Author Topic: Dimmable Fluorescent VHO or HO, Dimming Powergroove lamps  (Read 189 times)
dieselbulb
Newbie
*
Offline

Posts: 18
View Gallery

Dimmable Fluorescent VHO or HO, Dimming Powergroove lamps « on: April 11, 2017, 09:41:48 AM » Author: dieselbulb
Ok, I think the GE Powergroove lamp is a work of art and I want to be able to appreciate it's curves more in an indoor in home setting. I have investigated dimming fluorescent lamps, primarily when it comes to F40 lamps.

I'm curious how I could operate a F48 or F96 Powergroove lamp on a dimming circuit. I know this would require cathode heating but does anyone know of what kind of components could be combined to accomplish this?

The Powergroove is a 1500MA lamp, quite current heavy but I have seen others here operate them on 800MA Rapidstart which has the necessary cathode heating to prevent sputtering. I'd settle for a Dimming 800MA setup also, doesn't have to be 1500MA.

In experimenting with the F40 Dimming ballasts, I acquired two F40 ballasts for two lamp operation and observed how they operated with the appropriate Lutron dimmer. I think the same dimmer would work but with an interesting ballast combination (RS ballast plus cathode preheat transformer separate from power of ballast).

Has anyone else thought of a setup like this.

Thanks for the read.

Logged
Ash
Hero Member
*****
Offline

Posts: 3574
View Gallery


Re: Dimmable Fluorescent VHO or HO, Dimming Powergroove lamps « Reply #1 on: April 11, 2017, 10:24:42 AM » Author: Ash
Magnetic ballasts make a high voltage impulse if the current to them is stopped abruptly. Therefore you want a leading edge dimmer - One that switches on by firing its thyristor where the setting is, and goes off at the times where the current naturally drops off to 0

Capacitors pull a high current impulse if the voltage is applied to them abruptly. And here i would be a bit concerned : Most RS ballasts contain a capacitor for what i know. I am not sure whether it would be ok with voltage being applied in a "step" every half cycle

It might be better to use a capacitor-less ballast for the arc supply. For F96 a HX ballast for 100W Mercury lamp (HO) or 175W (VHO) or something like that might be acceptable. I guess it would atleast start normally, and then you can wait for everything to heat up and measure the lamp current to check whther it is acceptable for the lamp and for the ballast. For F48 gotta find something else meant for lamps of about the same arc voltage

It might be possible to use a dimming electronic ballast together with the magnetic heating transformer. The issue in this case would be how to take power from the ballast using one wire for each lamp end (since you dont use its built in cathode heating feature). If you take one wire from each end (and the correct one at that) it might think the lamp is EOL and cut out. If you short the 2 pins of each output you might damage the ballast's internal cathode heating supply
Logged
dieselbulb
Newbie
*
Offline

Posts: 18
View Gallery

Re: Dimmable Fluorescent VHO or HO, Dimming Powergroove lamps « Reply #2 on: April 11, 2017, 01:23:24 PM » Author: dieselbulb
Thanks for the comments!

In studying the F40 Dimming ballast I have, I don't believe it's HPF, so i don't think it has a cap. Probably for the reasons you've mentioned.

I didn't think of using a Mercury/MH ballast for the arc, that's a good idea. Probably one from a 200W MH for the F96.

Still have to figure out how to start the lamp and an appropriate magnetic heating transformer that would work with these cathodes.
Logged
xmaslightguy
Hero Member
*****
Offline

Gender: Male
Posts: 667
View Gallery

^homebuilt fixture


GoL ATL
WWW
Re: Dimmable Fluorescent VHO or HO, Dimming Powergroove lamps « Reply #3 on: April 13, 2017, 07:47:10 PM » Author: xmaslightguy
This is a really cool idea! A dimmed PG lamp would be sweet!

I kinda remember someone on here posting a pic of a dimmable either HO or VHO ballast!
Logged

Colored Fluorescent's such as F40T12 Red or  Green or Blue are awesome...

Print 
© 2005-2018 Lighting-Gallery.net | Powered by SMF 1.1.21 | SMF © 2015, Simple Machines