Thane Heins Perepiteia.

[Steven Dufresne]

1)  the 2000 turns on Toroid 1 is meant for one side of the core, say on its left side and there is also 2000 turns on its right side,  so that all together Toroid 1 has got 4000 turns?  (Because you wrote 2000 turns per secondary coil and you also wrote each toroid has  two secondary coils, right?)

That's correct, you read it right. I don't have the answer to your second question.
-Steve
http://rimstar.org

[gyulasun]

1)  the 2000 turns on Toroid 1 is meant for one side of the core, say on its left side and there is also 2000 turns on its right side,  so that all together Toroid 1 has got 4000 turns?  (Because you wrote 2000 turns per secondary coil and you also wrote each toroid has  two secondary coils, right?)

That's correct, you read it right. I don't have the answer to your second question.
-Steve
http://rimstar.org

Steve,  thank you for confirming the number of turns question.  Re my second one, maybe Thane will be kind to answer.
I would have one more question, what is the DC resistance of the 4000 turn coil on Toroid 2 and of the 5500 turn coil on Toroid 3? 
Thank you for taking your time.

rgds,  Gyula

[johnnyl]

Ok, I've got some more questions:

Steve:
- When you say the toroid 1 output is appox. 12W out, you are saying that each of the two secondary coils of toroid 1 are giving 6W out, right?  Same with toroid 2 having 12W out per secondary and toroid 3 having 15W out per secondary, right?

Anyone:
- I have been trying to find information on the web describing the relationship between the primary and secondary coil of a transformer and how the back emf from the secondary affects the primary.  I am looking for this so that I can understand how a magnetically isolated primary, as in Thanes design, will differ from a regular transformer.  It would help me to see equations pertaining to this so I can get a quantitative idea of the effect and consequences.  So far, I have only found information referring to the back EMF of the primary coil inducing current in the secondary, but no discussion of the consequences of the induced back EMF of the secondary and the effect or role it plays on the primary.

Even when I read about load losses in a transformer, I have not seen any mention of the back EMF from a secondary and it's effect on a primary being a source of concern.  Documentation I have read so far lists winding resistance as the major load loss factor.  Having said that, if we are to continue increasing the windings on the secondary legs, are we also not increasing the winding resistance proportionally?  Since I haven't found any equations describing the beneficial effect of a magnetically isolated primary, how do these competing and oppositional factors compare to one another in magnitude?  For instance, is the magnetic isolation of the primary (a beneficial effect) stronger than that of increased winding resistance (a detrimental effect)?

If anyone has web links handy which address any of the questions, please post them so I can educate myself some more...  Thanks...

According to what I have read, an ideal transformer with no losses should have Power_in = Power_out.  Given the rough numbers Thane gave to Steven and Luc (which they can confirm or update later), the efficiencies of toroid 1, 2, and 3 are approximately: (12W/50W =) 24%, (24W/50W =) 48%, and (30W/50W =) 60%.  Assuming I have calculated this correctly (please correct me if I am wrong) I have a few questions:

- Transformers are supposed to be highly efficient (up to 99.75%).  Does it make sense that toroid 1, 2 and 3 could have losses of 76%, 52% and 40% respectively?  I've never built a transformer or tested any so I don't know what would be a normal loss range for a transformer of this sort.

- Obviously the efficiency of the toroidal transformer is increasing as N2 increases, but why?  With more copper the winding resistance is also increasing as N2 increases, so why is the efficiency going up?  What am I not understanding?  Is this due to the effect of the magnetically isolated primary?  (Afterthough: Hmm...  Could the increase in effeciency be because like the Power_waste = I^2*R equation used for electrical transmission lines, the efficiency goes up in this transformer as voltage goes up and therefore current goes down thus minimizing Power_waste?)

Johnny

[Steven Dufresne]

I would have one more question, what is the DC resistance of the 4000 turn coil on Toroid 2 and of the 5500 turn coil on Toroid 3? 

By DC resistance, do you mean connecting the probes of a multimeter to the wire ends and setting it to measure resistance? If not, tell me how to do it. If so, read on...

You opened up a can of worms. :-) I think there are issues with the coils on Toroid 3 so I can give you an estimated answer now and need more information before I can complete the measurements.

For Toroid 1, secondary 1: 25.71 ohms measured
For Toroid 1, secondary 2: 25.63 ohms measured
For Toroid 2, secondary 1: 53.08 ohms measured
For Toroid 2, secondary 2: 53.04 ohms measured
For Toroid 3, secondary 1: 73.7 ohms estimated
For Toroid 3, secondary 2: 73.7 ohms estimated

First off, if you look closely at the photos, you'll see that there are lots and lots of wires coming out of the coils. That's because the coils are wound 1000 turns at a time. Then the ends are connected up in series (well some were connected already, some I connect.) So for Toroid 1's secondary one, there are two 1000 turns wires and four ends. Connecting two of those ends gives a single 2000 turn winding. For Toroids 2 and 3, the actual turns are done with 24 AWG wire but the ends are different colored 22 AWG. So for the first 1000 turns, one end is a black 24 AWG wire and the other end is a white 24 AWG wire. I think it's done this way so that a wiring table can be made up and they can be connected in the right order. The partial wiring table I have for Toroid 3 is:
black - white (so these are the colors of the ends for one 1000 turn wire)
brown - orange
red - yellow
blue - gray
... and then there are striped wires for which I don't have a diagram and they aren't all connected. So I connect white with brown, orange with red, yellow with blue, ...

QUESTION 1: does the order matter? Can I connect white with red, yellow with brown, orange with blue instead? I ask because some are connected differently on the two secondaries (e.g. secondary 1, gray with striped red but secondary 2, gray with striped blue.) If the order doesn't matter then that may be why they're different.

QUESTION 2: does the direction matter? For example, when connecting the first two can I go black with orange instead of white with brown? It seems to matter since if on secondary one I connect them as above then my meter goes a little crazy but if I go with yellow - red instead of red - yellow then it's fine. Note that when I measure the turns individually with no wires connected then each is around 13.4 ohms, except for one of the stripped pairs which gives infinity. The meter is a Fluke 187 true RMS digital multimeter. On the resistance setting with beeping turned off, it keeps flashing "-0L kohm" and the bar graph keeps going off scale and repeating that display. With the beeping turned on, it correctly displays 41.2 ohms (approx. 3 x 13.4) but beeps every half second or so.

Anyway, to estimate Toroid 3 resistances, I took the first 1000 turn wire and measured its resistance, 13.4 ohms. I then did (13.4 / 1000) * 5500 = 73.7 ohms.

I wonder who had these Toroids before me because these resistance measurements are all I've done so far and there are definately issues.
-Steve
http://rimstar.org

[Heinstein]

Dear All,

I am responding to: aether22

?It would seem to me that the only way this can work is if indeed each secondaries flux shorts through the other* and this would leave little in the way of any net field from either of the secondaries freeing them up to have more ampere-turns than the field provided by the primary without canceling out the primary.?

Fluxes don?t CANCEL ? but they do ADD. You cannot cancel opposing fluxes inside ferromagnetic material, it is impossible because flux always follow the path of least reluctance ? which would be air once saturation is reached. Notice the directions of PRIMARY FLUX 1 and INDUCED SECONDARY 2 FLUX  (BI - Toroid Transformer NYKOLAI 2.jpg) in the transformer diagrams are in the same direction and are ADDATIVE so NET FLUX can only increase.

If this were not true then there would be no such thing as Lenz?s Law because the magnet field entering a coil of wire would be cancelled by the induced field exiting.

Lenz's Law
When an emf is generated by a change in magnetic flux according to Faraday's Law, the polarity of the induced emf is such that it produces a current whose magnetic field opposes the change which produces it. The induced magnetic field inside any loop of wire always acts to keep the magnetic flux in the loop constant. In the examples below, if the B field is increasing, the induced field acts in opposition to it. If it is decreasing, the induced field acts in the direction of the applied field to try to keep it constant.

?Another thought is that if the secondaries don't create a magnetic or inductive field then they should I think have a 90 degree phase relationship with the primary as opposed to a 180 degree phase relationship in a normal transformer. (except when it's unloaded then normal transformers show a 90 deg relationship)?

Using a purely resistive load (for now) the power factor for the secondaries is 1 (current and voltage in phase) ? which is also in phase with the primary.  Perhaps Steve and Luc can come to the lab on Tuesday with the ?small? toroid 1 and we can verify this on my watt/power factor meter.  I have already confirmed this for myself but I might still be wrong.

You can also see from the Toroid Coil Evolution diagrams ? that FLUXES DON?T CANCEL BUT THEY DO ADD ? if they did cancel the Toroid Generator application would not work but indeed it does.

To Gyula?s question:

?2) When the load tests were performed how much input energy increase has been noticed  on the watt meter in the moment of connecting the load to the secondary coils?  Putting it otherwise: the 50W input includes already the (possible) reflective effect of the load and if so then how much Watt the 50W input power decreases to when the load is disconnected??

None or virtually no primary power increase from no load to full load (short circuit). If the primary power goes up then your primary reluctance is too low and secondary Back EMF is causing it to go up ? time to make a new primary ? either with less area in the core ? less primary turns ? or a lower grade core material or increase the relative permeability of the secondary (which is our choice so we can get away with less copper and have a greater output as well).

The primary must not deviate from it?s 50 W no load value if it does something is amiss.

Note: The primary will respond (slightly) to the increase in flux in the secondary as load is applied because the reluctance of the secondary is increasing as the load on the secondaries is increased.

Cheers
Thane