The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Category: Oddities

Who’d’a thunk it?

OPB815 Optical Switch: Always Measure Your Components

Given this ID printed on the side of an old OPB815 optical interrupter switch:

OPB815 Optical Interrupter Switch – detail

And this pinout diagram from a randomly chosen datasheet for that part number:

OPB815 Datasheet Pinout Diagram

One might reasonably be led to believe that the white dot on the part marks the LED anode. That’s what I thought, too, but the innards are actually rotated 180° from the picture: the dot marks the transistor collector.

Took me a while to figure that out; I eventually tore one apart and used my pocket camera to look for the blue-white glare of the IR emitter.

After the dust settled, I rummaged around in the impacted shitpile holding my paper documents and found the original 1982 datasheet, with my very own scrawled notes:

Original OPB815 Datasheet Pinout Diagram

Back in the day, the dot on pin 1 marked the transistor collector…

Memo to Self: No, scanning all that old paper wouldn’t help.

2011-06-12
Architectural Forethought: Lack Thereof

Plumbing trim plate vs tiled wall

This from a restroom near the new high school auditorium, rebuilt at vast expense over the course of several years. You’d think for all the big bucks, somebody would remember that trim plates require a flat surface.

It’s not like I’ve never forgotten a detail in any of my designs. In this case, though, several different people surely noticed this situation and none of them were sufficiently empowered to fix the problem.

I’ve got a ten cent bet with myself that this will never get repaired. I’ll likely never know, though, as my Shop Assistant graduates this year.

2011-05-24
Mysterious Warning Glyphs
Found this on the hand-cranked reel that deployed an outdoor table umbrella in DC…

Table Umbrella Cable Winch

I think you’re not supposed to:
- Stand under something held by this cable
- Use it for motive power (?)
- Hang from it
I think they’re violating the first warning, as the cable holds the umbrella open over your head. On the other paw, it’s not a monster dead weight, so maybe it’s OK.

The food was pretty good.
2011-05-16
Look Alive!

You know how, in those old cartoons, whenever the vultures started landing in nearby trees, that was an indication of trouble ahead for the hero?

Turkey Vulture in pine tree

The local Turkey Vulture flock has a roost a few miles away and they’re often seen circling in the thermals overhead.

A few years ago I encountered one dismantling a squirrel flapjack on the road:

Vulture dismantling squirrel

It’s an ugly job, but somebody’s got to do it…

2011-04-21
Target Unit Pricing Amusement

I’m not sure whether all unit prices must be converted to “per 100 count” or not, but it really doesn’t work out well for CFL bulbs (clicky for more dots):

CFL 2-bulb pack

That’s $549.50 per 100 bulbs, if you can’t make it out.

On the shelf below, however, a single-bulb pack priced out to $979 per 100 count, so the 2-pack is definitely a better deal!

2011-03-17
Winter Wonderland

The NYS DOT recently spiffed up Raymond Avenue in Arlington, installing three small diameter rotary intersections and rows of street lights with lenses cunningly contrived to glare directly in your eyes. Why installing black, non-reflectorized bollards two feet away from the travel lane at each crosswalk seemed like a good idea escapes me, too.

Anyhow, it seems one of those streetlights was a bit too close to the corner. The ruts across the top of the picture came from a truck that evidently clipped the pole and neatly fractured the entire aluminum (?) base casting without bending anything else.

Fractured street lamp post

Further south, this wall in Wappingers Falls shows why flat-roof building aren’t such a great idea in snow country:

Ice flow across wall

That isn’t a new problem, by the way. Last year it looked like this:

Ice-covered gas meters

Not much one can do: water goes where it will.

2011-03-10
Wal-Mart Unit Pricing Amusement

OK, let’s see how well you do on this round…

In the Mysteriously Missing Label category, we find three similar products with only one shelf label. Which one is the better deal?

Caffeine unit pricing

You might think it’d be the Wal-Mart Equate house brand. In order to find out, you’d have to haul all three offerings down the aisle and around the corner to the price scanner, which would reveal it’s the one on the far left, by a considerable margin. Oddly, that one says “Double Strength” even though it has the same 200 mg dose as the others.

In the Bizarre Units category, we have two very similar products with completely different unit-price units of measure. Seeing as how a “fluid ounce” is a unit of volume and a “pound” is a unit of weight (or, for the pedantic, force), even the dimensions aren’t compatible. Clicky for bigger pictures.

Vanilla unit pricing – 2 oz

And, just to show that wasn’t a one-off mistake that could happen to anyone, the smaller size containers continue the theme.

Vanilla unit pricing – 1 oz

Given that nothing in a Wal-Mart store happens by accident, someone was directed to remove two of those three labels and another someone deliberately chose incompatible units.

Of course, anyone I’ve ever asked has no idea why that would happen…

Previous rants live there and there.

2011-03-07