Volts and electrical potential energy?

Status
Not open for further replies.

DanielHickman

Member
Location
USA
Is anyone able to explain to me what a volt is without telling me that it is "one joule per coulomb"?

I know what voltage is - the potential difference. I understand that. The difference between the electrical potential energy in two places on the circuit.

I just don't quite understand what a volt IS.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Is anyone able to explain to me what a volt is without telling me that it is "one joule per coulomb"?

I know what voltage is - the potential difference. I understand that. The difference between the electrical potential energy in two places on the circuit.

I just don't quite understand what a volt IS.

First, a volt is NOT one joule per coulomb. A potential of a volt is capable of passing one joule of energy per coulomb, it is not the energy itself.

A volt is the amount of potential required to pass a current of one amp through a resistance of one ohm. It is just a way to measure potential, a way to put a label on it's amount.
 

RichB

Senior Member
Location
Tacoma, Wa
Occupation
Electrician/Electrical Inspector
I hate doing this comparison, but-:ashamed1:-a volt is analogous to pressure in a water hose, it is what "Pushes" the electrons through the wire like pressure pushes the water through a hose
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
I hate doing this comparison, but-:ashamed1:-a volt is analogous to pressure in a water hose, it is what "Pushes" the electrons through the wire like pressure pushes the water through a hose

I have found that for most issues, the water analogy is OK, but later as the subjects become more complex, it doesn't work so well.

I think it's more important that the OP knows or learns the difference between force and energy and power.
 

RichB

Senior Member
Location
Tacoma, Wa
Occupation
Electrician/Electrical Inspector
I agree--I just cringe a bit because I have had Journey level electricians try and tell me things like,,"It doesn't work that way--just look at a valve" when talking about open and closed on a switch!!:jawdrop:But yes it does work ok, especially for initial understanding
 
Another analogy from the world of physics

Another analogy from the world of physics

Maybe a comparison with height will make sense to you.

Voltage tells you how much energy (NOT power) is involved when any particular amount of charge flows through that potential difference, just like the height of a waterfall tells you how many kilowatt-hours you can generate when one ton of water falls over it.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Maybe a comparison with height will make sense to you.

Voltage tells you how much energy (NOT power) is involved when any particular amount of charge flows through that potential difference, just like the height of a waterfall tells you how many kilowatt-hours you can generate when one ton of water falls over it.

Our POCO changed it's name from Consumers Power to Consumers Energy because they eventually figured out they weren't selling power, they were selling energy. The funny part was they spelled energy wrong on the new (decades ago, now) sign in the billing office. It read Consumers Engergy.

I should have taken a pic of it. The other day I drove by there and the building was completely gone.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
For starters, voltage makes no sense at a single point. It is always measured between two points. It is the difference in potential between those two points. But to understand that statement, you would have to know what "potential" means in this context. I don't want to take on that explanation just yet.

See if this helps. If a source creates a difference in potential of one volt between two points along a wire, then the source would use up one joule of energy to complete the task of moving one coulomb of charge from the first point to the second point.
 

Besoeker

Senior Member
Location
UK
If a source creates a difference in potential of one volt between two points along a wire, then the source would use up one joule of energy to complete the task of moving one coulomb of charge from the first point to the second point.

Or do nothing.
 

xformer

Senior Member
Location
Dallas, Tx
Occupation
Master Electrician
For a simple definition I have sometimes used the phrase " volts is similar to pressure or P.S.I for those who understand air compressors." It is merely the force that pushes the amps though the conductor. That measurement occurs between two points the compressor tank and normal air pressure.
As far as defining the word potential, Think of a big boulder sitting on the ground right next to a deep valley. The boulder has the potential to fall into the valley and release lots of energy, but doesnt because it is on the ground way above the valley floor. With electrical potential the electrons are in one conductor, panel, or buss waiting to be pushed to another point, BUT the electrons go nowhere because there is no circuit pathway for them to travel on. No complete circuit, No current flow. :)
 
Status
Not open for further replies.
Top