Grounding - Understanding what it really is and does.

[D.A.(Tony)Stewart]

MusicManic. I'm afraid you are still confused when you mix up charges and active electrical circuits.

Grounding can be used discharging "charged objects" by connection to that common potential. Charge is transferred until the potential difference is null. There may or may not be energy lost in the from of heat from path resistance.

However on electrical circuits that are floating such as a car battery -ve terminal, there may or may not be any charge on the vehicle body and thus connecting it to earth simply reduces the impedance from > gigaohms to milliohms and there may be no current transferred in the process ( unless the vehicle had a static charge on the body) but the active electronics in the car do not conduct to earth if say a the -ve terminal is earthed.

Similarly for a radio jack ground or a laptop earphone jack ground, these are generally floating by virtue of the insulation in the transformer and thus examples of a FLOATING COMMON POTENTIAL. Although there is value in connecting the metal jack to earth ground for noise reduction on high impedance microphones due to my original reason for a COMMON POTENTIAL. These examples are intentionally not earth grounded for safety leakage reasons by default. The user may earth them for EMI reasons understanding there are isolated risks for not doing so that do not occur frequently such as ground faults.

Consider that even the EARTH is a floating object of common potential compared to other celestial objects and the currents of solar winds can create charges and other effects (Wilkinson Effect}.

So just remember that all these grounds are just common reference points which may be connected to other "grounds" without any power transfer.
e.g. connect the grounds of two cars is a perfect example. No power is transferred when these common potentials are connected until the power leads are connected.
Unless there is a significant conductance or capacitance or permeance between the two objects with their own "grounds", there is no significant power transferred between them when the grounds are connected to each other.

 

[jeffrey samuel]

There should be no positrons or protons involved in this discussion. What you really mean is "holes".

well in semi conductors charge density involve holes and not metallic conductors

holes is just the absence of an electron

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gnd is a reference point for efficient draining of over voltage created in a ckt that is it

with out this common point there may be some probable mishap if we have high voltage working stations

 

[Music Manic]

....................However on electrical circuits that are floating such as a car battery -ve terminal, there may or may not be any charge on the vehicle body and thus connecting it to earth simply reduces the impedance from > gigaohms to milliohms and there may be no current transferred in the process ( unless the vehicle had a static charge on the body) but the active electronics in the car do not conduct to earth if say a the -ve terminal is earthed. ..............................

I see! The grounding is a separate part of the "active" circuit. That makes it clearer on how it operates.

Thanks

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gnd is a reference point for efficient draining of over voltage created in a ckt that is it

with out this common point there may be some probable mishap if we have high voltage working stations

Is this relative to an external voltage Samuel? Don't zener diodes regulate voltage and protect a circuit internally.

This is getting clearer by the day.

Thanks

 

[jeffrey samuel]

exactly here the gnd relates the over voltage with a common point of 0 potential thereby there is protection

zener diode uses completely different principle there is no point in bringing it here