Thane Heins BI-TOROID TRANSFORMER

[Kator01]

Hi SchubertReijiMaigo,

indeed the signal is destorted  to a triangle which means, all meters read wrong values. So this test is useless.
The standart ac-meters are all build for pure ac-sinuswave.

Regards

Kator01

[broli]

Also to say something on noise a transformer makes. An "unloaded" transformer, ie one that's purely an inductor, makes so much noise because the magnetic domains are constantly flipping back and forward which has a mechanical aspect to it (magnetostriction). However when it's loaded the secondary which causes an opposite field reduces this domain flipping action and thus the mechanical vibration. An ideal conventional transformer that is fully loaded (powerfactor of 1) should have no domains being flipped because the field of the secondary is continuously canceling out the primary field.

Since in a BTT type transformer the powerfactor is 0 (as if the transformer is unloaded) we should see the vibration remain instead of decrease or vanish when the transformer is loaded. In fact it might even increase as the secondary core will also start to vibrate when it's loaded.

Just my 2 cents on that particular subject.

[penno64]

Hi Jack,

Any progress ?

Penno

[Jack Noskills]

Well I got me a true rms volt meter, BSI model BS1704. Those light bulbs are a bit misleading, I made several tests:

With no load both output coils showed 108 volts. I put 1 watt light bulb on one secondary and voltage on the other was 120 volts. With 40 watt bulb voltage was 170 volts, with 350 watt electric saw voltage was 190 volts and when secondary was shorted voltage was 198.5 volts. So adding load increased voltage in other side.

Test using 350 saw as load and primary shorted, no light bulbs.
Current in primary side settled down to 167 mA and output settled from 350 mA to 287 mA. Shows OU but not very good, maybe about 1.85 depending what value is used as output voltage, safe assumption is that 190 volts but I think it is actually higher. So input power used was about 37 watts and output 54.5 - 63.1 watts. I would need a true RMS wattmeter to confirm exactly. This is understandable as the amount of core that is in the alternate path is almost the same size in diameter that goes through the primary. To get more power out this ratio needs to be increased using more alternate paths or use different permeability cores.

When I used normal trafo version current in primary side was 287 mA and in secondary side it was 280 mA.

I think I will try a 3d version next, it will be easier to build. I put those E-I plates in top and bottom (as they are all I got) then I connect them with laminated iron rods and just put coils in there, primary in the center and secondaries in the corners. I have 4 coils I can play with and I should be able to measure the effect in third coil when load is added to two other secondaries. I have also in mind a third variation but lets see what I can get from this version. I have one big primary coil but it does not fit inside the E-I plates so I try putting it outside and couple it with intermediate coil. If I get any notable effects I can draw pictures of the setup.

[penno64]

Thanks Jack