Weekly Builders Update Diary

[HumblePie]

@All,

Ward here; I have placed solid wire 6 Prime's side by side, 30 turns each, .65 mH or .64mH each.  Anybody found the perfect spacer for the Primaries yet?  I am having trouble with even rough spacing because the Secondary windings peaks and valleys want to guide the Primaries where they will and Prime's are very tight.  I should have loaded up the faces with wax even if it does melt out later.  Also, I should have used different color tape every other segment to mark them Vs felt pen which wears off.  My Primes do not all resonate the same frequency yet because of spacing and some crossed leads as I have taped them temoparily I think.  At least I did find Primary resonance  less than 1MHz now.  I know from laying experimental side by side wires, inter-woven Primaries before this, that measuring the CCW end of Prime' being driven from CW end is really very accurate, (where the isolated twin's CCW end measures same as when CCW end of the Prime being driven from CW end is measured).   So this is how I measure resonance now.  Feedback anybody?  Since I got hung up on the resonant frequencies before this, while experimenting with different Primary # turns and fills, here is my first resonace data in case it helps.
Primary data before perfect spacing:
1) .65mH (all same), 1.1 Ohm (all same), 781KHz
2) 781KHz
3) 877KHz
4) 892KHz
5) 781KHz
6) 746KHz
I see other weaker res points above these, Prime' #4 for example has also 1.19MHz, or 1.33x the fundamental.
Thanks to Wer for posting the Boyce / Patrick Kelly pdf who's Pg 28 explains what Bob means by "The HV Bias along with # turns on Secondary determine optimum Primary winding ratio".   Since I will first use rectified 110VAC for 155V pulsing DC, I also aim for 25% of that amount of potential to be across load (even though DC blocked).   My Secondary is 129 turns, my Prime's are 30 turns, so ratio is 1:4, telling me drive electronics shall drive Primes using 10VDC so that 4x step up equals 25% of target HV Bias that is on Secondary.  It seems I can increase HV Bias simultaneous with Primary driving voltage to preserve these ratios and get more potential across the load.  Next task is to make the GAL to divide the Clocks.  I will purchase the $87 HVPS Model SM10 from http://www.gammahighvoltage.com/html/contact_us.htm so that I can get higher Bias voltages.  Note this unit's max Amps is 250uA, so the DC Blockig Cap better not leak, else I'll need next model down that only goes to 500VDC vs 1000VDC

[Spencer]

Started Bias windings, finished all but the inner one. I have primary winding wire coming in this week along with sample chips ordered to Texas Insturments. I don't expect to get much done this week coming up since I will be out of town most of the week on vacation.

Spencer

[Thaelin]

   Have finally settled in on a choice for the driving frequencies. All parts in house so to build. I find that opto isolating the signal inputs to the driviers makes my individual signals steady not to mention a ground cap over each section. More to come.

thaelin

[Jdo300]

HI Everyone,

I'm heading for the home stretch on my DDS controller. I've got just about all the schematics finished for the card wit the AD9959 and supporting hardware on it. But I'm running into another brick wall trying to find an appropriate clock generator to run the chip. I need one that runs on 1.8V and has a frequency of at least 100MHz (with low jitter). The challenge at this point is finding a chip that I can actually buy somewhere without getting 1000 minimum. If anyone has any ideas, I would definitely be open for some help as this is the only thing slowing me down. Once I find the right part, I would like to finish the board layout and get the first PCBs for this ordered.

God Bless,
Jason O

[Dad-Be-lectric]

Fianlly started Winding. got outer done today, start facial tomorrow. making jig for inner now.