Simple to build isolation transformer that consumes less power than it gives out

[JouleSeeker]

Lynx asked:

For those of you still exploring this, do me a favor and try this:  Feed the circuit with 120 vac but through a common wall mount dimmer.  The dimmer chops the AC sine wave into a saw tooth.

I did just that, feeding the dimmer directly from the mains.  The efficiency did improve somewhat, from about 76% to 83% (without cap).  120.2V in  20.2W Pin  69.1Vout   16.8W Pout, eff = 83%

With two trafos; which is pretty good considering that the Pout/Pin for a SINGLE trafo (one of the pair) is about the same and here we are going through two.

Adding a 5uF cap // to TR2 gave essentially no change; adding a 45uF cap dropped the eff to about 47%.   
   I put two dimmers in series, then into the dual-trafo; eff = 81%, a little less/about the same. 
Adding a second 40W bulb, eff ~80%, about the same.
I replaced the two 40W bulbs with 2 7.5W LED bulbs, and the eff dropped to about 50%

I also tried switching connections, this time on TR2 output -- and the eff went down to less than 40%.

[Magluvin]

Lets say we have the original circuit, 2 trafo's and the load across 1 coil of the second trafo. What is the input with and without the load connected? Is there much difference?

If not, does the output to the load equal the difference of input with and without the load?

Just something to try. If the difference in input is smaller that what is output to the load, there might be something in the mix. ;]  Simple enough to try.

MaGs

[wattsup]

@all

I have done my set-up with my new isolated transformers and did not see anything out of the ordinary in the regular connection. I am putting down the same diagram as @JN did on page one but this time I am identifying each side of each coil so that guys can speak in terms of connections and "polarities".

I am saying polarities because even though this is AC fed to A-B, hence AC is transferred to C-D, once the AC from C-D hits the point E from one side and point G plus one side of the Load, the game changes, but how? It seems like the AC is forced into one directionality that would have one side slightly off phase. 

Anyways, when you set-up this circuit, you may have to change connections around and test the set-up in all variables while still keeping the diagram disposition intact. If you do that then you will eventually find the set-up I just made that is pretty freaky.

So I am also adding some info on my new transformers.
They are presently hooked up on all sides in the 120 volts mode.

But it depends on the transformer model, you start with this one below in one connection method, then just start switching the connections around to only one coil at a time.

I uploaded to youtube the following video....
http://www.youtube.com/watch?v=H7hfbVE4Hfo

Now going to work so tonight I will make a diagram showing the connections in that video.

wattsup

[a.king21]

Hi, wattsup
re dot convention.  Should there be a dot at E in your diagram?

[T-1000]

I uploaded to youtube the following video....
http://www.youtube.com/watch?v=H7hfbVE4Hfo

The wattmeter most likely shows measurent error. In best case you could find 100W+ 1 Ohm resistor and attach to "cold" wire from mains in series then put oscilloscope on resistor and see RMS amps.
You are mixing reactive power comming back from transformers with conventional power so funny things happen.