Return to the thumbnail page Display/hide file information See next file

The Ballast in my Benjamin Electric Light

The Ballast in my Benjamin Electric Light

Click to view full size image

The ballast in the first light is an old Jefferson Electric one. The other light had a GE ballast with a paper label. Because of this, and the fact that these lights came out in 1949, I would guess they both date from 1949. They could also date from 1955, since GE did go back to the paper label after a few years. The Jefferson ballast also has a date code of D-5.

Interestingly, if the ballast has only 16w losses, then the lamps receive 84.3w combined, or 42.15w each. This means that they compensated for the 0.95 power factor, which they don’t seem to do with modern ballasts.

8D4D10EB-E1F3-44D6-9D0C-3259EAC042E4.jpeg 1B0832C1-EBF4-4199-837A-7D833D363AEF.jpeg C77D25B7-F967-42B8-8BA3-21FAE14920C1.jpeg 59A6C0AE-9D77-42CF-976A-CFB3B138335A.jpeg

Light Information

Light Information

Manufacturer:Jefferson Electric
Model Reference:234-881-200
Lamp
Lamp Type:Fluorescent
Fixture
Ballast Type:Tulamp Preheat
Electrical
Wattage:100.3w
Voltage:118v
Current:0.85a

File information

File information

Download: Download this File
Filename:8D4D10EB-E1F3-44D6-9D0C-3259EAC042E4.jpeg
Album name:Mr. Orthosilicate / Fluorescent Fixtures
Keywords:Gear
File Size:501 KB
Date added:Jan 25, 2020
Dimensions:2464 x 1848 pixels
Displayed:46 times
Date Time:2019:10:08 17:39:29
DateTime Original:2019:10:08 17:39:29
Exposure Bias:0 EV
Exposure Time:1/15 sec
FNumber:f 2.2
Flash:No Flash
Focal length:4.15 mm
ISO:320
Make:Apple
Model:iPhone SE
Software:12.4.1
White Balance:0
URL:https://www.lighting-gallery.net/gallery/displayimage.php?pos=-171942
Favorites:Add to Favorites
Comments
ace100w120v
Hero Member
*****
Offline

Gender: Male
View Posts
View Gallery


View Profile Personal Message (Offline)
Jan 25, 2020 at 09:37 PM Author: ace100w120v
Thing of beauty! These older fixtures always drove lamps nice and brightly.
Bert
Newbie
*
Offline

Gender: Male
View Posts
View Gallery


View Profile Personal Message (Offline)
Jan 26, 2020 at 01:31 PM Author: Bert
Need to also take into account that these are not 100% power factor. Not all the current produces real power.

If they are 95% power factor then the total wattage is 118v x 0.85a = 100va x 0.95pf = 95w - 16w internal loss = 79w to the lamps.
jercar954
Newbie
*
Offline

Gender: Male
View Posts
View Gallery


View Profile Personal Message (Offline)
Jan 26, 2020 at 03:01 PM Author: jercar954
Is this rapid start or preheat? Rapid start was introduced in 1952 so a ballast that is r-s could not be from the 1940s.

Preheat and T-12 fluorescents forever! Down with LED's and instant start T-8 fluorescents.

Mr. Orthosilicate
Jr. Member
**
Offline

Gender: Male
View Posts
View Gallery

View Profile Personal Message (Offline)
Jan 26, 2020 at 03:02 PM Author: Mr. Orthosilicate

Need to also take into account that these are not 100% power factor. Not all the current produces real power.

If they are 95% power factor then the total wattage is 118v x 0.85a = 100va x 0.95pf = 95w - 16w internal loss = 79w to the lamps.



I remembered to account for power factor the morning after I wrote this, and I’ve fixed the description now. It’s not smart to try to write things at 1 o’clock in the morning, since you make dumb errors like that.

On an unrelated note, I would think that wasted power would still contribute to electrode heating. Reactive power does still contribute to heating from the power loss across a run of wire, which is why you have to consider KVA and not KW when sizing wires and breakers. I can imagine that since the electrodes are heated by bombardment during the anode phase of the cycle, the extra power running through them which does not contribute to the discharge still has an effect on the temperature of them.
Mr. Orthosilicate
Jr. Member
**
Offline

Gender: Male
View Posts
View Gallery

View Profile Personal Message (Offline)
Jan 26, 2020 at 03:03 PM Author: Mr. Orthosilicate

Is this rapid start or preheat? Rapid start was introduced in 1952 so a ballast that is r-s could not be from the 1940s.


This is a preheat ballast.
joseph_125
Hero Member
*****
Offline

Gender: Male
View Posts
View Gallery


GoL
View Profile Personal Message (Offline)
Jan 26, 2020 at 07:21 PM Author: joseph_125
Nice! I have a Benjamin fixture that looks a lot like yours and it came with the same ballast.
© 2005-2020 Lighting-Gallery.net | Powered by: Coppermine Photo Gallery