-
How a Transformer works .... wow
I had no idea the stepdown power worked by magnetism .... thats wild
https://www.youtube.com/watch?v=wW24wvx_hvc
Its 1 hour long , but within the first 10 minutes you get the basics
Tell your Cat I said "Psst Psst Psst"
It seems like everywhere I go the AC is broken
-
-
stepup too ?
-
That's also why we talk of transformers in VA and not watts, it's due to the losses due to magnetism. Think I learned that in a Jr High electrical class.
Originally Posted by
Snapperhead
I do a triple evac with nitro to remove non condensables.
-
Post Likes - 1 Likes, 0 Dislikes
-
This is why AC power won the battle with DC power.
You step up the voltage with transformers so you can send it long distances.
This was the Nicola Tesla approach to power and in conflict with Edison and his limited DC systems.
It was quite a battle, Edison people would tour the nation electrocuting dogs with AC voltages to show how dangerous it was.
I'm thinking you could have done it with DC also, but the "dangers" of AC were proclaimed.
The generation station produces a lower voltage that is then boosted up to sometimes nearly 500,000 volts.
Every time you double the voltage, the same hardware (wire size) can carry 4 times the energy.
Also with less voltage drop, because the amperage has dropped which is the cause of line loss thru heating.
So at higher voltages smaller wire can carry more energy. Now the next limitation is the insulators that support the cables, they get expensive and aerial towers are placed at a compromise of install and maintenance expense.
-
Originally Posted by
BBeerme
That's also why we talk of transformers in VA and not watts, it's due to the losses due to magnetism. Think I learned that in a Jr High electrical class.
Not sure about that
Tranny's are rated by VA due to the measurement being independent of power factor... If I'm remembering a long ago apprenticeship class correctly. I'm probably not.
-
The proper term is Induction, but magnetism is what makes it work. One winding excites the electrons in the other winding, and the varying numbers of "turns" in the coils determine the voltage conversion.
-
Post Likes - 2 Likes, 0 Dislikes
-
In simple terms, we call it VA instead of watts, because power is required to make the magnetic field, and that power is a loss to the system.
Originally Posted by
Lahrs
Not sure about that
Tranny's are rated by VA due to the measurement being independent of power factor... If I'm remembering a long ago apprenticeship class correctly. I'm probably not.
I do a triple evac with nitro to remove non condensables.
-
Originally Posted by
BBeerme
In simple terms, we call it VA instead of watts, because power is required to make the magnetic field, and that power is a loss to the system.
Perhaps you are confusing VAR for VA? Or I'm wrong/misunderstanding.
VA is true, regardless of PF. In a resistive load VA = W. In loads with an inductive or capacitive component, VA is greater than W... If a tranny was rated in W, you could overload it if PF is less than 1.
PF = W ÷ VA
VAR is the capacitive or inductive component of a system, which includes magnetic losses. I think.
Going a step further, PF becomes important for utility companies. There are requirements for commercial/industrial customers to maintain a minimum PF, otherwise the utilities meter which reads in KW/h will under report the actual power used for billing and could cause overloading of their equipment. This is where capacitors and synchronize motors are added to correct PF.
This is all from many moons ago. Happy to be wrong, best way to learn. But I'm pretty sure a tranny is rated in VA as that is how much actual work it is doing, no matter what kind of load it is supplying.
-
Just the opposite. One reason we call it VA is because that's what we read with our meter, but the actual work being done is less.
Originally Posted by
Lahrs
Perhaps you are confusing VAR for VA? Or I'm wrong/misunderstanding.
VA is true, regardless of PF. In a resistive load VA = W. In loads with an inductive or capacitive component, VA is greater than W... If a tranny was rated in W, you could overload it if PF is less than 1.
PF = W ÷ VA
VAR is the capacitive or inductive component of a system, which includes magnetic losses. I think.
Going a step further, PF becomes important for utility companies. There are requirements for commercial/industrial customers to maintain a minimum PF, otherwise the utilities meter which reads in KW/h will under report the actual power used for billing and could cause overloading of their equipment. This is where capacitors and synchronize motors are added to correct PF.
This is all from many moons ago. Happy to be wrong, best way to learn. But I'm pretty sure a tranny is rated in VA as that is how much actual work it is doing, no matter what kind of load it is supplying.
I do a triple evac with nitro to remove non condensables.
-
Originally Posted by
Special-K
The proper term is Induction, but magnetism is what makes it work. One winding excites the electrons in the other winding, and the varying numbers of "turns" in the coils determine the voltage conversion.
Damn K, you make it sound erotic.
-
Post Likes - 1 Likes, 0 Dislikes
-
Originally Posted by
BBeerme
Just the opposite. One reason we call it VA is because that's what we read with our meter, but the actual work being done is less.
Perhaps my use of the word 'work' to describe the affects of VA on a transformer isn't quite right 'load' may have been a better choice.
A tranny is rated in VA because it's independent of PF, in other words the type of load connected. You could have a load at 100w and 1000VA, or 100w and 100VA. A transformer rated for 1000VA could supply both of those loads. If it was rated for 100w, it would depend... 100w at PF 1 or 100w at PF 0.1?
A tranny being rated in VA has nothing to do with being able to calculate it with a standard meter. That's just a convenient byproduct.
-
If you have a 100VA transformer, you won't get 100W of work out of it.
Originally Posted by
Lahrs
Perhaps my use of the word 'work' to describe the affects of VA on a transformer isn't quite right 'load' may have been a better choice.
A tranny is rated in VA because it's independent of PF, in other words the type of load connected. You could have a load at 100w and 1000VA, or 100w and 100VA. A transformer rated for 1000VA could supply both of those loads. If it was rated for 100w, it would depend... 100w at PF 1 or 100w at PF 0.1?
A tranny being rated in VA has nothing to do with being able to calculate it with a standard meter. That's just a convenient byproduct.
I do a triple evac with nitro to remove non condensables.
-
Originally Posted by
coolwhip
Damn K, you make it sound erotic.
That's what Mrs. K said...
-
Post Likes - 2 Likes, 0 Dislikes
-
Originally Posted by
BBeerme
If you have a 100VA transformer, you won't get 100W of work out of it.
For sake of a basic electrical calculation for demonstration purposes, sure you can.
-
I watched the YT but I didn't here him talk of the why of inductance. Maybe I missed it but it's the why of how a TR works.
Without the alternating current changing direction the induction wouldn't happen. It's the result of the collapsing magnetic field. Like the
energy has to go somewhere. That's the why of inductance.
There are no DC transformers. DC doesn't create inductance because DC doesn't chance direction. DC can magnetize say an iron rod and make
a relay but won't make induce current in another coil unless the current is interrupted or pulsed.
The clever engineers knew they could create an inductance effect by pulsing DC. Like a set of points in a car (well an older car)
The points grounded the ignition coil and when they opened the inrush current loaded the secondary enough to create a current to make a spark.
The system had a built in problem. It took time for the coil to saturate. Result was a weak spark at higher RPM.
Today each cylinder has a coil so saturation isn't as much of a problem.
I had a hot rod that had an ignition system called a dual coil. Two sets of points, a rotor with two contacts, and two coils.
It allowed twice the saturation time.
We are here on Earth to fart around ......Kurt Vonnegut
You can be anything you want......As long as you don't suck at it.
USAF 98 Bomb Wing 1960-66 SMW Lu49
-
For demonstration purposes, you can get 125 watts out of a 100 VA transformer. For awhile.
Originally Posted by
Lahrs
For sake of a basic electrical calculation for demonstration purposes, sure you can.
I do a triple evac with nitro to remove non condensables.
-
Originally Posted by
BBeerme
For demonstration purposes, you can get 125 watts out of a 100 VA transformer. For awhile.
You can have a 125w load overload a 1250VA transformer too. That's why PF is important. Fun with tranny's.
About the halfway mark in OPs vid touched on overloading. Though in his demonstrative case, talking about drawing 40 amps on 20 amp CB without tripping breaker, inverse time yaddi yadda.