The Gold Ring

[Littleenki]

Fonetic spelling   Seems it worked as you understood

English  Bah Humbug

I agree, lets switch to Deutsche!

Chus!

[deuem]

How big would a lifter need to be to noticeably provide trust for a locomotive that weighs several tons?

You would not use a locomotive. You would just push with the lifter. Forget heavy cargo, just see if someone can get a flatbed to move on its own. Sort of like putting a jet engine on the caboose........

[PLAYSWITHMACHINES]

After frying a few (rare) flybacks, i found a better solution, using circuits from flatbed scanners, & trashing a lot of microwave ovens, i give you:

The Peggy ultralite 30Kv supply!Full details tomorrow (if my job doesn't get in the way )

[PLAYSWITHMACHINES]

I had a rather frustrating time when i fried a TV flyback transformer, so i decided to look for an alternative.

Since we are looking for a lightweight HT lifter supply, i thought i'd have a go.......

So here is the 'peggy' ultralight 30Kv supply!



These are two circuit boards from a flatbed scanner, they power the tiny lamp that moves over the paper.
They give about 3Kv each, in their original set-up.

I copied the circuit diagram for you. It's dead simple, just 2 transistors, a few caps & resistors...
Tip for inventors: You can do this directly with big trannies like 3055's all you need to do is drop the base bias resistor to about 300-500 ohms...

I placed tiny foil heatsinks on the transistors, coz i'm gonna run them at full power & they are gonna sweat
Here you can see how small these circuits are:




So i've got 2 of them running in antiphase, each with it's own Cockroft-Walton multiplier for the + and - outputs.
Good for about 30Kv and some good current there as well.....



Here are the current & voltage meters:



9V at 930mA is about 8.5 Watts!
(this is on full load during a discharge, without a spark it sits around 350mA, just over 3 watts)


So now that's done, i thought about building a 'standard model' lifter to try it on.
With long wires, because this lifter won't lift this supply, but a bigger one will

I've used plastic straws with a 'bendy bit' in them, i used the bends to make nice rounded corners for my lifter











The foil goes around the lower beam, giving it a large radius opposite the wire, trailing to a thin edge.
Rather like an aeroplane wing...

Hopefully there will be a test-flight tomorrow, if i get the time
Aeronautically yours,
PWM

[Littleenki]

Bad ass setup there Luke, especially withthe voltage multiplier!
Its gonna fly, I can feel it!
Cheers!

[PLAYSWITHMACHINES]

I'll be happy if it flies before it fries 

Off to bed, & electric dreams...

[Littleenki]

I'll be happy if it flies before it fries 

Off to bed, & electric dreams...

Electric dreams in an electric universe!
At 30 kv my triangular lifter lasted about two minutes before the balsa wood caught fire!
As you are the PWM I know you have a fire extinguisherhandy at all times!

Any idea what frequency your going to pulse it at?
Le

[PLAYSWITHMACHINES]

Both circuits freely oscillate at about 65KHz, but all those caps & diodes make it pretty much DC.
I won't know until i put a scope on it (which i'm pretty reluctant to do) maybe i'll use the battery portble scope, as it's fully isolated....
Also got a dirt cheap plastic kitchen scale for 1 euro
Ideal for thrust measurements.
Right now, i have to move the wire down a bit & re-tension it, not easy since it's only 0.1mm thick (2 thousands of an inch) and can break very easily.
Peggy has a short skirt, only 36mm, so the wire distance still has to be found by trial & error.
I'm off for the weekend, so maybe no more experiments till next week.
Later!

[robomont]

i would think a wire that thin would vaporize.

[Pimander]

Try not to burn the place down mate. 

[Littleenki]

the thinner the better when deciding the top electrode. I use what would amount to one strand of an rca cable center conductor.

It will only vaporize if it arcs heavily.

Aside from that itll last quite a while.

65khz is pretty fast, so yes essentially DC but still a/c in fact. I found the lower the frequency, the better ability to get it off the ground..then increasing the frequency makes it hover quite softly with nearly zero chance of arcing.

I never arced across when using frequencies above 20khz..so 65 khz should be quite safe. Mine wouldnt lift at at anything above 25khz though, so good luck Luke!

Also, lower frequencies can cause arcing at the flyback pins, so using the Peggy will make that a non issue.

Cheers!

[robomont]

thanks le ,for the advice.
its nice being around tallented people.
what about using a needle as the top electrode instead of a wire?

[Littleenki]

thanks le ,for the advice.
its nice being around tallented people.
what about using a needle as the top electrode instead of a wire?

Anytime brother!

not sure how a needle would work, it might create a cone shaped field though...Hmmm.

[robomont]

i thought it was dc pulses.
it doesnt go into the negative range ,does it?
wouldnt that reverse the polarity?

[Pimander]

i thought it was dc pulses.
it doesnt go into the negative range ,does it?
wouldnt that reverse the polarity?

Pardon?