[amsat-bb] KR-400 transformer wiring

[H. Stephen Nipper]

The manual I found online stated that they used a different transformer for
120 or 220 volts.  To check the operating voltage on the back of the
controller and to return it to factory to get the right voltage transformer.

Check with Yaesu and see if they can offer any help.

On Sun, Oct 21, 2018, 8:40 AM Glenn Little WB4UIV <
glennmaillist at bellsouth.net> wrote:

> The transformer has two primary windings so that the two windings can be
> placed in series for 220 and in parallel for 110 VAC.
> It looks like your transformer is set with taps to finely adjust the
> input voltage to match your mains supply.
>
> None of the online schematics, that I can find, show how the primary is
> wired for 110/220 VAC.
>
> Search for your rotor on line for further information.
>
> 73
> Glenn
> WB4UIV
>
> On 10/21/2018 9:12 AM, Hans BX2ABT wrote:
> > I got this old KR-400 azimuth rotor as a gift, but is wired for 220V
> > and I need to run it off of 110V. The transformer's wiring now looks
> > like this:
> >
> >
> >      |  220V  |
> >      |        |
> > |~~~~|~~~~|   |~~~~|~~~~|
> > 5    1    3   6    2    4
> > |                  |
> > |__________________|
> >
> >
> > If the drawing is messed up, here is the gist of it: The primary
> > consists of two (parallel/separate) windings, one with odd, one with
> > even numbering (3-5 and 4-6) with the center of the winding named 1
> > and 2. Currently 2 and 5 are shorted and 220V comes in at 1 and 6. So
> > current flows from 1 to 5 to 2 to 6 and vice versa.
> >
> > To rewire to 110V I guess I just use any of the combination 1-3, 1-5,
> > 2-4 or 2-6. But I am just curious why the 220V wiring was done over
> > two coils, not one? Was this factory standard or has my unit been
> > modified with a different transformer?
> >
> > Once I get the control unit powered up it time to test the rotator and
> > see if it needs any maintenance (probably will, because it hasn't been
> > used for a long while).
> >
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> --
> -----------------------------------------------------------------------
> Glenn Little                ARRL Technical Specialist   QCWA  LM 28417
> Amateur Callsign:  WB4UIV            wb4uiv at arrl.net    AMSAT LM 2178
> QTH:  Goose Creek, SC USA (EM92xx)  USSVI LM   NRA LM   SBE ARRL TAPR
> "It is not the class of license that the Amateur holds but the class
> of the Amateur that holds the license"
>
> _______________________________________________
> Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>