I think @BobTPH and I were correct regarding it should not matter if one winds up or down.
One thing to note here though I still believe it is important to keep winding in the same orientation. Although I did not confirm this I am not going to even bother. That seems so obvious to me by now. No nagging thoughts about that one.


Here you can see 27 consecutive winds around a 100mm diam tube. the custom field meter reads. .3


Here You see the results when I wind back half way through.

 

A real 4.1kVA transformer

By the way. If I may be so sensitive. In what way is my transformer not real?

 

I think @BobTPH and I were correct regarding it should not matter if one winds up or down.
One thing to note here though I still believe it is important to keep winding in the same orientation. Although I did not confirm this I am not going to even bother. That seems so obvious to me by now. No nagging thoughts about that one.

View attachment 267010
Here you can see 27 consecutive winds around a 100mm diam tube. the custom field meter reads. .3

View attachment 267011
Here You see the results when I wind back half way through.

This also answers the question if we can stack the windings of coils. YES we can

 

This also answers the question if we can stack the windings of coils. YES we can

Well here comes the fine print. Apparently stacking is possible but it wont give us double the output.
So earlier suggestions regarding not to stack seem very valid.
I for one will no longer stack

 

Well here comes the fine print. Apparently stacking is possible but it wont give us double the output.
So earlier suggestions regarding not to stack seem very valid.
I for one will no longer stack

Sorry guys. Changing my mind again about stacking or not.
Please help me reach a conclusion that sticks a bit longer
With 27 non stacked winds.
To reach a custom field strength of .3 we need to pass 331 mvolts through the coil which it self draws 4.5 amps.

With around 13x2 stacked winds
To reach a custom field strength of .3 we can pass a bit less mvolts (317) and the coil is drawing a bit less amps (4.23)

That makes me think having a fat coil helps is delaying saturation of the coil. Certainly have a good core helps better with that but I am no longer so sure that stacking is a bad thing.

However I will try and prevent stacking non the less. Because it also helps make the transformer look a bit better. I know I've said I can care less about how it looks. I am starting to change my mind about that.

 

A real4.1kVA tra nsformer I measured a while ago had an off-load primary current at 240V of 0.63A.
How does yours compare?

@Ian0 , come one man. what made you imply my transformer is not real?

What if I told you that even vigortronic UK are telling me that they can't get it better than 60%. And what if I tell you that I will die trying to get anywhere near that?

And what If none of the above is true. (which it is) then still there is nothing that warrants the distinction between a real and an unreal transformer unless you tell us all how that distinction is made for all to determine valid or not.

ADDITION to: 1kVA tra nsformer I measured a while ago had an off-load primary current at 240V of 0.63A.
I have absolutly no idea what that all means.
what is KVa, off-load, and what has one.
I am a slow learner once again.
One of us suggested to go the inductance measurement route earlier.
And then I went and gave it a go and got intimidates reallllly quickly

ADDITION2:
So I kindly request all readers to react to my requests for help. Suggests ways on how to find information to learn more.
Suggest new ways of field testing, but then explain how to do it for dummies like I am.
And many other ways I have not thought of yet.

But I do not welcome just random blowback unless it is backed up

 

@Ian0 , come one man. what made you imply my transformer is not real?

I don't see ones like it offered for sale!

What if I told you that even vigortronic UK are telling me that they can't get it better than 60%.

That's typical for a very small transformer. Larger transformers are more efficient, >95% at 4kVA

ADDITION to: 1kVA tra nsformer I measured a while ago had an off-load primary current at 240V of 0.63A.
I have absolutly no idea what that all means.
what is KVa, off-load, and what has one.

kVA is the same as kW for a resistive load.
off-load = nothing connected to the secondary

 

May I please ask for some assistance?
For the life of me I can't find a schematic on how to hook up the 2 diode components that were suggested earlier into a single phase full bridge rectifier.

Is there anyone that can draw something crude? I need only the slightest of lines as long as it is clear what is connected to what.

 

I am not sure anymore who suggested compacting the powder.

I did try today.

I can compress it using a vice. It is compressible yet it will never become a solid structure with the force my vice can apply.
Also there is no noticeable field enhancement in compressed state.

I am not sure if it is worth trying to get bigger tools to compress more extreme

 

May I please ask for some assistance?
For the life of me I can't find a schematic on how to hook up the 2 diode components that were suggested earlier into a single phase full bridge rectifier.

Is there anyone that can draw something crude? I need only the slightest of lines as long as it is clear what is connected to what.

can you post a (low res) picture of the diode components in question?

 

can you post a (low res) picture of the diode components in question?

certainly.

 

Have you thought about using a coil of steel wire as the core?
https://www.toolstation.com/galvani...ZeHs302BwuWfy3JC-9caAsSREALw_wcB&gclsrc=aw.ds

 

Have you thought about using a coil of steel wire as the core?
https://www.toolstation.com/galvani...ZeHs302BwuWfy3JC-9caAsSREALw_wcB&gclsrc=aw.ds

I have not yet, at first glance though I am not sure it is electrically insulated thus of no use. Also it is rather thick. I am going with .4mm wire for the coils.

This was not to say I am not open to suggestions and not willing to change my mind. I constantly change my mind.
It's a process.

EDIT: ugg. sorry core is not the same as coil. my apologies. I will have to have some more time to get this one through my slow moving head

 

I have not yet, at first glance though I am not sure it is electrically insulated thus of no use. Also it is rather thick. I am going with .4mm wire for the coils.

This was not to say I am not open to suggestions and not willing to change my mind. I constantly change my mind.
It's a process.

EDIT: ugg. sorry core is not the same as coil. my apologies. I will have to have some more time to get this one through my slow moving head

True, it could perhaps do with a bit of insulation to stop eddy currents. You could spray it with varnish.

 

True, it could perhaps do with a bit of insulation to stop eddy currents. You could spray it with varnish.

Although I am happy for suggestions. I am not going to entertain this one at the moment. I am waiting to go all out on the powder route.
If I fail to improve on the 39% efficiency I have now as my baseline I will report it. At which time please remind me again about this avenue then if one thinks it could help boost efficiency.

 

With regards the question of full wave rectification using only 2 diodes, this requires a centre tapped transformer, where the centre tap is the zero volt line and the plus volts is fed from each of the windings via a single diode. With a single secondary winding, a bridge rectifier consisting of 4 diodes is needed to achieve full wave rectification.

 

The VS-UFB280FA20 diode modules are 2 diodes in 1 package so you have 4 and can therefore make a full wave bridge rectifier.

Like this:

 

The VS-UFB280FA20 diode modules are 2 diodes in 1 package so you have 4 and can therefore make a full wave bridge rectifier.
View attachment 267723
Like this:
View attachment 267724

I drew that a stupid way. I don't know why, I was trying to make it as close to the normal symbol for bridge rectifier. And now that I realized there is a better way to draw it I'm not sure why the normal symbol is drawn the way that it is. I think I will draw bridge rectifiers this way from now on. Simpler and makes more sense to me.

 

I drew that a stupid way. I don't know why, I was trying to make it as close to the normal symbol for bridge rectifier. And now that I realized there is a better way to draw it I'm not sure why the normal symbol is drawn the way that it is. I think I will draw bridge rectifiers this way from now on. Simpler and makes more sense to me.
View attachment 267733

Hahaha it happens to the best of us. Have no shame about it

I will stare at this schematic as well for a while. I think I have your first one now totally second nature in the meantime.
It will take me some more staring to also incorporate this one.

They both work do they? It's only the schematic-al layout that is different? I am guessing it should be otherwise that would mean there are more ways to connect 4 diodes in a single phase full bridge rectifier setup than one.

Anyway I already started experimenting with how to get a 35mm2 wire on these tiny terminals.

Should I fail I will get 1000 amp diodes if they exsist so that the terminals will be elephant size

 

Anyway I already started experimenting with how to get a 35mm2 wire on these tiny terminals.

https://uk.farnell.com/multicomp-pr...m6-2awg-pk5/dp/2915579?st=ring crimp terminal