V
Victor Roberts
- Jan 1, 1970
- 0
I've had some tests run on metal halide lamps by a certified
independent laboratory (since I don't have a sphere.) The
main goal of this work was to quantify the high frequency
efficacy of metal halide lamps. The common wisdom is that
there is no high frequency efficacy gain, but there are one
or two papers that claim otherwise. This is my poster paper
for LS:11.
The results are in and they are a bit strange.
The tests were run on three 320-watt pulse start metal
halide lamps. there is more money from the sponsoring
organization to run 6 more 320-watt lamps if necessary.
As part of the test I measured lamp performance on five
types ballasts:
1) Standard reference ballast
2) Commercial linear inductor ballast
3) Commercial CWA ballast
4) Brand A 100 kHz electronic ballast
5) Brand B 100 KHz electronic ballast.
There were three of each type of commercial ballast.
Since I suspected that the commercial ballasts would not all
run the lamp at the same power, and since lamp efficacy is a
function of power, I had the lab operate the lamp on the
reference ballast at rated power, rated power + 15% and
rated power -15%, so I could construct a correction curve.
The really strange result is that lamp efficacy on both
types of commercial ballasts was lower than on the reference
ballast, even after correcting for the fact that the
commercial ballasts ran the lamp below rated power. The
corrected efficacy loss is about 6% to 7%. The only
explanation I have right now is that these lamps have lower
efficacy when operated with a high current crest factor
system. I don't see any other obvious difference between
lamp operation on the reference ballast and on the
commercial ballasts that operate the lamps at the same
frequency.
Any other suggestions for a cause?
--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.
This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.
independent laboratory (since I don't have a sphere.) The
main goal of this work was to quantify the high frequency
efficacy of metal halide lamps. The common wisdom is that
there is no high frequency efficacy gain, but there are one
or two papers that claim otherwise. This is my poster paper
for LS:11.
The results are in and they are a bit strange.
The tests were run on three 320-watt pulse start metal
halide lamps. there is more money from the sponsoring
organization to run 6 more 320-watt lamps if necessary.
As part of the test I measured lamp performance on five
types ballasts:
1) Standard reference ballast
2) Commercial linear inductor ballast
3) Commercial CWA ballast
4) Brand A 100 kHz electronic ballast
5) Brand B 100 KHz electronic ballast.
There were three of each type of commercial ballast.
Since I suspected that the commercial ballasts would not all
run the lamp at the same power, and since lamp efficacy is a
function of power, I had the lab operate the lamp on the
reference ballast at rated power, rated power + 15% and
rated power -15%, so I could construct a correction curve.
The really strange result is that lamp efficacy on both
types of commercial ballasts was lower than on the reference
ballast, even after correcting for the fact that the
commercial ballasts ran the lamp below rated power. The
corrected efficacy loss is about 6% to 7%. The only
explanation I have right now is that these lamps have lower
efficacy when operated with a high current crest factor
system. I don't see any other obvious difference between
lamp operation on the reference ballast and on the
commercial ballasts that operate the lamps at the same
frequency.
Any other suggestions for a cause?
--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.
This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.