Transformers work using AC not DC. You will need to view the sine waves with an oscilloscope to see the changes.
Last edited by ankhseeker; 02-22-2014 at 09:39 AM. Reason: Typos
Take two volt and half cells and connect them in series and spin it around at 60 revolutions per second letting the ends rub against two slip rings and you will have three volts AC at 60 Hz. Hold then in place and it will be three volts DC. Connect a three volt light to these two batteries connected in series and it will burn. Connect a 240 volt appliance across the secondary of the transformer and it will work.
With this three volt bulb burning a center tap of these two batteries and two 1.5 volt light bulbs can burn with one on one cell and the other on the other cell. All three are burning at one time.
Install a center tap on that secondary winding and two 120 volt appliances can be connect with one on one end and the other on the other end at the very same time the 240 volt appliance is in operation.
In order to have electrons flow there has to be a difference in potential or is you please a positive and a negative. If the two 120 volt sine waves were 180 degrees out of phase with each other this would mean that both ends of the winding would have to be positive at the same time and the center tap negative which would change 60 times a second. Also if they are 180 degrees out of phase the 240 volt appliance would not work.
Connect the scope channel A to one end of the secondary and the ground to the other end of the winding you would see one sine wave of about 340 volts peak or 240 volts RMS. Now move the ground to the center tap and a sine wave of only half of the winding or 120 volts RMS. When channel B is connected to the other end we get to see both ends of the winding at the same time, channel A in positive and channel B is negative which is in sync with each other not 180 degrees out of phase.
Using vector math we add the two together to come up with the single phase winding of the secondary. From the 120 volt reverence at both ends we have 240 volts. 120 from neutral to one end and 120 from neutral to the other end, is vector not degree of sine wave. We also use vector math when adding the two batteries, from the center tap to one end is 1.5 volts and from center to the other end we have 1.5 volts. This is the same as with the AC with the exception of the oscillation which AC has, or in other words while one end is positive the other end is negative.
JW, very good explanation which makes it clear you have perfect understanding of this subject. (not that any one ever doubted)
Two rods plus the copper pipe would certainly get the job done, certainly. But that is not what we have on hand.
Why do I get these duplicate posts?
When you get the message "Do you want to leave this page" after clicking Post Reply Click No, do not click Post Reply again.
That should put your post on the server.
Then close the page, you may get "Do you want to leave this page" again, Click Yes.
It works something like that but is hard for me to splain.
What the scope is showing is a vector that is referenced from half way through a 240 bolt winding. As can be clearly seen is that while channel A is positive channel B is negative which means they are in phase not 180 degrees out of phase.
In order to be 180 degrees out of phase then both ends would have the same polarity.
Ever hear the old saying to believe nothing you hear and only half of what you see? Well that applies here until you take a course in vector math.