Hi all ,

It may be a stupid and funny question,but do everyone know what exactly ground is?
Why some simulation software need ground to start the simulation?
Thanks for the answer

 

Originally posted by Iwan@Oct 19 2004, 04:17 AM
Hi all ,

It may be a stupid and funny question,but do everyone know what exactly ground is?
Why some simulation software need ground to start the simulation?
Thanks for the answer

[post=2994]Quoted post[/post]​

Ground is where potatoes and carrots live.

In electronics ground is nothing more than what we call the reference point. Remember, every voltage you encounter is with respect to some other point - it is a potential _difference_. we find such a point in our circuit and call that our reference point for with respect to all other points that we wish to examine the voltage - it is nothing more than that. Sometimes ground is literally the earth, sometimes it is an aircraft frame, sometimes it is just a plane of copper in a printed circuit board.

So lets think about your simulator, it doesnt really need a "ground" it doesnt even know what that is.. But it does need a reference point (node) for which to calculate all your voltages with respect to. You tell it where that is by attaching the ground symbol to that point(node). Some places are more convenient to pick than others like for example, pick the node that all the return currents will flow to like the negative terminal of a battery...

The real ground is where potatoes and carrots live.

 

Hi,

You're right about the reference point aspect, Optikon, but for power distribution, the earth is a very real ground. All AC power is distributed with the earth acting as a point of reference and an attachment. That's why the ground buss in your house's breaker panel is wired out to a copper rod buried in the ground. That way, when an appliance or an instrument case is grounded, it can't develop a potential and become a shock hazard. Potatoes and carrots and a great source/sink for electrons.

 

also the ground or earth is like this large sink of of electrons and positive charges...so if if u connect a positively charged obkect to ground electrons flow into the sphere from the gnd and neutalize the charge thus givin the sphere a net zero potential(which is wat we call ground potential)... if u connect a negatively charged object the electrons on the object flow to gnd and gives the object zero potential....however we must note that inspite of this exchange of charges between ground and the object the potential of the ground remains unchanged.... which is why the gnd is an infinite sink or charges of charges

 

also the ground or earth is like this large sink of of electrons and positive charges...so if if u connect a positively charged obkect to ground electrons flow into the sphere from the gnd and neutalize the charge thus givin the sphere a net zero potential(which is wat we call ground potential)... if u connect a negatively charged object the electrons on the object flow to gnd and gives the object zero potential....however we must note that inspite of this exchange of charges between ground and the object the potential of the ground remains unchanged.... which is why the gnd is an infinite sink or source of charges

owing to its zero potential the gnd is used as a refn point of voltages...however in elctronic ckts a certain point in the circuit is assumed to be at zero potential and calcuations are made with refn to that point.... in electrical appliances(heavy duty ones) the body of the appliance is connected to an terminal called earth... a wire thru this terminal actualy runs to a copper plate placed in earth thru the circuit breaker panel...thsi is a safety measure in case of short circuits or current leakeage into the body of the appliance

 

Originally posted by beenthere@Oct 19 2004, 06:44 PM
Hi,

You're right about the reference point aspect, Optikon, but for power distribution, the earth is a very real ground. All AC power is distributed with the earth acting as a point of reference and an attachment. That's why the ground buss in your house's breaker panel is wired out to a copper rod buried in the ground. That way, when an appliance or an instrument case is grounded, it can't develop a potential and become a shock hazard. Potatoes and carrots and a great source/sink for electrons.

[post=2999]Quoted post[/post]​

I'm familiar with power distribution. I never meant to imply ground wasn't real for power distribution. Of course it is real.. it is a real reference and a big one too. Oh and a lousy one too..