# Recent content by courteous

1. ### How to get (frequency response) from this [difference equation]?

I haven't made any progress on this ... anybody help me out, please?
2. ### How to get (frequency response) from this [difference equation]?

I'd appreciate (any) help. Continuing from 1st post: \cdots = \left[ x(k-2K+2) + 2x(k-2K+3) + \cdots + (K-1)x(k-K+1) + \cdots + x(k) \right] Applying Z-transform, we get X(z) \left[ z^{-2K+2} + 2z^{-2K+3} + \cdots + (K-1)z^{-K+1} + \cdots + 1 \right] So, the transfer function H(z) of the whole...
3. ### How to get (frequency response) from this [difference equation]?

Homework Statement Given this difference equation y(k) (of a bandpass FIR filter) ... y(k) = \frac{1}{K^2} \sum_{m = k-K+1}^k \; \sum_{n = m-K+1}^m x(n) - \frac{1}{L^2} \sum_{m = k-L+1}^k \; \sum_{n = m-L+1}^m x(n) ... how does one derive this frequency response H(f)? H(f) = \frac{1}{K^2}...
4. ### Z-transform of conjugated sequence ( a straightforward exercise)

You mean those "R" and "I" indices (as in X_R and X_I)? Say x[n]=\{..., 1-j2, 5+j, ...\}. Then, x_R[n]=\{..., 1, 5, ...\}, x_I[n]=\{..., -2, 1, ...\}, and so x[n] = x_R[n] + jx_I[n] ... also, x^*[n]=\{..., 1+j2, 5-j, ...\}. So, Z\{x[n]\} = \sum_{n=-\infty}^\infty (x_R[n] + jx_I[n]) z^{-n} =...
5. ### Z-transform of conjugated sequence ( a straightforward exercise)

That's like cat chasing its tail. :) And it also doesn't help shedding light on my 1st, erroneous attempt. Hope you'll find something out; I'll most surely post as well if I find the error.
6. ### Z-transform of conjugated sequence ( a straightforward exercise)

rude man, thank you for the nudge in the right direction: Z\{x^*[n]\} = \sum_{n=-\infty}^\infty x^*[n]z^{-n} = \sum_{n=-\infty}^\infty \left(x[n](z^*)^{-n}\right)^* = \left(\sum_{n=-\infty}^\infty x[n](z^*)^{-n}\right)^* = \left(X(z^*)\right)^* = X^*(z^*) Is this correct? If so, what did I do...
7. ### Z-transform of conjugated sequence ( a straightforward exercise)

What am I doing wrong in trying to show x^*[n] \stackrel{Z}{\leftrightarrow} X^*(z^*)?
8. ### Z-transform of conjugated sequence ( a straightforward exercise)

Z-transform of a conjugated sequence ("a straightforward" exercise) Homework Statement The conjugation property is expressed as x^*[n] \stackrel{Z}{\leftrightarrow} X^*(z^*) This property follows in a straightforward maner from the definition of the z-transform, the details of which are left...
9. ### Audio/Video DIY headphone wiring (nylon-stranded wire)

Yes, that is a mess. :) I'll clean it up and solder it. Thank you for your reassurance that I wasn't making some blunder regarding the casing behaviour.
10. ### Audio/Video DIY headphone wiring (nylon-stranded wire)

I've connected the 3 wires as shown in the picture: GROUND, GREEN, and RED (the latter 2 having their enamel removed). [PLAIN]http://img821.imageshack.us/img821/4133/nylonstranded.jpg [Broken] But I'm getting only low-volume (un-amplified) sound. Now, if I connect either GREEN or RED wire to...
11. ### Heating oil: effective or real output/yield (per liter)

The 120,400 are in btu units, right? So, from this number (presuming 86% efficiency, etc.) it follows that the NET yield is 9.28 kWh/L, correct? In short, the net yield (using an average boiler) certainly comes closer to 8 kWh/L (than to 6.5 kWh/L)? The latter number of 6.5 kWh/L was put...
12. ### Heating oil: effective or real output/yield (per liter)

Hope I'm allowed to re-ask (after almost 2 months). :smile:
13. ### Heating oil: effective or real output/yield (per liter)

Heating oil: effective or "real" output/yield (per liter) http://en.wikipedia.org/wiki/Heating_oil" [Broken] says that which is about 11 kWh/L. I was given an unbiased (but not necessarily correct) number that the effective output is about 8 kWh/L ... ... and a potentially biased number...
14. ### Given capacitance & energy dissipated, find the charge Q

Thank you Dmytry!
15. ### Given capacitance & energy dissipated, find the charge Q

I know that \overline{P}_{dissipated}\times t=\overline{P}_{supplied}\times t=3.60\text{ }mJ. How do I find V?