Author Topic: Under running high pressure sodium lamps  (Read 526 times)
HIDLad001
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Alex - a fan of Jefferson Electric ballasts


GoL UCwvPaxz1-rbLAjLpk55zl1A
Under running high pressure sodium lamps « on: July 01, 2022, 03:03:16 PM » Author: HIDLad001
I am wondering if it is possible to under run a high pressure sodium lamp in such a way that pressure broadening doesn't occur, and it stays that beautiful monochromatic yellow like a low pressure sodium lamp  :lps:. The way I think it would be done is by starting it on a regular ballast, but when the lamp turns yellow, you disconnect it and then connect it to something like a CCFL inverter. Is this possible or am I just crazy?
Logged

HID Fixtures should stay HID!
Any new photos are taken with a Panasonic Lumix DMC-FZ35!
Local power is 120/240VAC 60Hz, TV is NTSC 480i 59.94, DTV is ATSC 1.0 and simulcast ATSC 3.0.
Using Lighting-Gallery since 2022

Medved
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Re: Under running high pressure sodium lamps « Reply #1 on: July 01, 2022, 03:53:07 PM » Author: Medved
Formally HPS use to be rated for dimming down to below 30% (some rate it down to 20%, but not sure if that is general thing) using impedance dimmers (essentially connecting an extra choke in series; speaking about European 230V territory with series chokes). That will narrow the peak a lot, but I don't think it will really make it monochromatic. Because formally rated forit, I would assume electrodes are still able to maintain sufficient temperature for emission.
Going below that means you will be risking cold electrode operation, so their damage (and the consequent arctube blackening) by sputtering.
Plus the other components (Hg,...) present in the fill will pop up in the spectrum, so even when really cold, it won't be the LPS color you are, my guess, aiming for...
Logged

No more selfballasted c***

HIDLad001
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Alex - a fan of Jefferson Electric ballasts


GoL UCwvPaxz1-rbLAjLpk55zl1A
Re: Under running high pressure sodium lamps « Reply #2 on: July 01, 2022, 05:45:04 PM » Author: HIDLad001
Ah, I figured it wouldn't be possible.  :sadbulb:
Logged

HID Fixtures should stay HID!
Any new photos are taken with a Panasonic Lumix DMC-FZ35!
Local power is 120/240VAC 60Hz, TV is NTSC 480i 59.94, DTV is ATSC 1.0 and simulcast ATSC 3.0.
Using Lighting-Gallery since 2022

108CAM
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Diehard MV, HPS, SOX & Preheat Fluorescent Fanatic


UCG6Xojn8dNgDuN9J7_Gnj8w
Re: Under running high pressure sodium lamps « Reply #3 on: July 01, 2022, 07:45:29 PM » Author: 108CAM
Even if it was possible, the light emitted may still not be fully monochromatic due to the small amount of mercury inside the lamp. You're better off using an SOX lamp if you have one and turning off or blocking out as much unwanted light as you can so the monochrome effect isn't ruined by other light sources that have a higher CRI.   
Logged

Fluro starter pings combined with a 50hz ballast hum and blinking tubes is music to my ears.

Rest in Peace Electronic Lamp Manufacturers of Australia
1925-2002

Bring back the AJF Zodiacs!

Total incidents since joining LG: 17
Lamps accidently broken or smashed: 14
Ballast explosions/burnouts: 3

WorldwideHIDCollectorUSA
Member
*****
Offline

Gender: Male
View Posts
View Gallery

HID, LPS, and preheat fluorescents forever!!!!!!


Worldwide HIDCollectorUSA
Re: Under running high pressure sodium lamps « Reply #4 on: July 02, 2022, 03:29:09 AM » Author: WorldwideHIDCollectorUSA
From what I am aware of, some high pressure sodium lamps have been known to last a very long time due to being underdriven after they are warmed up to full power before being dimmed down. I remember having an extensive discussion with some knowledgeable LG members about high pressure sodium lamps and mercury vapor lamps lasting longer being underdriven on a LG post, but I do not seem to find that post anywhere as of now.
Logged

Desire to collect various light bulbs (especially HID), control gear, and fixtures from around the world.

DISCLAIMER: THE EXPERIMENTS THAT I CONDUCT INVOLVING UNUSUAL LAMP/BALLAST COMBINATIONS SHOULD NOT BE ATTEMPTED UNLESS YOU HAVE THE PROPER KNOWLEDGE. I AM NOT RESPONSIBLE FOR ANY INJURIES.

dor123
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Other loves are computers, office equipment, A/Cs


WWW
Re: Under running high pressure sodium lamps « Reply #5 on: July 02, 2022, 04:23:30 AM » Author: dor123
Here in Israel, we have lots of small lanterns with 70W HPS ballasts that run 125W MV lamps. They are slightly underdriven, but still runs in hot cathodes mode.
Logged

I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.

I only working with the international date format (dd.mm.yyyy).

I lives in Israel, which is a 220-240V, 50hz country.

Foxtronix
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Formerly "TiCoune66". Also known here as Vince.


GoL UCs4tSgJSCoCIMGThBuaePhA
WWW
Re: Under running high pressure sodium lamps « Reply #6 on: July 02, 2022, 09:04:09 AM » Author: Foxtronix
I think it can be done with capacitors as well. Constant-wattage ballasts in North America already have one in series with the lamp, so lowering its value can do the trick. Like say replace the original one with a set of equivalent parallel, smaller value units and switch some of them in and out of circuit. Or a string of series capacitors and bypass one of them (in that case the switching action would have an opposite effect on the active capacitive reactance in the circuit). If you have basic knowledge of AC circuit analysis, it's fairly easy to figure out a way to modify the final impedance of the ballast circuitry so that it can run the lamp at more than one power level. And HPS lamps, because of how they were designed, can run at lower power. I guess their arc voltage remains the same and it's actually the current that's lower.

Now I wonder if it's possible to do that with a reactor or HX ballast as well. I assume it is.
Logged

WorldwideHIDCollectorUSA
Member
*****
Offline

Gender: Male
View Posts
View Gallery

HID, LPS, and preheat fluorescents forever!!!!!!


Worldwide HIDCollectorUSA
Re: Under running high pressure sodium lamps « Reply #7 on: July 02, 2022, 11:40:13 AM » Author: WorldwideHIDCollectorUSA
To get any discharge lamp to run at a lower operating current on simple choke ballasts and HX autotransformer ballasts, you will need to lower the mains voltage by using a variac. One of our knowledgeable LG members has used the lowered mains voltage technique to operate North American 700w H35 mercury vapor lamps and North American 1500w M48 probe start metal halide lamps properly on British 220v-240v 50hz mains on HX autotransformer ballasts.
Logged

Desire to collect various light bulbs (especially HID), control gear, and fixtures from around the world.

DISCLAIMER: THE EXPERIMENTS THAT I CONDUCT INVOLVING UNUSUAL LAMP/BALLAST COMBINATIONS SHOULD NOT BE ATTEMPTED UNLESS YOU HAVE THE PROPER KNOWLEDGE. I AM NOT RESPONSIBLE FOR ANY INJURIES.

Print 
© 2005-2024 Lighting-Gallery.net | SMF 2.0.19 | SMF © 2021, Simple Machines | Terms and Policies