LPS SOX Sodium Lamps

[Sigurthr]

Hey everyone!

I just got a nice 55W Osram SOX (Low Pressure Sodium) lamp in today and snapped a few quick photos with it hooked up to my NST. I have a ballast for it coming in the mail some time next week, and an adapter to use the BY22D (B22 bayonet) in a standard E26/E27 screw in fixture.

I'm not one to collect flashlights or different light sources, but I love these bulbs for both the cool neon/argon glow when warming up and the awesome 589nm monochromatic light when on. I can't wait to build a nice fixture for it once the rest of the parts come in. These lamps used to be very common here in the US in the 70s, but people complained about the monochomatic light and they switched off to less efficient white light bulbs instead. They're still heavily used in Europe, which is where this bulb was manufactured. As a result they all use 220V and a bayonet type socket, which you can't buy/source in the US. A workaround is to get or make an adapter and run it on an Instant On Fluorescent ballast, which is what I'll be doing.

Since it is only 55W I'll probably use it indoors in my office for when I want a softer light source, my main light is a 200W 6500K dual CFL assembly, which is great most of the time, but keeps you wide awake at night and can cause some eye strain. Since the 589nm emission is so close to the eye's peak at 555nm the light appears very bright for the amount of wattage it really is. A 55W 589nm will look like a little over a 100W of light most people say.

Right after powering it up:

After about 10min some sodium has begun to liquify and vaporize:

My Phone's camera isn't great and doesn't pick up the color well; before the Na ion really get around the lamp has a very strong near-UV emission, which I suspect is from Argon. It appears to be an Argon/Neon mixture of mostly Argon as there is the red line from Neon but none of the orange/yellow ones and to the eye it almost looks like Nitrogen plasma.

I'll update this when I get the ballast in and again when I build the custom fixture for it.

Anyone else enjoy Sodium lamps?

 

[Things]

I love LPS lamps! They're still pretty common around here in Aus, I love watching them warm up. I'd loooveeee to pick one up one day

Is this the seller you got it from? Seems like a pretty nice price: http://www.ebay.com.au/itm/BN-PHILI...SURE-SODIUM-SOX-LAMP-LIGHT-BULB-/251025216481

 

[Sigurthr]

Nope; I got mine here:
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

The seller had a "Best Offer" option up and I sent an offer of $20 which was rejected, then he accepted my next offer of $30. So I got a brand new bulb shipped from Canada for $30, and it arrived VERY quickly.

I was able to pick up a Fulham Workhorse5 ballast for $35 shipped, and the socket adapter was only ~$8 shipped (from within the US!). Total cost of $73, you can't beat that hehe. I've been wanting one of these for a very, very long time.

Last thing on my "MUST GET" list is a tesla coil. I'm bidding on a supreme deal for one now, but it's one of those long drawn out 7 days auctions, with 6 days left, and I'm on a budget. So, I'm keeping my fingers crossed that I can swoop in right before it ends and nail it at a good price. That of course all depends on people not being stupid and bidding throughout the week!

 

[TacoHerder]

wow, i bet it looks cool lighting up a room with 589nm. I want one!

 

[Things]

I just made an offer of $20AUD for one in the UK. Hoping I may be able to get away with using a fluorescent lamp ballast, seeing as 55W is a pretty common fluoro wattage here.

 

[DashApple]

Nice Find , I love sox lamps im wating on a 180 watt one to arrive 44 inches long and 32000 lumens of yellow and i have a 135 watt one and a few smaller ones 35w and 18w

Its annoying that the ballast are expensive though , such a awsom colour

 

[Things]

They seem pretty easy to drive, seeing as they're almost electrically identical to fluorescent tubes. I think the only difference is they need a slightly higher starting voltage. I've seen a pic of a 180W LPS, what a monster!

The 55W one I just made an offer on is 425mm long. Curious whether it'd survive shipping

 

[Sigurthr]

Very nice!

Yes, most SOX tubes are electrically identical to fluorescent lights, right down to the single electrode ends (not coils with two contacts per side), so you can use any fluorescent ballast which can handle the wattage and will supply the 600V starter voltage needed.

I did some experiments on mine using a resistive ballast and seeing if I could trigger the lamp with a HV pulse, but it would not ignite this way, so you definitely need a ballast with continuous HV start.

The Fulham "Workhorse" line will happily run SOX lamps continuous duty, with no complaints. They are fairly inexpensive as well, the gold standard one for small to medium SOX lamps is the Workhorse 5, which is usually only $35. eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

For those who haven't seen a SOX run on one of these ballasts: (NOT MY VID)
Philips 55W SOX Low Pressure Sodium startup [HD] - YouTube

 

[jimdt7]

I am thinking of buying one also
I love their colour

Jim

 

[DashApple]

They seem pretty easy to drive, seeing as they're almost electrically identical to fluorescent tubes. I think the only difference is they need a slightly higher starting voltage. I've seen a pic of a 180W LPS, what a monster!

The 55W one I just made an offer on is 425mm long. Curious whether it'd survive shipping

Hmm Ill have a look around for a fluro ballast , i have found 180W LSP ballasts for 50 pounds but that still needs a ignitor aswell so i may have a look down the fluro route . Yeah when i got my 135W LSP i was amased by the size so the 180W is a monster .

Yeah thats the problem large glass tubes are never keen on postal service

 

[Cyparagon]

I've got a 35W and a 55W. I didn't want to dick around with the weird base, so I just soldered a standard (E27) base to the end instead . LPS ballasts are almost extinct in the US and when you do find one, they want $200 for it I run mine on a 100W metal halide ballast with a variac.

Running it on a NST is bad for the electrodes. It operates in cold-cathode mode and will cause sputtering.

 

[Sigurthr]

I've got a 35W and a 55W. I didn't want to dick around with the weird base, so I just soldered a standard (E27) base to the end instead . LPS ballasts are almost extinct in the US and when you do find one, they want $200 for it I run mine on a 100W metal halide ballast with a variac.

Yep, cheapest LPS ballast I could find was priced at $90, and didn't include an ignitor, and it looked like it had been through a war.

Running it on a NST is bad for the electrodes. It operates in cold-cathode mode and will cause sputtering.

Aye, verily. I forgot to mention that as a disclaimer. I simply wanted to power it up and make sure it survived shipment. I figure one time on the NST shouldn't cause any noticible trouble, and visually the electrodes look fine with no sputtering.

 

[Things]

Hmm, was at the hardware store today. Bayonet sockets are still widely used here in Aus, though for some reason while I was there, I had in my mind that I needed a ceramic one. It occurred to me after I got home that you didn't seem to mention ceramic at all in your post. So I'm assuming you've been running the lamp fine from a plastic socket?

I suppose the plastic sockets are designed for much hotter incandescent lamps, so a 55W LPS shouldn't be any issue at all in terms of heat.

No reply on my offer yet, though even if they decline it I'll probably buy it anyway

Was thinking of using some PVC pipe and metallic spray paint as a DIY reflector/housing.

Was thinking of giving this ballast a shot: http://www.ebay.com/itm/Fluorescent...ocket-55W-for-H-Tube-Lamp-Light-/290676565655

It's cheap enough for a try I suppose. One thing I did notice though, is the ballast has 4 output wires, for the filament. Seeing as a LPS lamp doesn't have a filament, what do you do with the 2 sets of wires?

 

[Cyparagon]

Yeah, plastic would be fine even for the 180W lamps. They don't get very hot, partly because they're so efficient and partly because they're so long.

LPS lamps have filaments, but the lamp electrode leads to both ends of the filament. You want an instant-start ballast. Pick a ballast that gets as close to 0.59A as possible.

 

[Sigurthr]

Aye plastic is fine, these lamps waste very little energy. Yep, you need an instant start ballast (they typically say "open circuit voltage: 600V") and not a run of the mill current limiting ballast (instant starts do that too though). You'll never get the tube ignited without an instant start HV ballast.

 

[Things]

Hmm, why is it seemingly impossibly to find an instant start ballast around 55W for 240V line voltage??

I'll see what happens with the ballast I bought. I can always add a bit more of a HV kick if it can't start the tube. Wikipedia suggests that the 2nd pair of wires are simply connected across a capacitor.