Re: MOT Power Supply Questions

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Finn Hammer by way of Terry Fritz <teslalist-at-qwest-dot-net>" <f-h-at-c.dk>

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      +--------------+-------------+----------------------
      |              |             |
      |       |------+-------|-----+-------|---------------
      |+      |o     |+      |o    |+      |o
      |       |      |       |     |       |
      |       |      |       |     |       |
      uuuuuuuuu      uuuuuuuuu     uuuuuuuuu


      uuuuuu         uuuuuu        uuuuuu
      |    |         |    |        |    |
      |    |         |    |        |+   |o
      |    |         |    +--------+-   |
                     |                  |
                     | <-measure here-> |

Hi Simonas.

Without a scope, you can still phase these transformers. The only thing
that you will miss, is the information about, wether the secondary`s are
in phase with the primary`s. Since that doesn`t matter in this case,
proceed like this:
On all 3 sets, mark the secondary`s with a neutral (o) on one wire.
On one of the sets, mark the primary`s with both neutral (o) and hot (+)

Now arrange the transformers like the schematic above, keping the
neutrals together on the secondary`s, and connect these to the mains.
You should now get about 20 volts on the primary`s.

Now connect one unknown secondary with the reference secondary. If you
get double voltage, the wire that goes to the (+) terminal of the
reference is a neutral (o). If you get about 0 volts, the wire that goes
to the + terminal on the reference is a + wire.

Repeat the procedure on the other unknown transformer, and you are ready
to go.

Hope this helps.

Cheers, Finn Hammer


Tesla list skriver:
 >
 > Original poster: "Simonas by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
<rasim-at-takas.lt>
 >
 > Yes, I was trying to connect low voltage transformer (~25V) to the primary,
 > and as I don't have scope, tried to find hot wire with standart voltage
 > indicator (neon one), but it was failure, i don't know why, maybe because
 > low voltage transofmer had ferite core, but indicator showed phases on both
 > secondary outputs..(and somehow it looked so harmless with only 25V input,
 > that I forgot carefullness and touched secondary wires with both hands..
 > ouch! ;) ~250V is not very pleasant ;)
 > anyway, thanx to all of you  for the advices, hope I'll find scope and get
 > this thing working in a month or so.. surely, I'll post my screams of joy
 > informing all about success and spark length ;)
 >
 > Greetings from lonely coiler in Lithuania ;)
 >
 >  > Original poster: "Finn Hammer by way of Terry Fritz 
<teslalist-at-qwest-dot-net>"
 > <f-h-at-c.dk>
 >  >
 >  > Simonas,
 >  >
 >  > I take it that you intend on running secondary"s in series, primary`s in
 >  > parallel.
 >  > To avoid having to measure at excessively high voltages:
 >  > With the secondary`s connected to the mains, or a low voltage
 >  > transformer, check with a scope that primary and secondary are in phase.
 >  > Chose one wire from each set of windings, and mark them as "0",
 >  > "neutral".
 >  >
 >  > Now, on the primary side, connect all neutrals to mains neutral, the
 >  > other 3 wires to each phase.
 >  >
 >  > On the secondary side, connect neutrals, and take the juice out from the
 >  > other 3 wires.
 >  >
 >  > It would be nice to have a 3-phase variac to ramp up voltage slowly,
 >  > would it not:
 >  >
 >  > http://www.helmut-singer.de/stock/936192399.html
 >  >
 >  > http://www.helmut-singer.de/
 >  >
 >  > Hope this helps, Finn Hammer
 >  >
 >
 >  >  >  >
 >  >  >  >
 >  >  >  >
 >  >  >  >
 >  >
 >  >