Update On the Trace Eliott ELF That I Blew Up.

[Old Garage-Bander]

I had a question on a final asking for the definition of the universe... and to give 3 examples!

LOL. Sounds like a Philosophy class.
1) The universe is where I am.
2) The universe is where I am not.
3) I may be wrong about 1 and 2.

 

[agedhorse]

Ah but! Did you pass? Enquiring minds need to know. LOL

Yes, but I'm sure a provided a smart ass answer fueled by the frustration of long lost youth

I would think the older magnetic ballast systems would be most affected, whereas the newer electronic ballast systems could probably easily be designed to overcome the issue. Although even with magnetic ballast and 25 Hz AC I would assume the flicker would be at 50 HZ (the voltage to goes to 0 twice per cycle), and for short duration I would think most folks would find that okay.

IIRC 50 CPS is the place where most folks start to become comfortable that they have a continuous light source. Although I have read studies where working fro long periods of time in fluorescent light with magnetic ballast (and the associated 120 CPS flicker rate) still caused physical symptoms like fatigue, eye strain, and headaches.

Magnetic ballasts are what I was thinking of, the flicker would be awful, anything moving would lend itself to motion artifacts. Electronic ballasts are no problem because they typically look more like a switching constant current power supply, operating at between ~20kHz and ~50kHz.

My guess is that's what convinced him that he was better off in engineering than the humanities! At least most of the engineering, math, and science tests (except theoretical physics and power plant balance equations) had real answers, plus or minus 10%.

Those of you who went through an engineering program cherish the value of partial credit

I forgot to mention that 60hz. was something that was chosen for the ability to be dividable by 3. A 50hz. systems did not lend itself well to 3 phase which was something that heavy industries at that time in the U.S. desired to use.

I think you have phase mixed up with something else. Phase is referenced to 360 degrees, 3 phase has the 3 voltages offset by 120 degrees each, 3 x 120 = 360. Exactly the same applies to 50Hz, most of Europe operates from a similar 3 phase network to ours, except at a higher secondary voltage and 50Hz.

I think 60Hz was more or less arbitrarily chosen because it fit well within the mechanical nature of the

 

[Old Garage-Bander]

I forgot to mention that 60hz. was something that was chosen for the ability to be dividable by 3. A 50hz. systems did not lend itself well to 3 phase which was something that heavy industries at that time in the U.S. desired to use.

Oh! I'm trying to wrap my head around that.
Why do we care about dividing 60 Hz (or 50 Hz) by three?

 

[Old Garage-Bander]

View attachment 2962755

Man, an elf just can't catch a break around here this week.

 

[Kevin1960]

I think you have phase mixed up with something else. Phase is referenced to 360 degrees, 3 phase has the 3 voltages offset by 120 degrees each, 3 x 120 = 360. Exactly the same applies to 50Hz, most of Europe operates from a similar 3 phase network to ours, except at a higher secondary voltage and 50Hz.-per agedhorse
You are quite probably right about this, as I am not an electrician and am trying to remember a lot of this stuff that was told to me by my father, who was a electrician, many many years ago. I do remember him explaining that the use of 3 phase in heavy industry allowed better efficiency for larger machinery.

 

[Kevin1960]

Found it. I guess I am getting old and my brain is twisting things around. Wiki to the rescue.
Three-phase supplies have properties that make them very desirable in electric power distribution systems:

• The phase currents tend to cancel out one another, summing to zero in the case of a linear balanced load. This makes it possible to reduce the size of the neutral conductor because it carries little or no current. With a balanced load, all the phase conductors carry the same current and so can be the same size.
• Power transfer into a linear balanced load is constant, which helps to reduce generator and motor vibrations.
• Three-phase systems can produce a rotating magnetic field with a specified direction and constant magnitude, which simplifies the design of electric motors, as no starting circuit is required.

 

[Artman]

This thread has become awesome!

 

[Kevin1960]

This thread has become awesome!

Yes, all due to one nuked ELF.

 

[Al Kraft]

Oh! I'm trying to wrap my head around that.
Why do we care about dividing 60 Hz (or 50 Hz) by three?

This article I was sent a number of years ago from a EE colleague may shed some light on the whole frequency thing: IEEE Xplore Full-Text PDF: . It's funny because he sent it after we had a big conversation that was quite similar to the dialogue today. FWIW I think all production of 25 HZ power ceased in 2009, last customer for it was some company in Canada IIRC.

 

[Old Garage-Bander]

This article I was sent a number of years ago from a EE colleague may shed some light on the whole frequency thing: IEEE Xplore Full-Text PDF: . It's funny because he sent it after we had a big conversation that was quite similar to the dialogue today. FWIW I think all production of 25 HZ power ceased in 2009, last customer for it was some company in Canada IIRC.

Wow! Interesting that they were using 25 Hz, up at Niagra, and up into this century.
Wonder what their last customer(s) used that wasn't convenient or cost effective to switch to 60 Hz?

 

[Al Kraft]

Wow! Interesting that they were using 25 Hz, up at Niagra, and up into this century.
Wonder what their last customer(s) used that wasn't convenient or cost effective to switch to 60 Hz?

I think it was Washington Mills in Canada, not 100% sure, but that name sticks in my head for some reason.

EDIT: Just Googled Washington Mills Corporation Canada and this article popped up...looks legit and looks like 2009 was the end of the line of 25 Hz: Invalid Link Removed

 

[Kevin1960]

Wow. All good stuff to read on the early history of power generation. I see from some of these articles they mention arc lighting in movie theaters. I do remember a visit to a theater with a childhood friend back in the 60's when the whole projection room was a film projector and an arc lamp stood in the center of the room thru which the extreme white light would come out of while the film ran around the room and across a window to project the film on to the screen. It was an impressive thing to see for a 7 year old at the time.

 

[agedhorse]

Found it. I guess I am getting old and my brain is twisting things around. Wiki to the rescue.
Three-phase supplies have properties that make them very desirable in electric power distribution systems:

• The phase currents tend to cancel out one another, summing to zero in the case of a linear balanced load. This makes it possible to reduce the size of the neutral conductor because it carries little or no current. With a balanced load, all the phase conductors carry the same current and so can be the same size.
• Power transfer into a linear balanced load is constant, which helps to reduce generator and motor vibrations.
• Three-phase systems can produce a rotating magnetic field with a specified direction and constant magnitude, which simplifies the design of electric motors, as no starting circuit is required.

The phase currents don't cancel, but there are no neutral currents because in a pure 3 phase system delta and Y connections become electrically the same.

The rotating magnetic field, and one less distribution conductor than 2 phase (which is virtually gone) or 3 phase Y, plus the ease of conversion between delta and Y make 3 phase a no-brainer.

I think it was Washington Mills in Canada, not 100% sure, but that name sticks in my head for some reason.

EDIT: Just Googled Washington Mills Corporation Canada and this article popped up...looks legit and looks like 2009 was the end of the line of 25 Hz: Invalid Link Removed

Very cool... interesting to see those big DC exciter current (field current) generators, these are virtually identical to the generators I used to work on in the electroplating industry. Some interesting construction methods were used back then, including all bushings rather than ball bearings, the bushings being maybe 12" in diameter and 14"-16" long, passing through an oil box with a slinger ring sitting on the shaft with the bottom of the slinger sitting in the oil sump. The load on the oil film was quite low by today's standards and the bushings would last almost the lifetime of the machine. They were very low RPM, multi-pole machines. The ones I worked on operated from 440/480V delta and on the DC side were maybe 6-12 volts and 5,000-10,000 amps (DC). The commutator brushes consisted of 2" x 2" blocks of brush grade carbon/graphite, and there were maybe 96 brushes per machine (12 pole 4 brushes per pole per half). This is from memory, I worked on this stuff back in the 1970's while going to school. THIS is what made America, and other advanced developed countries so powerful, the enormous scale of BIG manufacturing.

 

[-Asdfgh-]

I would think the older magnetic ballast systems would be most affected, whereas the newer electronic ballast systems could probably easily be designed to overcome the issue. Although even with magnetic ballast and 25 Hz AC I would assume the flicker would be at 50 HZ (the voltage to goes to 0 twice per cycle), and for short duration I would think most folks would find that okay.

IIRC 50 CPS is the place where most folks start to become comfortable that they have a continuous light source. Although I have read studies where working fro long periods of time in fluorescent light with magnetic ballast (and the associated 120 CPS flicker rate) still caused physical symptoms like fatigue, eye strain, and headaches.

My wife complains about flicker, but she is unusually, for a woman, colourblind, but has exceptional night vision. She can also read incredibly quickly, but then she could read when she was two. I have a friend with the same issues with flicker, and the same colour blindness.

 

[-Asdfgh-]

I was forgetting that rectification can turn 25Hz into 50Hz. I now propose 12.5Hz, and that should be fine with modern electronics components and LED lights

 

[BassmanPaul]

[QUOTE="agedhorse, post: 21138611, member: 68399”]................I think 60Hz was more or less arbitrarily chosen because it fit well within the mechanical nature of the[/QUOTE]

Don’t keep us in suspenders Andy! The mechanical nature of the what?

 

[agedhorse]

Sorry, of motion, motors, generators and such.

 

[Wood and Wire]

Don’t keep us in suspenders Andy! The mechanical nature of the what?

It's a family secret...

 

[-Asdfgh-]

[QUOTE="agedhorse, post: 21138611, member: 68399”]................I think 60Hz was more or less arbitrarily chosen because it fit well within the mechanical nature of the

Don’t keep us in suspenders Andy! The mechanical nature of the what? [/QUOTE]

I was concerned that the Illuminati had burst in and kidnapped him before he could reveal the secret.

 

[-Asdfgh-]

Sorry, of motion, motors, generators and such.

I'm stealing that line for any steampunk prog band I might put together