Signal Definition and 989 Threads

When I put an o-scope probe into my (120VAC) wall socket, with no ground (reference) attached, just a single wire, I get a perfect 60 Hz sine wave, with about 35Vrms magnitude. When I plug the o-scope probe into the socket with the ground attached appropriately to the return of the same...

Hey, all. I've run into a real problem with my control circuit. The circuit is simple enough. I am designing a controller for a servovalve that looks something like this.The frustrating thing is, it works in one direction, but when I flip the switch to reverse polarity, it stops working...

i have a signal y(t).I have sampled my signal at T0,so i got y(nT0).I multiply this signal with a random number r uniformly distributed in the range 0.95-1.05.Now z(t)=r*y(nT0).How to get z(t) mathematically?

Homework Statement Solvinf the unit time step equation mathematically. Homework Equations x(t) = u(t+1) - 2u(t) + u(t-1) The Attempt at a Solution How can i solve this signal mathemtically :( and using plotted signals , i couldn't understand, here is my approach and I'm...

Considering the ADF (automatic direction finding) of an aircraft. Assuming the transmitting aerial is vertically polarised i.e mag field lies in the horizontal plane. And it is the magnetic field of the incoming signal that induces current in the loop. And what would be the rotating plane of...

it seems like a pretty commonly used computational/mathematical method in analyzing experimental data, such as voltage signals

How many out there have hearing problems? Can you suggest a way to add heads up display to a noisy sports car? Old sports car I am constructing uses one light bulb [on each side, at the rear] to indicate 1. turnsignal 2. braking 3. nighttime driving. I figure, if I can create a separated...

I recently simulated a parallel resonant tank circuit on multisim. I put an oscope across the tank circuit and I get an AC signal, but what interests me is that it is amplitude modulated. The oscillations slowly build up in amplitude, hit a peak and then die back down. I think that the...

How do I determine what percentage of a signal is reflected and what percentage goes through a wall. I know that I am over simplifying things, but for the purpose of my project I need a simple answer to this problem. What parameters are needed for the solution and how do we calculate this...

Hi everyone I really don't know how to start this questions, please help me. Thank you in advance for all your help & support. Determine if each of the following CT signals is periodic. If periodic find it period. a) x(t)=2sin(10\pit-30degrees) b) x(t) = 2 cos (\sqrt2\pit) c)x(t) = 2...

Homework Statement Suppose we are given the following information about a continuous-time periodic signal with period 3 and Fourier coefficients a_{k} 1. a_{k} = a_{k+2} 2. a_{k} = a_{-k} 3. \int_{-0.5}^{0.5}x(t)dt = 1 4. \int_{0.5}^{1.5}x(t)dt = 2 Determine x(t) Homework Equations if x(t)...

has a transfer characteristic |H(f) given in the link below. The transmission is at maximum error-free rate of 4,800 bps. Compute the SNR (signal-to-noise-ratio) at the channel output. Does the output signal suffer from any distortion? http://imageshack.us/photo/my-images/263/79465468.jpg/...

hey there.. i just don't know how to start answering this question.. please help me get through this question.. thanks.. A channel has amplitude response and phase shift shown in the link below. State what type of distortion is imposed for each of the inputs given below: i) (cos 20 pi t) +...

Hi guys, I'm a bit embarassed that my first post here is in this section, but I'm taking a Elec. Eng. course abroad, which is out of my confort zone (i'm majoring in automotive eng.) and I'm trying to solve a few model problems. This one in particular deals with the DFT. Anyway:Homework...

I am using an FFT package (GFT) to analyze a signal from a pressure sensor. I am unsure of the results I am getting, so I decided to try to verify the FFT package using a known input. I am using a signal generator to produce a sine wave of +/- 5V @ 5 and 100 Hz. When I run the FFT on the...

Hi, I have trouble understanding these concepts http://cnx.org/content/m10055/latest/ if I understand is correctly, the energy is basically a number telling us how "big" a signal is while the power, is used for signals that don't decay, thus give us a infinite amount of energy, but still we...

I have a set of discrete data that I have performed multiple Gaussian smoothing filters on to act as a low-pass filter. What I have come up with is something like this: http://i51.tinypic.com/152kieg.jpg I'm using findpeaks() in matlab, and a peak that I want is being taken over by the...

Hello. I've made a lab experiment of interference and with a CCD camera photographed fringe pattern which one can understand as a periodic signal. My question is: When I apply an FFT to the image is there any limit to the amplitude information I may get from lower frequencies? I read in the...

I don't understand why cells have thousands of different receptors which then exert their effects through the same few intracellular pathways. For example, I know that many different neuromodulators which act through metabotropbic receptors exert their effects on cAMP, which then exerts effects...

Hey guys, first of all this is my first post in here so I hope I am doing the procedure of asking questions the right way. My problem is; I want to add two signals and generate a 1.5 period of sinusoidal wave only at the beginnig. It will be a sine wave starting at t=0 and ends at t=1.5T...

Homework Statement Consider the signal x(t)=cos(4t)+cos(5t)+cos(6t), and the SLIT with impulse response: h(t)=\begin{cases} 1, & \mbox{if } |t|<T \\ 0, & \mbox{if } |t|>T \end{cases} For what value of T is the output of the system y(t) equal to Acos(4t)+Bcos(5t), when x(t) is the...

Hello, Recently I've been very interested into going into signal processing. I have a couple questions... 1) Exactly how much math do you need? Do you need anything past PDE's? 2) How are job prospects for this field? 3) Are you required to do any hands-on stuff? (e.g. build...

Hi I have a practical problem/question: I need to wire 2 PLC-s for communications (RS485 signal) and I am planning to use shielded twisted pair cable (Cat5 FTP). The signal cables are quite short - approx. 6 m. One possible problem that could arise: between the 2 PLC-s, there is a...

I'm trying to plot the PSD of a signal, I did it using the fft function but I was wondering if there is another direct method?

Homework Statement y[n] = x[-n] + 2Is this signal linear? for signal to be linear, y3[n] = a*y1[n] + b*y2[n] IF x3[n] = a*x1[n] + b*x2[n] -------------------------------------------------------------- x1[n] -> y1[n] = x1[-n] + 2 x2[n] -> y2[n] = x2[-n] + 2 x3[n] = a*x1[n] + b*x2[n] y3[n] =...

If I know the: Frequency Effective Radiated Power Height Above Average Terrain Radiation Center Above Mean Sea Level Radiation Center Above Ground Level of a radio signal / tower, is there a way to determine the rough range of the radio signal?

Hi Does anyone know what a 2-wire dc polarity reversing voltage signal is? I have never heard of this type of signal before. I have gone insane trying to google it but to no avail. Any sort of help will be much appreciated.

Homework Statement For radio transmission in free space, signal power is reduced in proportion to the square of the distance from the source, whereas in wire transmission, the attenuation is a fixed number of dB per kilometer. The Attempt at a Solution this is not the whole problem...

When a signal from an accelerometer is being filtered should a high or low pass filter be used? I am trying to isolate a particular instance in which we suddenly stopped but I am not sure wether a high or low pass would isolate this.

First off let me just say that I am not a EE and have never taken a signals course before though I am sort of willingly having to over come this for a work project. I am working with a sensor that is giving me a noisy signal and I am trying to figure out if there is any usable data in my data...

Hi Everyone, below I've attached an embarrassing drawing of a circuit with switches. Signal enters from the left side at both line. Given that each switch has a 50% chance of being open, what is the probability of signal reaching the end of the circuit(far right)? The answer that I got...

Hi, I am not very good at electronic circuit,, I just want to ask: How to amplify voltage signal resulted by piezoelectric? Since the voltage resulted by this material is very small,, thank you for any help

wave signal, bit-rate help! Homework Statement Suppose we use QAM, in which the phases can be resolved only down to difference of π/12, π = pie symbol. And amplitudes down to differences of 1/23 of the range between the minimum and maximum amplitudes. Assuming that 1/9 of the bits are not...

Homework Statement I am trying to construct a Mathematica notebook that will be able to import sound in the form of a .wmv file and then create the frequency spectrum for a given time interval. Homework Equations I managed to complete this part, though I am trying to figure out: a)...

A singal x(t) is bandlimited to B Hz. Show that that the signal x^{n}(t) is bandlimited to nB Hz. I have no idee on how to adress this problem. Can get some help?

Refer to the delayed choice quantum eraser (DCQE) ...for example the kim paper http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser" i have a few questions, to understand this better, 1. Once the signal photon has been detected at D0, can the path of idler photon be...

I believe its possbile but wanted to ask if its possible to light a single LED light by and RF signal if its strong enough. I know there are LED's that are as low as 3 milliwatt that could work. Thanks in advance.

Dear all I am slightly confused over the definitions of digital and analogue signals. Is a digital signal discrete in time AND voltage or just discrete in voltage. For example, could a square wave that is continuous in time, but has discrete voltage levels be considered a digital signal...

Dear Experts, I am looking for some rf vhf diodes. could you recommend a particular model for me? I am quite new to this diode. Are these synonymously called microwave diode / MOSFET / rectifiers / field effect transistor? I am confused what should be the right diode to amplify gsm...

Hello , I'm working on a project where I'm using a wii remote to track an infra red LED. The wii remote is connected to the computer via bluetooth. I've no experience with dealing with the wii before. My questions are: 1- How can I read the data send by the wii remote to the computer ...

I have a sinusoidal AC voltage with roughly Vrms = 50mV. I wanted to amplify with a non-inverting amplifier circuit with the LM358 op-amp. I used resistors of 100ohm and 10kohm for a theoretical gain of 100x. However, my output signal is rectified so that only the positive half of the signal...

I am looking for ideas on how to make a motor run for a certain period of time, but I do not have much experience in circuits. The design is to have the system start at the push of a button. The design can be mechanical or electrical. As of now I am wondering if there is a device that will...

hello, this is not a homework question, but i can't understand something, we're currently learning about signals, bandwidth, transfer rate etc, but i don't understand something i can understand that when we talk we create signals with a specific frequency, then this signal travels through...

Homework Statement Consider \phi_{FM}(t) = Acos[2\pif_{c}t + k_{f}\int^{t}_{-\infty}m(\alpha)d\alpha] where the message signal is m(t) = 10\picos(2\pif_{0}t) with f_{0} = 4kHz and the carrier is given by c(t) = 10cos(2\pif_{c}t) with f_{c} = 10MHz. The bandwidth of [tex]\phi_{FM}, using...

hello fine people, some days back saw a signal generator. it has buttons labelled as 1hz, 10hhz,1k,2k,5k,etc. it does not has its own display. you can connect it to some external device for display. me do not have access to it now. it had a dial which could be turn with markings 0.5,2.5,0.1...

Homework Statement I have the task of finding the first peak (percussion peak) per each period of a ICP signal. I was told to filter the signal to get rid of some noise and a dc offset, find the percussion peak indicies and then plot those back onto the original signal. I am unable to only...

Hi, How to check my transmitter signal power? I have found my transmitter in my friend shed and needs some new output transistors. But i don't know what is the power of my transmitter and if it worth to repair it. There is the RF board and also a encoder. There is also an amp so i don't know...

Homework Statement given this discrete time signal x[n] = u[n] - u[n-6] find for which n the even part of x is 0The Attempt at a Solution the even part is x' = 1/2(x[n] + x[-n]) = 1/2(u[n] - u[n-6] + u[-n] - u[6-n]) now i find that u[n] + u[-n] is 2 for n = 0 and 1 for n != 0 u[n-6] +...

small signal equivalent circuit model for the HJFET?? hello all, Looking for small signal equivalent circuit model for the HJFET. can someone knows ? Please help me it's urgent... Thank you in advance, N

Hi guys, I am designing an OFDM system and then upconverted at 1 GHz. Now I have an idea of implementing TDM for this 1 GHz signal. Is it possible, please explain from theoretical point of view and if possible, please help from MATLAB perspective. Thank you very much,