Why do we need negative voltage?

[fazan83]

Why we need V-Negative?

Guys,
I am beginner in this field and need your help on understanding a very fundamental aspect of electronic.

Why do we need negative voltage?

Voltage is the difference of electrical potential between two points of an electrical or electronic circuit.

But for V-Negative charge move from where to where?

If the V negative just mean the current flow to opposite way then why we need it like this? For what reason? Why some of the op amp need V Negative please advise.

 

[fsahmed]

Re: Why we need V-Negative?

Current moves to and from ground.

You must understand that all measurements in a circuit are made relative to a reference point called ground. Ground is a point in the circuit where u assume the potential to be 0. If current moves from a point in the circuit, that point is considered positive with respect to ground. If current flows from ground to a point in a circuit........... well.......... it is still assumed to be going into the ground and hence the sign is reversed to ease matters on mathematical levels. Just remember that whatever positive or negative there is in a circuit, it has no absolute meaning, the polarity is with respect to the ground!

OP-AMPS need -V to provide negative volatge at output when they are dealing with AC.

 

[fazan83]

Re: Why we need V-Negative?

op-amps need a negative source so that the output is allowed to swing negative otherwise clipping may occur.

Thanks guys your answer really help.

 

[Meridian]

Re: Why we need V-Negative?

Guys,
I am beginner in this field and need your help on understanding a very fundamental aspect of electronic.

Why do we need negative voltage?

Voltage is the difference of electrical potential between two points of an electrical or electronic circuit.

But for V-Negative charge move from where to where?

If the V negative just mean the current flow to opposite way then why we need it like this? For what reason? Why some of the op amp need V Negative please advise.

Not all Op-Amps need a dual voltage. There are many with a single supply.
See link to read up on it:
**broken link removed**

 

[masri]

Re: Why we need V-Negative?

need negative because the free charges in the electrical current is the free electrons while protons stay fixed in their positions
current flow from high to low voltage
op amp output varing bet:ween +vcc and -vcc
if you havent negative the -ve portion of the output signal will be clipped