Hello Group,
During the email list evolution, and after I posted the tube schematic, I
was contacted by Bert Hickman and Greg Leyh, an honor to be sure!
Bert pointed out the limitations of the (6) 8020 Tube Rectifiers and other
limitations related to plate dissipation and Greg pointed out his early
projects had a triple stack of motor driven Superior Powerstats on the input
and some very well thought out safety designs in his control cabinet and
relevant resonate 3P calculations - clearly an "open source" minded guy :).
Bert also pointed out, I need to lower the voltage at the input which is
208V wye if I resonate 2x charge (I'm about to do a turns ratio test). Armed
with that knowledge, I decided to ditch the very cool valves in favor of HV
diode strings. I have (500) UF5408 3A @ 1Kv peak inverse voltage diodes (and
I will test every one used) that can go in the oil if I remove the filament
transformer and install a much lower value Inductor (150H presently). The
output is rated 24KVDC - who knows if that takes into account the inductor
kick - without the step up transformer ratings on the name plate. Bert
pointed out it would take multiple cycles to charge with such a huge
inductor. I surmise Time1 = L/R L=150H R=564 ohms = .27 seconds! Except when
XL=XC, if I still get this after all these years (ha ha, we used slide rules
do phase angles in college, class of 1974)!
So both paths lead to a triple stack of 1256's and solid state 6 pulse and
resonant charging inductor which is so elegant for old school and very
scalable. I have (2) Powerstats (1256- 2S) in a stack that I mistakenly
thought were for 480 volt use only. They "can be" in series as it turns out,
and were not terminal wired - oh joy!!! I have a single 1256d in my single
phase cabinet to remove.
The schematic of (3) 1296's (I guess are very similar) shows a triple wye
arrangement without balancing coils which makes sense. So my question now to
the group, this early on is: how are the shafts joined? - by collars or do I
need a new shaft, and I would very much like to acquire a Powerstat 1256D
type stack drive motor. I only just opened the Raytheon tank and am keeping
it well covered from condensation and dust. Soon I'll move the HV assembly
completely out of the tank and set it on my trailer bed at work level and
covered with doubled 55 gal bags top and bottom and set on cardboard under-
laid with plastic. The tank will be carefully lowered into a small rigid
type wading pool Poly(X) containment area and well covered. There's a
Google Blog link started if you are interested and haven't seen the Raytheon
guts exposed on a chain lift.
Please chime in on the Powerstat issues and possible motor drive 4 sale if
someone wants to sell one. I can turn it manually as I have one of the
vintage wheels in good condition - some old school iron!
Thanks all,
Jim Mora
Conveniently, the Inductor is across the 2 tall horns, assuming I don't
replace the entire top with epoxy painted .25" plate steel... Also, is there
any issue with silver/tin (Radio Shack) numerous soldered epoxy diodes
strings attached to .125" G10 with nickel plated eyelets immersed in
transformer oil as a potential contaminate? No info on the leads. Please
contact me off list if so...I intend to over build the strings incase this
migrates to three small pigs or PT's and make an attempt at ball soldering.
http://www.teslawavetuner.blogspot.com/
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