Negistor + %^&*roft-Walton = WTF?

[earthtonesaudio]

How about a circuit that uses a negistor as the oscillator to charge up a %^&*roft-Walton multiplier, and provide high-voltage/low current to something cool, like high-headroom JFET or op-amp circuits, or even tubes?
Using a negistor for the oscillator reduces power requirements for the caps and diodes, so it would be small, even surface mount.

The mundane use that I had in mind: to be able to use MOSFETs as soft-clippers to ground, but have more voltage going in to play with, to get a good range of soft-to-hard clipping (maybe).

(note: partially inspired by Z. Vex and his Nano power supply, but not quite as cool as the Nano)


Whatcha think?

A couple initial problems with the idea, I think: ripple on the output, and the more voltage you want, the longer it would take to charge up.
Comments and feedback always welcome.

[earthtonesaudio]

Maybe this would help:

http://home.earthlink.net/~jimlux/hv/cw1.htm

And this:



Sorry it's "upside down" with the +9V and ground on the left... I couldn't rotate the transistor using the DIYLCbeta... maybe operator error.  Anyway I have no idea if it would work well, but I think it should work a little bit.

Negistor section is a high frequency sawtooth oscillator, don't know what the AC output voltage would be... but if I did I could figure out the DC output of the %^&*roft-Walton.  Breadboard, look out!

[puretube]

Also check Villard,
and take care to keep the frequency out of the audio-range,
(or otherwise take care of "noise" injection)
and make sure the active device can source the power...

[John Blund]

Another alternative might be a voltage booster, oscillator + small coil. A few more parts but could probably deliver a bit more current.
I think this is the type of PSU used in the nano head.

Papareil synth labs uses one to drive gas discharge bargraph tubes
http://m.bareille.free.fr/vu-in13/vuin13_v21_schem.pdf

Another one made for nixie tubes 10m 70-200v
www.ledsales.com.au/kits/nixie_supply.pdf

and a bit boring already assembled one. 50-25ma 90-190v, could perhaps be used to run two 12ax7 or similar in a small enclosure
http://www.allspectrum.com/store/product_info.php?products_id=521

[earthtonesaudio]

I was thinking of the low-current high-voltage applications that could be possible, and one thing that might be worth trying is a tube-compressor type thing that runs at high voltage, with a medium sized filter cap at the output of the power supply.  The filter cap acts like a small battery that is constantly being recharged by the charge pump.  Every time you play a note hard, the current drops, and the cap discharges and takes some time (RC time constant) to recharge.  Could be adjustable via oscillator frequency and or a simple lowpass filter on the filter cap.  If it works, I call dibs on naming the effect "Brownout."

[earthtonesaudio]

The good news: I did get the Negistor to charge up the %^&*roft-Walton, and I did get a voltage increase...
The bad news: I should have got 32V DC at the output, but only got 11.   

New drawing (removed the unnecessary diode and wire at the end, changed cap values, added resistive load):


I know there are some losses through the diodes, but I'm getting less than half the calculated voltage I "should" be getting.  Anyone care to speculate as to why this is happening?

[earthtonesaudio]

I just found out that my meter was loading down the voltage multiplier output.  That's why my output voltage read so low.  There's probably something more like 25-30 volts coming out, depending on the losses through the components.  It's hard to find info on %^&*roft-Walton multipliers, but one thing I did find out was that they're easily loaded down.  Even a 500M load on a particular multiplier drops the output voltage by 20%!  Not a typo, that's 500 million ohms.

I'll try increasing the decoupling cap value to about 10uF and also increasing the load resistors, to see if that helps.