Planning a portable UVC lamp with a 60V, 9W CFL bulb

[joeybuddy96]

My first attempt using an E26 to G23 adapter plugged into a 120VAC lamp burned out the 60v bulb. The bulb is technically 8.6W, 0.17A, 60V. It's a 2-pin, G23-base CFL. I'm keeping in mind that it has an integrated starter.

Philips specifications for the model 325126 bulb I'm using, the TUV PL-S: https://www.assets.lighting.philips.com/is/content/PhilipsLighting/fp927901704007-pss-en_us
Amazon ASIN: B00172Y0H4. They go for about $11.

Any G23 socket should work. They're about $7 on Amazon; e.g. Edwin Gaynor LH0178 1181-9-4H, ASIN B00DP3GK9Y.

I haven't been able to find 60V, 0.17A ballasts, so it looks like I'm going to have to make my own. The closest thing I could find was a 120V, 0.19A ballast marketed for driving 9W CFL bulbs (link). That's 0.02A more than the Philips' specification brochure lists, double the voltage, and isn't intended for CFLs with built-in starters. I'm going to need a 2:1 or 120VAC to 60VAC stepdown transformer. I read the thread on using diodes or resistors to reduce the voltage, but that was with much smaller voltages. I haven't been able to find 120v to 60v by looking around online. It seems like it wasn't too long ago that CFLs were ubiquitous, but is seems like hardware for them is difficult to find now.

What should I do next to build the ballast?

 

[rjenkinsgb]

See here:

Magnetic Ballast for 2-pin 5W 7W and 9W CFL bulbs

BallastShop has magnetic ballasts for 2-pin 5, 7 and 9 Watt CFLs in stock and ships same day.

ballastshop.com

 

[joeybuddy96]

See here:

Magnetic Ballast for 2-pin 5W 7W and 9W CFL bulbs

BallastShop has magnetic ballasts for 2-pin 5, 7 and 9 Watt CFLs in stock and ships same day.

ballastshop.com

Thank you for replying! Something I'm worried about with ballasts is that they're 120v, but the bulb is 60v, and trying to figure out if the type is suitable for the bulb. I think you're right about the Keystone one being more suitable than the Sola one. The Sola brand ballast I mentioned above and the Keystone one CC579TP you mentioned yesterday are both 120v, magnetic-type ballasts. The Sola one, however, only mentions T4 bulbs as compatible. I'm not literate in reading spec sheets, so I'll assume the Keystone one is the only one that will work. The differences between the two brands is this, if anyone else finds them useful:
Sola/Keystone: input watts: 10/9; input current (Amps): 0.16/0.15; ballast factor: 0.86/0.75; ballast efficiency factor: 8.641/8.33; power factor: 0.52/0.54; maximum THD%: 12/15%; crest factor: 1.6/1.58.

I looked up the CC579TP reviews on Amazon (ASIN B008YY1VNO), and apparently might need a starter component according to one reviewer:
"This can only work with a companion starter circuit. Never occurred to me that it would not start the bulb?" It's possible the reviewer had an incompatible bulb though.
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I've made an Amazon list with the components required so far:

Check out my list on Amazon

www.amazon.com

It will be about $37 for the components, not counting a reflector I already have. I'm just going to mount them on some 2x4 scrap wood. If I were scaling this up to making more lights, I'd mention those components too. I plan on getting the least expensive non-UV G23 bulb I can find (cheapest I've seen is a $5 5W bulb), so that I'm not destroying any more $10 CFL bulbs, especially considering that Philips G23 TUV bulbs are an endangered species, and once they're gone, they're gone.
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Here's my component diagram. If I'm missing something, let me know.

I could also save myself $12 and a lot of work if I get a certain mass-produced fixture (ASIN B08QQ1KD6G) that uses F8T5 8W bulbs; the total cost for a used unit and a Philips 299305 TUV would be about $25. I'm only now realizing this after I've added the components to a cart to see the total.

 

[rjenkinsgb]

Something I'm worried about with ballasts is that they're 120v, but the bulb is 60v,

The ballast controls the current, and the voltage across the bulb itself will be set by the bulb power rating.

It's a bit like the series resistor needed for an LED; the resistor sets the current but the LED voltage is defined by the LED type.

 

[Lightium]

If it's portable, shouldn't you be considering a drill battery powering an inverter?

 

[joeybuddy96]

If it's portable, shouldn't you be considering a drill battery powering an inverter?

You're right. It'd be more accurate to call it non-fixed or moveable. It's just like a desk or floor lamp, and not something permanently attached to the wall or ceiling. I do have a big car battery starter/jumper that has an outlet I can plug any household device into if I really needed it, but yeah, to make it portable and self-contained I'd add that in--I hadn't thought of that. Thanks!

 

[Lightium]

I need an engineers pdf on this lamp. So, my search will take awhile.

 

[Pommie]

You can get fluorescent ballasts(?) that run on 12V. I used one with a sterilising lamp to make ozone when I was cultivating mushrooms. Do you have a cheap auto shop in your country as that might be a good source for a 12V lamp. Google is your friend.

Mike.

 

[Lightium]

Is there circuitry inside the base of the bulb?

 

[Lightium]

I have two solutions, but I need to know is the bulb seen as a 343 ohm resistor on a meter?

 

[Les Jones]

I would expect the resistance between the 2 pins on a 9 watt CFL bulb to be close to infinity. A 2 pin bulb will contain a starter switch connected between the two filaments. This will be open circuit until the gas inside it ionises when it sees a high voltage from the supply. This then heats the bi metal strip in the starter switch which shorts out the starter switch pins. This causes the 2 filaments to heat up. (Which is required for them to emit electrons.) The bi metal strip cools down causing it's contacts to open. This causes a high voltage pulse due to breaking the circuit through the choke and this pulse is enough to ionise the gas in the tube. Once ionised the tube will conduct with a much lower voltage between its pins. If you are measuring 232 ohms between the pins of the bulb I think it indicates that the internal starter switch is shorted and you are seeing the resistance of the 2 filaments in series. (So you need a new bulb.) I have confirmed that a good 2 pin 9 watt CFL bulb measures open circuit between it's pins.)

Les.

 

[Lightium]

Not infinity though. I've calculated the resistance of a spark gap to be in the Exa range. I am scrambling to find my calc i did not too long ago.

 

[joeybuddy96]

Thank you for all of your replies everyone! Back in January I ended up simplifying the project and went with an under-the-counter portable cfl holder and bought a uvc cfl for it. I found that white vinegar worked better for treating the mold than the uvc light. I'm a little curious about a future project with it, but it's a low priority. I'm thinking of starting another project for a different application, which I'll start with a new post. I'll be asking about making a portable, motion-sensitive floodlight for my car in case of intrusions. Although, I guess if I wanted to permanently damage the intruder's vision, I could still use the portable uvc light project, but I'd probably accidentally set it off myself, ha.

I do sort of understand your responses. I have a multimeter and a cfl tube (non-uvc) I can use to answer Les Jones ' question about the resistance of the tube itself. Lightium, it's a regular ole cfl tube, no circuitry on this one.

 

[Tony Stewart]

FWIW, I bought some UVC 8W LED lamps in Edison bases with a remote control for the Edison base that could replace this.