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16  Using Arduino / General Electronics / voltage fluctuation in filter circuit on: January 27, 2013, 11:35:23 am
When the output of bridge rectifier is filtered through inductor filter,capacitor filter,lc filter or any other filter there will still be small voltage fluctuation.Can this voltage fluctuation be regarded as electrical noise?Will such type of fluctuation still prove to benefical in any circuit

?
17  Using Arduino / General Electronics / Re: What is electrical noise? on: January 22, 2013, 05:43:15 am
Electronic noise is any fluctuation in voltages that you don't want.
It could be from the operation of a chip, capacitors help smooth this.
Here is one example of noise being generated and being suppressed.
http://www.thebox.myzen.co.uk/Tutorial/De-coupling.html

Noise can also be generated by thermal agitation of electrons, this is know as thermal noise. There are other mechanisms that generate noise but in digital electronics this is normally too small to be a problem.

Noise can also be injected into a circuit through radiation when the circuit is acting unintentionally like a radio receiver.
here + and - denotes the source but i failed to understand how the IC'S here are  producing the varying current and here it is shown that the varying current is going to the ICA and thus the other current going to ICB  and ICcare also changing due to changing current produced by ICA .
18  Using Arduino / General Electronics / Re: What is electrical noise? on: January 22, 2013, 04:51:27 am
Often audio amplifiers and equipment use a small-valued capacitor across the input(s) to present a virtual short-circuit
to radio-frequency signals - this really helps prevent the unintended radio-receiver effect (the non-linear elements in
the amplifier circuit can inadvertantly act like an amplitude-modulation detector at radio frequencies).

Even quite a small value capacitor like 100pF can severely attenuate radio frequencies (MHz and above) without doing much
at all at audio frequencies.

Often the source of unwanted noise is from the cables (which here can be acting as radio aerials / antennas).   Mains
wiring often has sporadic noise spikes (clicks) when switches and thermostats are operated - main wiring is everywhere in
buildings and thus tends to inject such noise into any other wiring running near it.
stuck in virtual short circuit. can we create virtual short circuit?or it is the feature of capacitor?
19  Using Arduino / General Electronics / Re: Problems with Transistor TIP122 on: January 20, 2013, 01:51:33 pm
You need some kind of load in between emitter and ground.  Anything really.  A resistor and LED would do.  Without it you're running the risk of blowing up the batteries.
is battery being short circuited here?since there is no load in going frm positive to negative terminal or the transistor will prevent since some amont of current will be flowing through the transistor too?
20  Using Arduino / General Electronics / Re: Max input voltages? on: January 19, 2013, 10:53:24 am
Quote
Then this was the last time you use your arduino board.

Just to elaborate, you can change the upper end of the 0-5v analog scale to a voltage other than 5v by using the AREF pin and analogReference(External) but it makes it very clear here that the AREF voltage must never be over 5v.
Is it gonna damage the arduino board if the aref voltage is over 5V?
21  Using Arduino / General Electronics / Re: CONCEPT OF SELF INDUCTANCE on: January 17, 2013, 01:09:21 pm
The key bit is that the induced emf always opposes the increase or decrease of current in the coil. As Faraday's Law says, "The induced electromotive force in any closed circuit is equal to the negative of the time rate of change of the magnetic flux through the circuit." Think of an inductor as a device that likes to have a constant (or zero) current flowing through it, and that argues with you whenever you try to change that current.
but why does the additional current flows with the main coil current when the main coil current decreases?Still why it doesn't flow against the main coil current like the one when the main coil current is increasing?
22  Using Arduino / General Electronics / Re: CONCEPT OF SELF INDUCTANCE on: January 17, 2013, 12:27:45 pm
I understood that part...but similarly
"The induced voltage creates a current in the coil that flows either with or against the main coil current,depending on whether the coil current is incresing or decresing.if the coil current is incresing,the additional current flows against the main coil current but when the coil current is decresing, the additional current flows with the main coil current"
and my qsn is why does it happen so?why the additional current flows against when the main coil current when the coil current is increasing and similarly flows with the main coil current if the coil current is decrasing??
23  Using Arduino / General Electronics / CONCEPT OF SELF INDUCTANCE on: January 17, 2013, 11:49:01 am
The back emf is produced because the changing current in the inductor causes a changing magnetic field around it and the changing magnetic field causes,in turn, an emf to be induced back into the inductor. This process is called self inductance.
now my question is why does the changing magnetic field necessarily causes an emf to be induced back? smiley-confuse
24  Using Arduino / General Electronics / Re: pull up resistors and pull down resistors.. on: January 10, 2013, 11:59:23 am
thank you guys for your help   smiley
25  Using Arduino / General Electronics / Re: Transistor on: January 10, 2013, 11:38:28 am
You can even go through Electronics for Dummies by wiley publication..
26  Using Arduino / General Electronics / pull up resistors and pull down resistors.. on: January 09, 2013, 05:59:41 am
Do anybody have sound knowledge ?can even help me with some good links.. smiley-mr-green
27  Using Arduino / General Electronics / Re: connecting two common ground on the breadboard to one on arduino? on: January 08, 2013, 07:07:45 am
and this was the circuit....
28  Using Arduino / General Electronics / Re: connecting two common ground on the breadboard to one on arduino? on: January 08, 2013, 07:00:42 am
And this one didn't even worked at all....
29  Using Arduino / General Electronics / Re: connecting two common ground on the breadboard to one on arduino? on: January 08, 2013, 03:35:56 am
Even without connecting common ground it worked and i am wondering how this circuit worked!!!Having problem in it....
30  Using Arduino / General Electronics / Re: connecting two common ground on the breadboard to one on arduino? on: January 07, 2013, 07:36:59 pm
here ground fromarduino is not connected with the grounds from two leds...
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