In medicine, a pulse represents the tactile arterial palpation of the cardiac cycle (heartbeat) by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the neck (carotid artery), wrist (radial artery), at the groin (femoral artery), behind the knee (popliteal artery), near the ankle joint (posterior tibial artery), and on foot (dorsalis pedis artery). Pulse (or the count of arterial pulse per minute) is equivalent to measuring the heart rate. The heart rate can also be measured by listening to the heart beat by auscultation, traditionally using a stethoscope and counting it for a minute. The radial pulse is commonly measured using three fingers. This has a reason: the finger closest to the heart is used to occlude the pulse pressure, the middle finger is used get a crude estimate of the blood pressure, and the finger most distal to the heart (usually the ring finger) is used to nullify the effect of the ulnar pulse as the two arteries are connected via the palmar arches (superficial and deep). The study of the pulse is known as sphygmology.
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!
Hey guys,
I'm working on finding a circuit which will allow me to pulse about 200A for 50-100 us. My external load is about 0.05 ohm and 3uH. The repetition rate of the pulse is 360 Hz. I require the pulses to be in alternating polarity.
Thus far, I have been thinking about using a...
Homework Statement
A radioactive source which is known to emit gamma rays only at a single energy is placed in front of a gamma ray detector. The gamma ray pulse height spectrum shows three distinct pulse heights of 7.38,6.49 and 5.60 volts. What is the energy of the gamma ray?
The Attempt...
Hey guys. I made myself a pulse circuit but my power supply failed.
Now I need a way to use a 12v magneto as a power supply.
But a magneto puts out pulses. Can I put a capacitor or a diode there to make it a steady stream of dc current?
This is for my go kart 5hp briggs. for turn signal...
I am new to electrical systems, but I wanted to know, how would someone be able to make a piece of metal positively charged for a short time and pulse?
ok i need to know the value of the capacitor which i need.
i have a pulse voltage of 6mV which i want to stabilise to create a voltage which will power a small L.E.D. i currently have a bridge rectifier and i know i need a capacitor but what would the value of this capacitor be.
Hi everyone,
I am trying to understand the basic design requirements and rules for designing a pulse transformer which includes two secondary coils, one of which acts as a DC reactor.
Does anyone know of any papers or software or have any experience with such a design?
ok how would i stabilise a voltage pulse of 6 V pulse to a straight forward DC voltage I am under the impression that using a resistor in series with with the voltage source of 1K ohm and a capacitor in parallel, (how do you calculate the capacitance value).
thanks Dan.
Homework Statement
Hi, I am trying to inject some faults into a CPU manually. But I am not sure what should the soft error (SET) pulse width should be? I know that is different in different case. Therefore, I am going to set up a random generator to generator the SET pulse width. But what range...
Hello all,
I have a few questions about calculating efficiency, torque and horsepower for a small pulse dc motor. The only parameters that I have are input voltage = 39Vdc, input current = 2A and rpm = 90,000 rpm. Are the above values obtainable with the given information?
This is not a...
Hi all,
I am trying to create a square wave pulse that lasts for a relatively small amnount of time which corresponds (as close as possible) to the peak of a sin wave input of period about 1 second.
The only way that I can think of doing this is via a programmable device such as an arduino...
What is meant by phase of a pulse? (Gaussian or sech or any other pulse)
How can we mathemaitcally express it and what is the physical meaning of it?
I know about the phase of a wave but not sure about that of a pulse since it is a combination of waveforms of different frequencies.
Thanks
I have a simple home built pulse sensor that uses light from an LED to measure the opacity of my skin. As my heart beats the opacity of my skin goes up an down in a saw tooth like pattern. The frequency of this wave is my heat beat. The frequency is easy enough to find manually (by counting the...
A steady state electrical current is called DC. A periodic rising and falling current is called AC. What is a single-polarity pulse of rising current ( a single rectified hump of a sine wave e.g.) called? AC? DC? or something else?
Why does the SCR remain 'ON' even though the gate pulse is removed?
I understood the two transistor model but I want to know the bare physics of it. If you remove the gate pulse only the +ve anode w.r.t. cathode remains, thereby making junction J2 reverse biased hence current should fall of...
Hi to you all,
I have a quick question about laser pulse energy.
For Q-switching solid state laser source, can you change the energy of a laser pulse without changing the wavelength? If so, how?
Thanks so much...
Homework Statement
So this is a physics problem, but this question doesn't really have to do with the "physics" part of it as much as simply calculating the Fourier transform. (This is a second year physics course and our prof is trying to briefly teach us math tools like this in learning...
I'm confused as to what to expect when I take, for example, the Fourier transform of a sequence of 16 pulses of varying duty cycles, repeating. That is, after the 16th pulse, the entire sequence repeats.
My confusion is in the interaction of the frequency components of each pulse within the...
Hi! I have been getting really confused about this one thing. Can someone please clear my confusion ?
Is there a difference between Pulse Wave and Pulse Width Modulation? If yes, what is it ? If no, can one be used in place of the other ? :smile:
Thanx !
I am trying to compute the Fourier transform of a square pulse with MATLAB's FFT.
Code:
Fs=1000; %Sampling rate (Hz)
T=1/Fs; %Sampling time interval
P=10; %Period of pulse
t=0:1/Fs:P/2; %Time axis
N=length(t);
x=rectpuls(t,P); %Pulse amplitude
n=pow2(nextpow2(N)); %Number of frequency...
Hi, long time user, first time poster.
A while back someone posted a great question
https://www.physicsforums.com/showthread.php?t=33584
To paraphrase, can you explain on a spin-by-spin level exactly how a 181* pulse is possible?
You always hear this really intuitive explanation of...
Homework Statement
A ski gondola is connected to the top of a hill by a steel cable of length 620 m and diamter 1.5 cm. As the gondola comes to the end of its run, it bumps into the terminal and sends a wave pulse along the cable. It is observed that it took 16 s for the pulse to return...
Just like the tittle. I never understand why EMP destroy electronics. People talked about a nuclear explosion will destroy electronic that is on, not off. Why?
I just never understand this.
For a pin photodiode, risetime=bandwidth/0.35
i get ~3ns for s5973
will it be affecting the measurement of 10ns laser pulse?
How can i reduce the rise time?
I'm trying to design my first switching regulator circuit. I require three voltage rails, 5V, 3.3V and 1.8V. But to get started, I'm just focusing on 1.8V. I've decided to use the LT3507 as it seems to be commonly available here. It also has 3 buck regulator outputs, so it's a one-chip solution...
Hi,
I'm new here and I'm really hoping that someone could answer my question.
i am trying to design a PDE but the problem about this is that the temperature caused by detonation (3461 K) is so high that it is really difficult to find a suitable material for the detonation chamber and thermal...
Frequency distribution not determined by the temporal variation of the pulse?
In his book Modern Optical Spectroscopy, William Parson says
Light from an incoherent source such as a xenon
flash lamp contains a distribution of frequencies that are unrelated to the length
of the pulse...
Homework Statement
A wave pulse travels down a slinky. The mass of the slinky is m = 0.86 kg and is initially stretched to a length L = 6.5 m. The wave pulse has an amplitude of A = 0.22 m and takes t = 0.494 s to travel down the stretched length of the slinky. The frequency of the wave...
Homework Statement
Suppose that total population inversion could be achieved in a ruby laser. If half of the electrons in E2 could then drop to E1 in 30 ns, what would be the avg power of the resulting laser pulse over this time interval? Assume that the ruby crystal is a cylinder 5.00cm long...
B=Boexp[-(kz-ωt)2)] i(hat)
Calculate the electric field associated with the above magnetic field pulse.
Calculate the Poynting vector for the EM field and the total energy per unit area.
Use Maxwell's equations in vacuum and assume electric potential is zero.
Homework Equations...
Homework Statement
I: A telephone line can transmit a range of frequencies \Delta f = 2500 Hz. Roughly what is the duration of the shortest pulse that can be sent over this line?
II: A space probe sends a picture containing 500 by 500 elements, each containing a brightness scale with 256...
Hi there,
So I am doing this lab write-up at the moment with a single channel analyser. The following diagram pretty much sums up the setup:
So pretty much I have found a suitable operating voltage gain by recording number of counts vs. gain and now I must change the Baseline-E...
If we take a CW laser,say, and operate a pulsed regime, will this directly effect the spectral content of the emitted light?
Is there anyway that we can pulse this laser without introducing linear chirp?
Thank you
Homework Statement
Pulse radar:
Parameters:
Carrier frequency: 5.3*10^9 Hz
Pulse length: 20*10^-6s
PRF: 30*10^6Hz
Homework Equations
The question is this:
"100 pulses are reflected from a moving target and received by the radar.
-What is the resolution of a speed...
Hi quick question, I have an rc circuit which is to be charged with an input voltage of 3.6 V but what happens if a pulsing current source is connected to the capacitor as well?
So I have a rc circuit but also a pulsing current source connected directly to the resistor.
I have attached the...
This is my first posting with the forum and I hope I have chosen the appropriate topic. I am a 25 year automotive technician and have been pursuing an alternative application for the automotive industry. It is the electromagnetic pulse engine, which basically utilizes a regular 4 cylinder...
I have a question, I used pulsed Nd:YAG laser to weld a steel part but I didn’t measure the pulse energy during the experiment. I was wondering if there is a way to calculate it somehow?
I have laser pulse duration, frequency (repetition rate), and laser (mean) power.
Thanks
My research involves using a detector that I am trying to test with a pre-experimental setup. To test the functionality of the detector, I am pulsing a light source near the detector using a Picosecond Pulse Labs pulse generator. Here is where my troubles/question comes in: the pulser is...
i just want to double check this is right because i am not given answers.
i have a wave traveling at 5cm/s traveling in the positive x direction.
when t=0 it has intercepts at 1cm and 4cm.
if i have to draw the graph at t=2
will the graph look exactly the same except the intercepts are at...
Homework Statement
Hi, I have a 1Hz pulse and wish to obtain a very short pulse at the low edge of the 1Hz pulse. The following is what I'm referring to:
The Attempt at a Solution
Since I cannot use a capacitor, I was thinking maybe something with flip flops but I'm still a bit...
I've been doing some reading about Orion-drive spacecraft , but I don't understand the requirement of a high Z propellant like tungsten. Assuming that the pulse unit were detonated further away from the craft to prevent it from drilling a hole in the pusher plate due to its narrower angle, why...
Hi,
I have some interferometric autocorrelation traces of ~20fs pulses. Does anyone know how to convert to or calculate the actual pulse duration from the fringes of the trace?
Thanks,
Richard
I have impedance values for an electrode (used for nerve stimulation) over a wide frequency range using sinusoidal current. Now I have to calculate how much voltage I need to stimulate the electrode at a current of 5mA, using the equation (V=IR). I have to use monophasic pulse train of 5 to 10...
Ok, I used one of these in an experiment the other day but i did not fully understand it. I was setting up an RC circuit, and a pulse generator was connected to the circuit setting a repetition rate of 1ms. But
a) What was the role of the pulse generator
b) Is the repetition rate like inverse...
I have a laser with a short pulse duration (sub 20 fs) and i want to know how long the pulse would be after it passes through X amount of material. I don't know the refractive index of the material, but I do know its GDD over the wavelength I'm operating at.
How do I go about calculating the...