Pulse Definition and 323 Threads

Hello everyone, I am working with my modern physics professor Dr. Parshar to make a pulse laser for my modern physics lab. I have to make an itemized expense report for the materials and all that. I need help figuring out what crystal or doped glass would be best to use, not super expensive...

As part of an EMT shift at an athletic event yesterday, I took vitals on a 45y/o female Pt who had completed the stressful event about 30 minutes prior. She is very fit and experienced in athletic competition. When I was auscultating her BP, I thought that it sounded like she was skipping some...

Hi everyone, my question is related to producing a magnetic field from an array of straight parallel wires. In my scenario, imagine the wires as being stacked into a regular array similar to the way a pile of lumber is usually stacked, so that the ends are exposed, eg: ====================...

Hi all, I am looking for circuits that control the pulse widths of digital signals and their applications. Specifically, I am looking for circuits that map and a single input pulse width x to a single output pulse width y through function f(x)=y. Thoughts?

I am not a classroom student but study what I feel like knowing. As such I don't have access to professional teachers to ask questions like this one. The reason I ask is that my daughter has epilepsy and pulsing lights cause seizures. It is my understanding that florescent lights actually...

When a pulse of light enters a denser medium(slow medium) then is there phase shift or rather it passes unshifted?

Hi I was working on delay-lines and I wanted to know if a pulse is delayed by 10 pulse lengths through a delay-lines than what is the corresponding storage bit for that delay line. Thanks

when i use this MATLAB code but with rectangular pulse shape instead of chirped pulse i didn't get the predicted output , so is there a limitation with this method in case of rectangular pulse or the MATLAB code is wrong...

I have a constant 100 uA square wave DC 10Hz signal that needs to have a pulse width of 50ms. I was reading up on using an electronic timer relay (recycle type) or a solid state relay controlled via PWM. I need some help choosing which route to take, or if there are better/easier ways to...

Hi. Can you do a computer simulation of a membrane with a standing wave(s)/node(s) with a shape of a cube or cone? It is possible on a string so why not on a membrane. Can you do a computer simulation of a spherical membrane with a standing wave(s)/node(s) with a shape of a cube or cone...

Hey, Just doing some reading on this and I'm a little confused as to why absorption produces a progressive lengthening of a seismic pulse. Quote from the textbook "In general, the effect of absorption is to produce a progressive lengthening of the seismic pulse". I understand how the...

If I make a single, short (GHZ) negative voltage pulse propagate down a long, single wire which forms a closed circuit, will there be a corresponding negative charge density in the conductor (shown as bunched-up green electrons) which propagates with the pulse?

If I send a pulse down a conducting wire, does the pulse emit an electric field?

So I'm designing a system that requires an extremely high amount of current for an extremely short pulse lengths. These pulses would be consecutively spaced at relatively large intervals from one another. I'm just wondering if there is some sort of instantaneous power limit to wires, even if the...

a wave pulse on a string has the dimension shown in figure (see attachment) the wave speed is v=1 cm/s. point o is a free end, the shape of wave at time t=3s is? someone please explain why would the answer to this question differernt if the point O was a fixed end? how does it make a difference...

Homework Statement Find increase in pulse duration for 10 fs laser pulse going through 20 mm of fused silica (\phi^{(2)})=361.626 fs^{2} for 10 mm of fused silica)Homework Equations The Attempt at a Solution I have no idea where to begin with this. Can anyone give me some equations or send me...

Does changing the amplitude or width of these pulses do anything? I'm trying to figure out how to increase a motors speed! Thanks in advance!

Homework Statement Consider the circuit below. If the source υs represents a 12-V, 100-ms-long rectangular pulse that starts at t = 0 and the element values are R1 = 6 kΩ, R2 = 2 kΩ, R3 = 4 kΩ, and C = 15 μF, determine the voltage response υ(t) for t ≥ 0. Homework Equations The...

I was wondering how can i generate 1 sec. clock pulse using flip-flops?

Homework Statement one end of a fixed string is moved transversly at a constant speed u for a time τ and is moved back to it's starting point with velocity -u during the next time interval. as a result a triangular pulse is set up and moves along the string with speed v. Calculate the...

hi all, i am interested in MRI, and i wish to know what is the scientific theory telling us that the spins will precess in phase if they were placed in an external field and exposed to a 90° RF pulse. what i know is that the nuclei will precess at the same angular frequency (or same angular...

Let's say i have a 2-3Ah LiPo RC battery pack, rated at 80C discharge, and 2C charge. It gets connected to an inductor for several milliseconds, allowing a current of about 200A to build up. Then it gets disconnected, and a set of diodes rectify the current from the inductor back into the...

Homework Statement What is the Fourier transform of a single short pulse and of a sequence of pulses? The Attempt at a Solution In class we haven't dealt with the mathematics of a Fourier transform, however my professor has simple stated that a Fourier transform is simply a equation...

Hey guys. I have been theoretically playing around with a single phase full bridge inverter. What I wanted to do was determine the waveforms for the current going through each of the components (ie. the four diodes and the four thyristors). I assumed all of them were ideal. Since I have no idea...

Hey all, new to the forum. Had a tough question that I was trying to work out about an orbiting pulsar and the doppler shifted pulse period. So, if we have a pulsar orbiting some central object in circular orbit, with a constant orbital velocity v, and a pulse period of P_0, how can we write...

Homework Statement A traveling wave pulse is shown in figure 1 below, traveling at v=6 m/s across a string. In figure 2, a short segment of the string is shown zoomed in. The angle of this string goes from θ1 = 17o to zero within a small horizontal distance Δx = 3 mm. Homework...

Hi, I am hoping someone here could help me understand the finite slope of the counting plateau in Geiger Muller Tubes. Master Knoll says this, "In real cases, the counting plateau always shows some finite slope, as shown in Fig. 7.5b. Any effect that adds a low-amplitude tail to the...

If I have a pulse generator what is the current it can output? It doesn't say in the datasheets IF I have a 5V pulse and 50ohm output impedence am I supposed to believe it outputs 100mA? And then if my load is 1ohm I should get something near 100mA through it?

Whats the way to go to apply filter to a pulse signal? I have a signal with some weak triangle pulses, positive or negative, mixed with some very slow sine wave. I've tried to illustrate this in the attachment. The sine is actually slower than it looks in the chart I don't really know how low...

Square Pulse Train Fourier Series help?? Homework Statement problem+directions below: Homework Equations ω=2\pif β=\frac{2\pi}{\lambda} The Attempt at a Solution Since the problem asks to make all time-dependent sinusoidal functions deal with x-direction, i don't think i need to...

Hi, I am trying to create a laboratory scale system, where I would like to deliver 0.25 mg of a substance which is granular and powder like consistency. I would like to pulse it for a few seconds and stop it. Can anybody tell me a good delivery mechanism for this. I have a method to disperse...

So basically, I have 4 LED strips (each rated for 12v) that I’d like to make pulse to the bass of the music, such as in this video . There are a lot of misinformed people on YouTube who just hook up their LEDs directly in parallel with the subwoofers, which doesn’t work well at all and will...

I tried to used the Crank-Nicolson method to solve the advection equation for a Gaussian pulse using the code on this page and I'm lost at trying to setup the initial values for the Gaussian which is passed as an array into the advection matrix. The Gaussian pulse is defined initial...

Hi, I need to design a circuit which gives positive half cycle of sine wave when logic 1 is given as input and negative cycle of sine wave when logic 0 is input. Please let me know how to design the same using cadence.

I've heard about pulse rifles in movies and games, but I haven't been able to understand how they work. I know that they have to do something with plasma, but they shoot pulse slugs too. Please explain how they work.

A mono-stable multivibrator is used to create a pulse in response to an external trigger. Why do you need such a complicated circuit for that? Can't we have a simple circuit with resistances and voltage sources. Whenever there is an external trigger something completes the circuit(earlier the...

why the pulse is positively chirped pulse in picture 20130320182307.png ? thank you! I also confused by another picture(20130320183049.png ).Does a femtosecond laser pulse contain a lot of wavelength?if so, a pulse should contains photons which have different energy. why we always say...

Hey, I wanted to generate a pulse of ON time of about 10-50 ns and time period of around 1us. Don't know how to get such precision ? Thanks

Hello everyone! I am studying the spreading of a pulse as it propagates in a dispersive medium, from a well known book. My problem arise when i have to solve an expression. Firstly i begin considering that a 1-dim pulse can be written as: u(x,t) = 1/2*1/√2∏* ∫A(k)*exp(ikx-iw(k)t) dk...

Homework Statement The problem and its solution are attached. Homework Equations N/A The Attempt at a Solution I'm very confused about how output pulse trains work. I already checked online (including Wikipedia) so, could someone please give me an explanation of the absolute basics in...

I have read a lot of articles on pulse width modulation and I am none the wiser as to how it generates different voltages by simply varying the pulse width of the waveform. What I read was that if you have a rectangular wave train of some amplitude and change the 'ON' period the "NET" voltage...

Homework Statement Consider a Gaussian pulse exp[-(t/Δt)^2/2]exp(i*w*t), where Δt is its approximate pulse width in time. Use the Fourier transform to find its spectrum. Homework Equations The Fourier transform of a Gaussian is a Gaussian. If a Gaussian is given by f(t) = exp(-t^2/2)...

I have pulse frequency as 2.5kHz. How to calculate laser pulse duration at FWHM (full width half maximum)

Hi, Let's say I have a creation operator that creates a photon in some spatial mode. It has a spectral distribution given by f(\omega_{k}) So we have \mid 1_{p} \rangle=\int d\omega_{k}f(\omega_{k})a^{\dagger}_{k}\mid 0 \rangle Normalization implies that \int d\omega_{k}|f(\omega_{k})|^{2}...

Scientists can produce laser pulses of order one wavelength in "length" see, http://www.bbc.co.uk/news/science-environment-19489384 Do Maxwell's equations admit solutions of such short pulses? Can one approximate such a solution by multiplying a plane electromagnetic wave by the...

Hello, I wish to switch ON and OFF a high-voltage (that generates a high electric field) using a ultra-fast laser as a trigger. Basically I have a flow of charged particles that I want to quickly deflect using an E-field. The timing must be correct and controlled by a LASER. Does anyone...

I have pulse generator that produces negative Gaussian pulses with fwhm~0.3ns. It is driven by the falling edge of a regular square wave from a function generator. I want to make some kind of measurement on an oscilloscope of the jitter of the pulse by comparing the output from the function...

What equations can I use to find the tension in this cable?? "Transverse pulse"?? I know I'm given the following but I have no idea what equation to use...does anyone know? Mass: m = 0.180 kg Length: L = 4.20 m μ = mass (m) / unit length of cord (L) Time for 4 trips down and back: 0.845 s...

I'm wondering if there is such thing as a spdt which reverses upon being energized/de-energized? So each time a voltage is disconnected then reconnected the switch flips once and locks in place till the next disconnect/connect. I'm interested in this for a low voltage dc circuit.

HI,my dear friends! I have find some materials about π/2 pulse and π pulse ,but I still can't understand the "physics" behind these concept! Anyone can shed light on this problem would be highly appreciated!Thank you!