Mills Throne of Music changer motor Booster Transformer question

Hi to everyone,

Question for anyone with experience rebuilding a Mills Throne of Music
or Mills Empress. My question is regarding the "Booster Transformer"
for the Mechanism Motor ("changer motor", as Mills calls it.)

As far as I can see (if I am wrong, please explain), the Booster
Transformer's only purpose is to increase the AC voltage 15 volts. With
modern AC household voltages being much higher than the 1930s, is using
the Booster Transformer either necessary or recommended?

It seems as though Mills expected the average Line Voltage to be 110v,
and maybe was concerned that loads would drop the line voltage to less
than 110v. Well, it is my understanding that 117-125 is the normal
range in North America. In my home, 123v is the norm. For example,
when connecting the booster transformer to my AC, it outputs 137v. The
motor is marked 110v.

Would you guys keep the Booster Transformer, or eliminate it? A
side-reason for asking this, is that the insulation on the red and white
wires of the Booster Transformer is very much dry-rotted, and to replace
those wires would require major surgery inside the booster transformer
(which the transformer case does not open easily at all). ALL other
wiring inside the jukebox is being 100% replaced, so I hate to leave
this one component as-is unless there is a solid reason for doing so.

Best regards,
bob

I would try to run the juke with the booster bypassed, but would leave it in
place for future value reasons.
If the mech is clean and well lubed, it should run fine without the booster.
Remember to clean and/or replace the brushes in the mech motor!

"rpesq" wrote in message
news:WN0yi.908$A57.68@trnddc04...
Hi to everyone,

Question for anyone with experience rebuilding a Mills Throne of Music or
Mills Empress. My question is regarding the "Booster Transformer" for the
Mechanism Motor ("changer motor", as Mills calls it.)

As far as I can see (if I am wrong, please explain), the Booster
Transformer's only purpose is to increase the AC voltage 15 volts. With
modern AC household voltages being much higher than the 1930s, is using
the Booster Transformer either necessary or recommended?

It seems as though Mills expected the average Line Voltage to be 110v, and
maybe was concerned that loads would drop the line voltage to less than
110v. Well, it is my understanding that 117-125 is the normal range in
North America. In my home, 123v is the norm. For example, when
connecting the booster transformer to my AC, it outputs 137v. The motor
is marked 110v.

Would you guys keep the Booster Transformer, or eliminate it? A
side-reason for asking this, is that the insulation on the red and white
wires of the Booster Transformer is very much dry-rotted, and to replace
those wires would require major surgery inside the booster transformer
(which the transformer case does not open easily at all). ALL other
wiring inside the jukebox is being 100% replaced, so I hate to leave this
one component as-is unless there is a solid reason for doing so.

Best regards,
bob

Hi Keith,

Thanks for the info, much appreciated.

No problem!
I haven't done a 40's Seeburg in a few years so it's good to dig out the old
notes and wipe the cobwebs out of my brain!

"rpesq" wrote in message
news:c8gAi.5053$oh1.1507@trnddc04...
Hi Keith,

Thanks for the info, much appreciated.

On Aug 20, 5:24 am, rpesq wrote:
Hi to everyone,

Question for anyone with experience rebuilding a Mills Throne of Music
or Mills Empress. My question is regarding the "Booster Transformer"
for the Mechanism Motor ("changer motor", as Mills calls it.)

As far as I can see (if I am wrong, please explain), the Booster
Transformer's only purpose is to increase the AC voltage 15 volts. With
modern AC household voltages being much higher than the 1930s, is using
the Booster Transformer either necessary or recommended?

It seems as though Mills expected the average Line Voltage to be 110v,
and maybe was concerned that loads would drop the line voltage to less
than 110v. Well, it is my understanding that 117-125 is the normal
range in North America. In my home, 123v is the norm. For example,
when connecting the booster transformer to my AC, it outputs 137v. The
motor is marked 110v.

Would you guys keep the Booster Transformer, or eliminate it? A
side-reason for asking this, is that the insulation on the red and white
wires of the Booster Transformer is very much dry-rotted, and to replace
those wires would require major surgery inside the booster transformer
(which the transformer case does not open easily at all). ALL other
wiring inside the jukebox is being 100% replaced, so I hate to leave
this one component as-is unless there is a solid reason for doing so.

Best regards,
bob

Not having seen the actual machine or transformer, I can only
speculate on similar instances I have seen in other devices.

It seems strange that they wouldnt simply design the motor to run on
the lower voltage in the first place (or have a "high and low tap" on
the motor.). It's possible though that they used an "off the shelf"
motor, and couldnt specify the input voltage and therefore supplied
the booster to be used for areas where the mains voltage was low.

Even today, mains voltages vary a lot and can play havoc with
electical equipment and MUST be corrected in in most amusement
equipment to avoid excessive heating of the machine, as well as damage
to bulbs and mechanical parts if too high, or poor performance (weird
problems on solid state and computer based machines) if too low.

Note that this correction should be for the WHOLE machine and not just
a motor

I personally have seen (on a 240v system) voltages vary from 220-258v
(equates to 110-129v on a US 120v system) in some locations. In both
extremes, they were found within medium size cities, not in some rural
area with a lousy single wire HT power system. If in a premises with
3 phase power, you should check all phases as there can be big
differences between them.

Hi Kreed,

Mains voltage is an interesting topic. A while ago, I reading some
guy's website (he was a Tube Amp collector), and he was talking about
some quirky issues that arise. He was talking about some old tube amps
that run quiet when operated at 115v through a Variac, but have a
noticeable hum when operated at full Line voltage (which was somewhere
in the 120+). Something about the transformers having a small vibration.



-----
"Even today, mains voltages vary a lot and can play havoc with
electical equipment and MUST be corrected in in most amusement
equipment to avoid excessive heating of the machine, as well as damage
to bulbs and mechanical parts if too high, or poor performance (weird
problems on solid state and computer based machines) if too low."