Fluorescent T9 Circline Light Fixtures

[Smucky]

And the lamp shade appears to be lost in transit. It was supposed to arrive yesterday.

[Smucky]

Wait, why did it leave KY and end up in AZ? That's the completely wrong direction.

[Smucky]

Spent most of yesterday going down a rabbit hole of ballast technology. Not much to choose from but thought it was weird that whether the price was $10 or $50, the data in spec sheets was mostly the same. Which that made me look into the terminology more so. Pretty much everything available had a "ballast factor between .75 and .80. Which means it will be putting out 20-25% less light. Had to do a bunch of digging on archive.org on old versions of manufacturer's websites to see what was top of the line back before 2010 when this stuff was more popular.

And for the circular fc8t9 lamps that left only two options, both from Robertson. The older version RSW122C120WS with a ballast factor of .98 and a newer version PSM226CQMVDWCE and RSO126CQ120 with a ballast factor of .85.

Also I realized that fluorescent products are being banned in a few states and a few countries even Guess I better stock up

[Smucky]

Did more reading on ballasts yesterday. Then found some NEMA docs with ballast test reqs and specs. Read a bunch of that too Starting to get tired of this. Want it to stop

But anyway, still waiting on the lamp shade. Might be here tomorrow. For today, I will probably get the lamp running half assembled on the floor with the crappy OEM ballast and take some measurements for volts and amps, etc.

[Smucky]

Tried to take some measurments. I guess too many harmonics coming off of the ballast to really work with my multi-meter. I could measure that the lamp is being driven at 30khz. But measuring lamp voltage showed 200 volts, and clamping on an amp meter showed .13 on one leg and 2.00 on the other. Clearly wrong. Measuring the wires going into the ballast showed 122 volts and .14 amps. That is not really right either since the power factor is only .5 and the lamp is supposed to get around 20 watts.

Then I remembered I had a "kill-a-watt" plug in meter. That was most proper somehow. Showing from the wall, 121.9 volts, .29 amps, 20 watts, 35 VA, and power factor of .58


The ballast is supposed to be "rapid start" but filming at 240fps, seems to show it being instant start. For rapid start, there should be a quarter second delay or so to preheat the filaments. But here, one frame the lamp is off, the next it is on This is two seconds stretched into nearly 10.

PXL_20250724_001145013~2_720.webm

(1.6 MiB) Downloaded 10 times

The lamp lit up the room much less than I had thought. We'll see if that improves when it is hung from the ceiling. Also, a new ballast might give me 8-10% more light. The color is kinda... lol. The current ceiling fixture has two cree high cri 40 watt equivalent bulbs with 2700k color. I really don't have any complaints other than I'm bored of them. The new lamp has a cri of 80 and color of 3000k. The color difference is way more than I would have thought. But it is a generic bulb. It is definitely noticeable, I guess I'll live with it. After all, I was going for style and "art" anyway

[NinjaPoodle]

Also I realized that fluorescent products are being banned in a few states and a few countries even Guess I better stock up

Why even bother? LED equivalent is always better and they will also become better. Here you are making 20 posts on florescent lights while the world has moved on to LED light fixtures which are better in every aspect. You could have just bought a LED replacement and avoided all the crap about ballasts and inverters and all that crap.

[Smucky]

Alright got the old fixture off the ceiling.

Wiring wasn't what I expected

Five white wires tired together. More wires behind those tired together

Probed around with the multi meter. Seems everything works as expected. With switch on, black has 120v to ground and white wires. No volts on anything with switch off.

Progress++

[Smucky]

Got it mounted. Got the shade on. Flipped the switch and was surprised it seemed brighter than I was expecting. Probably more so than the old fixture. I guess trying to judge the output without it mounted was premature

Before:

AFTER:

[Smucky]

Went to put the bulbs from the old fixture up in the "bulb cabinet". Realized how much of a light autist I am

[Smucky]

Anyway, feels good to be back in the fluorescent game

[Smucky]

I was going to tape a thermistor to the ballast just so I could keep an eye on temperatures.
But I forgot to add that.

Waving an IR thermometer around shows the base around 95 degrees. I guess that is fine

[Smucky]

Now that it is dark, pretty sure the new lamp is putting out more light. A few family members walked through and were like wtf.

As a test, I took a sheet of paper, stood directly below the fixture, took three steps back and placed the paper on the floor. Held the camera at a 45* angle resting on the floor and arrange the bottom of the sheet to line up with the bottom of the picture. All things considered, the camera should auto adjust the exposure settings and we can compare and see what image gets the shortest exposure.

New lights:

Old lights (used identical fixture and bulb set up from kids bedroom):

exif data for new lamp comes out to:
ƒ/1.85
1/24
6.81mm
ISO484
compared to old lamp:
ƒ/1.85
1/24
6.81mm
ISO624

Ok, so they are the same But the old lamp used a higher ISO, which means it was made more sensitive to light. Hence old lamp has lower lumens (probably)

[Smucky]

The color temp is different, haven't had any complaints. I've heard that certain colors in low CRI situations can be washed out. And then I suddenly noticed my yellow fluke IR meter next to me looking rather pale:

With the flash on, this is what I would normally see:

Our first CRI victim

[NinjaPoodle]

What does CRI mean?

[Smucky]

What does CRI mean?

Color rendering index

In this case with older tech fluorescent bulbs, they only had two phosphors so part of the spectrum is missing. Clearly effecting yellow in this case.

I'm going to make a CD powered spectrometer and get some pics maybe

[NinjaPoodle]

I'm going to make a CD powered spectrometer and get some pics maybe

Why do you need to make one? Just buy one and they are one of the most simple device ever. I'm talking about the analog ones now, not the digital ones. It's basically two glass pieces with a gap in between them that gradually increases in one direction. Another possibility is to use diffraction to separate the wavelengths.

[Smucky]

I'm going to make a CD powered spectrometer and get some pics maybe

Why do you need to make one? Just buy one and they are one of the most simple device ever. I'm talking about the analog ones now, not the digital ones. It's basically two glass pieces with a gap in between them that gradually increases in one direction. Another possibility is to use diffraction to separate the wavelengths.

I'm not familiar with any of that. How about a link?

[NinjaPoodle]

I'm going to make a CD powered spectrometer and get some pics maybe

Why do you need to make one? Just buy one and they are one of the most simple device ever. I'm talking about the analog ones now, not the digital ones. It's basically two glass pieces with a gap in between them that gradually increases in one direction. Another possibility is to use diffraction to separate the wavelengths.

I'm not familiar with any of that. How about a link?

If you want to make it yourself, well you can.

https://starfishmedical.com/resource/sp ... materials/

Anyway, the ones I'm referring to are these.

https://www.amazon.se/-/en/spectroscope ... B0728C8WDT

Tube like things that are completely analogue and passive. Some of these have a reticle scale that shows the wavelength.

[Smucky]

Changing out the oem ballast to something older but maybe better quality

Old ballast:
121.9 volts,
.29 amps,
20 watts,
35 VA,
power factor .58

New:
121.8 volts,
.31 amps,
20 watts,
37 VA,
power factor .53

Can't tell if lamp is any brighter but maybe once it gets dark outside. I'll try to measure some temps. 103 was the hottest previously

[Smucky]

My growing lamp inventory

[NinjaPoodle]

Why don't you setup a lamp store. You will be like the Forrest Gump of florescent lamps.

You should name the store -- Florescent Gump.

[Smucky]

Hard to tell if the new ballast is brighter but it seems to run the bulb cooler. Highest temp I could find was 99 vs 103

[Smucky]

But thinking about cutting some vent holes into the glass shade. I got a bit for it. And an old beer bottle to practice on

But still, took forever to find that shade and I paid $47 for it. Would hate to break it but in my mind some vent holes look so aesthetic

[Smucky]

But thinking about cutting some vent holes into the glass shade. I got a bit for it. And an old beer bottle to practice on

Lets go

I thought I was making a video here, but I guess not

Took several minutes to get through

As suspected, right before you punch through the backside, because the glass gets so thin, it has a tendency to just "blow out". Not too bad, but even this was with very light pressure.

[NinjaPoodle]

But thinking about cutting some vent holes into the glass shade. I got a bit for it. And an old beer bottle to practice on

But still, took forever to find that shade and I paid $47 for it. Would hate to break it but in my mind some vent holes look so aesthetic

Don't you destroy the look of the glass lamp shade if you drill in them?