ty
The earth is BIG and it is electrically neutral. It is neither positive nor negative. It has a MASSIVE ability to soak up our unwanted/misdirected electricity without harming anything.
When we talk about earthing (UK) or grounding (USA, I think), we are talking about providing a route to safely discharge electricity into the ground. Without grounding/earthing, the electricity could pass through our body causing death or injury. Strictly, grounding/earthing is required at some point to enable the electricity to be generated and used but that is not the point of your question.
Where there is a risk of damage or electrocution from electrical faults, a very low resistance route to earth redirects the electricity to where it can do no harm. In doing so, it may well be that the current exceeds the fuse rating for that circuit in which case the fuse will blow, so preventing further danger until the fault is fixed. A circuit may also be protected a miniature circuit breaker that serves much the same function as fuse, tripping on current overload, or by a residual current device (also called a trip switch or an earth leakage circuit breaker) that detects any imbalance in live or neural wires and shuts the power off before it can do any harm.
So, we ground circuits for safety.
In early electrical powering earth was a convenient way to make a common reference but ground is only a common reference point from which to measure all other points in a circuit. Think about a ship or an aircraft or a satellite, they are not connected to ground(earth). but they do have a common buss called ground or in fact Circuit Common.
Ground is just a hold over from early language terms of circuitry.
In house wiring Earth Ground is a safety point.
It is not a real earth grounding joint in electronic circuit. It is called a COMMON that might refer to either NEGATIVE ( for NPN device or N-type) or POSITIVE (for PNP device or P-type). It has another name called CIRCUIT GROUND. Do not mix up with the real earth ground point that usually is connected to case and/or main transformer iron core from the AC power source.
For many low voltage simple circuits grounding = earthing in some countries is neither necessary nor desirable.
We ground a circuit for safety reasons. Earth is a good ground since its resistance is very small and it is at 0 petential everywhere.
doesn't that make grounding to Earth a short circuit?
Earth and "ground" are not synonymous.
Have a look at this http://www.davidbridgen.com/earth.htm
Its our reference...for example 5volts with respect to ground...
ground on schemas are not earth.....it is a common connection..
What properties of Earth make grounding useful?
ty
