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Constant Voltage Transformer Question

J

Jim Thompson

Jan 1, 1970
0
A major pain-in-the-ass in Arizona is lightbulb lifetime, particularly
this time of year, where one day will require heat and the next not.

So the AC voltage regulation sucks... often popping up to 130VRMS.

I was wondering how Constant Voltage Transformers would perform with
lamp loads.

I'm thinking of room-by-room regulation for ceiling fixtures... since,
15' up, it's tricky with a lamp changer pole :-(

I have easy attic access, pull-down-stair ladders, and the attic is
tall enough that I can stand upright to work in most locations.

...Jim Thompson
 
J

John Stewart

Jan 1, 1970
0
Jim said:
A major pain-in-the-ass in Arizona is lightbulb lifetime, particularly
this time of year, where one day will require heat and the next not.

So the AC voltage regulation sucks... often popping up to 130VRMS.

I was wondering how Constant Voltage Transformers would perform with
lamp loads.

I'm thinking of room-by-room regulation for ceiling fixtures... since,
15' up, it's tricky with a lamp changer pole :-(

I have easy attic access, pull-down-stair ladders, and the attic is
tall enough that I can stand upright to work in most locations.

...Jim Thompson

The Solas used to make lots of odd order harmonics.
But incandescent bulbs don't care.
Induction motors don't like that at all.

Cheers, John Stewart
 
W

Watson A.Name - \Watt Sun, the Dark Remover\

Jan 1, 1970
0
Jim Thompson said:
A major pain-in-the-ass in Arizona is lightbulb lifetime, particularly
this time of year, where one day will require heat and the next not.

So the AC voltage regulation sucks... often popping up to 130VRMS.

I was wondering how Constant Voltage Transformers would perform with
lamp loads.

I'm thinking of room-by-room regulation for ceiling fixtures... since,
15' up, it's tricky with a lamp changer pole :-(

I have easy attic access, pull-down-stair ladders, and the attic is
tall enough that I can stand upright to work in most locations.

...Jim Thompson
--

Why don't you get away from incandescents and go with CFLs? After I
posted that thread "CFLs for a buck seventy-nine", Home Depot had a six
pack of corkscrew CFLs for even less than that. At those prices, if
they last twice as long as incandescents, they'll more than pay for
themselves in electricity savings. Amd you only have to change them
half as often, if that much.

I'm sure you'll get other expert opinions, especially from Don K. I've
been happy with the cheap CFLs I've been using, So..

Or you can probably pick up a Triplett or whatever ferroresonant
transformer in a box for cheap, and if you can stand the buzzing, it
should help.
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Jim Thompson
4ax.com>) about 'Constant Voltage Transformer Question', on Fri, 31 Dec
2004:
I was wondering how Constant Voltage Transformers would perform with
lamp loads.

There might be 'start-up' issues, if you have a fitting with a lot of
lamps in it, due to inrush current, but AFAIK CVTs work very well with
resistive loads.
I'm thinking of room-by-room regulation for ceiling fixtures... since,
15' up, it's tricky with a lamp changer pole :-(

Why not regulate all the lighting circuits with one CVT?

You do know that they are liable to hum, don't you? And, no, they can't
learn the words.
 
S

Spehro Pefhany

Jan 1, 1970
0
Why don't you get away from incandescents and go with CFLs? After I
posted that thread "CFLs for a buck seventy-nine", Home Depot had a six
pack of corkscrew CFLs for even less than that. At those prices, if
they last twice as long as incandescents, they'll more than pay for
themselves in electricity savings. Amd you only have to change them
half as often, if that much.

I'm sure you'll get other expert opinions, especially from Don K. I've
been happy with the cheap CFLs I've been using, So..

Or you can probably pick up a Triplett or whatever ferroresonant
transformer in a box for cheap, and if you can stand the buzzing, it
should help.

Voltage stabilizers are pretty common in third-world countries. I
can't remember where I've seen them for sale though. They look like
the usual metal box with a transformer in it (like 120/240
autotransformers). Not very expensive (China/India etc.). Mohammed has
one here, but he's got little feedback and the item location seems a
bit odd (is it NYC or is it Houston, "Taxes"?).

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4660&item=3862579284


Best regards,
Spehro Pefhany
 
W

Winfield Hill

Jan 1, 1970
0
Jim Thompson wrote...
I was wondering how Constant Voltage Transformers would perform with
lamp loads. I'm thinking of room-by-room regulation for ceiling
fixtures... since, 15' up, it's tricky with a lamp changer pole :-(

Why not change to electronic mini-fluorescent lamps? I'd imagine
they aren't very voltage sensitive and now they're available with
decent color-temperature phosphors, and some can work with dimmers.
Save on electricity, cooling energy, and manpower.
 
J

Jim Thompson

Jan 1, 1970
0
I read in sci.electronics.design that Jim Thompson
4ax.com>) about 'Constant Voltage Transformer Question', on Fri, 31 Dec
2004:


There might be 'start-up' issues, if you have a fitting with a lot of
lamps in it, due to inrush current, but AFAIK CVTs work very well with
resistive loads.

Why not regulate all the lighting circuits with one CVT?

Probably too much for one transformer... I have 500W just in the
kitchen; but I'm open to suggestions... all the ceiling lighting is
off of a single sub-panel.
You do know that they are liable to hum, don't you? And, no, they can't
learn the words.

Sno-o-o-o-o-rt ;-)

...Jim Thompson
 
J

Jim Thompson

Jan 1, 1970
0
Jim Thompson wrote...

Why not change to electronic mini-fluorescent lamps? I'd imagine
they aren't very voltage sensitive and now they're available with
decent color-temperature phosphors, and some can work with dimmers.
Save on electricity, cooling energy, and manpower.

Do they make those with floodlight shaping?

I haven't been impressed with the light output of the CFLs I've seen.

I have 5x 75W halogen floods just over the cooking area... 15' up,
that's barely adequate.

...Jim Thompson
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Winfield Hill <hill_a@t_rowland-
dotties-harvard-dot.s-edu> wrote (in said:
Jim Thompson wrote...

Why not change to electronic mini-fluorescent lamps? I'd imagine
they aren't very voltage sensitive

I didn't recommend them for that specific reason. The problem is the
rectifier filter cap. It is quite heavily stressed with voltage and
temperature when the lamp is running at its rated voltage, and I didn't
like to guess the life at 130 V input.
 
S

Spehro Pefhany

Jan 1, 1970
0
Do they make those with floodlight shaping?

Yes, but the ones we've tried have woefully inadequate light output. I
use the 85W incandescents in some places, because the 65W ones are too
dim for my eyes. The floods and the small base ones (candelabra based
etc.) are two weak spots right now. The regular replacement bulbs are
pretty good and we've got them in most places that used to have
indandescents. I'm going to try conformally coating one and put it in
the MB shower fixture unless Home Despot carries small outdoor types.
I haven't been impressed with the light output of the CFLs I've seen.

I have 5x 75W halogen floods just over the cooking area... 15' up,
that's barely adequate.

...Jim Thompson


Best regards,
Spehro Pefhany
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Jim Thompson
4ax.com>) about 'Constant Voltage Transformer Question', on Fri, 31 Dec
2004:
I have 5x 75W halogen floods just over the cooking area... 15' up,
that's barely adequate.

You won't get a household-type CFL with as much light output as a 75 W
halogen. Do the luminaires have to be 15 feet up? Three 35 W (or so; I
don't know what ratings are available for 120 V) linear fluorescent
tubes would give you more light, but you would need to arrange a
suitable luminaire.
 
J

Jim Thompson

Jan 1, 1970
0
I read in sci.electronics.design that Jim Thompson
4ax.com>) about 'Constant Voltage Transformer Question', on Fri, 31 Dec
2004:

You won't get a household-type CFL with as much light output as a 75 W
halogen. Do the luminaires have to be 15 feet up?

That's where the ceiling is ;-) (They're recessed PAR3 floods.)
Three 35 W (or so; I
don't know what ratings are available for 120 V) linear fluorescent
tubes would give you more light, but you would need to arrange a
suitable luminaire.


...Jim Thompson
 
D

Dan Mills

Jan 1, 1970
0
Jim said:
A major pain-in-the-ass in Arizona is lightbulb lifetime, particularly
this time of year, where one day will require heat and the next not.

So the AC voltage regulation sucks... often popping up to 130VRMS.

I was wondering how Constant Voltage Transformers would perform with
lamp loads.

I'm thinking of room-by-room regulation for ceiling fixtures... since,
15' up, it's tricky with a lamp changer pole :-(

I have easy attic access, pull-down-stair ladders, and the attic is
tall enough that I can stand upright to work in most locations.

...Jim Thompson

Silly thought, but if the load is just incandecents, why not just use a big
thyristor dimmer to (possibly automatically) trim the RMS value to whatever
you happen to like?

seems like it would be smaller and lighter then a CVT and would probably hum
less.

Regards, Dan.
 
A

artie

Jan 1, 1970
0
Been a while since I dealt with these beasties, and I'm operating under
the influence of OTC cold medication, but I seem to remember the
constant-voltage devices were saturated-core, and ran hot and noisy.
Had a 6800 development system (Jupiter II, all wire-wrapped) which used
a ferroresonant transformer. Hot and noisy! And if I leaned back in
my chair while using the phone, the headset got close to the thing,
inducing all sorts of fun into the conversation!
 
M

Martin Riddle

Jan 1, 1970
0
Jim,

Why not look into Buck and Boost setups. Sounds like 500W's is doable with a small buck transformer in series during the peak.
Usually its employed for Brownouts in the boost configuration. A relay and some hysterisis switching will keep the bulbs in a happy
range of voltages.

Happy New Year!
 
J

JeffM

Jan 1, 1970
0
J

James Meyer

Jan 1, 1970
0
Been a while since I dealt with these beasties, and I'm operating under
the influence of OTC cold medication, but I seem to remember the
constant-voltage devices were saturated-core, and ran hot and noisy.
Had a 6800 development system (Jupiter II, all wire-wrapped) which used
a ferroresonant transformer. Hot and noisy!

Ferroresonant transformers have terrible efficiencies. If you want to
double your power usage, they're great! Although Jim T's description of his
house seems to indicate that power usage is the least of his worries. :cool:

Jim
 
R

Richard Crowley

Jan 1, 1970
0
James Meyer said:
Ferroresonant transformers have terrible efficiencies. If you want to
double your power usage, they're great! Although Jim T's description
of his
house seems to indicate that power usage is the least of his worries.
:cool:

I've seen big variacs with servo-controlled motors that keep
the line voltage constant.
 
T

The Phantom

Jan 1, 1970
0
A major pain-in-the-ass in Arizona is lightbulb lifetime, particularly
this time of year, where one day will require heat and the next not.

So the AC voltage regulation sucks... often popping up to 130VRMS.

Here in the Pacific Northwest, high line voltage is the norm (130V is quite common).
Home Depot and others sell incandescents rated at 130V. Since the life of incandescents
varies as the inverse of the 12th power of the applied voltage, switching from 120V bulbs
to 130V bulbs makes quite a difference.
 

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