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Constant Voltage Transformer Question

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

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.
Reply to
Jim Thompson
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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

Reply to
John Stewart

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.

Reply to
Watson A.Name - "Watt Sun, th

I read in sci.electronics.design that Jim Thompson wrote (in ) 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?

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

--
Regards, John Woodgate, OOO - Own Opinions Only. 
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
Reply to
John Woodgate

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"?).

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Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
Reply to
Spehro Pefhany

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.

--
 Thanks,
    - Win
Reply to
Winfield Hill

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.

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

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.
Reply to
Jim Thompson

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

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.
Reply to
Jim Thompson

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.

--
Regards, John Woodgate, OOO - Own Opinions Only. 
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
Reply to
John Woodgate

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.

Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
Reply to
Spehro Pefhany

I read in sci.electronics.design that Jim Thompson wrote (in ) 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? 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.

--
Regards, John Woodgate, OOO - Own Opinions Only. 
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
Reply to
John Woodgate

That's where the ceiling is ;-) (They're recessed PAR3 floods.)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.
Reply to
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.

Reply to
Dan Mills

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!

--
Namaste--
Reply to
artie

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!

Reply to
Martin Riddle

Yup.

100W-equivalent floods are available.
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Standard (non-flood) units go up to 55W (300W equiv).

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Reply to
JeffM

On Fri, 31 Dec 2004 14:56:31 -0800, artie wroth:

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. 8-)

Jim

Reply to
James Meyer

I'm looking for PAR3 equivalent bulb size. The site is less than lucid, but it appears that the 100W-eq units are outdoor size.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.
Reply to
Jim Thompson

I've seen big variacs with servo-controlled motors that keep the line voltage constant.

Reply to
Richard Crowley

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.
Reply to
The Phantom

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