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Common Emitter is an expression to indicate exactly an electrical configuration where a part on three of BJT transitor (and only that kind of transistors) is used as reference for the other two.
So keep in mind it's impossible to make confusion with other contexts.

But... what's an emitter, or a transistor? why bjt? I'm instead confused!
And you're right if never seen one of them, neither in theory exposition.

Generally a transistor is a semiconductor device which you can regulate voltage and/or current in output with; maybe its name's explanation could give a bit of information more: transistor is the contraction of "transfer resistor".
According to their inventors it's been so called "because it's a resistor or semiconductor device that can amplify electrical signals as they are transferred through it from input to output terminals". ...continue reading "Common Emitter. Why and how to"

Scidavis-logoIn every-day life compromise is a good way to go on; not only with people but in interaction with our world.
Think when you have to remember something, a good old friend you still don't meet since many years: how could you preserve the last record? but above all, how could you record every his/her single particular?
It's impossible; you have to retain just some important points, but not all.
In other words, some informations are lost: a truly necessary compromise. But remaining ones are enough to rebuild the original?

That's our article's target!

...continue reading "SciDAVis. Art of approximation"

Differential Solution

In this theoretical article we will try to solve as easier as possible a generic first order differential equation.
This equation is always there to ruin our days 😆
If you try to solve a simple RC circuit is there and waiting for you.
It is quite annoying how many times you will find it at your way so we decided to solve this equation even for people who does not have a lot mathematical knowledge.
Lets start.

This is a generic First Order Linear Differential Equation

{{dy} \over {dx}} + P(x)y = Q(x)

Another way to remember it is

y' + P(x)y = Q(x)

So as you can see it is a first order differential equation since the y function is only derivated once.

...continue reading "First Order Linear Differential Equation"

LCD16x2

A liquid crystal display (LCD) is an attractive way for easy communication between the user and hardware.
In this tutorial we will see how to connect a 16x2 LCD display on our arduino using only 6 pins.
As you may noticed always we start from the documentation offered for free of the various hardware manufacturers.
Here is the data-sheet of the LCD Module 1602 A1 .

...continue reading "Connecting a LCD to an Arduino"

Voltage Divider

The voltage divider is a circuit that produces an Vout that is a fraction of an Vin.

The two resistors in series can be seen as a single potentiometer.

This circuit will be heavily used in our website so we have decided to do a standalone article for this circuit.

From the Ohms law we know that V=I*R

From the Kirchhoff's current law (first rule) we know  ΣI=0 So we have I1=I2+I3

From the Kirchhoff's voltage law (second rule) we know that ΣV=0 So we have Vin=V1+V2

Observe that V2=Vout

Let's now do some considerations about this circuit.

...continue reading "Voltage dividers explained"