Did your city ever have DC?

Status
Not open for further replies.
K8MHZ said:
Cool!

133 years ago, tomorrow.
Click to expand...

I grew up a few houses down the street. It was not a museum when I was young.
We often found junk in the woods behind the house. One memorable treasure was an 'Edison style' light bulb. Didn't think it was special at the time, except that it was old and intact.
 
Philly had DC and 2 phase

Philly had DC and 2 phase

Philly had DC in some areas and it also had 2 phase ( not 240/120 single phase ) which was before 3 phase.
 
just the cowboy said:
Philly had DC in some areas and it also had 2 phase ( not 240/120 single phase ) which was before 3 phase.
Click to expand...

My daughter's grandmother was from Philly and her father or grandfather, I can't remember which, was an electrical engineer there and designed some of Philly's first electrical stuff.

My X's dad was in the service, a sub vet, passing through Philly and met Marie. They fell in love, got married and moved back here to Muskegon.
 
I worked at a steel mill for about 8 years we had 250v DC. And 25 cycle as well as 60 cycle. Turn of century mill. I worked ther in 1990's. The DC was for ease of speed control but the 25 was originally there because Carnegie thought 25 was the way to go. But obviously 60 prevaied. The incandescent lighting in plant that was still in 25 cycl was easy to see the flicker when reading. We also had a generator well 2 and an m-g set and distributed 25 cycle power to our sister plants up and down the river.
 
K8MHZ said:
Did Pearl Street supply electricity for a residence? I think all the electricity was for businesses and public lighting.
Click to expand...

The Pearl Street Station served just under 100 customers when it went into operation in 1882. At it's peak, roughly 500 customers were connected to the system. A few of the buildings supplied with electric lighting were indeed residences for employees of the New York Times which had offices on Pearl Street.

I have seen a few articles that claim Edison personally wired J.P. Morgan's home with an isolated lighting plant, but that didn't occur until 1884 and none of the work was performed by Edison himself. He was simply present went the system went into operation.
 
There were all kinds of first during the period from 1879-1882.

The true first Edison system was at Menlo Park in December of 1879. The laboratory complex, three private homes (including Edison's), and street lamps were first exhibited in nightly demonstrations between December 21 and December 27. The big one being on the 27th for Edison's investors. Public demonstrations occurred on December 30, 31, and the night of January 1. The street and dwelling lamps continued to burn nightly for several weeks.

The 2nd first occurred in March of 1880 when Edison installed a lighting system on the steamship Columbia. This was also the first installation to include lamp sockets, key switches, and fuses.

So, Pearl Street and Vulcan Street came almost two years after these two firsts.

All of them are incredibly interesting and historic...
 
150929-2224 EDT

The photograph in post #10 shows the type of dynamo used in 1879 at Menlo Park, and the same type was used on the Columbia. This was about a 5 kW unit with about 96% efficiency from mechanical power input to electrical power generated, but this is reduced to an overall efficiency of about 82% when the energy used to excite the field is subtracted from the generated power.

In the summer of 79 during the development of the dynamo a constant voltage with varying load current version was developed. In otherwords a compound generator was developed.

I have looked at the models in Menlo Park in Dearborn and any compound coil setup is not obvious.

Following is a photograph of the only surviving dynamo from Pearl Street:


PICT3486-1280.jpg

.
 
150929-2346 EDT

Following is photograph of a replica of the dynamometer (tangential force gage) used by Edison in 1879 to study the characteristics of his Dynamo. This is a good study in statics to understand how this gage works. Statics is a study in mechanical engineering of how forces interact where there is no acceleration. Dynamics includes the effect of acceleration.

Edison used a correction of 5% for the angle of the belt. Do you know how that was determined? Consider the force vectors to help in this answer. There was also a belt friction correction. I don't know how that was determined.

PICT3441-1280.jpg

.
 
keith gigabyte said:
I worked at a steel mill for about 8 years we had 250v DC. And 25 cycle as well as 60 cycle. Turn of century mill. I worked ther in 1990's. The DC was for ease of speed control but the 25 was originally there because Carnegie thought 25 was the way to go.
Click to expand...

I worked in a steel mill in the 1980's (Beth Steel, Sparrows Point). It was a new continuous caster but the cranes were all 250vdc with on-site rectifiers. OTOH the overall plant's power station still generated 25Hz, I was told it was for the larger motors in some of the rolling mills and large fans in others 'Larger' in this case meant "walk-in" motors :).

FWIW, as I understand AC motors with commutators are happier at lower frequencies; there's a description of this a ways down http://cs.trains.com/trn/f/743/t/211543.aspx (find post by erikem on Sunday, November 11, 2012 2:24 PM)
 
Installed in the 60’s to replace a mercury arc unit. 300KW @220V

DSC_0271_zps63f7deec.jpg

DSC_0264_zpsc9616478.jpg
 
Status
Not open for further replies.
Top