reduce 125VAC to 120VAC, small form factor, and clean 60Hz s

"John Larkin" wrote in message
news:63a9m8p7rbb0k0ni9r98el90o1hmnc4uck@4ax.com...

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

On Fri, 05 Apr 2013 10:55:16 -0700, John Larkin
jlarkin@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.
Click to expand...
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
 
On Tue, 9 Apr 2013 20:55:41 -0400, "P E Schoen" <paul@peschoen.com> wrote:

"John Larkin" wrote in message
news:63a9m8p7rbb0k0ni9r98el90o1hmnc4uck@4ax.com...

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

On Fri, 05 Apr 2013 10:55:16 -0700, John Larkin
jlarkin@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
Click to expand...

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
 
"John Fields" wrote in message
news:vh39m8lbdv2e6vf7936v1eenlo5b19uj18@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."
Click to expand...
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
 
On Tue, 09 Apr 2013 16:47:23 -0700, John Larkin
<jlarkin@highlandtechnology.com> wrote:

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

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

On Thu, 04 Apr 2013 18:48:43 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

George Herold wrote:
On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:

"John Larkin" wrote in message

news:fmkol855vrrjgo6tvge7eg2tbhngseicbl@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spamt...@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


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.

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

Jamie

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

"John Fields" wrote in message
news:vh39m8lbdv2e6vf7936v1eenlo5b19uj18@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
Click to expand...
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
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators
 
On Wed, 10 Apr 2013 07:10:30 -0500, John Fields <jfields@austininstruments.com>
wrote:

On Tue, 09 Apr 2013 16:47:23 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

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

On Thu, 04 Apr 2013 18:48:43 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

George Herold wrote:
On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:

"John Larkin" wrote in message

news:fmkol855vrrjgo6tvge7eg2tbhngseicbl@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spamt...@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


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.

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

Jamie

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.

---
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?
Click to expand...
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
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators
 
On Tue, 09 Apr 2013 18:52:08 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

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

"John Larkin" wrote in message
news:63a9m8p7rbb0k0ni9r98el90o1hmnc4uck@4ax.com...

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

On Fri, 05 Apr 2013 10:55:16 -0700, John Larkin
jlarkin@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?
Click to expand...
---
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
 
On Wed, 10 Apr 2013 08:59:23 -0500, John Fields <jfields@austininstruments.com>
wrote:

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

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

"John Larkin" wrote in message
news:63a9m8p7rbb0k0ni9r98el90o1hmnc4uck@4ax.com...

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

On Fri, 05 Apr 2013 10:55:16 -0700, John Larkin
jlarkin@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.
Click to expand...
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?.
Click to expand...
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 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
 
On Wed, 10 Apr 2013 06:48:37 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

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

On Tue, 09 Apr 2013 16:47:23 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

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

On Thu, 04 Apr 2013 18:48:43 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

George Herold wrote:
On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:

"John Larkin" wrote in message

news:fmkol855vrrjgo6tvge7eg2tbhngseicbl@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spamt...@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


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.

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

Jamie

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.

---
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?

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

--
JF
 
On Wed, 10 Apr 2013 11:27:07 -0500, John Fields
<jfields@austininstruments.com> wrote:

On Wed, 10 Apr 2013 06:48:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

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

On Tue, 09 Apr 2013 16:47:23 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

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

On Thu, 04 Apr 2013 18:48:43 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

George Herold wrote:
On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:

"John Larkin" wrote in message

news:fmkol855vrrjgo6tvge7eg2tbhngseicbl@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spamt...@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


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.

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

Jamie

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.

---
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?

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.

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

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.
 
On Wed, 10 Apr 2013 12:39:59 -0400, krw@attt.bizz wrote:

On Wed, 10 Apr 2013 11:27:07 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 10 Apr 2013 06:48:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

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

On Tue, 09 Apr 2013 16:47:23 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

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

On Thu, 04 Apr 2013 18:48:43 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

George Herold wrote:
On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:

"John Larkin" wrote in message

news:fmkol855vrrjgo6tvge7eg2tbhngseicbl@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spamt...@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


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.

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

Jamie

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.

---
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?

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.

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


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

...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.
 
On Wed, 10 Apr 2013 08:07:37 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

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

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

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

"John Larkin" wrote in message
news:63a9m8p7rbb0k0ni9r98el90o1hmnc4uck@4ax.com...

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

On Fri, 05 Apr 2013 10:55:16 -0700, John Larkin
jlarkin@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.
Click to expand...
---
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?
Click to expand...
---
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.
Click to expand...
---
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.
Click to expand...
---
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
 
On Tue, 09 Apr 2013 16:12:13 -0700, John Larkin
<jlarkin@highlandtechnology.com> wrote:

On Tue, 09 Apr 2013 17:07:07 -0500, John Fields
jfields@austininstruments.com> wrote:

On Fri, 05 Apr 2013 10:53:49 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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



"John Fields" wrote in message
news:9tbtl8p3gsg2m4a8sa64pdrs1p5ki1mln2@4ax.com...

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

On Thu, 04 Apr 2013 18:31:34 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 03 Apr 2013 18:41:41 -0700, John Larkin
jjlarkin@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."

Trivial, tedious, predictable fathead.
Click to expand...
---
Ah, the name-calling ad-hominem attack we've come to expect, again and
again, from Larkin.

--
JF
 
On Wed, 10 Apr 2013 10:04:27 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Wed, 10 Apr 2013 12:39:59 -0400, krw@attt.bizz wrote:

On Wed, 10 Apr 2013 11:27:07 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 10 Apr 2013 06:48:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

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

On Tue, 09 Apr 2013 16:47:23 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

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

On Thu, 04 Apr 2013 18:48:43 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

George Herold wrote:
On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:

"John Larkin" wrote in message

news:fmkol855vrrjgo6tvge7eg2tbhngseicbl@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spamt...@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


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.

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

Jamie

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.

---
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?

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.

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


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.

I see you've added lack of reading comprehension to your ignorance of
the workings of hydraulic servos.
Click to expand...
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.
 
On Wed, 10 Apr 2013 13:28:00 -0400, krw@attt.bizz wrote:

On Wed, 10 Apr 2013 10:04:27 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Wed, 10 Apr 2013 12:39:59 -0400, krw@attt.bizz wrote:

On Wed, 10 Apr 2013 11:27:07 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 10 Apr 2013 06:48:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

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

On Tue, 09 Apr 2013 16:47:23 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

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

On Thu, 04 Apr 2013 18:48:43 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

George Herold wrote:
On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:

"John Larkin" wrote in message

news:fmkol855vrrjgo6tvge7eg2tbhngseicbl@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spamt...@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


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.

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

Jamie

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.

---
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?

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.

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


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.

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

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.
Click to expand...
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.

...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.
 
On Tue, 09 Apr 2013 16:16:53 -0700, John Larkin
<jlarkin@highlandtechnology.com> wrote:

On Tue, 09 Apr 2013 18:00:20 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 09 Apr 2013 15:12:46 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

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

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

On Thu, 04 Apr 2013 18:48:43 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

George Herold wrote:
On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:

"John Larkin" wrote in message

news:fmkol855vrrjgo6tvge7eg2tbhngseicbl@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spamt...@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


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.

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

Jamie

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

---
Got some data to support your claim?

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

...Jim Thompson

---
Silly me...

You two old gits are sad.
Click to expand...
---
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,
Click to expand...
---
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.
Click to expand...
---
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.
Click to expand...
---
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
 
On Wed, 10 Apr 2013 03:12:14 -0400, "P E Schoen" <paul@peschoen.com>
wrote:

"John Fields" wrote in message
news:vh39m8lbdv2e6vf7936v1eenlo5b19uj18@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
Click to expand...
---
Was I wrong? ;)

--
JF
 
On Wed, 10 Apr 2013 12:39:59 -0400, krw@attt.bizz wrote:

On Wed, 10 Apr 2013 11:27:07 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 10 Apr 2013 06:48:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

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

On Tue, 09 Apr 2013 16:47:23 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

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

On Thu, 04 Apr 2013 18:48:43 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

George Herold wrote:
On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:

"John Larkin" wrote in message

news:fmkol855vrrjgo6tvge7eg2tbhngseicbl@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spamt...@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


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.

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

Jamie

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.

---
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?

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.

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


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.
Click to expand...
---
You obviously don't understand the meaning of:

"preaching to the choir".

Typical of the hoi polloi

--
JF
 
On Wed, 10 Apr 2013 13:20:37 -0500, John Fields
<jfields@austininstruments.com> wrote:

On Wed, 10 Apr 2013 12:39:59 -0400, krw@attt.bizz wrote:

On Wed, 10 Apr 2013 11:27:07 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 10 Apr 2013 06:48:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

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

On Tue, 09 Apr 2013 16:47:23 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

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

On Thu, 04 Apr 2013 18:48:43 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

George Herold wrote:
On Apr 3, 1:10 pm, "ScottWW" <spamt...@dcorp.com> wrote:

"John Larkin" wrote in message

news:fmkol855vrrjgo6tvge7eg2tbhngseicbl@4ax.com...

On Tue, 2 Apr 2013 16:47:02 -0400, "ScottWW" <spamt...@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


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.

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

Jamie

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.

---
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?

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.

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


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.

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

"preaching to the choir".

Typical of the hoi polloi
Click to expand...
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 >:-}

...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.
 
On Wed, 10 Apr 2013 12:14:33 -0500, John Fields
<jfields@austininstruments.com> wrote:

On Wed, 10 Apr 2013 08:07:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

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

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

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

"John Larkin" wrote in message
news:63a9m8p7rbb0k0ni9r98el90o1hmnc4uck@4ax.com...

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

On Fri, 05 Apr 2013 10:55:16 -0700, John Larkin
jlarkin@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.

---
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.
Click to expand...
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
VME thermocouple, LVDT, synchro acquisition and simulation
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top