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There are plenty of UV bulbs waiting in the supply chain. These could be used to make germicidal chambers. Grandma and Grandpa could throw a package in there, let the light shine on it for a while, and poof, no coronavirus. Beats having to wipe down every box from Amazon or food delivery with bleach if you're immunocompromised.

The problem is, all these UV bulbs come in odd sizes:

  • E17
  • F5, 1' tube
  • G23

And they also take low voltages. Even if you get an E26 (standard) to E17 adapter, the bulb will blow the moment you plug it in. Most of these little germicidal bulbs only handle 3, 3.5 watts. What voltage their expecting, I haven't found documented. Presumably the lamps they go into already step down the voltage appropriately.

This seems like it should be a trivial solve. Home Depot carries a page of E17 bulbs. What lighting fixtures do they carry that those will go in? Ikea also has their own E17 bulb. Which lamp does it fit? I'm striking out on finding documentation for this.

I can't begin to guess how many germicidal bulbs are sitting in the supply chain, waiting to be put into service. Once the concept is proven in a DIY Sterilization Chamber for incoming packages, I'd like to take it further. I'd love to fasten a battery powered candelabra atop a roomba and let it bump around any grocery store that will have it overnight, taking a second pass at sterilizing all the surfaces that don't get wiped down or mopped at the end of the day: The cereal boxes that people touched and then put back on the shelves, and everything else like that.

Safety note: Do not expose yourself to a powered germicidal bulb. There's a reason these things are usually enclosed in ductwork, air purifiers, etc.. Hard UV light is bad for you, m'kay? If you're reading this and wanting to build your own, great. Just, enclose the light or set it loose on a roomba when no one is around, ok?

  • Are they 12v or 24v? – Solar Mike Mar 21 at 5:53
  • Doesn't say anywhere I can see. No documentation. – baudot Mar 21 at 13:55
  • That being said, all the evidence suggests very low voltage. For the first bulb I could get my hands on under current conditions (pun unintended but accepted) the one thing that WAS labeled was the wattage: 3.5. No other information was provided. – baudot Mar 21 at 14:09
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Okay, so you're keen on UV bulbs but don't really have any background in lighting tech. That's fine.

E17 is a type of Edison screw-in base used with incandescent bulbs (and LED conversions). It is the third most popular after E27 (standard lightbulb) and E10 (Candelabra). Many fixtures will apply effectively 120V to an E17 Edison base.

However, the E17 germicidal light bulbs require a very special controlled current and voltage. You must drive them to specification. They will burn out if hooked to voltages intended for E17 incandescent bulbs.

F5 is not a bulb. It is a very particular size of fluorescent tube.

G23 also is not a bulb and is a very particular size of fluorescent tube.

With both fluorescents, it is not enough to read the spec sheet and drive them at specification current. Fluorescents are not as simple as that. The preheat filaments need to be warmed, and then an arc must be struck down the filaments. Commercial off-the-shelf units which do this are readily available; they are called ballasts. One should not reinvent the wheel.

Note that F5 and G23 tubes use a physical form-factor similar to other (lighting) fluorescent tubes (which have different names). The compatibility of the form-factor does not mean the ballasts are compatible. You must consult the ballast data sheet for which tubes it does support.

Your best bet may be to find a fixture that takes a visible-light fluorescent of the same form-factor, then change out the ballast to make it compatible with the germicidal fluorescents.

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  • Thanks for restating what I already knew? – baudot Mar 21 at 15:03
  • @baudot and how one earth would I know what you "already knew"? By what you say in your question. Thats always guesswork, but it seemed pretty clear you don't know these things, or are at least quite unsure. While there is nothing wrong with that, hubris will get you nowhere in this business. Best of luck with your project. – Harper - Reinstate Monica Mar 21 at 18:44
  • I asked for help finding fixtures, or even documentation, and said I was running into trouble with sizes. I got an explanation that opened by telling me I knew nothing about lighting tech, went on to explain that these were different sizes, and said that I shouldn't trust the documentation. In conclusion, that I should find a matching fixture. I'll ask you to forgive me for being a bit frustrated by that response. – baudot Mar 22 at 15:46
  • Honestly trying to be helpful here: I didn't really say that, you weren't that precise, and you have downvoted more posts on diy than I have... which suggests to me you tend to read answers with an eye to be offended. That's not compatible with your goal. The knowledge you need is hidden, it's buried in the margins at best. Your quest amounts to panning for gold, you have to sort a lot of rocks to get gold. You also can't blame people for not guessing your skill level, or for laying down basics to get others up to speed. My last 3 paragraphs may have some gold. – Harper - Reinstate Monica Mar 22 at 17:25
  • And to be clear on that last point, SE isn't a custom research service. The whole point of SE is to become the #1 google answer for everyone with a similar question. That "everyone" will certainly have different levels of skill. Therefore answers should lay down the basics before getting into the meat. – Harper - Reinstate Monica Mar 22 at 17:30

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