Donald Smith Devices too good to be true

[Wistiti]

you could try the Ultrafast version of 1N5408, just replace "1N" with "UF". UF5408
http://www.vishay.com/docs/88756/uf5400.pdf
75 ns recovery time

I ordered a lot of these cut them short, connect by soldering and wrap them with teflon then electrical tape, put it inside a ballpen *case for extra protection and sturdiness and you will have UF high voltage diode with less leakage (its just going to be longer than the expensive ones.), but it works, this is what I use.

or maybe the low amp version of it. uf4007 (1kv 1A). these are more flexible and much easier to connect to form like a spiral, so it wont be that long (considering you have to connect 30 in series to achieve 30kv).

The 5408 also have an "SF" version SF5408 it is also rate 1kv/3a/75ns.



Thank you Soundiceuk for the reply on the pot. I have another question about the fixed capacitor c1-c2. The one I have under hand are ceramic disc (see the photo) They are quite smaller than the doorknob one I see in the photo of guys steup... Do you think they will do the job?

[Wistiti]

Better scale image.

[tswift]

It might work, at least it's worth a try. The amount of ripple current through them is the problem, they will be subject to many charge/discharge cycles per second with every pulse of the PPV. If the gap breakdown voltage was the full 20KV rating of the cap I think you might have a problem with this, but running at a narrow gap width the breakdown voltage is probably more like 1000-1500V and I'm sure they can handle this. I tend to suspect that in the yet-to-be-seen future improvements of the device they will be operated closer to their voltage ratings and you might find them getting warm or failing entirely. But for now I would use them so it's one less part to spend money on.

[soundiceuk]

The 5408 also have an "SF" version SF5408 it is also rate 1kv/3a/75ns.

Got to be 100ns

I have another question about the fixed capacitor c1-c2. The one I have under hand are ceramic disc (see the photo) They are quite smaller than the doorknob one I see in the photo of guys steup... Do you think they will do the job?

I'll find out if they will do for a proof of concept.

These are what one of the builders is using.

[soundiceuk]

Yes, these will work.


These look huge in comparison!

[Wistiti]

Thank you guys for the info on the cap. It is good news!

Sorry for that but I have another question... (as I have said before I may have many!! )

It is the second time I see a replication using magnet wire on the hv side. (L1-L2) Do these wire are really enough insulate for that??? If so it is another good news cause I have a bunch of them. For how much volt are they be made for? Maybe using these magnet wire with some spacer between the turn to avoid arcing, I think of something like plastic wire from a grass trimmer...

[Wistiti]

A question about the ant. Can the 468ft be put over an existing building (like in the schematic) or it is not recomand??

[soundiceuk]

The coil is put there just for the photo.

The real coil should be HV wire.

The only third party working replication I have seen is Mwtj and his uses HV wire.

Mwtj did say in a post that there was loads of static and corona with magnet wire so he switched to 1KV magnet wire.

That was really on its limits using 15kv-20kv.

Magnet wire isn't ideal.

Maybe if you space it out you will get away with it for a proof of concept.

[soundiceuk]

A question about the ant. Can the 468ft be put over an existing building (like in the schematic) or it is not recomand??

As long as it is well insulated that will be fine.

It is only for experimentation purposes and not for use in thunder and lighting storms or you will need a lightning arrestor.

Consider Mwtj's grid design also.

[Wistiti]

Hi Soundiceuk and thank you for your quick reply! It is appreciate.

My last question ... ...for today!

Do the variable air cap really need to be 1,5kv rating?? In the new version (V.7.0.0) they both are on the low voltage side... I don't understand why a 250v will not do the job?
If so it will be another great news cause these are much less expensive and easily found than the 1500v ones.

Thank you again for your great support!

[soundiceuk]

They were used to prevent the primary and secondary arcing out.

The ions flow in surges and sometimes the surges are huge. Like waves of the ocean!

Overkill if you are not using a high voltage multiplier.

You could get away with using 50V rating for a proof of concept.

[med.3012]

another technical request


How much level can the earth ground quality effect an over energy device ? i am doing some experiment where the earth play a critical role , standing waves can be seeing very easily either with a small light bulb or using a scope probes ..

all the test are based on the ETBC but with a ferrite rod inside, the capacitors banks can be charged only when there's an earth ground, now the question arise to how much level will affect the system ?


thanks in advance !

[med.3012]

this is a quote from smith.pdf

[Wistiti]

My question of the day!

How do you guys achieve and measure the 500khz?
I suppose it is by varying the gap on the PPV'X' but, in the past, I fried MANY meters on project with spark gap and I need help on the correct way to achieve it...

Any help will be appreciate!

[soundiceuk]

Ideally you need a frequency meter.