Joule Thief

[Mk1]

@electricme

Nice picture!

Also when shopping for iron wire , remember that so far the ones that have been used with success are soft iron(same as electromagnet)
Ans it is coated with green paint isolating it ,it may prevent shorts.The reason i think this is important is that stainless or harden types of iron stay magnetized even if a little , but may create a problem .The reason soft steel is used in electromagnet is it will not become a magnet no mater how much volts you put in.

I think the good material is one that also is a good radio waves isolator(shield)

Mark

Edit : also have you tried all your taps in parallel?And getting that reading is real hard on iron coil it the reason i was mentioning the bulb.

[Pirate88179]

@ Jim:

Nice pics!!!


@ All:

This business about the iron wire.....I really think we need to find a way to insulate it when wrapping a toroid.  This could be done in several ways.  Like others on here, I have done a lot of work with the Stubblefield bifilar coil using iron and copper wire.  As Jim mentioned, when shopping for iron wire, take a magnet with you....it will save you a lot of trouble from buying "iron" wire that has little to no iron in it.

The florist's wire, painted, is one way to do this.  I was thinking about spraying my wire with a clear coat of poly, or anything else that would make it more like magnet wire.  Or, one could, as I did, wind cotton string, or some other insulation material, in between the wires on the toroid.  I don't like this method as we don't have a lot of room to begin with.  But, knowing what little I know, if we just wrap iron wire on a toroid, I believe it will short to itself and not work the way we intend it to.  Maybe it would be easier to get this Florist's wire?  Maybe I am wrong here but, I can't see how this would work if the coil windings are shorted.  My 2 cents.

Bill

[Mk1]

@pirate

Good comment , but since no book as far as i know tells us about what is going on , we may need to check it anyway, lets do it right this time!

Thanks, for letting me in your Topic.

Mark

I don't see many tpu master around here , Are they just hiding .They must be busy some how.

[electricme]

@MK1
No, the taps are in series with each other, eg
Wire start at 1 turn put on 100 turns
(I should have begun 20 turns here myself and left out the 1st 100 turns it would have given me a higher output)

Take out a loop, twist the wire (dont cut it)

put on 20 more turns take out another loop
put on another 20 turns take out a loop

Do this another 8 times
So 100 + 10x20s = 300 turns in total.

Feed the AC from the first JT into the primary of the 2nd JT, its a multi step transformer, used oppersate to a multi tap stepdown plugpack

The reason I did this, is because I wanted to see if I could control a much higher output voltage by the lower primary voltage, because to lower the risk fooling about HT settings, does this make sence?

To see the principle working, take 2 identical transformers, and put them back to back.

                                                WARNING,    DANGEROUS VOLTAGES
Due to the nature of the internet, where anyone can read this post and not notify they have done so and decide to carry out the following experiment, you do so at the sole risk to yourself and absolve all blame to anyone other than yourself if you suffer from an electric shock.

If you know you are not qualified, or a novice, DON'T do this experiment.
If you ignore this warning and injure yourself thats not my fault.
Only suitably qualified exprerienced persons who know and understand what they are doing should try this.

If you carry out this experiment, you take upon yourself the consquences and can only blame yourself.

*********************************************************************************************************************************

Using a 240v ac power cord that has a 3 pin plug attatched, solder the free ends  to the Primary 240v input tabs of T1 (1st transformer).

Solder 2 insulated hookup wires from the 12v ac out tabs on the T1,
Next solder the free ends onto the 12v tabs onto T2 (transformer 2).

Solder a 12v tail light bulb onto these wires.

Solder another 240v lead to the output of T2 of the 2nd transformer.

Then afix a 240v bayanet light fitting to the ends of this lead

Install a 240v bulb to the bayanet fixture

When the power is applied, it is converted from 240v ac to 12v ac, taken to the 2nd transformer and converted again back to 240v AC
The smaller 12v bulb glows showing you it is at 12v.

This principle works on big and small transformers, on low and high voltages.

jim

[Pirate88179]

@ Jim:

(Quote from Jim)  "If you know you are not qualified, or a novice, DON'T do this experiment.
If you ignore this warning and injure yourself thats not my fault.
Only suitably qualified exprerienced persons who know and understand what they are doing should try this.

If you carry out this experiment, you take upon yourself the consquences and can only blame yourself."


Well, I guess this leaves me out, ha ha.  Great post, thanks.



@ MK1:

No, thank you for posting here and being a part of all this.  You have done a lot and answered many questions and provided much information and ideas.  We are very happy to have you here!

Bill