Electronics is the study of electric circuits and electrical components, and the design of useful devices. Some questions in this tag may be more appropriate for the [Electrical Engineering(http://electronics.stackexchange.com/) SE site.
4
votes
2answers
67 views
Is it viable or possible to make your own transistor?
Just wondering if it is possible/viable to construct your own transistor, not small like todays, but the same scale as the one created at Bell Labs.
1
vote
1answer
50 views
When does Thevenin's theorem not apply (modelling a power source with a ohmic internal resistance)
Most physics text books say that a power source can be modelled as an EMF with a internal resistance. This is also know as Thevenin's theorem or Norton's theorem. However I have read in some sources ...
2
votes
0answers
59 views
How did the Bardeen-Brattain point-contact transistor work?
How did the Bardeen-Brattain point-contact transistor work?
What are the conditions under which a Schottky barrier injects minority carriers?
In a bipolar junction transistor the forward-biased ...
0
votes
2answers
149 views
How does current flow from the emitter, through the base and to the collector in a NPN transistor?
So, I understand that for a NPN transistor to work the emitter-base junction needs to be forward biased and the collector-base junction needs to be reverse biased. I understand how current flows from ...
0
votes
1answer
78 views
If we connect a block of p-type semiconductor only to a positive terminal, will it become positively charged?
Connect the positive terminal of a battery to a piece of p-doped semiconductor, say, silicon doped with boron. Will the terminal pull electrons out of the doped silicon, or equivalently, inject holes ...
0
votes
1answer
75 views
Full wave rectification [duplicate]
In the construction of a full wave rectifier, why is there central tapping in the secondary winding of the power transformer? What's the pure reason behind it? If there was no central tapping, what ...
2
votes
2answers
208 views
Working of a p-n junction diode when forward biased
If p-type semiconductor and n-type semiconductor of a diode are equally doped, and if the diode is forward biased, then holes will move toward the n-type semiconductor and electrons will move toward ...
1
vote
1answer
126 views
Electrical conductivity of an intrinsic semiconductor
On which factor does the electrical conductivity of an intrinsic semiconductor depend? It doesn't have an excess of charge carriers in fact, does it?
4
votes
1answer
332 views
Can electrons move through vacuum?
I studied that electronics is the branch of physics which deals with the practical applications of moving electrons through vacuum, semi-conductors and gasses. Can electrons move through vacuum?
2
votes
2answers
95 views
Electronic filter
Can you explain, please, step-by-step how Electronic filter does work?
For example, high pass filter. I know It's a trivial things, but I can't get it completely. Don't bring me formula and etc... ...
2
votes
2answers
60 views
Is it possible to record the 'blue air" effect when a core goes critical?
I've been studying about radiation, and I saw something called the Demon Core. Apparently, it was a core that was under experimentation by the government in Los Alamos to see the exact point at which ...
2
votes
1answer
45 views
How does rust behave as a PN junction?
Reading about old-fangled radios the reference quoted below indicates it was/is possible to use a rusted razor (or perhaps any similar thin corroded metal strip) as a detector.
Some resourceful GIs ...
0
votes
1answer
193 views
What is the role of center-tapping in a full wave rectifier?
Note: I have already tried googling. Although similar questions have been asked on different forums, I couldn't find a detailed explanation, which I could really understand.
Circuit diagram ...
1
vote
1answer
44 views
Why is spectral sensivity of a photodiode expressed in A/W
Can someone explain me the meaning of the A/W unit of the photosensivity when reading a spectral response function of the wavelength characteristic of a photodiode?
0
votes
0answers
36 views
How can a force be applied on hole? [duplicate]
What is actually a hole? Actually that is not a particle, but books are explaining that in semiconductors the polarity of Hall effect depends on the type of charge carriers whether it is p type or n ...
0
votes
0answers
36 views
The things to consider when choosing a mesh for an electron detector (MCP detector)
I am designing a electron velocity map imaging setup. I need a copper mesh just infront of the detector to accelerate the electrons towards the MCP detector. I am doing the instrument design for the ...
1
vote
2answers
198 views
In the diode equation, why the exponential $\exp$ and the ideality factor $n$ are there? What do they represent & what is their significance?
In the Shockley diode equation, why the exponential $\exp$ and the ideality factor $n$ are there? What do they represent & what is their significance?
I have to work on Solar Photovoltaics, and ...
1
vote
1answer
75 views
Instrumentation handbook [closed]
Does anyone have any suggestion on a handbook of instrumentation?
In particular NIM instrumentation...
I would like an approach which will explain the techniques and how to use NIM modules.
In ...
0
votes
1answer
343 views
PN Junction Depletion Region
So it took me a little bit to understand this, but I want to make sure I have a few things right.
First of all, when a Crystal Structure with One side N-Doped, One Side P-Doped are in the same ...
0
votes
1answer
348 views
Explanation for transistor as amplifier
In transistor as an amplifier, we have NPN transistor (base in the middle and emitter and collector at the sides). The collector has electrons in majority because it is N-type. similarly, holes are in ...
3
votes
1answer
176 views
Explanation of the Graetz circuit
My knowledge of circuits is pretty rudimentary and I've never really understood circuits, so I'm having trouble with the concept of Graetz circuits:
When you register the voltage on the resistor R ...
0
votes
0answers
58 views
Explanation of NMOS processes
So, gate (poly-si + $SiO_2$) and $p^{-}$ silicon operate as capacitator.
But how are voltages and charges are applied? In order for inversion to occur, there should be charges formed in poly-Si, ...
0
votes
0answers
75 views
Is there an equation for the magnetic field of a conductor attached to a magnet?
Let's say I have a hollow conductive rod, 10mm diameter (O.D.), and I place a magnet of known strength 50mm up the shaft. What is the microTesla (mT) or Gauss (G) of the magnetic field (or flux ...
0
votes
2answers
562 views
Current through the reverse biased junction in transistor
A transistor is a three terminal device. One terminal is called emitter, one collector and in between them is base. Now, during biasing the junction between emitter and base is made forward biased and ...
0
votes
1answer
730 views
Characteristic of a common emitter transistor [closed]
How is Base emitter junction and collector emitter junction biased? How do we determine the value of potential difference between emitter and collector required to be maintained in order to determine ...
5
votes
2answers
154 views
how does zener diode maintain potential across its terminals?
My physics book has a topic about zener diodes being used as voltage regulators in the reverse bias.
Well, I'm curious to know how does the zener maintain the potential across its terminals after it ...
0
votes
0answers
66 views
Quantization in room temperature
I can't understand
Why is quantized conductance in this scheme ?
http://postimage.org/image/4nujpfe7j/
1
vote
2answers
171 views
Nodal Analysis of an electrical circuit
I have several doubts about solving circuits.
Can any circuit be solved using Nodal Analysis?
If some circuit can be solved using Nodal Analysis, can it be solved using Mesh Analysis too?
Why do we ...
0
votes
0answers
54 views
Experimental Physics [closed]
A heater and thermocouple are used to measure and control the temp. T of a sample at $T_{0}=250^{o}C$. A feedback circuit supplies power P to the heater according to the equation $P=P_{0}+G(T_{0}-T)-D ...
0
votes
0answers
120 views
When the p-n junction of a transistor is reverse biased? [closed]
When the p-n junction of a transistor is reverse biased?
A. current flows from the p-type to the n-type.
B. no current flows from the p-type to the n-type.
C. conduction of current occurs.
D. ...
0
votes
1answer
87 views
Horsepower achieved with multiple motors
Scenario
I'm planning to build an electric motor for fun (not for any practical purpose). I recently purchased a shapeoko CNC mill kit and intend to manufacture most of the parts housing, stator etc. ...
2
votes
4answers
1k views
How does power consumption vary with the processor frequency in a typical computer?
I am looking for an estimate on the relationship between the rate of increase of power usage as the frequency of the processor is increased.
Any references to findings on this would be helpful.
2
votes
0answers
100 views
Problems in the modern semiconductor/electronics technology?
From what I have read, the problem with modern semiconductors/electronics seems to be quantum tunnelling and heat. The root of these problems is the size of the devices. The electrons are leaking out, ...
4
votes
2answers
220 views
What are the effects of cosmic rays on consumer electronics?
When electronics/computer companies design a new chip, processor/ memory card/ or a solar cell, do they study the effect of cosmic rays on such electronically sensitive materials? If not, why not?
1
vote
0answers
164 views
Algorithmic approach for applying Kirchhoff's Rules to circuit analysis
Working with Kirchhoff's rules, I am attempting to device an algorithmic approach to finding the unknowns of the problems, I am of a Computer Science background and I am finding it difficult to ...
2
votes
2answers
238 views
What is the difference of the two stable states of a Flip-flop?
In electronics, a flip-flop or latch is a circuit that has two stable
states and can be used to store state information. [...] Flip-flops and latches are used as data storage elements. Such data ...
0
votes
1answer
112 views
Is it possible to make an RFID-like device which responds to a metal detector?
Would it be possible to make a small device which can be easily detected with a metal detector (or similar) from several feet away?
It would need to operate kind of like a shop-security tag but it ...
1
vote
1answer
137 views
Could a variable capacitor divider replace a Variac?
Hmmm... You can definitely drop down the voltage, and ideal capacitors don't dissipate any power. So it seems, at first glance, that you could use a capacitor divider as a lossless voltage step-down ...
4
votes
1answer
675 views
Why does it spark when I push a plug in the electrical socket?
When I slowly push a plug into the electrical socket I can often see sparks. Can anybody explain why? Can this be possibly harmful for the devices I plug in?
3
votes
0answers
237 views
Turn-on delay time for Laser diode
Do you know any simple explanation on the reason why the turn-on delay time on a laser diode is reducing while we increase the bias current?
Turn on delay,is the time that the laser needs from the ...
0
votes
1answer
292 views
Increase of threshold current by temperature in a laser diode
I read somewhere that if we increase the temperature of the material in a laser diode the threshold current for lasing also increases. Can someone explain to me why is this happening? What is the ...
1
vote
0answers
76 views
Simplifying a biquadratic filter equation [closed]
I am trying to calculate input impedance of a multiple feedback low pass filter. What I need is the symbolic expression as simple as possible so that later I fill in the values and get the impedance ...
0
votes
0answers
144 views
Plot of electric potential inside a p-n junction for nonzero bias [closed]
I'm looking for a plot/cartoon of the electric potential inside a p-n junction that is under forward or reverse bias. Something just like ...
0
votes
1answer
115 views
Modem and cooler pad [closed]
I have a modem.Due to heating issues i fixed a double cooling fans with that.now i get a small doubt.that is "will the magnet in the fans will affect the modem in anyway?"
thanks in advance.
3
votes
2answers
249 views
number of electrons my laptop uses in a second
in order to confirm whether I understand the relation ship between amps, columbs and electrons I decided to try out the following.
my laptop adapter's label reads 3.34 amps.
I assume that:
amps are ...
2
votes
2answers
130 views
Mechanical work to required battery power
I have a very practical question where I've calculated the mechanical work needed by a simple mechanical system by solving the line integral $W = \int_C \ F \ dx$. However, since I have a black spot ...
4
votes
2answers
354 views
lifetime of a PN junction in a diode
diodes are made of silicon, which have been enriched in phosphorus and boron to create the PN junction. Since the electrons are always going in the same direction, from N to P in the junction, I was ...
4
votes
5answers
3k views
What would be the effective resistance of the ladder of resistors having n steps
I'm a tutor. This is a high school level problem. In high school, every one have might have solved a problem of effective resistance of a ladder of resistors having infinite steps. Now the problem is ...
0
votes
1answer
156 views
Waveforms for a given ideal inverters circuit
I have the following circuit. All the inverters are ideal CMOS.
I need to draw the waveforms for each point (A, B, D, E, Vo), given that waveform at input.
What I want to ask is if what I did so ...
0
votes
2answers
300 views
The diode of the lowest voltage
Which diode (semiconductor material) has the lowest voltage in the direction of conductivity?
