part. They are different, but in general allow you to achieve the same thing, ...
• 1,744
1 vote

### Are T-parameters the same thing as ABCD parameters?

As far as I know they are simply a mathematical artifact to help in calculation. They carry the same information as the S parameter, which are important since they are easy to measure (for some ...
• 7,225
1 vote
Accepted

### Can admittance (Y) be used to calculate reactance when L and C values are calculated from the Y12 and Y11 parameters like normal as X=XL-XC?

S parameters, Y parameters, and all the other parameters, are model-free. They just represent the voltages and currents at the device ports. At any one frequency, a one port measurement has two ...
• 140k
1 vote

### Is the resistive component of impedance the same as DC resistance for a given component?

Is the resistive component of impedance the same as DC resistance for a given component? In general NO, but YES for Conductors, e.g. Inductors always DC resistance in datasheets as DCR. For ...
1 vote

### How would you find the impedance of this circuit?

Is there a way this circuit can be redrawn to have more of an intuitive layout? Yes there is: - simulate this circuit – Schematic created using CircuitLab This redraw allows you to see what ...
• 380k
1 vote
Accepted

### A non-inductive behavior in low frequency of an inductor

As an example, here is some kind of modelling ... You can see the effect of coupling. Sorry, no core losses taken into account in this case. Other inductor model needed.
• 3,916
1 vote

### Impedance Divider Network

Exactly, $$Z_{C1}$$ has no effect at all, as it is parallel to the voltage source and the voltage divider branch. You could treat them like resistances, given the linear property of this circuit, ...
1 vote

### Meaning of "impedance looking into..."?

Let's try this. Rather than thinking of the circuit as having an output at A, consider this circuit simulate this circuit – Schematic created using CircuitLab and ask, "What will the AC at ...
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