Hi,
I need a couple of small potted-brick HV supplies for a pollen-sorting device, to be used in the field. I was thinking about the little inverters that have a dc output proportional to input, 1-3 kv range, I'm guessing. We don't need current, as this will be pure electrostatics. Apart from the pirates at Pico, who makes stuff like this? I don't see any in Mouser or Digikey. Surplus would be fine... some sort of copying machine thing?
Anybody played with stuff like this?
John
Will you have AC available where these are used? There are some nice supplies made for copiers and laser printers that might be suitable. How much space do you have? I may still have a couple clean, used supplies that you can have. Another source might be one of those cheap
4" B&W $10 TV sets. Remove the PC board and just use the Horizontal drive circuit and flyback, fed from a 15,734 HZ pulse.-- Service to my country? Been there, Done that, and I\'ve got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida
In message , dated Fri, 4 Aug 2006, John Larkin writes
You could modify spark igniters.
-- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immensely. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
You could use a photomultiplier power supply - more current than you need, and probably better stability than you want to pay for.
Or you could look at Jim Williams application notes on drivers for cold-cathode lamps for back-lighting lap-top displays. The lamps use HV AC, so you'd have to add a rectifier - possibly a Cockroft-Walton voltage multiplier if you really don't need much current.
Check out application notes AN45, AN49, AN51, AN55, AN61, AN65.
The only thing wrong with them is that he is using a Baxandall inverter
and calling it a current-driven Royer inverter.
Peter Baxandall described his parallel- and series-resonant class-D oscillators in 1959 in a paper in the Proceedings of the (British) Institute of Electrical Engineers (Baxandall, P.J, Proc I.E.E 106, B,
748 (1959)).-- Bill Sloman, Nijmegen
Hello John,
Glassman makes HV bricks but they could be out of BOM budget in this case:
Usually made my own. With flyback transformers or whatever was cheap. The TV parts mostly came with the diode cascade included as a bonus :-)
Bug zappers also have nice HV transformers in them but they won't be much good above line frequency. However, since you don't need any current to speak of and thus not much capacitance after the rectifier they might work.
Yet another option would be if you could find Hi-Pot testers in an auction or at a used electronics dealer. We only have one such dealer in town but S.F. has got to be a lot better there.
-- Regards, Joerg http://www.analogconsultants.com
Have I had my antihistamine tablet or am I sneezing because this is about pollen? Oh yeah, I remember, this piriton is to stop an allergic reaction to alcohol so I can drink more.
Anyway, how does that work?
You know.... like if you are sorting pollen then it sounds like you are sorting pollen so sticking 3kV across stuff sounds like it goes and sticks all the pollen on one of the electrodes and it isn't sorted. Like it's all stuck on one electrode so it isn't sorted.
So, what's the other part of the sorting process?
Ta
DNA
Like piezoelectric lighters for cigarettes. Where I live, they can be found en masse in the streets.
-- Sven Wilhelmsson http://home.swipnet.se/swi
In message , dated Fri, 4 Aug
2006, Sven Wilhelmsson writesNot so easy to use piezo lighters, because pollen sorters need a fairly continuous supply of high voltage. Battery-operated spark lighters would work.
-- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immensely. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
Hello John,
Out here they have usually been transformed into flat structures by the time you see them. Truck tires are unforgiving.
Just watch out for whether there is anything other than the battery that limits the number of sparks. After seeing the "electrolytic" in a disposable camera I realized why they are called disposable. Had been used once and the thing was already bulging.
-- Regards, Joerg http://www.analogconsultants.com
A CCFL backlight inverter with a couple of stages of CW multiplier might work. ( Use fast diodes like UF4007)
Yes.
Nice. G60CT looks good.
thanks,
John
Why do you refer to Pico as "pirates?" Did they do something bad or just charge too much?
Someone mentioned Emco and Glassman. There is also Ultravolt.
Good day!
-- _____________________ Christopher R. Carlen crobc@bogus-remove-me.sbcglobal.net SuSE 9.1 Linux 2.6.5
On Fri, 04 Aug 2006 10:02:32 -0700, John Larkin Gave us:
Mouser actually did carry small 2.5 x 3 x .75 inch proportional 3W bricks for a time. If you have any three year old catalogs, you could find it. Or you could ask them if they still have any on their shelf anywhere.
They were 1kV 2kV 3kV and 4kV. 4 pins. Power and output. Full floater.
On Fri, 04 Aug 2006 10:02:32 -0700, John Larkin Gave us:
I found these:
Twice the power in these:
On Fri, 04 Aug 2006 17:55:59 GMT, Joerg Gave us:
Dude, you're nuts. That's not a brick! That's a pyramid stone!
"brick" usually refers to PCB mountable, in this case.
Also, 15 Watts is a bit much for his need.
On Fri, 04 Aug 2006 19:00:33 GMT, Sven Wilhelmsson Gave us:
Litterbug society. Smokers are lame. Well over 99.9% anyway.
On Fri, 4 Aug 2006 20:40:04 +0100, John Woodgate Gave us:
A piezo is a mere instantaneous spark, not unlike an electrostatic discharge.
A "sorter" needs a continuous voltage to create an "attractor", as you correctly stated.
On Fri, 4 Aug 2006 17:31:28 -0400, "scada" Gave us:
The site I listed makes a better supply than Emco.
Don't be a top posting Usenet retard, dumbass.
On Fri, 04 Aug 2006 15:04:43 -0700, John Larkin Gave us:
Epoxy encapsulation... very bad. 100% NON-servicable.
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