thats very cool! I stuck a couple known values in there and it aint far off for example F40T12 103V 430mA PF 0.87 220V Mains gives me an impedance of 402 Ohms,

the Reference ballast spec for such a tube according to IEC spec is 220V input, 390 Ohm with a ballast PF of 0.10, ie what is the PF of the ballast itself if you stuck it across the mains with no tube etc, since I dont know what ballast Power Factor your using here, i'd say you have done very well

ditto a I get more or less the correct ballast impedance for a F125T12 tube also (296 Ohms from your calculator vs 300 Ohms for the official IEC spec)

and for a 175W mercury lamp I get 100 ohms which is damn as near it 99.5 Ohms of the official ANSI spec




BTW I think your calculated lamp PF discharge values are a bit off, I know for a fact that HPS lamps have a lower power factor then mercury lamps, usually somewhere in the mid 0.8's


and the SOX one is a bit high


the thing to remember is the nominal wattage of a lamp is often not always its *actual* wattage


for example the British 125W 8ft Tube is actually 123W, many US designs will incorporate cathode heating losses into the wattage ratting which will skew factors as well

this is where study of IEC, ANSI, JIS standards documents is very handy since they will often tell you whats actually what

In my last post about running MV lamps on MH ballasts, I learned a lot from @Ash and @RRK. I have messed around in Desmos graphing calculator a lot with some equations and I think I have set up a pretty accurate calculator for ballast impedance for discharge lamps. Here is the link:

https://www.desmos.com/calculator/y8cmvxxsfh

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It requires the following inputs:

"V oc" - The unballasted RMS input voltage
"V lamp" - RMS discharge voltage
"I lamp" - RMS discharge current
"P f" - Discharge power factor which I have calculated:
MV: 0.831
MH: 0.873
HPS: 0.913
LPS: 0.976
FL: 0.915

These power factors may or may not be the actual power factors of the lamp discharges, but they are the numbers that on average make the outputted impedance more or less correct based on existing datasheets. I don't really care what they mean to be honest. MH and FL lamps are a little less accurate than other lamps with this method due to the wider range of wattages and types, but generally still tolerable results in my opinion.

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The calculator simply outputs ballast impedance ("Z bal") in ohms, nothing shows on the graph. This output would be the impedance of a series choke. Obviously more calculation would need to be done to determine the proper inductance based off of that number given out. I am absolutely certain that people will comment on here shouting about how improper this is, and I am definitely ready to learn more. Maybe don't use this to calculate something super critical, but I find it interesting to compare different lamps and see which ones might be able to run off the same ballast.

As far as I know, the pink E39 base lampholders are designed for use with open rated quartz metal halide lamps with the proprietary EX39 base and have a structure that prevents standard E39 base lamps from running while the yellow E39 lamp sockets have a notch that allows the use of horizontal burning quartz metal halide lamps that use a locating pin on the base to prevent accidental installation in regular E39 base fixtures. However, you can use standard E39 base lamps in the yellow E39 lampholders just fine. Lastly, the white E39 lampholders are the standard lampholders.

Just had to provide an updated link as the original link seems to not easily direct us to the catalogs anymore:

https://esctlg.panasonic.biz/iportal/designCustomize/type_retireOut_sp/jsp/pewcustom/category.html?designID=retireOut_sp&categoryID=553670000

Here are two Advance YS-2S85-TPs. Each one can power 1 or 2 tubes. Kind of expensive but it is a pack of two ballasts.
https://www.ebay.com/itm/255543314322

Yes, it’s more of a cyan colour 😎

The white-ish light from an uncoated lamp does not look green. It looks a blueish white to most people. But then you let someone look at their hands - zombie colors.
It's one demo i do at work at talks about lamps and color rendering.

I'm looking for an F36T12/HO 2 or 1 lamp ballast. I found some lamps and I want to convert some fixtures to them. It needs to be 120v. I'm hoping someone knows the model numbers of the ballasts?

The lamp power factor consists of both Harmonic power factor and Displacement power factor :

The Harmonic power factor is result of the voltage waveform, approximately square. This accounts for most of the lamp power factor

The Displacement power factor is result of the lamp reignition behavior after zero crossing, where each half cycle begins with a high voltage overshoot before the flat area of the voltage clamped by the arc. Part of the voltage waveform is leading before the current peak, but in terms of the current that's lagging

The significance of the latter effect may vary based on lamp technology, on how much the specific lamp is pushing the stable Varc limits (higher power lamps are naturally more stable, but then they are also designed with higher Varc so push the limit as well), and how hot the lamp is



Then we have the ballast resistive losses, which sum up with the lamp Varc according to your old formula. If we account for them, the new formula will be :

Vballast_reactance = sqrt( Voc^2 - ( Varc + Vballast_losses )^2 )
I = Vballast_reactance / Xballast

Vballast_losses approx = ( 1 - BallastEfficiency ) * Voc

HID ballasts (series choke, and probably HX choke part bahaves the same) have typical efficiency around 0.90..0.92 for >100W lamps, 0.85..0.87 for <100W lamps

This is almost exactly what it should look like: https://www.lighting-gallery.net/gallery/displayimage.php?album=7562&pos=1&pid=249898
That's a 400w one caught using a film camera. I corrected it to look like real life.