Win's next 10kV project, a 1us ramp

Hello Win,

What if you'd package the avalanche part of the presentation with some really scientific lingo, lots of complicated math going all the way back to Maxwell, tons of integrals in there? Maybe folks won't ask out of fear to embarrass themselves in front of everybody.

Regards, Joerg

Hello John,

My favorite is the QB5/1750. The plate connection alone is an impressive steel rod of about 1/3" diameter. This tube has no problem whatsoever to sink a few amps. Even with the grid at 0V it already sits around 500mA.

Regards, Joerg

Hello Kevin,

Do you know what their peak current rating is for short duty cycles? The specs only cover the mA range because that's all they needed in TV designs.

Regards, Joerg

Hello Win,

Sven is right. Toroids don't leak much if the AL value of the core is high enough. Designing highly isolated supplies and signal coupling is my bread and butter and I never had leakage become a problem. #77 ferrite is great, or #43 for fast stuff. Getting certified wire for the primary is a huge job but only because my designs go into production in a heavily regulated industry. For a lab test rig you might get away with spark plug wire from the auto shop if you don't need many turns.

It's not difficult. Especially not in a lab situation, as long as your tech fully understands how not to compromise a 13kV barrier. And as long as the techs never, ever fire it up on their own.

Take a large enough core to make it easy for the techs. Up to 2" OD is often in stock and should be fine, larger could be special order.

Regards, Joerg

I don't think it's that big a deal. P-E will ask you what the end use is, and you can get in trouble if you export them. I have a couple, surplused out of Los Alamos. I could post a pic.

You might wear them out if you pulse them a lot, though. They were never intended to fire very many times.

John

Only if you honor abs max specs. I'd try it at 10KV. There's a lot of vacuum inside one of those jugs.

John

Hello Jim,

They are fast but there is no peak current data because it didn't matter for the HV regulator. If you overdo the peaks they might not live long.

Regards, Joerg

Hello Win,

You can get very large cores up to almost three pounds of weight, just have to make sure it's available in the right material:

Regards, Joerg

Hello Ken,

The simplified midwestern edition would consist of just three parts: Wires, a helluva big piezo, huge sledge hammer. And a six-pack of Schlitz, of course.

Regards, Joerg

They will want to talk to you, but if satisfied, they'll go away again. EGG now Perky-Elmer makes them, I think.

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You can stack them up to make a bigger core.

In article , John Larkin wrote: [...]

I like designs that involve "solid copper boxcars" too.

Hello Ken,

Yes, but be careful in a HV project. You don't want to re-create the northern lights in there.

Once I had a test setup where there was a somewhat regular clicking noise. Since I was certain that it didn't contain relays I turned off the lights and saw a blueish cloud. Upon a 'click' it disappeared and slowly built itself up again.

Regards, Joerg

Hello Win,

Get one that's not potted all the way. Take the long screws out or drill away the rivets if it has those. Then you can remove the spacers for the airgap between the core halves. AS long as you don't saturate it.

Regards, Joerg

That flyback isn't going to be doing much flybacking unless the load is blocked off during charge up.

A better tube might be the good-ol 715-ABC! WWII radar modulator tube, good for several amps at 20KV IIRC. At a very short duty-cycle of course as the plate can only dissipate a cople dozen watts. Still being made to this day!

Didn't you get the memo? This is the driver stage for the newest high power mind control equipment. It will penetrate a full quarter inch thick aluminum hat. Just think about it. All of those suckers who just wear tin foil hats won't stand a chance against this baby! A single, full power pulse will vaporize the foil, along with the scalp and part of the skull. That's why the thing has a 5% tolerance. If it was any looser, it would cause the brain to explode! ;-)

Wow, up to 6-inch diameter by 3/4-inch thick. Nice.

I can't quite picture what you're saying, can you expand? What do you mean, splitting the shield? Are you saying the coax will have 10kV across its dielectric for the last primary section?