# Tagged Questions

Math or Mathematics is the abstract study of topics such as quantity (numbers), structure, space, and change.

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### Affine Non Autonomous State Space system

Normally We all know the state space model of the the form der(x) = F*x(t)+G*u(t) y = H*x(t)+J*u(t). However I came across a state space model which has the following form der(x) = F*x(t)+G*u(t) + ...
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### How does one compute the ripple currents seen by a boost converter output capacitor?

Suppose one is designing a boost converter, with a known maximum current load, and a known inductance: The ripple current seen by the output capacitor is critical. If that current is too high, the ...
1answer
743 views

### How does one compute the ripple currents seen by a rectifier filter capacitor?

Suppose one is designing a full-wave rectifier bridge, with a known maximum current load, and a known input inductance. Assume three-phase for this example, though the same concept applies to ...
3answers
235 views

### Does LTSpice support a “Remainder” or “Modulus” function?

I am trying to change a parameter in LT Spice with if statements and make it change on whether a different value is even or odd. Mathematically, this would be easy with a remainder or modulous ...
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### Are descriptor systems necessarily non-minimal?

I am working with model order reduction for electrical circuits. I am looking to implement Balanced Truncation as a form of model reduction. The systems I work with are definitely stable, but not ...
2answers
226 views

### How to mathematically determine the frequency of a tone based on components being used

My REAL question is how to choose the right components if you want a specific frequency spit out from a 555. In my particular case I want a potentiometer to control an output frequency from 16Hz to ...
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220 views

### Addition and subtraction in digital electronics

Why is it that addition of the 2's complement is an efficient method of subtracting? Does this simplify the circuit?
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### How fast does a 64-bit multiply or divide execute on an FPGA?

When using a regular FPGA such as Xilinx Spartan 3 or Virtex 5, how many cycles does a double-precision floating-point 64-bit multiplication or division take to execute? As far as I understand, the ...
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419 views

### Using a Laplace transform to figure something out in a DC circuit

When would you use a Laplace transform to figure something out about a circuit? Does the circuit have to have capacitors?
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### How would a Laplace transform be useful in analyzing this circuit?

I'm expecting a midterm question about the circuit below that involves the equation t=RC and using a Laplace transform. We won't actually be using differential equations. Memorizing a certain equation ...
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### SQNR of 16 bit signed multiplication with MSB storing in 16 bits

I'm trying to figure out what the SQNR is if I multiply 2 16-bit signed integer values and store the result as a 16-bit signed integer, dropping the least significant bits. For example: a (16 bit ...
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181 views

### What “rule of thumb” to use for mapping -3dB frequency to ideal response for 2nd order Sallen-Key?

For a first order passive filter (RC circuit), we often reach for a the familiar 10X rule. If the -3dB corner frequency is f, then "ideal" frequency response starts at 10f. What similar factor can be ...
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99 views

### Calculating run time for a device with variable current draw

I recently built a small microcontroller-based project for a friend that consumed different amounts of current at different times. I wanted to calculate the run time for a given battery type (but ...
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### Can you sum and difference in a single op-amp?

I want to take two independent differential signals (audio line inputs with unknown properties which may be present or not), remove any common-mode noise from each of them (they could each have ...
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### Math: Temperature tranform equation [closed]

While reading the MAX6605 datasheet, which is an analog temperature sensor, I ran across the following: The temperature-to-voltage transfer function has an approximately linear positive slope and ...
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425 views

### Calculating dBFs from RSSI

I have RSSI calculated as vector magnitude. $$RSSI = \sqrt{I^{2}+Q^{2}}$$ I and Q are 12bit values from ADC. Is there a way to convert RSSI to dBFs and how it is done?
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801 views

### What is the function of a Fourier Series?

What is a Fourier Series? What it is used for?
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298 views

### Why am I not arriving to non-inverting amplifier equation?

I was trying to derive the non-inverting amplifier equation and I ran into some trouble deriving it. By making the voltage between R1 and R2 VRef, I set my equation to Vin - VRef = Vout. Because ...
5answers
723 views

### Advanced Math in day to day Electronics? [closed]

So i've been watching the MIT 6.002x Classes and they are really interesting, I feel like i've got a good grasp of Circuits and the Basics (I graduated with a CS degree...but EE appeals to me too). ...
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### Block Diagrams with offset in control theory

I have an equation in the form $$y = mx+b$$. In block diagram form, I could draw this with a proportional gain block and a summer. I was wondering if there are some clever tricks where I can make ...
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191 views

### How can I do a frequency sweep when the frequency modulation index is dependent on the amplitude?

I have a question regarding frequency modulation and the modulation index. I know that the modulation index can be given by $$\beta = \frac{\Delta \omega}{\omega_m}$$ So the value of the ...