reduce 125VAC to 120VAC, small form factor, and clean 60Hz sine-wave

[ScottWW]

Two occasional (electrical) causes of hum in electric motors (specifically
ceiling fans) are overvoltage and a noisy sine-wave.

If a US home is measured over 127VAC the local power utility will often
install a line conditioner. If a home is measured at 125VAC, in most cases
the power utility states that it is "within tolerances".

Tracking the source of line noise on 120VAC is often trial and error and
cannot always identify a single culprit. O'scopes are not commonly carried
by the installers. But I have documented a few overvoltage situations where
the line noise was also present; and I suspect creating some of the measured
overrvoltage.

I would like a device, that can reduce 125VAC voltage by 10% while
maintaining a smooth sine waveform. The last time I researched 120V
transformers for a 10% voltage reduction, they were too large (4"x 4" x 4")
for my purposes. Optimally I would like to this device to fit within a
"pancake box" outlet box, but even a 4" octagon outlet box.

Are there any new developments in small sized transformers capable of doing
this?
Does anybody have any ideas how else this could be accomplished?

Thanks!
Scott
Dunedin FL

[Jim Thompson]

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spam...@dcorp.com>
wrote:

There was recent thread on S.E.D...

"Mains wiring question: Sizing buck-boost transformer?"

Starting with Message-ID:
<0001HW.CD7B40B6...@news.eternal-september.org>

that addresses your very problem.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

[Tim Wescott]

It depends on the current you need it to carry -- lower current = smaller
size. What current are you asking of it?

If you want a traditional transformer with iron laminates and wire
windings then there's a pretty strict volume vs. volt-amp rating that has
to be adhered to, which is limited by the physics of copper wire and
magnetic steel. Making one that's a pancake shape just complicates the
transformer design and (probably) increases the volume even as you get
the thickness smaller.

Note that the fact that you want to install these in electrical boxes
complicates things -- you need something that'll be compliant to wiring
codes so it'll pass inspection. So you have legal hoops to jump through,
too. And of course if you select some 5V power supply transformer to use
in buck and some dip s**t burns down their house or gets electrocuted
through ordinary human stupidity, his/her kin will hire a lawyer who will
blame you and try to extract $$$ from you.

I assume that you're a professional fan installer who's at the mercy of
the ceiling fan manufacturers. Given that you're not going to like what
I have to say, but here's my ever so humble opinion:

If you're selling a product (like a ceiling fan) into a market where the
line voltages commonly go above 125V and are commonly dirty, and if you
make your ceiling fan so that it makes objectionable noises when these
commonly occurring conditions prevail, then you are making a poor product
and the best you deserve is to have your customers let you know why they
are abandoning you to other vendors.

If you're a manufacturer, ditto.

If you're an installer, you should be looking for a different
manufacturer to favor. Only if this problem exists across the whole
market, or if there's some compelling reason to avoid the fans that don't
hum at high voltages (like they're otherwise pieces of s**t or
something), should you try to fix the problem with bubble gum, spit, or
transformers in electrical boxes.

If _all_ the manufacturers out there are stupid, then there may be a
market opportunity here to make and sell these things. Of course, as
soon as you get really successful the ceiling fan manufacturers will have
lights go on in the dimness that dominates their brains and will realize
that there's money to be made in fans that don't hum, and they'll start
doing so and take away your business.

And it may be cheaper to just make your own damn fans.

Were it me and I did it, I'd sell out to the first ceiling fan
manufacturer that came sniffing around with enough cash to make it worth
my while -- because I would know that if I didn't, the next thing I'd see
would be "humless fans" on the market, and a big investment in useless
transformers sitting in unsellable piles in the soon-to-be-not-mine
business.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

[Jim Thompson]

On Tue, 02 Apr 2013 17:53:07 -0500, Tim Wescott <t...@seemywebsite.com>
wrote:

Used Popsicle sticks fix _many_ problems ;-)

[Jamie]

A line reactor may quiet it down a bit. You can find those where they
sell accessories for drives and motors. It's possible some one near you
on the same pole pig could be operating a welder or similar, if this is
intermitting.

P.S.
That little over voltage isn't going to cause noise, a distorted
wave form will.

Jamie

[ScottWW]

"Jim Thompson" wrote in message
news:8qhml8hr2ib6g1oll...@4ax.com...

*******************
Thanks,
I am reading further...

[ScottWW]

"Jamie" wrote in message news:eAJ6t.93922$Xw1....@newsfe20.iad...

*****************
Thanks!
I was not aware of this device. I am reading further.

[ScottWW]

"Tim Wescott" wrote in message
news:Zt6dnRbim-vO_MbM...@giganews.com...

***************************
Thanks for your reply. Your faint hostility towards ceiling fan
manufacturers aside, you bring up some valid points and concerns. ;) As a
distributor with close ties to a couple manufacturers producing our
products, I may be defensive in my reading. My intent is not to profit from
the multitudes of crappy fans; my intent is a solution that maintains
customer satisfaction even where more power is desired. I unfortunately
have become the last stop in customer service escalation.

The typical amperage of a fan motor is 0.7A at 120V, max 1.25A for the
largest motors (permanent split capacitor induction motors).
The overvoltage hum only occurs on the larger, heavier motors that are the
more powerful air movers.

The overvoltages are not 'commonly' occurring conditions. That is why I
seek a modular solution, as they would only be needed in a fraction of a
percent of cases. These cases are invariably from electrician installed
fans, so I am not really looking for homeowner installed solution, though
the "fit into an outlet box" size certain would be more convenient for the
DIYer.

We have documented many causes of audible motor hum of the past few decades,
and most can be solved by simple solutions - tightening screws, the use of a
proper control (dimmers truncate the sine wave peaks), or
reinforcement/tightening of the installation site (extruded metal
beams/studs, split wood in beams/rafters, and torsion-box-built ceilings,
all transmit vibrations). Only the ones found to be overvoltage/line noise
issues are currently without solution, unless the utility helps out.

Scott
Dunedin FL

[John Larkin]

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spam...@dcorp.com> wrote:

>Two occasional (electrical) causes of hum in electric motors (specifically
>ceiling fans) are overvoltage and a noisy sine-wave.

A cheapish motor may saturate at high line voltage and create its own harmonics.

A series inductor would be a good fix for both sorts of problems. It would
reduce the motor voltage and somewhat filter external harmonics. A series cap
would help with the over-voltage but not externals.

Ceiling fans are great (we have no air conditioning in San Francisco and it does
get warm once in a while) as long as they are quiet.



--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

[ScottWW]

"John Larkin" wrote in message
news:fmkol855vrrjgo6tv...@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spam...@dcorp.com> wrote:

>Two occasional (electrical) causes of hum in electric motors (specifically
>ceiling fans) are overvoltage and a noisy sine-wave.

A cheapish motor may saturate at high line voltage and create its own
harmonics.

A series inductor would be a good fix for both sorts of problems. It would
reduce the motor voltage and somewhat filter external harmonics. A series
cap
would help with the over-voltage but not externals.

Ceiling fans are great (we have no air conditioning in San Francisco and it
does
get warm once in a while) as long as they are quiet.

***************
Thank you for the reply. Jamie's reply to my post mentioned a Line Reactor
which appears to incorporate a series of inductors. I am reading more about
this now. I have suspected line noise is the true culprit and overvoltage
is a side-effect.

Core saturation in the motor has been discussed in the past with the
manufacturers (regarding heat rise), but the motors are designed to operate
at the median of saturation (at the normal voltage range) to limit heat
rise. I will bring this idea up again in regards to noise.

Scott

[Cydrome Leader]

You'll probably be breaking all sorts of codes, but an 8 volt doorbell
transformer might do what you want, if wired in buck mode. You'd want to
hide that in a box of some sort as there would be line voltage at the
screw terminals. Even if you wire the neutral to the low voltage side,
it's a nonstandard use and you don't want to confuse anybody. It might fit
in a deep two gang box.

[Jim Thompson]

I doubt that a doorbell transformer has sufficient KVA, but they're
generally box mountable and meet code, being metal enclosed and with a
stub that fits box knock-outs... at least here in AZ, no exposed screw
terminals.

[Cydrome Leader]

I've never seen a fully enclosed one around here as they're all screw terminals
staked onto some sort of fishpaper on the LV side, but you have so they must
exist.

I can't honestly say I have any idea how much current a ceiling fan draws, but if
it's just an amp or so, a wimpy doorbell transformer should be OK. Security
camera/alarm system/hvac transformers all seems to be rated too high in voltage,
but do seem to be beefier in power ratings.

[Jim Thompson]

On Wed, 3 Apr 2013 21:16:05 +0000 (UTC), Cydrome Leader

I have no idea how much power the fan needs either.

But it seems a transformer contained within a certified electrical box
should be OK, provided that "earth" in maintained IN-to-OUT, maybe add
a GCFI to CYA.

(I've added outlets onto my patio simply by punching thru the wall
from an existing indoor outlet and adding an outdoor-rated receptacle
on the patio side. Then I changed the indoor receptacle to a GCFI
unit with downstream "feed-through" protection.)

[Tim Wescott]

Faint?

> you bring up some valid points and concerns. ;)

It's not so much that I'm hostile against 'em -- it's that 125V is common
and getting more so, so if the fans really crap out at that point then a
bit of extra margin is a Good Thing. (And as you know, a problem that's
not complained about is a problem that's never addressed). If the noise
issues are really a small fraction of the problems then yes, a modular
solution makes sense.

You _may_ be able to explain the issues and ask the manufacturers if it's
possible to increase the design voltage by 5V or so -- but if the problem
really is rare then I suspect that the cost/benefit analysis won't play
out in your favor (and you may end up having problems with undervoltage,
or needing to increase the expense of the fan to make it work over a
wider range -- there's no free lunch).

> As
> a distributor with close ties to a couple manufacturers producing our
> products, I may be defensive in my reading. My intent is not to profit
> from the multitudes of crappy fans; my intent is a solution that
> maintains customer satisfaction even where more power is desired. I
> unfortunately have become the last stop in customer service escalation.
>
> The typical amperage of a fan motor is 0.7A at 120V, max 1.25A for the
> largest motors (permanent split capacitor induction motors). The
> overvoltage hum only occurs on the larger, heavier motors that are the
> more powerful air movers.
>
> The overvoltages are not 'commonly' occurring conditions. That is why I
> seek a modular solution, as they would only be needed in a fraction of a
> percent of cases. These cases are invariably from electrician installed
> fans, so I am not really looking for homeowner installed solution,
> though the "fit into an outlet box" size certain would be more
> convenient for the DIYer.
>
> We have documented many causes of audible motor hum of the past few
> decades, and most can be solved by simple solutions - tightening screws,
> the use of a proper control (dimmers truncate the sine wave peaks), or
> reinforcement/tightening of the installation site (extruded metal
> beams/studs, split wood in beams/rafters, and torsion-box-built
> ceilings, all transmit vibrations). Only the ones found to be
> overvoltage/line noise issues are currently without solution, unless the
> utility helps out.

I did a quick search on DigiKey for 5V to 6.3V transformers that would
handle currents close to your range. These should give you an idea of
the sizes you would really need, but just popping one of these in an
electrical box probably won't meet code (these are all intended to be
built into electronic equipment, not to be mounted in an electrical box
-- I'm sure NEMA would have something to say about using one of these).

Maybe find the manufacturer for one of the bigger transformers you're
looking at, and ask if they can make a 1.5A version?

http://tinyurl.com/d9z86gh

http://www.digikey.com/scripts/dksearch/dksus.dll?FV=fff4000c%2Cfff8012f%
2C19440006%2C19440033%2C19440061%2C19440065%2C1944008d%
2C1944008f&vendor=0&mnonly=0&newproducts=0&ptm=0&fid=0&quantity=0&PV1120=734&PV1120=1160&PV1120=732&PV1120=935&PV1120=994&PV1120=203&PV1120=95&PV1120=324&PV1120=198&PV1120=860&PV1120=402

[John Larkin]

A lot of cheap motors and transformers are designed to the edge of saturation to
save copper and steel, and magnetizing current increases radically as line
voltage goes up. The current waveform gets very spikey, and saturation is
usually audible.

A ceiling fan might use one amp maybe, and if you want to drop 10 volts or so, a
single series inductor of roughly 30 to maybe 100 millihenries would do it.

[George Herold]

On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:
> "John Larkin"  wrote in message
>
> news:fmkol855vrrjgo6tv...@4ax.com...
>

That should be pretty easy to test. At least the over-voltage part.
Variac's typically go a bit ~10% overvoltage so you could see (or
hear) if the over voltage is the problem. If not .. then getting rid
of the line noise is a filtering issue. I would think there would be
some commercial pi or Tee low pass inline filters... but I don't have
any experience with AC power stuff.

George H.

[Jamie]

A variac will hide noise and give you a false conclusion, Hence using
some sort of induction coupling, common mode style preferable.

Jamie

[John Fields]

---
Instead of giving a man a fish, why not teach a man how to fish?

--
JF

[John Larkin]

What do fish have to do with ceiling fans?


--

John Larkin Highland Technology, Inc

jlarkin at highlandtechnology dot com

http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom laser drivers and controllers

Photonics and fiberoptic TTL data links

VME thermocouple, LVDT, synchro acquisition and simulation

[John Fields]

On Thu, 04 Apr 2013 17:01:07 -0700, John Larkin
<jla...@highlandtechnology.com> wrote:

>On Thu, 04 Apr 2013 18:31:34 -0500, John Fields
><jfi...@austininstruments.com> wrote:
>
>>On Wed, 03 Apr 2013 18:41:41 -0700, John Larkin
>><jjla...@highNOTlandTHIStechnologyPART.com> wrote:

>>>A ceiling fan might use one amp maybe, and if you want to drop 10 volts or so, a
>>>single series inductor of roughly 30 to maybe 100 millihenries would do it.
>>
>>---
>>Instead of giving a man a fish, why not teach a man how to fish?
>
>What do fish have to do with ceiling fans?

---
Oh, my!!!

--
JF

[ScottWW]

"Tim Wescott" wrote in message

news:C5CdnXq37r08AsHM...@giganews.com...

************************
Thanks for the links.
Scott

[ScottWW]

"Jamie" wrote in message news:Yfn7t.303716$Hg7.3...@newsfe30.iad...

**************

I did not know an autotransformer outputs overvoltage. I guess I need to
determine if it is strictly overvoltage, saturation with harmonic noise, or
external noise before I attempt to requisition equipment.
Thanks!
Scott in Dunedin

[ScottWW]

"John Fields" wrote in message
news:9tbtl8p3gsg2m4a8s...@4ax.com...

***************************
I appreciate the description of the best lure.
Quick research into inductor calculations gave me a haddock.
Thanks!
Scott

[George Herold]

On Apr 4, 6:36 pm, Jamie

> Jamie- Hide quoted text -
>
> - Show quoted text -

No, I meant the variac to only test the over-voltage part. Do the
fans make noise because of a slight over voltage... or is it noise on
the line?

George H.

[ScottWW]

"Jamie" wrote in message news:Yfn7t.303716$Hg7.3...@newsfe30.iad...

*************************
In an effort to determine whether it is line noise or simply overvoltage, it
seems an autotransformer could recreate a clean overvoltage in our facility
for testing. Please clarify how the autotransformer would "hide noise". By
cleaning up the mains power? Would it also mitigate the internal harmonics
from saturation problems? It would be preferred if it didn't for testing
purposes.

I am hazy on "induction coupling, common mode style". Does this refer to a
choke? To reduce voltage and clean up the waveform? This is more
accurately addressing the subject line, but I think I 'm off on a tangent
now, about testing.

Thanks!
Scott in Dunedin

[John Larkin]

On Fri, 5 Apr 2013 09:29:19 -0400, "ScottWW" <spam...@dcorp.com>
wrote:

>
>
>"John Fields" wrote in message
>news:9tbtl8p3gsg2m4a8s...@4ax.com...
>
>On Thu, 04 Apr 2013 17:01:07 -0700, John Larkin
><jla...@highlandtechnology.com> wrote:
>
>>On Thu, 04 Apr 2013 18:31:34 -0500, John Fields
>><jfi...@austininstruments.com> wrote:
>>
>>>On Wed, 03 Apr 2013 18:41:41 -0700, John Larkin
>>><jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>
>>>>A ceiling fan might use one amp maybe, and if you want to drop 10 volts
>>>>or so, a
>>>>single series inductor of roughly 30 to maybe 100 millihenries would do
>>>>it.
>>>
>>>---
>>>Instead of giving a man a fish, why not teach a man how to fish?
>>
>>What do fish have to do with ceiling fans?
>
>---
>Oh, my!!!

The subject is acoustic noise from an induction motor. Not fish!

JF has been studying his cliche book again, and not his EE texts.

[John Larkin]

Variacs are usually pretty wideband, up to a KHz at least.

--

John Larkin Highland Technology, Inc

jlarkin at highlandtechnology dot com

http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom laser drivers and controllers

Photonics and fiberoptic TTL data links

[Jamie]

The problem with any induction device is, it's going to filter the noise
and with a auto transformer, this will happen unless you are at the 1:1
location and the noise will fade as you go above or below.

You really should monitor the voltage with a scope to see what it
looks like. I've seen a lot of distorted wave forms due to heavy and
uneven loads in the service area, mostly when it's hot and every one
is operating their air.

In the summer at work, we get back power to the machines due to heavy
loads we have operating from all the air handling units.. You can hear
the inverter drives doing random singing on units that do not have a
isolation transformer or line rectors.

In many cases with the 3 phase equipment we need no less than a 1:1
transformer for voltage sensitive devices. This is because there is a
3 phase floating delta and when a leg gets shorted somewhere, which
will not most of the time cause a problem directly, it will cause many
inverter drive types to sense over voltage and shut down. Some times it
actually burns out the sensing circuit in the drives and thinks it is
looking at over 800v on the bus, when it is only seeing 600 at the DC bus.

Have fun.

Jamie

[Jamie]

http://www.exergia.info/Lightning/lightning7.htm

Read the first couple of sections

Jamie

[Michael A. Terrell]

ScottWW wrote:

>
> Jamie wrote:
>>
>> A variac will hide noise and give you a false conclusion, Hence using
>> some sort of induction coupling, common mode style preferable.
>

> I did not know an autotransformer outputs overvoltage. I guess I need to
> determine if it is strictly overvoltage, saturation with harmonic noise, or
> external noise before I attempt to requisition equipment.

It depends to the model of the Variac, and how it's connected. The
standard model doesn't boost the voltage. The other type can be fed
from a tap, and with 120 VAC in can give 0-140 VAC out. Be careful with
anything Maynard Philbrook (AKA: Jamie) tells you.

[John Fields]

On Fri, 05 Apr 2013 10:53:49 -0700, John Larkin

<jla...@highlandtechnology.com> wrote:

>On Fri, 5 Apr 2013 09:29:19 -0400, "ScottWW" <spam...@dcorp.com>
>wrote:
>
>>
>>
>>"John Fields" wrote in message
>>news:9tbtl8p3gsg2m4a8s...@4ax.com...
>>
>>On Thu, 04 Apr 2013 17:01:07 -0700, John Larkin
>><jla...@highlandtechnology.com> wrote:
>>
>>>On Thu, 04 Apr 2013 18:31:34 -0500, John Fields
>>><jfi...@austininstruments.com> wrote:
>>>
>>>>On Wed, 03 Apr 2013 18:41:41 -0700, John Larkin
>>>><jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>>
>>>>>A ceiling fan might use one amp maybe, and if you want to drop 10 volts
>>>>>or so, a
>>>>>single series inductor of roughly 30 to maybe 100 millihenries would do
>>>>>it.
>>>>
>>>>---
>>>>Instead of giving a man a fish, why not teach a man how to fish?
>>>
>>>What do fish have to do with ceiling fans?
>>
>>---
>>Oh, my!!!
>
>The subject is acoustic noise from an induction motor. Not fish!
>
>JF has been studying his cliche book again, and not his EE texts.

---
Not a cliche at all, just a variation of: "Give a man a fish and
you've fed him for a day; show him how to fish and you've fed him for
the rest of his life."

My point was that your answer was simplistic and didn't really convey
anything helpful other than: "If that, then this", without really
delving into the "that",and all the while sending him out to buy a lot
of chokes.

I think that's what we've come to expect from you.

--
JF

[John Fields]

---
Got some data to support your claim?

--
JF

[Jim Thompson]

On Tue, 09 Apr 2013 17:07:07 -0500, John Fields

Even us atheists know about teaching how to fish >:-}

[Jim Thompson]

Larkin? DATA? You've got to be kidding.

[John Fields]

---
Silly me...

--
JF

[John Larkin]

On Tue, 09 Apr 2013 17:07:07 -0500, John Fields

Trivial, tedious, predictable fathead.

[Jim Thompson]

On Tue, 09 Apr 2013 18:00:20 -0500, John Fields

This is getting to be fun. Imagine... me playing the straight man
>:-}

[John Larkin]

On Tue, 09 Apr 2013 18:00:20 -0500, John Fields

You two old gits are sad. You have nothing to say on-topic, nothing to
contribute, and you only seem to admire one another. Your only
remaining skill is whining at people who are interested in
electronics. The rest of your life will only be worse.

[John Larkin]

On Tue, 09 Apr 2013 17:10:14 -0500, John Fields
<jfi...@austininstruments.com> wrote:

As I recall, you were wrong about Variacs the last time we discussed
them.

[P E Schoen]

"John Larkin" wrote in message

news:63a9m8p7rbb0k0ni9...@4ax.com...

> On Tue, 09 Apr 2013 17:10:14 -0500, John Fields
> <jfi...@austininstruments.com> wrote:

>> On Fri, 05 Apr 2013 10:55:16 -0700, John Larkin
>> <jla...@highlandtechnology.com> wrote:

>>> Variacs are usually pretty wideband, up to a KHz at least.

>> Got some data to support your claim?

> As I recall, you were wrong about Variacs the last time we discussed them.

They are perfectly fine and rated for full output up to 2kHz, at least for
moderate size units (2kVA):
http://www.danaherspecialtyproducts.com/uploadedFiles/Siteroot/Superior_Electric/Products_and_Solutions/POWERSTAT%C2%AE_Variable_Transformers/126-226(pg16-19).PDF

I made a transformer from a toroidal core (possibly from a Powerstat) and
tested it up to 16 kHz. The following are from my tests as presented in a
post here on 3/5/2012, with a primary of two coils of 8 turns each, about
#10 AWG, and the secondary is 100 turns of about #18 AWG. The core (IIRC) is
rated 80 VA at 60 Hz. Powerstats (Variacs) are toroidal autotransformers
with a very tight winding pattern so that adjacent turns can be flattened
and selected by means of a carbon brush. They are made from high quality
silicon steel. You can see that the efficiency increases and core loss
decreases at higher frequency, although rather lightly loaded.

Under no load conditions 500 Hz, I got:

4V 0.71A 2.84W 96V P-P
8V 1.24A 9.92W 194V P-P
12V 1.70A 20.4W 286V P-P

With a 1k 10W resistor load:

4V 1.22A 4.9W 93.6V P-P 2.2W
8V 2.25A 18.0W 190V P-P 9.0W
12V 3.15A 37.8W 277V P-P 19.2W 51%

Under no load conditions 1000Hz, I got:

4V 0.58A 2.32W 96V P-P
8V 1.01A 8.08W 192V P-P
12V 1.42A 17.0W 293V P-P

With a 1k 10W resistor load:

4V 1.10A 4.4W 89.6V P-P 2.0W
8V 2.00A 16.0W 180V P-P 8.1W
12V 2.89A 34.7W 266V P-P 17.7W 51%

Under no load conditions, 2000 Hz, I got:

4V 0.48A 1.92W 96V P-P
8V 0.87A 6.96W 192V P-P
12V 1.20A 14.4W 279V P-P

With a 1k 10W resistor load:

4V 1.00A 4.0W 93.6V P-P 2.2W
8V 1.86A 14.9W 186V P-P 8.7W
12V 2.70A 32.4W 274V P-P 18.8W 58%

At 4000 Hz with a 1k 10W resistor load:

4V 0.91A 3.6W 91.0V P-P 2.1W
8V 1.71A 13.7W 182V P-P 8.3W
12V 2.49A 29.9W 270V P-P 18.2W 61%

At 8000 Hz with a 1k 10W resistor load:

4V 0.81A 3.2W 94.0V P-P 2.2W
8V 1.54A 12.3W 179V P-P 8.0W
12V 2.25A 27.0W 267V P-P 17.8W 66%

At 16000 Hz with a 1k 10W resistor load:

4V 0.73A 2.9W 89.6V P-P 2.0W
8V 1.46A 11.7W 181V P-P 8.2W
12V 2.10A 25.2W 266V P-P 17.7W 70%

16000 Hz, No Load

4V 0.26A 1.0W 94.5V P-P
8V 0.50A 4.0W 183V P-P
12V 0.72A 8.6W 272V P-P

I used this transformer to boost 12VDC and later 24VDC to about 320 VDC to
power a VFD and a 2HP three phase motor. It was not entirely successful, but
mostly because I did not have a proper "soft start" or current limiting
precharge for the large bus capacitors. Here is a video of the contraption
in action:

http://www.youtube.com/watch?v=j5TyhdY-cHQ

Paul

[John Larkin]

On Tue, 9 Apr 2013 20:55:41 -0400, "P E Schoen" <pa...@peschoen.com> wrote:

>"John Larkin" wrote in message
>news:63a9m8p7rbb0k0ni9...@4ax.com...
>
>> On Tue, 09 Apr 2013 17:10:14 -0500, John Fields
>> <jfi...@austininstruments.com> wrote:
>
>>> On Fri, 05 Apr 2013 10:55:16 -0700, John Larkin
>>> <jla...@highlandtechnology.com> wrote:
>
>>>> Variacs are usually pretty wideband, up to a KHz at least.
>
>>> Got some data to support your claim?
>
>> As I recall, you were wrong about Variacs the last time we discussed them.
>
>They are perfectly fine and rated for full output up to 2kHz, at least for
>moderate size units (2kVA):
>http://www.danaherspecialtyproducts.com/uploadedFiles/Siteroot/Superior_Electric/Products_and_Solutions/POWERSTAT%C2%AE_Variable_Transformers/126-226(pg16-19).PDF

Thanks, Paul,

I'd recalled that Variacs were pretty good at audio frequencies. Even most big
ole EI transformers are useful up into the KHz.

JF: Happy now?


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom timing and laser controllers

Photonics and fiberoptic TTL data links

VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

[P E Schoen]

"John Fields" wrote in message

news:vh39m8lbdv2e6vf79...@4ax.com...

> Not a cliche at all, just a variation of: "Give a man a fish and
> you've fed him for a day; show him how to fish and you've fed him for
> the rest of his life."

Actually, when you teach a man to fish, he'll spend every day for the rest
of his life in a boat with his buddies drinking beer... :)

Paul

[John Fields]

On Tue, 09 Apr 2013 16:47:23 -0700, John Larkin

---
Well, it wouldn't be the first or the last time I was wrong about
something, so instead of dodging and running your big mouth, why don't
you post that 1kHz VARIAC data?

--
JF

[John Larkin]

And then go to McDonalds for a burger.

--

John Larkin Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom timing and laser controllers

Photonics and fiberoptic TTL data links

[John Larkin]

On Wed, 10 Apr 2013 07:10:30 -0500, John Fields <jfi...@austininstruments.com>

See the link that Paul posted, variac rated to 2 KHz.

A variac is a single-layer-wound toroid with a high-quality laminated steel
core. Leakage inductance is low and core loss is not a big deal, if it's
operated from a stiff source like the AC line. It;s pretty obvious that it would
work up into the KHz, and even more obvious that it will accurately pass a 60 Hz
voltage with some smaller harmonics on top, which was the situation with the fan
noise.

You don't know much about electronics, but you like to take bitchy contrary
positions, for emotional reasons, which makes you usually wrong. Playing bad
music or writing awful poetry don't require emotional discipline, but
electronics does.

--

John Larkin Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom timing and laser controllers

Photonics and fiberoptic TTL data links

[John Fields]

On Tue, 09 Apr 2013 18:52:08 -0700, John Larkin
<jjla...@highNOTlandTHIStechnologyPART.com> wrote:

>On Tue, 9 Apr 2013 20:55:41 -0400, "P E Schoen" <pa...@peschoen.com> wrote:
>
>>"John Larkin" wrote in message
>>news:63a9m8p7rbb0k0ni9...@4ax.com...
>>
>>> On Tue, 09 Apr 2013 17:10:14 -0500, John Fields
>>> <jfi...@austininstruments.com> wrote:
>>
>>>> On Fri, 05 Apr 2013 10:55:16 -0700, John Larkin
>>>> <jla...@highlandtechnology.com> wrote:
>>
>>>>> Variacs are usually pretty wideband, up to a KHz at least.
>>
>>>> Got some data to support your claim?
>>
>>> As I recall, you were wrong about Variacs the last time we discussed them.
>>
>>They are perfectly fine and rated for full output up to 2kHz, at least for
>>moderate size units (2kVA):
>>http://www.danaherspecialtyproducts.com/uploadedFiles/Siteroot/Superior_Electric/Products_and_Solutions/POWERSTAT%C2%AE_Variable_Transformers/126-226(pg16-19).PDF
>
>
>Thanks, Paul,
>
>I'd recalled that Variacs were pretty good at audio frequencies. Even most big
>ole EI transformers are useful up into the KHz.
>
>JF: Happy now?

---
Well, not entirely, since that data only applies to Paul's variac, and
yours was a blanket statement.

I have a Thordarson VAR-104 (120V 50/60 Hz in, 0->140V 10A out) which
I'll run some tests on and post the results in the next day or so.

If you have a variac, why don't you do the same and then we can
compare all three sets of data.

Oh, but wait...

You don't do that sort of thing because you might find you were wrong
and we just can't have that, can we?.

--
JF

[John Larkin]

On Wed, 10 Apr 2013 08:59:23 -0500, John Fields <jfi...@austininstruments.com>

wrote:

>On Tue, 09 Apr 2013 18:52:08 -0700, John Larkin
><jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Tue, 9 Apr 2013 20:55:41 -0400, "P E Schoen" <pa...@peschoen.com> wrote:
>>
>>>"John Larkin" wrote in message
>>>news:63a9m8p7rbb0k0ni9...@4ax.com...
>>>
>>>> On Tue, 09 Apr 2013 17:10:14 -0500, John Fields
>>>> <jfi...@austininstruments.com> wrote:
>>>
>>>>> On Fri, 05 Apr 2013 10:55:16 -0700, John Larkin
>>>>> <jla...@highlandtechnology.com> wrote:
>>>
>>>>>> Variacs are usually pretty wideband, up to a KHz at least.
>>>
>>>>> Got some data to support your claim?
>>>
>>>> As I recall, you were wrong about Variacs the last time we discussed them.
>>>
>>>They are perfectly fine and rated for full output up to 2kHz, at least for
>>>moderate size units (2kVA):
>>>http://www.danaherspecialtyproducts.com/uploadedFiles/Siteroot/Superior_Electric/Products_and_Solutions/POWERSTAT%C2%AE_Variable_Transformers/126-226(pg16-19).PDF
>>
>>
>>Thanks, Paul,
>>
>>I'd recalled that Variacs were pretty good at audio frequencies. Even most big
>>ole EI transformers are useful up into the KHz.
>>
>>JF: Happy now?
>
>---
>Well, not entirely, since that data only applies to Paul's variac, and
>yours was a blanket statement.

Idiot. Whining to the max.

>
>I have a Thordarson VAR-104 (120V 50/60 Hz in, 0->140V 10A out) which
>I'll run some tests on and post the results in the next day or so.
>
>If you have a variac, why don't you do the same and then we can
>compare all three sets of data.
>
>Oh, but wait...
>
>You don't do that sort of thing because you might find you were wrong
>and we just can't have that, can we?.

I have no doubt that most any Variac will work fine at a KHz or two.

Where will you get 120 VAC at KHz frequencies? I have the gear to do that, but
it's not worth setting up. I know about how a steel-laminated single-layer
toroid will behave.

[John Fields]

---
You're preaching to the choir, asshole.

--
JF

[k...@attt.bizz]

On Wed, 10 Apr 2013 11:27:07 -0500, John Fields

So you agree with John. You know nothing about electronics, you're a
bitchy contrarian, emotional, and wrong. You play bad music (don't
know but you admit to it), write awful poetry (we have had that
unfortunate exposure), and have no emotional discipline. That about
sums you up.

Amazing.

[Jim Thompson]

I see you've added lack of reading comprehension to your ignorance of
the workings of hydraulic servos.

[John Fields]

On Wed, 10 Apr 2013 08:07:37 -0700, John Larkin

---
Wow, "whining", to you, is anything you take umbrage at, huh?

Seems like it's becoming your mantra.
---

>>I have a Thordarson VAR-104 (120V 50/60 Hz in, 0->140V 10A out) which
>>I'll run some tests on and post the results in the next day or so.
>>
>>If you have a variac, why don't you do the same and then we can
>>compare all three sets of data.
>>
>>Oh, but wait...
>>
>>You don't do that sort of thing because you might find you were wrong
>>and we just can't have that, can we?.
>
>I have no doubt that most any Variac will work fine at a KHz or two.
>
>Where will you get 120 VAC at KHz frequencies?

---
Tricky bitch wants to change streams in mid-horse by trying to
discredit the experiment before it's even done!
---

>I have the gear to do that, but it's not worth setting up.

---
Just another Larkin dodge.

Time out of my life is certainly worth at least as much as out of
yours, so if you don't want to play, why should I be the little red
hen?
---

>I know about how a steel-laminated single-layer toroid will behave.

---
La-dee-da...

Then prove it in the real world, using real hardware, instead of in
that creepy Walter Mitty universe you've created for yourself.

--
JF

[John Fields]

On Tue, 09 Apr 2013 16:12:13 -0700, John Larkin

---
Ah, the name-calling ad-hominem attack we've come to expect, again and
again, from Larkin.

--
JF

[k...@attt.bizz]

Wrong and wrong, but I do notice that you, too, are trying for the
AlwaysWrong award. Between you three, it's going to be a busy month
for the judges.

[Jim Thompson]

You've become Larkinized. You think truth is whatever fallacy exists
in your mind. And again, like Larkin, that snarky/abusive language,
repeated louder and louder, trumps truth.

You obviously either didn't read Larkin's complete statement, or you
had trouble comprehending a simple-minded statement... and what Fields
agreed with.

As for understanding power steering, let me nominate you for village
idiot of the year. No matter how much you claim that you're right,
every rational person here knows your wrong.

May your asshole be enlarged by a power-assisted rack-and-pinion so
that you and Ian can be exactly as your mentally-retarded speech
center continually invokes... "butt buddies".

Change your Depends... your bad breath is wafting clear across the
country.

[John Fields]

On Tue, 09 Apr 2013 16:16:53 -0700, John Larkin

---
Geez, I don't think so...

Jim's got a nice family with kids that have amounted to something, a
nice home that's situated precisely where he wants to live and, it
seems, a stream of clients that keep those big bucks rolling in.

What's sad about that?

I, on the other hand, have a nice family with kids that have amounted
to something, a nice home that's situated precisely where I want to
live and, having retired from the job-shop business, enough time to
devote to - well, you get the idea, maybe...

So, what you're trying to say - in your clumsy way - is that we should
be sad because of _your_ negative regard for us.

I can't speak for Jim, of course, but as far as I'm concerned, why
would you think that your opinion mattered?
---

>You have nothing to say on-topic, nothing to contribute,

---
Not true.

If you check our posting histories and compare them to yours, I'm sure
you'll find that our on-topic and off-topic technical posts far
outnumber yours.
---

>and you only seem to admire one another.

---
Again not true, since there are only a few people here whom I don't
admire.
---

>Your only remaining skill is whining at people who are interested in
>electronics. The rest of your life will only be worse.

---
There you go, cursing me and wielding that "whining" thing again, as
if it was Excalibur.

And you claim to not be a redneck faggot???

--
JF

[John Fields]

On Wed, 10 Apr 2013 03:12:14 -0400, "P E Schoen" <pa...@peschoen.com>
wrote:

---
Was I wrong? ;)

--
JF

[John Fields]

---
You obviously don't understand the meaning of:

"preaching to the choir".

Typical of the hoi polloi

--
JF

[Jim Thompson]

On Wed, 10 Apr 2013 13:20:37 -0500, John Fields

krw has no reading comprehension, typical of the ignorant, scumbag,
all mouth, no brains "class".

krw would appear to be posting from _work_... nice information >:-}

[John Larkin]

On Wed, 10 Apr 2013 12:14:33 -0500, John Fields

Paul posted a link to a variac that is rated to 2 KHz. If I were to
test our variac, it would just prove that one more variac works at KHz
frequencies, which wouldn't satisfy you at all.

Sounds like you don't actually have a way to generate 120VAC over a
wide frequency range.

What's crazy is that you seem to think that the average Variac *won't*
work at KHz frequencies. What would its failure mode be? Would its
output drop to unusable levels? Would it catch fire? Why?

--

John Larkin Highland Technology, Inc

jlarkin at highlandtechnology dot com

http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom laser drivers and controllers

Photonics and fiberoptic TTL data links

[John Larkin]

I can get these guys to disagree about almost anything! (And look very
stupid doing it.)

--

John Larkin Highland Technology, Inc

jlarkin at highlandtechnology dot com

http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom laser drivers and controllers

Photonics and fiberoptic TTL data links

[k...@attt.bizz]

On Wed, 10 Apr 2013 10:48:35 -0700, Jim Thompson

Wrong again, AlmostAlwaysWrong. I just don't care for the way you've
gotten to be an old hag. Alzheimer's must be rough.

>You obviously either didn't read Larkin's complete statement, or you
>had trouble comprehending a simple-minded statement... and what Fields
>agreed with.

Wrong, again, AlmostAlwaysWrong. Fields' statement showed that he
agreed that he was an ignorant ass.

>As for understanding power steering, let me nominate you for village
>idiot of the year. No matter how much you claim that you're right,
>every rational person here knows your wrong.
>
>May your asshole be enlarged by a power-assisted rack-and-pinion so
>that you and Ian can be exactly as your mentally-retarded speech
>center continually invokes... "butt buddies".

You and Fields aren't quite joined at the hip, but close enough.

>Change your Depends... your bad breath is wafting clear across the
>country.

AlmostAlwaysWrong strikes again. You really are becoming a loser.

[k...@attt.bizz]

On Wed, 10 Apr 2013 11:45:45 -0700, John Larkin

That's Fields' MO. Thompson's brain has shriveled up so much he's no
different. Sad, really.

[John Larkin]

JF is always wrong about Variacs. JT knows nothing about Variacs.

Which is preferable?

[Jim Thompson]

Queers of a feather, Larkin/Ian/krw, flock together.

[Jim Thompson]

On Wed, 10 Apr 2013 16:00:09 -0700, Jim Thompson
<To-Email-Use-Th...@On-My-Web-Site.com> wrote:

[snip]

>
>Queers of a feather, Larkin/Ian/krw, flock together.
>
> ...Jim Thompson

And Domino is your friend >:-}

[John Fields]

On Wed, 10 Apr 2013 11:43:03 -0700, John Larkin

---
Not true.

Take the time to do the tests, post the test conditions and the data,
and we'll talk.
---

>Sounds like you don't actually have a way to generate 120VAC over a
>wide frequency range.

---
Mindless conjecture/wishful thinking.

--
JF

[John Larkin]

On Wed, 10 Apr 2013 12:19:39 -0500, John Fields <jfi...@austininstruments.com>

I'd much rather criticize something that you say about electronics, but you do
that so seldom.

--

John Larkin Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom timing and laser controllers

Photonics and fiberoptic TTL data links

[John Larkin]

On Wed, 10 Apr 2013 20:58:08 -0500, John Fields <jfi...@austininstruments.com>

Well, do you have the capability or not? [1]

And you snipped the serious question: what do you think would be the failure
mode of a variac at a KHz or two?

[1] I have a Peavey 800 watt dual-channel PA amp and a bunch of step-up and
step-down transformers, and a precise polyphase sine wave generator. I can make
a very stable voltage up to 480, or current up to 200 amps.

--

John Larkin Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom timing and laser controllers

Photonics and fiberoptic TTL data links

[John Fields]

On Wed, 10 Apr 2013 19:35:47 -0700, John Larkin

---
Yup.
---

>And you snipped the serious question: what do you think would be the failure
>mode of a variac at a KHz or two?

---
Because "Failure mode" is a bit too harsh, I think, since they're
designed to take a lot of abuse.

However, if you want to play specmanship, we might talk about the
increase of turn-to-turn leakage reactance with respect to frequency,
and the leakage from winding to core.
---

>[1] I have a Peavey 800 watt dual-channel PA amp and a bunch of step-up and
>step-down transformers, and a precise polyphase sine wave generator. I can make
>a very stable voltage up to 480, or current up to 200 amps.

---
I have a Denon POA-800, so I can only drive a load with about 150
clean watts.

Enough to characterize a 1.5kVA variac at far below its ratings.

Since you claim to have all of the big guns...
--
JF

[John Larkin]

On Thu, 11 Apr 2013 14:34:21 -0500, John Fields

What in the world could all that word salad blather possibly mean?

What, specifically, is a Variac going to do as the frequency is
increased from 60 Hz to 1 KHz?

--

John Larkin Highland Technology, Inc

jlarkin at highlandtechnology dot com

http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom laser drivers and controllers

Photonics and fiberoptic TTL data links

[John Fields]

On Thu, 11 Apr 2013 13:14:54 -0700, John Larkin

---
Blather because you don't understand it, perhaps?
---

>What, specifically, is a Variac going to do as the frequency is
>increased from 60 Hz to 1 KHz?

---

Why don't you tell us, then test your variac and see whether your
predictions were correct.

BTW, which variac are you using?

Manufacturer, Model/Part number?

And just as aside, the "K" in your "KHz" should be lower case, Mr.
Perfect.

--
JF

[John Fields]

On Wed, 10 Apr 2013 19:30:06 -0700, John Larkin

---
I often post on-topic material, and the reason - if you read it - you
don't criticize it is because it's beyond reproach.

--
JF

[Jim Thompson]

On Thu, 11 Apr 2013 22:38:31 -0500, John Fields

Mr. "Perfect" ?? Mr. "Head Up Ass" is more appropriate >:-}

[P E Schoen]

"John Larkin" wrote in message

news:s86em81bhs0q8glvl...@4ax.com...

This is getting rather silly, and JF seems to be grasping at straws. Toroids
are often used for high quality audio and high efficiency power transformers
because they have much less leakage inductance than EI and other core types.
Here is some information on toroidal power transformers where the corner
frequency is about 50 kHz:
http://www.toruspower.com/nbt-narrow-bandwidth-technology/

Even the lowest corner frequency was 3 kHz, but this was in the context of a
low pass filter where it was desired to attenuate higher frequency
components of power line noise. But it seems evident that these toroids work
well at high audio frequencies. My own measurements were supposed to
determine if a given core size for 60 Hz could be used at higher frequencies
and correspondingly higher voltage and power levels.

The results indicate that there will be higher core loss at higher frequency
which may be proportional to the square root of frequency, so if my toroid
has 0.5% core loss at 60 Hz it may have 1% at 240 Hz and 2% at 1 kHz and 4%
at 4 kHz. But that is also accompanied by total power capacity increase from
80 VA at 60 Hz to 1.3 kVA at 1 KHz. Thus there may be 26W of core loss, but
that may be acceptable if the smaller size is a major advantage.

Here is another link that may be helpful (although JF may never accept that
he is wrong):
http://www.ipst.org/TechPapers/2003/IPST03Paper9c-3.pdf

This is specifically for medium voltage (600V-5kV) conventional current
transformers (which are usually silicon steel tape wound toroids), and it
shows good linearity and phase shift up to at least 50 kHz, which is vital
for transient response in electronic protection systems.

According to the following information, standard Talema toroidal
transformers are rated only to 450 Hz, but with other core materials
frequencies up to 100kHz are possible. Tape wound cores with high nickel
content allow higher frequencies.

http://www.talema.net/en/products/pdf/Trafo%20Catalog%20-%20English%20Feb-08.pdf

Here is an interesting article on the "Variac":
http://sound.westhost.com/articles/variac.htm

Paul

[k...@attt.bizz]

On Thu, 11 Apr 2013 22:59:54 -0500, John Fields

Like your hair-balls? Too funny!

[Jim Thompson]

What is NOT "too funny" is your "all mouth", no facts... cite a
circuit that was a "hair-ball". You're white trash just like Larkin.

[John Larkin]

On Fri, 12 Apr 2013 01:31:53 -0400, "P E Schoen" <pa...@peschoen.com> wrote:

>"John Larkin" wrote in message
>news:s86em81bhs0q8glvl...@4ax.com...
>
>> On Thu, 11 Apr 2013 14:34:21 -0500, John Fields
>> <jfi...@austininstruments.com> wrote:
>
>>> Because "Failure mode" is a bit too harsh, I think, since they're
>>> designed to take a lot of abuse.
>>
>>> However, if you want to play specmanship, we might talk about the
>>> increase of turn-to-turn leakage reactance with respect to frequency,
>>> and the leakage from winding to core.
>
>> What in the world could all that word salad blather possibly mean?
>
>> What, specifically, is a Variac going to do as the frequency is
>> increased from 60 Hz to 1 KHz?
>
>This is getting rather silly, and JF seems to be grasping at straws. Toroids
>are often used for high quality audio and high efficiency power transformers
>because they have much less leakage inductance than EI and other core types.
>Here is some information on toroidal power transformers where the corner
>frequency is about 50 kHz:
>http://www.toruspower.com/nbt-narrow-bandwidth-technology/

Even if the laminations in a variac are optimized for cost at 60 Hz, core losses
will still be moderate at, say, 1 KHz. The OP was concerned with 60 Hz plus
harmonics, so in that case the HF component would be small, so core loss is not
an issue at all.

At high line frequencies, leakage inductance will soften up the load regulation
a bit, but toroids have very low leakage inductance. With the Variac in/out
ratio anywhere near 1.0, inductive effects are still smaller.

Yes, JF is flailing, tossing around words as if he understands what they mean.

Nice, but I don't understand the line...

"Care is needed to ensure that the variac's current rating is not exceeded at
low brightness settings, where filament resistance is much lower than normal."

--

John Larkin Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom timing and laser controllers

Photonics and fiberoptic TTL data links

[John Fields]

---
I like sardonicism better. :)

--
JF

[John Fields]

On Fri, 12 Apr 2013 09:01:25 -0400, k...@attt.bizz wrote:

---
We all post hairballs from time to time, except for you, who hasn't -
as I recall - ever posted a schematic of something he designed.

I wonder why???

--
JF

[John Fields]

On Fri, 12 Apr 2013 18:39:48 -0700, John Larkin
<jjla...@highNOTlandTHIStechnologyPART.com> wrote:

>On Fri, 12 Apr 2013 01:31:53 -0400, "P E Schoen" <pa...@peschoen.com> wrote:
>
>>"John Larkin" wrote in message
>>news:s86em81bhs0q8glvl...@4ax.com...
>>
>>> On Thu, 11 Apr 2013 14:34:21 -0500, John Fields
>>> <jfi...@austininstruments.com> wrote:
>>
>>>> Because "Failure mode" is a bit too harsh, I think, since they're
>>>> designed to take a lot of abuse.
>>>
>>>> However, if you want to play specmanship, we might talk about the
>>>> increase of turn-to-turn leakage reactance with respect to frequency,
>>>> and the leakage from winding to core.
>>
>>> What in the world could all that word salad blather possibly mean?
>>
>>> What, specifically, is a Variac going to do as the frequency is
>>> increased from 60 Hz to 1 KHz?
>>
>>This is getting rather silly, and JF seems to be grasping at straws.

---
I just want to see some real test data.
---

>> Toroids are often used for high quality audio and high efficiency
>>power transformers because they have much less leakage inductance
>>than EI and other core types. Here is some information on toroidal
>>power transformers where the corner frequency is about 50 kHz:
>>http://www.toruspower.com/nbt-narrow-bandwidth-technology/

---
Fixed "n" toroidal high quality audio and power transformers aren't
the same animals as variable "n" variacs, so equating one to the other
is a little risky, I think.
---

>Even if the laminations in a variac are optimized for cost at 60 Hz, core losses
>will still be moderate at, say, 1 KHz. The OP was concerned with 60 Hz plus
>harmonics, so in that case the HF component would be small, so core loss is not
>an issue at all.

---
You posted earlier that the bandwidth of the variac would be high
enough to pass the harmonics, and now you post that the harmonic
content will be small, without even having a clue as to the output
waveform of the variac.

Why don't you just test your variac and put the whole thing to rest?
---

>At high line frequencies, leakage inductance will soften up the load regulation
>a bit, but toroids have very low leakage inductance. With the Variac in/out
>ratio anywhere near 1.0, inductive effects are still smaller.
>
>Yes, JF is flailing, tossing around words as if he understands what they mean.

---
Whatever you say, John.
---

>>Even the lowest corner frequency was 3 kHz, but this was in the context of a
>>low pass filter where it was desired to attenuate higher frequency
>>components of power line noise. But it seems evident that these toroids work
>>well at high audio frequencies.

---
If it seems evident that those toroids work well at high audio
frequencies, consideration should be given to the fact that they
aren't variacs, and that they do so by design.
---

>>My own measurements were supposed to
>>determine if a given core size for 60 Hz could be used at higher frequencies
>>and correspondingly higher voltage and power levels.
>>
>>The results indicate that there will be higher core loss at higher frequency
>>which may be proportional to the square root of frequency, so if my toroid
>>has 0.5% core loss at 60 Hz it may have 1% at 240 Hz and 2% at 1 kHz and 4%
>>at 4 kHz. But that is also accompanied by total power capacity increase from
>>80 VA at 60 Hz to 1.3 kVA at 1 KHz. Thus there may be 26W of core loss, but
>>that may be acceptable if the smaller size is a major advantage.

---
But that's for transformers that aren't variacs.

Tell ya what I'm going to do: I'll go ahead and test my variac and
post what I find, regardless of what "Mr. Perfect" does.
---

>>Here is another link that may be helpful (although JF may never accept that
>>he is wrong):
>>http://www.ipst.org/TechPapers/2003/IPST03Paper9c-3.pdf
>>
>>This is specifically for medium voltage (600V-5kV) conventional current
>>transformers (which are usually silicon steel tape wound toroids), and it
>>shows good linearity and phase shift up to at least 50 kHz, which is vital
>>for transient response in electronic protection systems.

---
Since a variac is not a conventional current transformer, prove me
wrong with relevant data.
---

>>According to the following information, standard Talema toroidal
>>transformers are rated only to 450 Hz, but with other core materials
>>frequencies up to 100kHz are possible.

---
If frogs had wings...
---

>>Tape wound cores with high nickel content allow higher frequencies.

>>http://www.talema.net/en/products/pdf/Trafo%20Catalog%20-%20English%20Feb-08.pdf

---
OK, but why is that germane?
---

>>
>>
>>Here is an interesting article on the "Variac":
>>http://sound.westhost.com/articles/variac.htm
>>
>>Paul
>
>Nice, but I don't understand the line...
>
>"Care is needed to ensure that the variac's current rating is not exceeded at
>low brightness settings, where filament resistance is much lower than normal."

---
I think that's an error.

From abse:

news:7kbim858vdbgefe20...@4ax.com

--
JF

[John Larkin]

On Sat, 13 Apr 2013 05:49:50 -0500, John Fields <jfi...@austininstruments.com>

wrote:

>On Fri, 12 Apr 2013 18:39:48 -0700, John Larkin
><jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Fri, 12 Apr 2013 01:31:53 -0400, "P E Schoen" <pa...@peschoen.com> wrote:
>>
>>>"John Larkin" wrote in message
>>>news:s86em81bhs0q8glvl...@4ax.com...
>>>
>>>> On Thu, 11 Apr 2013 14:34:21 -0500, John Fields
>>>> <jfi...@austininstruments.com> wrote:
>>>
>>>>> Because "Failure mode" is a bit too harsh, I think, since they're
>>>>> designed to take a lot of abuse.
>>>>
>>>>> However, if you want to play specmanship, we might talk about the
>>>>> increase of turn-to-turn leakage reactance with respect to frequency,
>>>>> and the leakage from winding to core.
>>>
>>>> What in the world could all that word salad blather possibly mean?
>>>
>>>> What, specifically, is a Variac going to do as the frequency is
>>>> increased from 60 Hz to 1 KHz?
>>>
>>>This is getting rather silly, and JF seems to be grasping at straws.
>
>---
>I just want to see some real test data.

You claim to have all te necessary gear. If you e=want to see test data, why
don't you do it yourself? If I did measure a Variac up into the KHz, you'd most
likely not like the results and accuse me of faking the data.

Silly, useless old fart.

Can't wait.

[Jamie]

Film at 11:00

Jamie

[Michael A. Terrell]

Jamie wrote:
>
> Film at 11:00


Don't sell yourself short, slime.

[John Larkin]

He won't actually do it. And if he did, the stuff he measures won't make sense.

[John Fields]

On Sat, 13 Apr 2013 08:57:04 -0700, John Larkin

<jjla...@highNOTlandTHIStechnologyPART.com> wrote:

>On Sat, 13 Apr 2013 05:49:50 -0500, John Fields <jfi...@austininstruments.com>
>wrote:
>
>>On Fri, 12 Apr 2013 18:39:48 -0700, John Larkin
>><jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>>
>>>On Fri, 12 Apr 2013 01:31:53 -0400, "P E Schoen" <pa...@peschoen.com> wrote:
>>>
>>>>"John Larkin" wrote in message
>>>>news:s86em81bhs0q8glvl...@4ax.com...
>>>>
>>>>> On Thu, 11 Apr 2013 14:34:21 -0500, John Fields
>>>>> <jfi...@austininstruments.com> wrote:
>>>>
>>>>>> Because "Failure mode" is a bit too harsh, I think, since they're
>>>>>> designed to take a lot of abuse.
>>>>>
>>>>>> However, if you want to play specmanship, we might talk about the
>>>>>> increase of turn-to-turn leakage reactance with respect to frequency,
>>>>>> and the leakage from winding to core.
>>>>
>>>>> What in the world could all that word salad blather possibly mean?
>>>>
>>>>> What, specifically, is a Variac going to do as the frequency is
>>>>> increased from 60 Hz to 1 KHz?
>>>>
>>>>This is getting rather silly, and JF seems to be grasping at straws.
>>
>>---
>>I just want to see some real test data.
>
>You claim to have all te necessary gear. If you e=want to see test data, why
>don't you do it yourself? If I did measure a Variac up into the KHz, you'd most
>likely not like the results and accuse me of faking the data.

---
Not at all.

What I object to is your making claims which you refuse to back up
with real-world data which can be replicated.

Sort of like Joseph Newman, who's from your neck of the woods as I
understand it.

Then there's the matter of you apparently ignoring my request for your
variac's manufacturer and model/part number.

Why would you do that?
---

>Silly, useless old fart.

---

Wow, the anal references which you earlier found repugnant now seem to
emanating from your camp.

---
But, poor baby, you'll have to.

--
JF

[John Fields]

On Sat, 13 Apr 2013 11:41:28 -0700, John Larkin
<jjla...@highNOTlandTHIStechnologyPART.com> wrote:


>He won't actually do it. And if he did, the stuff he measures won't make sense.

---
To you, perhaps, since it may be at odds with what you want to hear,
but I'm intrigued...

Why don't you run your own tests and present them as prima facie
evidence to support your position instead of threatening to shoot down
everyone else's positions as being untenable?

--
JF

[John Larkin]

On Sat, 13 Apr 2013 14:00:19 -0500, John Fields <jfi...@austininstruments.com>

Forever!

[Jim Thompson]

On Sat, 13 Apr 2013 14:00:19 -0500, John Fields

Borrowing an epithet from Slowman... John "NOLA white trash" Larkin is
a "gormless asshole grommet" >:-}

[Jim Thompson]

Present data which can actually be confirmed or denied? Give me a
break. Hell will freeze over first.

[John Fields]

On Sat, 13 Apr 2013 13:24:59 -0700, John Larkin

---
Well, you don't seem to have a good handle on what constitutes the
infinite and, in the same vein, the infinitesimal, so the wait may be
shorter or longer than you'd like it to be.

As for the experiment, I expect to design, test it, and post the
results within the next two weeks, so there's your window.

--
JF

[John Larkin]

On Mon, 15 Apr 2013 16:52:45 -0500, John Fields

Great. Should be interesting.

--

John Larkin Highland Technology, Inc

jlarkin at highlandtechnology dot com

http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom laser drivers and controllers

Photonics and fiberoptic TTL data links

[John Fields]

---
I hope so.

In the meantime, what can you tell us about _your_ variac?

Just manufacturer and part number would be nice, and a link to a data
sheet would be even better.

What do you say; can/will you post either?

--
JF

[John Larkin]

On Tue, 16 Apr 2013 14:16:40 -0500, John Fields

<jfi...@austininstruments.com> wrote:

>On Mon, 15 Apr 2013 18:09:29 -0700, John Larkin
><jla...@highlandtechnology.com> wrote:
>
>>On Mon, 15 Apr 2013 16:52:45 -0500, John Fields
>><jfi...@austininstruments.com> wrote:
>
>>>As for the experiment, I expect to design, test it, and post the
>>>results within the next two weeks, so there's your window.
>>
>>Great. Should be interesting.
>
>---
>I hope so.
>
>In the meantime, what can you tell us about _your_ variac?
>
>Just manufacturer and part number would be nice, and a link to a data
>sheet would be even better.
>
>What do you say; can/will you post either?

The one in the engineering lab is a Calrad 45-470, rated 5 amps. We've
had it for ages.

[P E Schoen]

"John Larkin" wrote in message

news:1hprm8906ime83bvf...@4ax.com...

> The one in the engineering lab is a Calrad 45-470, rated 5 amps.
> We've had it for ages.

I couldn't find anything on that model. Is it GenRad (General Radio)? Is it
really old like this:
http://www.uvm.edu/~dahammon/museum/generalradiovariac.html

I have a large quantity of Staco and Superior "variacs". The Superior 120V
5A is model 21, and the Staco equivalent is 501. I also have some larger
240V units rated at 3.5 amps (Superior 216)
http://www.danaherspecialtyproducts.com/uploadedFiles/Siteroot/Superior_Electric/Products_and_Solutions/POWERSTAT%C2%AE_Variable_Transformers/116-217(pg10-13).PDF

The 216/217 versions (240V) are specified for full output to 2kHz. The
116/117 versions are derated about 7% from 1.6 kHz to 2 kHz.

BTW, when I tested the toroid I rewound (which may have been from a variac),
I went to 16 kHz. And that was a square wave, which still had very fast
rise/fall times. But to be fair it was not putting out much current.

Paul

[John Larkin]

On Tue, 16 Apr 2013 22:54:53 -0400, "P E Schoen" <pa...@peschoen.com> wrote:

>"John Larkin" wrote in message
>news:1hprm8906ime83bvf...@4ax.com...
>
>> The one in the engineering lab is a Calrad 45-470, rated 5 amps.
>> We've had it for ages.
>
>I couldn't find anything on that model. Is it GenRad (General Radio)? Is it
>really old like this:
>http://www.uvm.edu/~dahammon/museum/generalradiovariac.html

Not really old. Calrad mostly rebrands Asian stuff.

http://www.calradstore.com/calrad.html

Wiki says that "Variac" dates from 1934. I can't imagine that there is a lot of
variation among Variac clones any more.

--

John Larkin Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom timing and laser controllers

Photonics and fiberoptic TTL data links

[T]

In article <wtH6t.280368$Nq4....@newsfe21.iad>, spam...@dcorp.com
says...
>
> Two occasional (electrical) causes of hum in electric motors (specifically
> ceiling fans) are overvoltage and a noisy sine-wave.
>
> If a US home is measured over 127VAC the local power utility will often
> install a line conditioner. If a home is measured at 125VAC, in most cases
> the power utility states that it is "within tolerances".
>
> Tracking the source of line noise on 120VAC is often trial and error and
> cannot always identify a single culprit. O'scopes are not commonly carried
> by the installers. But I have documented a few overvoltage situations where
> the line noise was also present; and I suspect creating some of the measured
> overrvoltage.
>
> I would like a device, that can reduce 125VAC voltage by 10% while
> maintaining a smooth sine waveform. The last time I researched 120V
> transformers for a 10% voltage reduction, they were too large (4"x 4" x 4")
> for my purposes. Optimally I would like to this device to fit within a
> "pancake box" outlet box, but even a 4" octagon outlet box.
>
> Are there any new developments in small sized transformers capable of doing
> this?
> Does anybody have any ideas how else this could be accomplished?
>
> Thanks!
> Scott
> Dunedin FL

Around here all the outlets put out 125VAC. Works with pretty much
everything.

[P E Schoen]

"John Larkin" wrote in message

news:md4sm891hivhkujpv...@4ax.com...

> Not really old. Calrad mostly rebrands Asian stuff.

> http://www.calradstore.com/calrad.html

> Wiki says that "Variac" dates from 1934. I can't imagine that there is a
> lot of variation among Variac clones any more.

Hey, where is the test data promised by John Fields? Once I recover from hip
replacement surgery** I plan to run some tests on one or more of the
"variacs" I have, some of which are actually just the wound cores without
the sliders, rated 9.5A at 240 VAC. The reason I have a huge pile of them
(15-20 pieces of Staco 1520) is that they were built into a product that
assumed their rating was correct and could be used at the published overload
duty cycles. But they failed catastrophically and we got a settlement from
Staco so we could purchase larger units that met our needs. I performed the
testing and proved that the special thin brush (as opposed to the more
rugged wedge shape) would overheat and crack and the brush holder would drop
onto the turns, causing a spectacular short.

http://variac.com/staco_variable_transformer_1510_.htm

For this model with the same core, the 120V version was rated at 15 amps,
and one would expect the 240V version to be half that at 7.5A. For other
models, such as the 1010/1020, the 240V version is rated at less than half
the current (3.5A vs 10A).

http://www.variac.com/staco_variable_transformer_1000_1200.htm

Anyway, as you can see, these units are fully rated to 2 kHz, and I'm
betting they can work respectably to 10kHz or more. The name brand variacs
are probably wound with high quality thin silicon steel laminations with
good high frequency response. The cheapo Chinese brands selling at about 1/4
the price of Staco and Superior are probably made of cheaper materials. But
I think they will just run a little hotter or noisier but OK up to at least
400 Hz and probably 1-2 kHz or more.

I'll do some tests when I'm able to get around better.

**JF, what's your excuse?

Paul

[John Larkin]

On Fri, 10 May 2013 15:43:23 -0400, "P E Schoen" <pa...@peschoen.com> wrote:

>"John Larkin" wrote in message
>news:md4sm891hivhkujpv...@4ax.com...
>
>> Not really old. Calrad mostly rebrands Asian stuff.
>
>> http://www.calradstore.com/calrad.html
>
>> Wiki says that "Variac" dates from 1934. I can't imagine that there is a
>> lot of variation among Variac clones any more.
>
>Hey, where is the test data promised by John Fields?

I've asked that question myself.

Catch up on some good books.

>
>**JF, what's your excuse?

I suspect he doesn't know what to measure.

[John Fields]

On Fri, 10 May 2013 15:43:23 -0400, "P E Schoen" <pa...@peschoen.com>
wrote:

>Hey, where is the test data promised by John Fields?

---
Just lazy, plus there doesn't seem to be a pressing need for it, and
posting the data will only lead to another pointless argument with
Larkin, so why even bother?

--
JF