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Re: [TCML] 6 MOT stack?

Hi Ted in NZ here

Some ideas for you to consider

I'm currently operating MOT's in the following manner, if the weather ever lets me I'll do some more testing but if you have lots of MOT's this may work for you

Not too sure of your Cp but I've just run 6MOT's in DC mode in the following manner with success

*  Cp 90nF (Cornell Dubillier 942C 330nF/1600volt type)
* Quite big secondary and toriod 53kHz operation (8" sec dia form and 36" double toroid)
*  BPS 300 sync rotary (equal bang time spacing of 120deg)
* both 4 and 6 MOTs tried, all outer MOT's in oil, cores grounded (some float cores) * 1N5408's 24 per leg in bridge to rectify (no R/C equalising at all just overkill the number of diodes)
*  Choke I/P filter of 15Hy using MOTs (see note 1 below)
* DC filter of MOT caps after that 1uF (array of 4 series by 4 of that in //, MOT caps seem to take overvolts for a while well)
*  Ring up inductance of 15Hy (see note one again below)
*  DQ diode of 50 odd 1N5408's
* PFC appled (recall 90uF for each MOT side, not too sure of capacitance now, I run the MOT stack as two pairs for primary wiring purposes)

Note 1
The MOT inductors consist of 2 MOTs in // and two of those in series using original secondaries, prmaries removed and an air gap of a piece of that formica sample sheet (approx 0.3mm thick). Does not saturate at 600mA and holds back EMF OK. Each MOT is on 4 plastic mounts. I solder 6mm spade lugs on the steel core to get connections (that is tricky and technique for that requires slightly bending the lamination from the core with wood slice while soldering and polish lamination with sandpaper just before heating)

This beast is very smooth in operation, no surging it just hums along , makes about 2m arc and runs about 6kVA very roughly. I've only run this config once and for a short time so do not have much more data. Next modification is to put 1uF in front of the filter choke to get more voltage from the PSU. This beast is cheap and soakes up 14 MOTS.

Would like to check soon to run without any SRSG pahse control or variac control of main PSA, due smooth predictable operation beleive should work well in that mode
Good luck Jeremy, MOTS RULE OK

----- Original Message ----- From: "Jeremy Chan" <jeremy_runescape@xxxxxxxxxxx>
To: "TCML" <tesla@xxxxxxxxxx>
Sent: Wednesday, June 03, 2009 1:08 AM
Subject: [TCML] 6 MOT stack?

Greetings to all,
I have recently completed the construction of my first coil. It has a 3ft by 3ft primary with 17.5 turns, a 4.5'' by 23'' secondary wound with 22.5 AWG wire, and a 6.5'' by 16'' torroid. The primary and secondary is supported on a 4ft by 4ft 12mm plywood board, supported over a second lower deck by 8 threaded rods, which houses my circuitry. The whole set-up is mounted on 6 3'' diameter castor wheels so the thing is mobile. There is no problem with this set-up, in fact it is an over-kill where it comes to most aspects such as the supporting structures and wires etc. The problem is that i am currently running the <SNIP>
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