Cerebral shunts are commonly used to treat hydrocephalus, the swelling of the brain due to excess buildup of cerebrospinal fluid (CSF). If left unchecked, the cerebrospinal fluid can build up leading to an increase in intracranial pressure (ICP) which can lead to intracranial hematoma, cerebral edema, crushed brain tissue or herniation. The cerebral shunt can be used to alleviate or prevent these problems in patients who suffer from hydrocephalus or other related diseases.
Shunts can come in a variety of forms but most of them consist of a valve housing connected to a catheter, the end of which is usually placed in the peritoneal cavity. The main differences between shunts are usually in the materials used to construct them, the types of valve (if any) used, and whether the valve is programmable or not.
I'm trying to do a power analysis on my target, which runs on 3.3 volts. Without the resistor, the average current while running is roughly 140mA.
I used a 10Ohm resistor as a shunt resistor with a 5V power source. The voltage difference between VCC PIN and GND was measured using a shunt...
In the circuit equivalent of a solar cell, shunt resistor is described as "The irregular polycrystalline lattice grain boundaries that resist to the flow of electrical current in the silicon material."
If this explanation is correct, shouldn't it be "lower shunt resistance increases the current...
Hi,
My main question is: should we be subtracting the rotational power losses from the motor output power in our efficiency calculation?
My approach:
Will skip extra work as I have done the above parts of the question correctly.
I used power conservation to state that:
$$ P_{input} = P_{motor}...
Here are a couple of questions that I have been trying to answer and had a go at it.
Not sure if I answered some incorrectly so was hoping to get some guidance
For this one I have tried to make use of Kirchhoff's 2nd law to help me, but this is what I have ended up with when using it...
Here is the problem
I have tried to draw the set up for both cases which the question had described above, and came to these 2 equations. But I can't see how it would help me to work out the resistance of the shunt?
Any help would be really great! Thanks
How would I go about this question?
Here is my attempt at it but I haven't really gone anywhere with this :oldconfused:
Any help would be really appreciated!
Hello,
Hello,
For a project , i need to modele a photodiode with a current source in paralelle with a shunt resistance and in serie with a resistance to use it in a bigger circuit. The photodiode we will use is SFH7050, the datashhet is provideed here...
Homework Equations:
E=V-IaRa
n2 = (n1×E2)/E1
If = V/Rf
V×Ia
T∝ΦIa
E∝ΦN
i)
V = 500v, N1 = 600RPM, It = 45A, Rf = 220Ω, Ra = 0.3Ω
It = Ia + If
If = V/Rf = 500/220 = 2.273A
Ia = It - If = 45 - 2.273 = 42.727A
Now: T∝ΦIa and if the flux per pole is constant then T∝Ia
So Ia when the Torque falls...
Problem Statement :
Here's my attempt :
* By assuming that the fringing and leakage effects are ignored.
I find the flux density , the permeability and the reluctance of the iron , but then I get stuck .
Any help would be greatly appreciated .
Hi folks,
I think a lot about aeronautics and physics for the purposes of helping people. I stumbled across the idea of vacuum airships as a cheap method of transporting food and water to places where it's unsafe for vehicles, or where there are no roads. We all know it's unconventional and...
I still did not understand this from my previous threads, what is the way to determine the instantaneous voltage across the cavity plates at any given moment, in a klystron I suppose the voltage would be proportional to the arriving electron bunch density which would determine the overall bunch...
Hello, I'm having the damnedest time wrapping my head around a concept of audio electronics:
http://whirlwindusa.com/support/tech-articles/high-and-low-impedance-signals/
How exactly does a higher impedance bring down the frequency at which capacitance dominates? My current understanding is...
Hi,
I'm not able to understand how reversing Field terminals will help build magnetic flux in dc shunt generator
Have drawn diagrams below.
In 1st case machine doesn't generate as the flux opposes residual flux, so I reverse F1, F2 and draw below diagram...
But in second case the direction of...
Homework Statement
Homework Equations
Efficiency = o/p divided by i/p
I/P KW divided by input voltage gives input current
Field Current = voltage divided by field resistance
armature current = total current - field current
Back Emf = V - IaRa
T proportional to Ia
Back Emf proportional to...
Hi guys, can someone please have a look at the following problem that I am struggling with;
An 8.25 kW shunt DC motor is supplied with a terminal DC voltage of 300 V. The armature resistance of the motor Ra is 0.25 ohms, and the field resistance Rf is 40 ohms. The field winding consists of 1500...
I need to measure current in DC system. I have circuit breaker (125A), so 150A shunt is selected. On that shunt ammeter is connected. But that ammeter has 60mV, scale 0-150A. What does this 60mV means on ammeter? Is it correct?
i really need help about shunt and series resistances
i just want to know if they are constant or variable ?
if they are variable what make them increase or decrease?
Hello, I've been building my own solar panel system and throughout this process I've accumulated a lot of questions. If anyone could help answer them I would greatly appreciate it!
First I'll start off explaining what I have.
A polycrystalline solar panel 17V 2.2A and a mono crystalline panel...
Homework Statement
We have an ammeter with 20Ω resistance and a range of 10mA or 0.01A.
The different ranges are 3000mA, 300mA, 30mA.
Calculate the shunt resistors a, b and c.
Homework Equations
The Attempt at a Solution
Ia = 0.01A ; Ra = 20Ω ; I = 0.03A
Ua = Ia ⋅ Ra = 0.01A ⋅ 20Ω =...
An 8.25 kW shunt DC motor is supplied with a terminal DC voltage of 300 V. The armature resistance of the motor Ra is 0.25 , and the field resistance Rf is 40 . The field winding consists of 1500 turns. An adjustable resistance Radj is connected in series to the field winding. Radj may be...
I'm not entirely clear what shunt resistance is, it's fairly hard to find things on google which refer to it in the context of LEDs. So we did an experiment in which we measured the IV characteristics of InAs at different temperatures, and observed the gradients of these graphs (apparently those...
Homework Statement
The attached figure shows a "shunt feedback amplifier" circuit, and its AC equivalent model.
Verify that:
r_T = \dfrac{v_{out}}{i_{in}}=\dfrac{-R_B}{1+\dfrac{R_B+r_\pi}{(1+\beta)R_C}}
(assuming R_B\gg r_e, where r_\pi=(\beta+1)r_e.)
Homework Equations
In the...
Hi,
I am trying to find out series and shunt resistance of solar cell from I-V curve which starts from Isc and going to Voc.
I read some papers and for single illumination mostly said Rs= -(dv/dI)V=Voc
and Rsh= -(dv/dI)I=Isc.
so I am finidng Rs from slope between points from Vmax to Voc, and...
Suppose a motor is run at 1500 rpm and field rheostat is at minimum position (say 10Ω). Then the field rheostat resistance is increased to 100Ω and the speed obtained is 1700 rpm. Now the motor is shut down and started again. Will it now run at 1700 rpm?
My logic: No it won't, because:
the...
Homework Statement
Let's say I have a Langmuir probe I-V characteristic from the Helimak experiment. The plasma ions are singly ionized argon. The probe has an effective area of 0.000016 m^2. Estimate the floating potential, electron density,
and temperature. Based only on the nature of the...
I am having a hard time understanding how to measure current safely in the following circuit.
The circuit consists of an isolated step up transformer. 50V 1kHz pulsed dc on the primary and 500V 1kHz pulsed dc on the secondary @ 10mA max. I am wanting to measure current on the secondary side of...
We know that Universal Motors have field winding always in series with the Armature.They do not have field in shunt because of shunt fields' inductive reactance & they will produce negligible torque on AC supply.
Also because of different phase angles of currents in series & shunt path, the 'DC...
Homework Statement
DC circuit
2 resistors in parallel Rm and Rs
one resitance will be a meter (Rm =0.1 ohm), the other will be the shunt
Max current is 200A
Im (meter current is 1mA)
Homework Equations
I= Is + Im
V=IRt
The Attempt at a Solution
I am thinking first to find...
I was reading through an article on, "Shunt Reactors for Voltage Control" and I am slightly confused. (See link below for article)
http://www.onegrid.com.au/wp-content/uploads/2012/03/BR-EN-TH16-02_2006-Shunt_reactors_for_voltage_control.pdf
The article reads, "When the network load and...
I know meter shunts are used to direct most of the current away from the meter coil but my question is if you direct most of current away from the coil, how is the meter measuring the current flow accurately.
Im kinda slow in the head so no complex fried banana explanation. tnx
Homework Statement
A shunt generator has an armature resistance of 0.8Ω, a field winding resistance of 120Ω and a mechanical loss of 115W. The load resistance of 8.5Ω is connected to the output terminals of the generator. An external mover rotates the shaft of the generator at a speed of...
I know that the there is some small capacitance between the windings of an axial inductor let's say, but how does one measure this? The inductor is a short on an LCR meter...
I was using a signal generator to perform some tests. The circuit was simply the generator in series with a 1 ohm shunt resistor.
Even though I was working with high frequencies (1 to 20 MHz), shouldn't the voltage drop across the resistor be the generator amplitude itself? I was using the...
Hello All,
I'm designing a test setup that requires the use of a 50A 50mV current shunt to take measurements for a circuit which produces pulsed DC currents up to about 100 kHz or so (highest frequency component anyway). I would like to use this shunt here, but also amplify the signal 10x or...
Hi, anyone could explain what exact the "shunt susceptance" and "shunt conductance" are? and what's the difference between shunt susceptance and line charging susceptance?
In power system analysis, shunt susceptance and shunt conductance are bus elements. Whereas the line charging...
Homework Statement
A meter is shunted by a parallel resistance.
a) Determine the required value of the shunt resistance if the maximum value of the current I, is 200A. The meter can read a maximum of 1 mA and has a resistance of 0.1 Ω.
b) If the shunt is made of copper and has a...
In a simple zener shunt circuit consisting of a zener diode in parallel to the input voltage and load how does the regulator compensate for a drop in input voltage?
In other words the zener will conduct or 'shunt' when the source voltage exceeds the breakdown voltage of the zener diode. How...
Series shunt or series series??
Hello,
I'm having trouble in general determining the feedback topologies...
My guess is that this is series-series since the source is in series with Rf and since setting io=0 for the output loop disables Vf... But I'm not sure... Could someone please tell...
I have a question that iv been stuck on for wile. I am in year 2, electronic engineering and I am having a little trouble with this.
A separately excited shunt generator has the following nameplate data, 50kW, V(FL) = 125, R(A) = .01 ohms, R(F) = 16 ohms and an excitation voltage of 125 VDC...
Homework Statement
A 25-kW, 230-V shunt motor has an armature resistance of 0.124 Ω and a field-circuit resistance of 95 Ω. The motor delivers rated output power at rated voltage when its armature current is 73.5 A. When the motor is operating at rated voltage, the speed is observed to be 1150...
Hi everyone,
I'm working on a project where the processor is attached to a copper tape about 8cm long where it sticks from 1 end of the processor case to the other while remaining length was insulated with a cardboard. the other end was slightly exposed for temperature measurement
The...
I have a 12vdc, 5Amp power supply and need to connect to a 12vdc, 40 watt electromagnet. I put a SPDT relay switch between the power supply and the electromagnet to turn it on and off. Do I need to put in a shunt resistor or something else to protect the magnet and the power supply? How do I...
I have a 400A (125VDC) charger that feeds a battery bank and a few DC panels (critical). This poor design has the panels being fed from the high side of a 600A breaker that is between the charger and battery bank. I need to take the battery off line for a load test but the problem I'm going to...
In a field loss event, why does a shunt wound dc motor run away? From my understand of electric motor, the armature spins because it's magnetic field pushes/pulls against the field winding's magnetic field. If I remove power to the field winding, then shouldn't the motor slows down because the...
I've recently been researching how to measure strain using strain gauges. I came upon the subject of shunt calibration and hit a mental roadblock.
From what I understand, shunt calibration simulates a strain across a strain gauge using a comparatively large resistor placed in parallel with...
Questions about shunt motor
Homework Statement
Good evening everyone, I've got the following question :
Homework Equations
The Attempt at a Solution
Lets see,, I solved until part (e) and I didn't understand the rest.
My questions are :
(d)
, does it mean P =...
I need to find a shunt resistor (basically a low resistance resistor), that can handle 20-25 W, and is less than 1ohm resistance. Not really sure how to find some.. can anyone give suggestions?