On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

>On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:
>
>> Where's Sloman's design? I really wanted to see that.
>>
>> Here's a suggestion.
>>
>> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1
>>
>> It needs to be tested and maybe tweaked. I haven't designed with tubes
>> lately.
>
> Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
> Now, I'm waiting for parts.

I thought it was cute to have a single 6-volt power supply, but that
nails the positive grid (I keep wanting to say gate) drive at 6 too.

Whit's idea of push-pull drive is cute but needs another power supply,
and in its most basic form forces the + and - grid voltages to be
equal, although that is probably OK and easily fixed. One 556, the
dual 555, could drive both the grid and the cathode.

You should build in the scope pickoff, so you can see what's going on.
We usually build in a signal pickoff/monitor circuit on pulsers.

>
> I need to start thinking about a filter cap for my DC. I have seven, 1uf 2000V caps from microwave ovens.
> That's 140nF.
>
> Any reason I can't series them, as a first iteration filter?
>
>Upgrade when if we go to higher voltages. Pretty sure they have built in 1M? parallel resistors.
>
> Thanks, Mikek

You don't need much filter capacitance, driving a 10 Meg load, and
ripple won't matter much here. Equalizing/discharge resistors are a
good idea. Safety warning: a neon bulb relaxation oscillator. [1] [2]

I used to get military surplus HV oil caps, big metal cans.

Last-gen CRT-type TVs used to have a potted flyback-rectifier thing,
which would be another way to get HV. I'd expect that ebay has some.
They could make 25KV or some such, conveniently positive, and are
small and light and relatively safe. I think they used the CRT bulb as
the filter cap, but the flyback freq was 15K so they didn't need much
cap. There are old TV doorknob caps too.

[1] I had a project where I wanted to blink an LED from a HV supply,
which is an interesting problem. The breadboard worked but the
customer went away.

[2] Two neons in parallel is fun too. That was in an old PopTronics
mag.

On Saturday, May 13, 2023 at 8:50:52 AM UTC-5, John Larkin wrote:
> On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
> <amd...@gmail.com> wrote:
> >On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:
> >
> >> Where's Sloman's design? I really wanted to see that.
> >>
> >> Here's a suggestion.
> >>
> >> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1
> >>
> >> It needs to be tested and maybe tweaked. I haven't designed with tubes
> >> lately.
> >
> > Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
> > Now, I'm waiting for parts.
> I thought it was cute to have a single 6-volt power supply, but that
> nails the positive grid (I keep wanting to say gate) drive at 6 too.
>
> Whit's idea of push-pull drive is cute but needs another power supply,
> and in its most basic form forces the + and - grid voltages to be
> equal, although that is probably OK and easily fixed. One 556, the
> dual 555, could drive both the grid and the cathode.

I'm already thinking about two neon sign transformers, and another
complete tube switcher, with opposite polarity, so it will ± 7kV for a 14KV differential.

Would we build a negative switcher or to positives and invert the input to one?

>
> You should build in the scope pickoff, so you can see what's going on.
> We usually build in a signal pickoff/monitor circuit on pulsers.

Agree on that, Need to source a 1nF HV cap.

> >
> > I need to start thinking about a filter cap for my DC. I have seven, 1uf 2000V caps from microwave ovens.
> > That's 140nF.
> >
> > Any reason I can't series them, as a first iteration filter?
> >
> >Upgrade when if we go to higher voltages. Pretty sure they have built in 1M? parallel resistors.
> >
> > Thanks, Mikek
>
> You don't need much filter capacitance, driving a 10 Meg load, and
> ripple won't matter much here. Equalizing/discharge resistors are a
> good idea. Safety warning: a neon bulb relaxation oscillator. [1] [2]

I have searched for a Red blinking light, that would power on when the power is turned on.
I have couple setting in my Amazon cart, but as yet unsure what to do.
Now that filter caps are involved, I need something that will display until the filter caps are discharged.
I'm not sure a neon bulb would be enough of an attention getter.
Maybe a neon bulb and a phototransistor to trigger the red flasher until the HVDC is diminished :-)
But yes safety is of great importance.

>
> I used to get military surplus HV oil caps, big metal cans.
>
> Last-gen CRT-type TVs used to have a potted flyback-rectifier thing,
> which would be another way to get HV. I'd expect that ebay has some.
> They could make 25KV or some such, conveniently positive, and are
> small and light and relatively safe. I think they used the CRT bulb as
> the filter cap, but the flyback freq was 15K so they didn't need much
> cap. There are old TV doorknob caps too.
>
> [1] I had a project where I wanted to blink an LED from a HV supply,
> which is an interesting problem. The breadboard worked but the
> customer went away.
>
> [2] Two neons in parallel is fun too. That was in an old PopTronics
> mag.

That should have said I need to source a HV 1pf capacitor.
Mikek

On Sat, 13 May 2023 08:07:17 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

>On Saturday, May 13, 2023 at 8:50:52?AM UTC-5, John Larkin wrote:
>> On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
>> <amd...@gmail.com> wrote:
>> >On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:
>> >
>> >> Where's Sloman's design? I really wanted to see that.
>> >>
>> >> Here's a suggestion.
>> >>
>> >> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1
>> >>
>> >> It needs to be tested and maybe tweaked. I haven't designed with tubes
>> >> lately.
>> >
>> > Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
>> > Now, I'm waiting for parts.
>> I thought it was cute to have a single 6-volt power supply, but that
>> nails the positive grid (I keep wanting to say gate) drive at 6 too.
>>
>> Whit's idea of push-pull drive is cute but needs another power supply,
>> and in its most basic form forces the + and - grid voltages to be
>> equal, although that is probably OK and easily fixed. One 556, the
>> dual 555, could drive both the grid and the cathode.
>
> I'm already thinking about two neon sign transformers, and another
>complete tube switcher, with opposite polarity, so it will ± 7kV for a 14KV differential.

The oil emulsion thing is inherently AC-coupled, no? One supply and
one tube does that.

And one neon sign transformer could make +-HV if you really wanted
that.

>
>Would we build a negative switcher or to positives and invert the input to one?

I think Whit's idea is to drive the grid and cathode of the one tube,
0 and +12 maybe, antiphase. Not to have pos and neg HV.

My suggested circuit works well making low duty cycle negative HV
pulses. Positive-going pulses would be harder.

>
>>
>> You should build in the scope pickoff, so you can see what's going on.
>> We usually build in a signal pickoff/monitor circuit on pulsers.
>
>Agree on that, Need to source a 1nF HV cap.

Make it!

>
>
>> >
>> > I need to start thinking about a filter cap for my DC. I have seven, 1uf 2000V caps from microwave ovens.
>> > That's 140nF.
>> >
>> > Any reason I can't series them, as a first iteration filter?
>> >
>> >Upgrade when if we go to higher voltages. Pretty sure they have built in 1M? parallel resistors.
>> >
>> > Thanks, Mikek
>>
>> You don't need much filter capacitance, driving a 10 Meg load, and
>> ripple won't matter much here. Equalizing/discharge resistors are a
>> good idea. Safety warning: a neon bulb relaxation oscillator. [1] [2]
>
>I have searched for a Red blinking light, that would power on when the power is turned on.
> I have couple setting in my Amazon cart, but as yet unsure what to do.
>Now that filter caps are involved, I need something that will display until the filter caps are discharged.
> I'm not sure a neon bulb would be enough of an attention getter.
> Maybe a neon bulb and a phototransistor to trigger the red flasher until the HVDC is diminished :-)
> But yes safety is of great importance.
>
>>
>> I used to get military surplus HV oil caps, big metal cans.
>>
>> Last-gen CRT-type TVs used to have a potted flyback-rectifier thing,
>> which would be another way to get HV. I'd expect that ebay has some.
>> They could make 25KV or some such, conveniently positive, and are
>> small and light and relatively safe. I think they used the CRT bulb as
>> the filter cap, but the flyback freq was 15K so they didn't need much
>> cap. There are old TV doorknob caps too.
>>
>> [1] I had a project where I wanted to blink an LED from a HV supply,
>> which is an interesting problem. The breadboard worked but the
>> customer went away.
>>
>> [2] Two neons in parallel is fun too. That was in an old PopTronics
>> mag.

On Saturday, May 13, 2023 at 10:55:03 AM UTC-5, John Larkin wrote:
> On Sat, 13 May 2023 08:07:17 -0700 (PDT), Lamont Cranston
> <amd...@gmail.com> wrote:
> >On Saturday, May 13, 2023 at 8:50:52?AM UTC-5, John Larkin wrote:
> >> On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
> >> <amd...@gmail.com> wrote:
> >> >On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:
> >> >
> >> >> Where's Sloman's design? I really wanted to see that.
> >> >>
> >> >> Here's a suggestion.
> >> >>
> >> >> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1
> >> >>
> >> >> It needs to be tested and maybe tweaked. I haven't designed with tubes
> >> >> lately.
> >> >
> >> > Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
> >> > Now, I'm waiting for parts.
> >> I thought it was cute to have a single 6-volt power supply, but that
> >> nails the positive grid (I keep wanting to say gate) drive at 6 too.
> >>
> >> Whit's idea of push-pull drive is cute but needs another power supply,
> >> and in its most basic form forces the + and - grid voltages to be
> >> equal, although that is probably OK and easily fixed. One 556, the
> >> dual 555, could drive both the grid and the cathode.
> >
> > I'm already thinking about two neon sign transformers, and another
> >complete tube switcher, with opposite polarity, so it will ą 7kV for a 14KV differential.

I was thinking the differential to get higher voltage, in the end I would like to have 30kV,
whether that is single sided or ± I don't know what is best.
>
> The oil emulsion thing is inherently AC-coupled, no? One supply and
> one tube does that.
>
> And one neon sign transformer could make +-HV if you really wanted
> that.

> >Would we build a negative switcher or to positives and invert the input to one?
> I think Whit's idea is to drive the grid and cathode of the one tube,
> 0 and +12 maybe, antiphase. Not to have pos and neg HV.

I don't understand that.

> My suggested circuit works well making low duty cycle negative HV
> pulses. Positive-going pulses would be harder.

OK, I think that is a logic thing. Since the circuit is acting to bring the output to 0V,
you are calling that negative HV pulses?

> >>
> >> You should build in the scope pickoff, so you can see what's going on.
> >> We usually build in a signal pickoff/monitor circuit on pulsers.
> >
> >Agree on that, Need to source a 1nF HV cap.
> Make it!

Ya, I already looked at dielectric breakdown voltages, it seems it takes a thick dielectric.

A 1" long copper pipe with a 0.25" copper pipe in the center is 2pf.
If I fill it with silicone sealer (~3) I'm up to 6pf and can shorten it considerably.

Is silicone sealer better than air for breakdown voltage?

On Sat, 13 May 2023 09:37:47 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

>On Saturday, May 13, 2023 at 10:55:03?AM UTC-5, John Larkin wrote:
>> On Sat, 13 May 2023 08:07:17 -0700 (PDT), Lamont Cranston
>> <amd...@gmail.com> wrote:
>> >On Saturday, May 13, 2023 at 8:50:52?AM UTC-5, John Larkin wrote:
>> >> On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
>> >> <amd...@gmail.com> wrote:
>> >> >On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:
>> >> >
>> >> >> Where's Sloman's design? I really wanted to see that.
>> >> >>
>> >> >> Here's a suggestion.
>> >> >>
>> >> >> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1
>> >> >>
>> >> >> It needs to be tested and maybe tweaked. I haven't designed with tubes
>> >> >> lately.
>> >> >
>> >> > Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
>> >> > Now, I'm waiting for parts.
>> >> I thought it was cute to have a single 6-volt power supply, but that
>> >> nails the positive grid (I keep wanting to say gate) drive at 6 too.
>> >>
>> >> Whit's idea of push-pull drive is cute but needs another power supply,
>> >> and in its most basic form forces the + and - grid voltages to be
>> >> equal, although that is probably OK and easily fixed. One 556, the
>> >> dual 555, could drive both the grid and the cathode.
>> >
>> > I'm already thinking about two neon sign transformers, and another
>> >complete tube switcher, with opposite polarity, so it will ? 7kV for a 14KV differential.
>
>I was thinking the differential to get higher voltage, in the end I would like to have 30kV,
> whether that is single sided or ± I don't know what is best.
>>
>> The oil emulsion thing is inherently AC-coupled, no? One supply and
>> one tube does that.
>>
>> And one neon sign transformer could make +-HV if you really wanted
>> that.
>
>
>> >Would we build a negative switcher or to positives and invert the input to one?
>> I think Whit's idea is to drive the grid and cathode of the one tube,
>> 0 and +12 maybe, antiphase. Not to have pos and neg HV.
>
> I don't understand that.

Make a 0 to 12 volt positive pulse and apply it to the grid. Invert
it, still 0 to +12 but out of phase, and connect that to the cathode.
So the grid is usually -12 relative to the cathode and +12 during the
pulse. You can do it all with one NE556.

I hate the concept because I didn't invent it.

>
>> My suggested circuit works well making low duty cycle negative HV
>> pulses. Positive-going pulses would be harder.
>
>OK, I think that is a logic thing. Since the circuit is acting to bring the output to 0V,
>you are calling that negative HV pulses?

If a voltage is high positive and occasionally blips to ground, I call
that a negative pulse. Or negative-going maybe. Like the OUT here:

https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?dl=0

The tube circuit does that well. The opposite is trickier, frys the
resistors among other things.

>
>
>> >>
>> >> You should build in the scope pickoff, so you can see what's going on.
>> >> We usually build in a signal pickoff/monitor circuit on pulsers.
>> >
>> >Agree on that, Need to source a 1nF HV cap.
>> Make it!
>
> Ya, I already looked at dielectric breakdown voltages, it seems it takes a thick dielectric.
>
>A 1" long copper pipe with a 0.25" copper pipe in the center is 2pf.
>If I fill it with silicone sealer (~3) I'm up to 6pf and can shorten it considerably.

That's complex. I was thinking of a variant on the gimmick capacitor,
namely two pieces of insulated wire, parallel, with shrink tubing
overall. Or two layers on a PC board.

You could hack a small piece of copperclad FR4 too, and add wires. The
usual stuff is about 15 pF per square inch. You could make the entire
attenuator out of one piece of dremeled FR4!

On Saturday, May 13, 2023 at 1:46:08 PM UTC-5, John Larkin wrote:
> On Sat, 13 May 2023 09:37:47 -0700 (PDT), Lamont Cranston
> <amd...@gmail.com> wrote:
> >On Saturday, May 13, 2023 at 10:55:03?AM UTC-5, John Larkin wrote:
> >> On Sat, 13 May 2023 08:07:17 -0700 (PDT), Lamont Cranston
> >> <amd...@gmail.com> wrote:
> >> >On Saturday, May 13, 2023 at 8:50:52?AM UTC-5, John Larkin wrote:
> >> >> On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
> >> >> <amd...@gmail.com> wrote:
> >> >> >On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:
> >> >> >
> >> >> >> Where's Sloman's design? I really wanted to see that.
> >> >> >>
> >> >> >> Here's a suggestion.
> >> >> >>
> >> >> >> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1
> >> >> >>
> >> >> >> It needs to be tested and maybe tweaked. I haven't designed with tubes
> >> >> >> lately.
> >> >> >
> >> >> > Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
> >> >> > Now, I'm waiting for parts.
> >> >> I thought it was cute to have a single 6-volt power supply, but that
> >> >> nails the positive grid (I keep wanting to say gate) drive at 6 too..
> >> >>
> >> >> Whit's idea of push-pull drive is cute but needs another power supply,
> >> >> and in its most basic form forces the + and - grid voltages to be
> >> >> equal, although that is probably OK and easily fixed. One 556, the
> >> >> dual 555, could drive both the grid and the cathode.
> >> >
> >> > I'm already thinking about two neon sign transformers, and another
> >> >complete tube switcher, with opposite polarity, so it will ? 7kV for a 14KV differential.
> >
> >I was thinking the differential to get higher voltage, in the end I would like to have 30kV,
> > whether that is single sided or ą I don't know what is best.
> >>
> >> The oil emulsion thing is inherently AC-coupled, no? One supply and
> >> one tube does that.
> >>
> >> And one neon sign transformer could make +-HV if you really wanted
> >> that.
> >
> >
> >> >Would we build a negative switcher or to positives and invert the input to one?
> >> I think Whit's idea is to drive the grid and cathode of the one tube,
> >> 0 and +12 maybe, antiphase. Not to have pos and neg HV.
> >
> > I don't understand that.
> Make a 0 to 12 volt positive pulse and apply it to the grid. Invert
> it, still 0 to +12 but out of phase, and connect that to the cathode.
> So the grid is usually -12 relative to the cathode and +12 during the
> pulse. You can do it all with one NE556.
>
> I hate the concept because I didn't invent it.
> >
> >> My suggested circuit works well making low duty cycle negative HV
> >> pulses. Positive-going pulses would be harder.
> >
> >OK, I think that is a logic thing. Since the circuit is acting to bring the output to 0V,
> >you are calling that negative HV pulses?
> If a voltage is high positive and occasionally blips to ground, I call
> that a negative pulse. Or negative-going maybe. Like the OUT here:
>
> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?dl=0
>
> The tube circuit does that well. The opposite is trickier, frys the
> resistors among other things.
> >
> >
> >> >>
> >> >> You should build in the scope pickoff, so you can see what's going on.
> >> >> We usually build in a signal pickoff/monitor circuit on pulsers.
> >> >
> >> >Agree on that, Need to source a 1nF HV cap.
> >> Make it!
> >
> > Ya, I already looked at dielectric breakdown voltages, it seems it takes a thick dielectric.
> >
> >A 1" long copper pipe with a 0.25" copper pipe in the center is 2pf.
> >If I fill it with silicone sealer (~3) I'm up to 6pf and can shorten it considerably.
> That's complex. I was thinking of a variant on the gimmick capacitor,
> namely two pieces of insulated wire, parallel, with shrink tubing
> overall. Or two layers on a PC board.
>
> You could hack a small piece of copperclad FR4 too, and add wires. The
> usual stuff is about 15 pF per square inch. You could make the entire
> attenuator out of one piece of dremeled FR4!

Maybe I'm being to concerned with arc over. I have made disc caps using Rogers 5880 (0.036"),
using a paper punch, they are about 1.3pf. But, I think the 5880 is too thin.

If I use FR4, what is the max voltage you would go? Assumes the FR4 is larger than the copper.

Mikek

On 5/13/2023 12:37 PM, Lamont Cranston wrote:
> On Saturday, May 13, 2023 at 10:55:03 AM UTC-5, John Larkin wrote:
>> On Sat, 13 May 2023 08:07:17 -0700 (PDT), Lamont Cranston
>> <amd...@gmail.com> wrote:
>>> On Saturday, May 13, 2023 at 8:50:52?AM UTC-5, John Larkin wrote:
>>>> On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
>>>> <amd...@gmail.com> wrote:
>>>>> On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:
>>>>>
>>>>>> Where's Sloman's design? I really wanted to see that.
>>>>>>
>>>>>> Here's a suggestion.
>>>>>>
>>>>>> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1
>>>>>>
>>>>>> It needs to be tested and maybe tweaked. I haven't designed with tubes
>>>>>> lately.
>>>>>
>>>>> Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
>>>>> Now, I'm waiting for parts.
>>>> I thought it was cute to have a single 6-volt power supply, but that
>>>> nails the positive grid (I keep wanting to say gate) drive at 6 too.
>>>>
>>>> Whit's idea of push-pull drive is cute but needs another power supply,
>>>> and in its most basic form forces the + and - grid voltages to be
>>>> equal, although that is probably OK and easily fixed. One 556, the
>>>> dual 555, could drive both the grid and the cathode.
>>>
>>> I'm already thinking about two neon sign transformers, and another
>>> complete tube switcher, with opposite polarity, so it will ą 7kV for a 14KV differential.
>
> I was thinking the differential to get higher voltage, in the end I would like to have 30kV,
> whether that is single sided or ± I don't know what is best.
>>
>> The oil emulsion thing is inherently AC-coupled, no? One supply and
>> one tube does that.
>>
>> And one neon sign transformer could make +-HV if you really wanted
>> that.
>
>
>>> Would we build a negative switcher or to positives and invert the input to one?
>> I think Whit's idea is to drive the grid and cathode of the one tube,
>> 0 and +12 maybe, antiphase. Not to have pos and neg HV.
>
> I don't understand that.
>
>> My suggested circuit works well making low duty cycle negative HV
>> pulses. Positive-going pulses would be harder.
>
> OK, I think that is a logic thing. Since the circuit is acting to bring the output to 0V,
> you are calling that negative HV pulses?
>
>
>>>>
>>>> You should build in the scope pickoff, so you can see what's going on.
>>>> We usually build in a signal pickoff/monitor circuit on pulsers.
>>>
>>> Agree on that, Need to source a 1nF HV cap.
>> Make it!
>
> Ya, I already looked at dielectric breakdown voltages, it seems it takes a thick dielectric.
>
> A 1" long copper pipe with a 0.25" copper pipe in the center is 2pf.
> If I fill it with silicone sealer (~3) I'm up to 6pf and can shorten it considerably.
>
> Is silicone sealer better than air for breakdown voltage?

Teflon tape is what I'd use. (6000 V/mil according to American
Durafilm) Wrap the center conductor with multiple layers so
that it fits snugly in the outer pipe.
Ed

On Sat, 13 May 2023 12:49:33 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

>On Saturday, May 13, 2023 at 1:46:08?PM UTC-5, John Larkin wrote:
>> On Sat, 13 May 2023 09:37:47 -0700 (PDT), Lamont Cranston
>> <amd...@gmail.com> wrote:
>> >On Saturday, May 13, 2023 at 10:55:03?AM UTC-5, John Larkin wrote:
>> >> On Sat, 13 May 2023 08:07:17 -0700 (PDT), Lamont Cranston
>> >> <amd...@gmail.com> wrote:
>> >> >On Saturday, May 13, 2023 at 8:50:52?AM UTC-5, John Larkin wrote:
>> >> >> On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
>> >> >> <amd...@gmail.com> wrote:
>> >> >> >On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:
>> >> >> >
>> >> >> >> Where's Sloman's design? I really wanted to see that.
>> >> >> >>
>> >> >> >> Here's a suggestion.
>> >> >> >>
>> >> >> >> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1
>> >> >> >>
>> >> >> >> It needs to be tested and maybe tweaked. I haven't designed with tubes
>> >> >> >> lately.
>> >> >> >
>> >> >> > Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
>> >> >> > Now, I'm waiting for parts.
>> >> >> I thought it was cute to have a single 6-volt power supply, but that
>> >> >> nails the positive grid (I keep wanting to say gate) drive at 6 too.
>> >> >>
>> >> >> Whit's idea of push-pull drive is cute but needs another power supply,
>> >> >> and in its most basic form forces the + and - grid voltages to be
>> >> >> equal, although that is probably OK and easily fixed. One 556, the
>> >> >> dual 555, could drive both the grid and the cathode.
>> >> >
>> >> > I'm already thinking about two neon sign transformers, and another
>> >> >complete tube switcher, with opposite polarity, so it will ? 7kV for a 14KV differential.
>> >
>> >I was thinking the differential to get higher voltage, in the end I would like to have 30kV,
>> > whether that is single sided or ? I don't know what is best.
>> >>
>> >> The oil emulsion thing is inherently AC-coupled, no? One supply and
>> >> one tube does that.
>> >>
>> >> And one neon sign transformer could make +-HV if you really wanted
>> >> that.
>> >
>> >
>> >> >Would we build a negative switcher or to positives and invert the input to one?
>> >> I think Whit's idea is to drive the grid and cathode of the one tube,
>> >> 0 and +12 maybe, antiphase. Not to have pos and neg HV.
>> >
>> > I don't understand that.
>> Make a 0 to 12 volt positive pulse and apply it to the grid. Invert
>> it, still 0 to +12 but out of phase, and connect that to the cathode.
>> So the grid is usually -12 relative to the cathode and +12 during the
>> pulse. You can do it all with one NE556.
>>
>> I hate the concept because I didn't invent it.
>> >
>> >> My suggested circuit works well making low duty cycle negative HV
>> >> pulses. Positive-going pulses would be harder.
>> >
>> >OK, I think that is a logic thing. Since the circuit is acting to bring the output to 0V,
>> >you are calling that negative HV pulses?
>> If a voltage is high positive and occasionally blips to ground, I call
>> that a negative pulse. Or negative-going maybe. Like the OUT here:
>>
>> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?dl=0
>>
>> The tube circuit does that well. The opposite is trickier, frys the
>> resistors among other things.
>> >
>> >
>> >> >>
>> >> >> You should build in the scope pickoff, so you can see what's going on.
>> >> >> We usually build in a signal pickoff/monitor circuit on pulsers.
>> >> >
>> >> >Agree on that, Need to source a 1nF HV cap.
>> >> Make it!
>> >
>> > Ya, I already looked at dielectric breakdown voltages, it seems it takes a thick dielectric.
>> >
>> >A 1" long copper pipe with a 0.25" copper pipe in the center is 2pf.
>> >If I fill it with silicone sealer (~3) I'm up to 6pf and can shorten it considerably.
>> That's complex. I was thinking of a variant on the gimmick capacitor,
>> namely two pieces of insulated wire, parallel, with shrink tubing
>> overall. Or two layers on a PC board.
>>
>> You could hack a small piece of copperclad FR4 too, and add wires. The
>> usual stuff is about 15 pF per square inch. You could make the entire
>> attenuator out of one piece of dremeled FR4!
>
>Maybe I'm being to concerned with arc over. I have made disc caps using Rogers 5880 (0.036"),
>using a paper punch, they are about 1.3pf. But, I think the 5880 is too thin.
>
>If I use FR4, what is the max voltage you would go? Assumes the FR4 is larger than the copper.
>
> Mikek
>
>

A quarter-inch square copper patch, 0.062 thick FR4, would be about 1
pF. At, say, 500 volts/mil, that's about 30 KV to the other side.

A clever design could be hacked onto a 1"x2" slab. Maybe go 10,000:1
(discrete 10 nF cap) and include a BNC to go directly to the scope.

On 2023-05-13 17:13, John Larkin wrote:
> On Sat, 13 May 2023 12:49:33 -0700 (PDT), Lamont Cranston
> <amdx62@gmail.com> wrote:
>
>> On Saturday, May 13, 2023 at 1:46:08?PM UTC-5, John Larkin wrote:
>>> On Sat, 13 May 2023 09:37:47 -0700 (PDT), Lamont Cranston
>>> <amd...@gmail.com> wrote:
>>>> On Saturday, May 13, 2023 at 10:55:03?AM UTC-5, John Larkin wrote:
>>>>> On Sat, 13 May 2023 08:07:17 -0700 (PDT), Lamont Cranston
>>>>> <amd...@gmail.com> wrote:
>>>>>> On Saturday, May 13, 2023 at 8:50:52?AM UTC-5, John Larkin wrote:
>>>>>>> On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
>>>>>>> <amd...@gmail.com> wrote:
>>>>>>>> On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:
>>>>>>>>
>>>>>>>>> Where's Sloman's design? I really wanted to see that.
>>>>>>>>>
>>>>>>>>> Here's a suggestion.
>>>>>>>>>
>>>>>>>>> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1
>>>>>>>>>
>>>>>>>>> It needs to be tested and maybe tweaked. I haven't designed with tubes
>>>>>>>>> lately.
>>>>>>>>
>>>>>>>> Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
>>>>>>>> Now, I'm waiting for parts.
>>>>>>> I thought it was cute to have a single 6-volt power supply, but that
>>>>>>> nails the positive grid (I keep wanting to say gate) drive at 6 too.
>>>>>>>
>>>>>>> Whit's idea of push-pull drive is cute but needs another power supply,
>>>>>>> and in its most basic form forces the + and - grid voltages to be
>>>>>>> equal, although that is probably OK and easily fixed. One 556, the
>>>>>>> dual 555, could drive both the grid and the cathode.
>>>>>>
>>>>>> I'm already thinking about two neon sign transformers, and another
>>>>>> complete tube switcher, with opposite polarity, so it will ? 7kV for a 14KV differential.
>>>>
>>>> I was thinking the differential to get higher voltage, in the end I would like to have 30kV,
>>>> whether that is single sided or ? I don't know what is best.
>>>>>
>>>>> The oil emulsion thing is inherently AC-coupled, no? One supply and
>>>>> one tube does that.
>>>>>
>>>>> And one neon sign transformer could make +-HV if you really wanted
>>>>> that.
>>>>
>>>>
>>>>>> Would we build a negative switcher or to positives and invert the input to one?
>>>>> I think Whit's idea is to drive the grid and cathode of the one tube,
>>>>> 0 and +12 maybe, antiphase. Not to have pos and neg HV.
>>>>
>>>> I don't understand that.
>>> Make a 0 to 12 volt positive pulse and apply it to the grid. Invert
>>> it, still 0 to +12 but out of phase, and connect that to the cathode.
>>> So the grid is usually -12 relative to the cathode and +12 during the
>>> pulse. You can do it all with one NE556.
>>>
>>> I hate the concept because I didn't invent it.
>>>>
>>>>> My suggested circuit works well making low duty cycle negative HV
>>>>> pulses. Positive-going pulses would be harder.
>>>>
>>>> OK, I think that is a logic thing. Since the circuit is acting to bring the output to 0V,
>>>> you are calling that negative HV pulses?
>>> If a voltage is high positive and occasionally blips to ground, I call
>>> that a negative pulse. Or negative-going maybe. Like the OUT here:
>>>
>>> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?dl=0
>>>
>>> The tube circuit does that well. The opposite is trickier, frys the
>>> resistors among other things.
>>>>
>>>>
>>>>>>>
>>>>>>> You should build in the scope pickoff, so you can see what's going on.
>>>>>>> We usually build in a signal pickoff/monitor circuit on pulsers.
>>>>>>
>>>>>> Agree on that, Need to source a 1nF HV cap.
>>>>> Make it!
>>>>
>>>> Ya, I already looked at dielectric breakdown voltages, it seems it takes a thick dielectric.
>>>>
>>>> A 1" long copper pipe with a 0.25" copper pipe in the center is 2pf.
>>>> If I fill it with silicone sealer (~3) I'm up to 6pf and can shorten it considerably.
>>> That's complex. I was thinking of a variant on the gimmick capacitor,
>>> namely two pieces of insulated wire, parallel, with shrink tubing
>>> overall. Or two layers on a PC board.
>>>
>>> You could hack a small piece of copperclad FR4 too, and add wires. The
>>> usual stuff is about 15 pF per square inch. You could make the entire
>>> attenuator out of one piece of dremeled FR4!
>>
>> Maybe I'm being to concerned with arc over. I have made disc caps using Rogers 5880 (0.036"),
>> using a paper punch, they are about 1.3pf. But, I think the 5880 is too thin.
>>
>> If I use FR4, what is the max voltage you would go? Assumes the FR4 is larger than the copper.
>>
>> Mikek
>>
>>
>
> A quarter-inch square copper patch, 0.062 thick FR4, would be about 1
> pF. At, say, 500 volts/mil, that's about 30 KV to the other side.
>
> A clever design could be hacked onto a 1"x2" slab. Maybe go 10,000:1
> (discrete 10 nF cap) and include a BNC to go directly to the scope.
>
>

You have to worry about corona from the edges, especially if they're
square. I'd be looking at ignition cable with a bit of solid wire
wrapped round it, a few inches from one end.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Saturday, May 13, 2023 at 4:43:25 PM UTC-5, Phil Hobbs wrote:

> > A quarter-inch square copper patch, 0.062 thick FR4, would be about 1
> > pF. At, say, 500 volts/mil, that's about 30 KV to the other side.
> >
> > A clever design could be hacked onto a 1"x2" slab. Maybe go 10,000:1
> > (discrete 10 nF cap) and include a BNC to go directly to the scope.
> >
> >
> You have to worry about corona from the edges, especially if they're
> square. I'd be looking at ignition cable with a bit of solid wire
> wrapped round it, a few inches from one end.
> Cheers
>
> Phil Hobbs
>
> --
> Dr Philip C D Hobbs
> Principal Consultant
> ElectroOptical Innovations LLC / Hobbs ElectroOptics
> Optics, Electro-optics, Photonics, Analog Electronics
> Briarcliff Manor NY 10510
>
> http://electrooptical.net
> http://hobbs-eo.com

I have a good bit of HV wire for the neon signs rated at 15kV.
I'll make one.
Can anyone explain why the wire is so thick in the Neon Sign Transformer wire?
The usual max current is 30ma.
Mikek

Lamont Cranston <amdx62@gmail.com> wrote:
> On Saturday, May 13, 2023 at 4:43:25 PM UTC-5, Phil Hobbs wrote:
>
>>> A quarter-inch square copper patch, 0.062 thick FR4, would be about 1
>>> pF. At, say, 500 volts/mil, that's about 30 KV to the other side.
>>>
>>> A clever design could be hacked onto a 1"x2" slab. Maybe go 10,000:1
>>> (discrete 10 nF cap) and include a BNC to go directly to the scope.
>>>
>>>
>> You have to worry about corona from the edges, especially if they're
>> square. I'd be looking at ignition cable with a bit of solid wire
>> wrapped round it, a few inches from one end.
>> Cheers
>>
>> Phil Hobbs
>>
>> --
>> Dr Philip C D Hobbs
>> Principal Consultant
>> ElectroOptical Innovations LLC / Hobbs ElectroOptics
>> Optics, Electro-optics, Photonics, Analog Electronics
>> Briarcliff Manor NY 10510
>>
>> http://electrooptical.net
>> http://hobbs-eo.com
>
> I have a good bit of HV wire for the neon signs rated at 15kV.
> I'll make one.
> Can anyone explain why the wire is so thick in the Neon Sign Transformer wire?
> The usual max current is 30ma.
> Mikek
>

Corona again. The field at the surface goes as 1/r.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC /
Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

On Saturday, May 13, 2023 at 5:09:13 PM UTC-5, Phil Hobbs wrote:
> Lamont Cranston <amd...@gmail.com> wrote:
> > On Saturday, May 13, 2023 at 4:43:25 PM UTC-5, Phil Hobbs wrote:
> >
> >>> A quarter-inch square copper patch, 0.062 thick FR4, would be about 1
> >>> pF. At, say, 500 volts/mil, that's about 30 KV to the other side.
> >>>
> >>> A clever design could be hacked onto a 1"x2" slab. Maybe go 10,000:1
> >>> (discrete 10 nF cap) and include a BNC to go directly to the scope.
> >>>
> >>>
> >> You have to worry about corona from the edges, especially if they're
> >> square. I'd be looking at ignition cable with a bit of solid wire
> >> wrapped round it, a few inches from one end.

5 to 6 turns of #20 wire on a 1/4" HV wire is 1pf.

Lamont Cranston <amdx62@gmail.com> wrote:
> On Saturday, May 13, 2023 at 5:09:13 PM UTC-5, Phil Hobbs wrote:
>> Lamont Cranston <amd...@gmail.com> wrote:
>>> On Saturday, May 13, 2023 at 4:43:25 PM UTC-5, Phil Hobbs wrote:
>>>
>>>>> A quarter-inch square copper patch, 0.062 thick FR4, would be about 1
>>>>> pF. At, say, 500 volts/mil, that's about 30 KV to the other side.
>>>>>
>>>>> A clever design could be hacked onto a 1"x2" slab. Maybe go 10,000:1
>>>>> (discrete 10 nF cap) and include a BNC to go directly to the scope.
>>>>>
>>>>>
>>>> You have to worry about corona from the edges, especially if they're
>>>> square. I'd be looking at ignition cable with a bit of solid wire
>>>> wrapped round it, a few inches from one end.
>
> 5 to 6 turns of #20 wire on a 1/4" HV wire is 1pf.
>

Press on, next problem. ;)

--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC /
Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

On Saturday, May 13, 2023 at 8:09:57 PM UTC-5, Phil Hobbs wrote:

> > 5 to 6 turns of #20 wire on a 1/4" HV wire is 1pf.
> >
>
> Press on, next problem. ;)

Sure thing!
Give me some hints on how to minimize corona.
Other than no sharp points.
Tomorrow I'm building a voltage divider to supply four vessels, dropping the voltage by 25% at each step.
I have five 1" porcelain standoffs that I was going to mount on a Lexan strip. I'm using two 1.5MΩ for each section.
So, 12MΩ total. The HV wire that goes to the 4 vessels will attach to the Porcelain standoffs.
Do I want to minimize resistor lead lengths, i.e. put the standoffs closer together?
Or, do I want the Four- 14" HV wires going to each vessel spaced apart, put the standoffs farther apart?
This will be 2 quick tests to see if results are linear with voltage or if at some voltage you have diminishing returns.
1, 2, 3, and 4kV and 5, 6, 7, and 8kV.
Mikek

On Saturday, May 13, 2023 at 7:31:00 PM UTC-7, Lamont Cranston wrote:
> On Saturday, May 13, 2023 at 8:09:57 PM UTC-5, Phil Hobbs wrote:
>
> > > 5 to 6 turns of #20 wire on a 1/4" HV wire is 1pf.
> > >
> >
> > Press on, next problem. ;)
> Sure thing!
> Give me some hints on how to minimize corona.
> Other than no sharp points.

images.google.com has a load of examples of "HV wiring corona ring" and
some of 'em are just twists of wire.

At irregularities (like splices or joints) the field adjacent to the pointy is much lessened
if you put the same HV on an encircling tube or spring-like item

<https://www.huanengfitting.com/news/corona-ring-purpose-the-ultimate-faq-guide.html>

At 20 kV, outer diameter of uninsulated wire bits should be large (8mm?) like auto
spark plug wires' insulation. It's OK if all the current flows in a tiny wire inside. As long
as the outer shielding loop (or cylinder, ring, ball) is connected to the same HV as the wire,
there's zero field in the gap (and thus, at the pointy places).

On Saturday, 13 May 2023 at 22:01:26 UTC+1, ehsjr wrote:
> On 5/13/2023 12:37 PM, Lamont Cranston wrote:
> > On Saturday, May 13, 2023 at 10:55:03 AM UTC-5, John Larkin wrote:
> >> On Sat, 13 May 2023 08:07:17 -0700 (PDT), Lamont Cranston
> >> <amd...@gmail.com> wrote:
> >>> On Saturday, May 13, 2023 at 8:50:52?AM UTC-5, John Larkin wrote:
> >>>> On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
> >>>> <amd...@gmail.com> wrote:
> >>>>> On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:
> >>>>>
> >>>>>> Where's Sloman's design? I really wanted to see that.
> >>>>>>
> >>>>>> Here's a suggestion.
> >>>>>>
> >>>>>> https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1
> >>>>>>
> >>>>>> It needs to be tested and maybe tweaked. I haven't designed with tubes
> >>>>>> lately.
> >>>>>
> >>>>> Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
> >>>>> Now, I'm waiting for parts.
> >>>> I thought it was cute to have a single 6-volt power supply, but that
> >>>> nails the positive grid (I keep wanting to say gate) drive at 6 too.
> >>>>
> >>>> Whit's idea of push-pull drive is cute but needs another power supply,
> >>>> and in its most basic form forces the + and - grid voltages to be
> >>>> equal, although that is probably OK and easily fixed. One 556, the
> >>>> dual 555, could drive both the grid and the cathode.
> >>>
> >>> I'm already thinking about two neon sign transformers, and another
> >>> complete tube switcher, with opposite polarity, so it will ą 7kV for a 14KV differential.
> >
> > I was thinking the differential to get higher voltage, in the end I would like to have 30kV,
> > whether that is single sided or ± I don't know what is best.
> >>
> >> The oil emulsion thing is inherently AC-coupled, no? One supply and
> >> one tube does that.
> >>
> >> And one neon sign transformer could make +-HV if you really wanted
> >> that.
> >
> >
> >>> Would we build a negative switcher or to positives and invert the input to one?
> >> I think Whit's idea is to drive the grid and cathode of the one tube,
> >> 0 and +12 maybe, antiphase. Not to have pos and neg HV.
> >
> > I don't understand that.
> >
> >> My suggested circuit works well making low duty cycle negative HV
> >> pulses. Positive-going pulses would be harder.
> >
> > OK, I think that is a logic thing. Since the circuit is acting to bring the output to 0V,
> > you are calling that negative HV pulses?
> >
> >
> >>>>
> >>>> You should build in the scope pickoff, so you can see what's going on.
> >>>> We usually build in a signal pickoff/monitor circuit on pulsers.
> >>>
> >>> Agree on that, Need to source a 1nF HV cap.
> >> Make it!
> >
> > Ya, I already looked at dielectric breakdown voltages, it seems it takes a thick dielectric.
> >
> > A 1" long copper pipe with a 0.25" copper pipe in the center is 2pf.
> > If I fill it with silicone sealer (~3) I'm up to 6pf and can shorten it considerably.
> >
> > Is silicone sealer better than air for breakdown voltage?
> Teflon tape is what I'd use. (6000 V/mil according to American
> Durafilm) Wrap the center conductor with multiple layers so
> that it fits snugly in the outer pipe.
> Ed

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John

On Sunday, May 14, 2023 at 4:10:16 AM UTC-5, John Walliker wrote:

> Kapton tape has much better dielectric strength and it comes with adhesive as well!
> John

My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV..,
But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
He wants to use banana plugs for quick change.
Can we get away with this?
https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
Would it help to cover the Resistor divider with a few layers of Kaptan tape?
Thanks, Mikek

On Sunday, May 14, 2023 at 7:31:03 AM UTC-5, Lamont Cranston wrote:
> On Sunday, May 14, 2023 at 4:10:16 AM UTC-5, John Walliker wrote:
>
> > Kapton tape has much better dielectric strength and it comes with adhesive as well!
> > John
> My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
> 1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
> But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
> So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
> He wants to use banana plugs for quick change.
> Can we get away with this?
> https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
> Would it help to cover the Resistor divider with a few layers of Kaptan tape?
> Thanks, Mikek

Amazon has these HV banana jacks and plugs, seller says rated for 10kV.
https://www.amazon.com/White-Banana-Voltage-Connectors-Sockets/dp/B0BX9TGJHF/ref=sr_1_13?crid=2HTJKRKG8DOYN&keywords=High+Voltage+Banana+jacks&qid=1684067714&s=hi&sprefix=high+voltage+banana+jacks%2Ctools%2C160&sr=1-13
HV cable should fit inside of them, seems like a good idea!

On Sunday, May 14, 2023 at 7:48:34 AM UTC-5, Lamont Cranston wrote:
> On Sunday, May 14, 2023 at 7:31:03 AM UTC-5, Lamont Cranston wrote:
> > On Sunday, May 14, 2023 at 4:10:16 AM UTC-5, John Walliker wrote:
> >
> > > Kapton tape has much better dielectric strength and it comes with adhesive as well!
> > > John

Looking at Kaptan tape, I find 7500V per mil, if I cover the voltage divider with a couple
of layers of Kaptan Tape will that prevent corona?
Thanks, Mikek

On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

>On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:
>
>> Kapton tape has much better dielectric strength and it comes with adhesive as well!
>> John
>
>My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
>1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
>But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
> So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
> He wants to use banana plugs for quick change.
>Can we get away with this?
>https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
> Would it help to cover the Resistor divider with a few layers of Kaptan tape?
> Thanks, Mikek

Put a row of banana jacks on a piece of plastic. Solder the resistors
between the jacks the obvious way. Ordinary banana leads can run out
to the cells. Ignore corona. It's only an experiment and it's only
8KV.

Amazon has great banana jack assortments.

https://www.amazon.com/gp/product/B07KCRMV4V/

https://www.amazon.com/gp/product/B01CJDGWRU

These are cool on PC boards too.

On Sun, 14 May 2023 05:48:30 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

>On Sunday, May 14, 2023 at 7:31:03?AM UTC-5, Lamont Cranston wrote:
>> On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:
>>
>> > Kapton tape has much better dielectric strength and it comes with adhesive as well!
>> > John
>> My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
>> 1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
>> But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
>> So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
>> He wants to use banana plugs for quick change.
>> Can we get away with this?
>> https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
>> Would it help to cover the Resistor divider with a few layers of Kaptan tape?
>> Thanks, Mikek
>
> Amazon has these HV banana jacks and plugs, seller says rated for 10kV.
>https://www.amazon.com/White-Banana-Voltage-Connectors-Sockets/dp/B0BX9TGJHF/ref=sr_1_13?crid=2HTJKRKG8DOYN&keywords=High+Voltage+Banana+jacks&qid=1684067714&s=hi&sprefix=high+voltage+banana+jacks%2Ctools%2C160&sr=1-13
> HV cable should fit inside of them, seems like a good idea!

Gross overkill at 8KV.

As I keep telling my engineers, keep it simple and get it done.

On Sunday, May 14, 2023 at 8:15:40 AM UTC-5, John Larkin wrote:
> On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
> <amd...@gmail.com> wrote:
> >On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:
> >
> >> Kapton tape has much better dielectric strength and it comes with adhesive as well!
> >> John
> >
> >My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
> >1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
> >But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
> > So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
> > He wants to use banana plugs for quick change.
> >Can we get away with this?
> >https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
> > Would it help to cover the Resistor divider with a few layers of Kaptan tape?
> > Thanks, Mikek
> Put a row of banana jacks on a piece of plastic. Solder the resistors
> between the jacks the obvious way. Ordinary banana leads can run out
> to the cells. Ignore corona. It's only an experiment and it's only
> 8KV.
>
> Amazon has great banana jack assortments.
>
> https://www.amazon.com/gp/product/B07KCRMV4V/
>
> https://www.amazon.com/gp/product/B01CJDGWRU
>
> These are cool on PC boards too.

John, I'll take that under advisement, however,
there could come a point in experiments, that I add a second transformer
and go up to 18kV or even 30kV. When we go to a larger diameter vessel,
the electric field per cm goes down, to compensate our input voltage needs to go up.
I'm now hopefully going to start spending someone else's money on parts, so I have less concern. :-)
I'd like to build for possible future developments.
What about kaptan tape over the Resistive divider, does that help prevent corona?
Mikek

P.S. adding in my ignorance about HV projects, I'd rather err on the side of gross overkill!

On Sun, 14 May 2023 06:27:38 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

>On Sunday, May 14, 2023 at 8:15:40?AM UTC-5, John Larkin wrote:
>> On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
>> <amd...@gmail.com> wrote:
>> >On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:
>> >
>> >> Kapton tape has much better dielectric strength and it comes with adhesive as well!
>> >> John
>> >
>> >My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
>> >1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
>> >But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
>> > So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
>> > He wants to use banana plugs for quick change.
>> >Can we get away with this?
>> >https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
>> > Would it help to cover the Resistor divider with a few layers of Kaptan tape?
>> > Thanks, Mikek
>> Put a row of banana jacks on a piece of plastic. Solder the resistors
>> between the jacks the obvious way. Ordinary banana leads can run out
>> to the cells. Ignore corona. It's only an experiment and it's only
>> 8KV.
>>
>> Amazon has great banana jack assortments.
>>
>> https://www.amazon.com/gp/product/B07KCRMV4V/
>>
>> https://www.amazon.com/gp/product/B01CJDGWRU
>>
>> These are cool on PC boards too.
>
> John, I'll take that under advisement, however,
>there could come a point in experiments, that I add a second transformer
>and go up to 18kV or even 30kV. When we go to a larger diameter vessel,
>the electric field per cm goes down, to compensate our input voltage needs to go up.
> I'm now hopefully going to start spending someone else's money on parts, so I have less concern. :-)
> I'd like to build for possible future developments.
> What about kaptan tape over the Resistive divider, does that help prevent corona?
> Mikek
>
>P.S. adding in my ignorance about HV projects, I'd rather err on the side of gross overkill!
>
>

If you do simple stuff fast, you'll learn more.

søndag den 14. maj 2023 kl. 16.04.00 UTC+2 skrev John Larkin:
> On Sun, 14 May 2023 06:27:38 -0700 (PDT), Lamont Cranston
> <amd...@gmail.com> wrote:
> >On Sunday, May 14, 2023 at 8:15:40?AM UTC-5, John Larkin wrote:
> >> On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
> >> <amd...@gmail.com> wrote:
> >> >On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:
> >> >
> >> >> Kapton tape has much better dielectric strength and it comes with adhesive as well!
> >> >> John
> >> >
> >> >My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
> >> >1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
> >> >But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
> >> > So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
> >> > He wants to use banana plugs for quick change.
> >> >Can we get away with this?
> >> >https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
> >> > Would it help to cover the Resistor divider with a few layers of Kaptan tape?
> >> > Thanks, Mikek
> >> Put a row of banana jacks on a piece of plastic. Solder the resistors
> >> between the jacks the obvious way. Ordinary banana leads can run out
> >> to the cells. Ignore corona. It's only an experiment and it's only
> >> 8KV.
> >>
> >> Amazon has great banana jack assortments.
> >>
> >> https://www.amazon.com/gp/product/B07KCRMV4V/
> >>
> >> https://www.amazon.com/gp/product/B01CJDGWRU
> >>
> >> These are cool on PC boards too.
> >
> > John, I'll take that under advisement, however,
> >there could come a point in experiments, that I add a second transformer
> >and go up to 18kV or even 30kV. When we go to a larger diameter vessel,
> >the electric field per cm goes down, to compensate our input voltage needs to go up.
> > I'm now hopefully going to start spending someone else's money on parts, so I have less concern. :-)
> > I'd like to build for possible future developments.
> > What about kaptan tape over the Resistive divider, does that help prevent corona?
> > Mikek
> >
> >P.S. adding in my ignorance about HV projects, I'd rather err on the side of gross overkill!
> >
> >
> If you do simple stuff fast, you'll learn more.

too expensive, too late, or .. good enough