Getting Screwed by Edison

You can thank Thomas Edison for a lot of the screwing you do.

Of lightbulbs, that is.

Edison didn’t exactly invent the incandescent lightbulb, though popular
folklore would have you believe he did. He just purchased the patent
for it from another inventor. However, he did come up with the “Edison
Screw” fitting, as it’s now called, which makes it easy to twist a
lightbulb into a fixture.

The Edison Screw (or just “ES”, if you’re in the trade, avoiding
endless snickers from colleagues, I’m sure) has been around for over
one hundred years and has provided millions of people with light
screwing pleasure the world over.

It’s a brilliantly simple connection. Just a few twists of the wrist
applies minimal pressure to the fragile glass yet provides the bulb
with a firm enough fit to secure it in place.

So why, I pondered during a recent visit to Canadian Tire for new
lightbulbs, have halogen bulbs decided to eschew such a marvellous

I noticed no less than six completely different connection types for these chic little lightbulbs (the GY6.35, the GU5.3, and the R7s to name a few) — too many to remember what I actually needed. I had to drive home and dig a dead bulb out of the garbage so I could bring it down for a positive match.

Then the act of actually fitting the bulbs into their fixture sockets was an exercise in futility. They each had two little connector pins about the size of pine needles that poke into two little holes at the bottom of a deep socket (this is the “GU4” halogen connector I’m referring to).

There aren’t any alignment marks or screw guides that would help one successfully match up the pins to their associated receptacles. While attempting to replace four lightbulbs I managed to mangle the pins on two of them and somehow ruin the fixtures themselves. We remain without light in those rooms still.

All of this brings new meaning to lightbulb jokes.

Q: How many geeks does it take to screw in a lightbulb?
A: None. Geek houses use halogen and they’re all broken because they use GU4 sockets.

Where is Edison and his illustrious screw action today, when we most need it? It seems odd that in 2006, on the 100th anniversary of the still-used tungsten incandescent lightbulb, we would have gone backwards in terms of the technology’s usability.

One of the halogen connection designs, called the GU10, is possibly more brilliant than Edison’s screw. It, too, features two pins, but they’re very large and sturdy and have prominent heads at their ends. They slide easily into the the hole sockets of their fixtures and a quarter turn securely fastens them.

However, even this design is flawed, as there’s also a nearly identical GZ10 connector. The difference is that the base of the GU10 bulb is slightly bevelled and the GZ10 is not. When buying bulbs it would be very easy to mistake the two and end up frustrated because you can’t get the $%#@ bulb into the socket.

There is actually a halogen bulb that sports the classic Edison Screw, called an A-line. Why this isn’t the standard halogen connector beats me. I haven’t seen any halogen fixture that accepts this type of bulb.

So, if halogen bulbs’ connections are so problematic, why do we even bother with them?

Well, it’s not hard to better the age-old, pear-shaped incandescent lightbulb from an efficiency standpoint. After all, only about two percent of the energy applied to it actually produces light; the rest is wasted as heat.

But halogens do only slightly better at about 3.5% efficiency. They just happen to last a lot longer, though, because the filament inside is self-repairing due to the presence of halogen gas in the chamber.

On a side note, by far the most efficient form of lighting is the evil fluorescent. Running at about 8% efficiency, fluorescents cost a quarter of what incandescents do over time. There are even mini fluorescent lights now that know how to screw like Edison. Which is great if you can get over the nasty, unnatural light they cast.

Whatever the efficiency, though, halogens suck if you ruin the fixture just swapping out a bulb. If the industry didn’t like the way Edison screwed, they should have at least settled on an equivalently-usable connection standard that all halogen bulbs used.

I would vote for the GZ10, personally, with its sturdy rods and partial twist. Because, as the saying goes, a quarter screw is better than no screw at all.

First published in the Yukon News on Friday, January 6, 2006

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