Bodging my way through life

These parts are known as "op-amps", short for "operational amplifiers". The concept has been around for even longer than these parts, and is an integral* part of a wide variety of circuits, even today.

It is true that the (slightly) newer TL072 is better in pretty much every aspect than the 741, which was one of the early single-chip implementations, and had fairly poor performance in most categories. However, for many years, it was good enough, and well-known enough that many manufacturers offered it, it was made in enormous quantities, and was dirt cheap.

For a while, people would use the cheap ubiquitous 741 wherever it would do, and the nicer and more expensive TL072 where the better specs were required. Later, the TL072 was the go-to chip, and the more expensive 5532 (1977) would be used where a better chip was required.

Time continued to march on, and now the 5532 is cheaper than the older TL072, and a good choice for whenever you need an op-amp. It's overkill for a lot of uses, but these days it's cheap and ubiquitous. The audiophile crowd pooh-poohs it, and likes to swap in fancier chips to get the sonic character they want.

However, in moderate bandwidth analogue electronics, things are simply not obsoleted as rapidly as they are in the digital arena. All of the chips I mentioned are still made, and easily obtainable. There are, of course, more modern chips out there. Overlooking the bewildering variety of special-purpose chips, there are some newer general purpose op-amps to be had. The OPA627 came out in 1989 (a mere 28 years back), and has some truly impressive specifications. However, it costs nearly fifty times as much money as a 5532. The AD823 appeared in 1995 and is a fine chip, and more affordable than the OPA627. However, perhaps you want to use a chip introduced in this century for some reason. And sure enough, a successor to the OPA627, the OPA827 was introduced in 2006, only 11 years ago.

* pun intended: one common use for an op-amp is a lash-up known as an "integrator"

At least one problem was obvious: the plastic gears were crumbling (this being a common failure mode).

( the repair process (with pictures) )

The first order of business is to come up with the high voltage itself. When vacuum tubes were common, high voltage power supplies were too. These days, electronics are solid state, and run on low voltage. For a long time, 5 volts was the norm, and now voltages are getting even lower to support both devices with smaller geometry and reducing power consumption and its attendent heat generation. 3.3 volts was popular for a while, and newer devices run on 1.8 volts. In this arena, parts to produce high voltages are uncommon. As I like to share my designs, I'd prefer to use current production parts that other people can obtain fairly easily and cheaply. Happily, there is a current source for high voltage transformers. LCD screens need backlights, and one popular technology for backlights is the "cold cathode fluorescent light" (CCFL). These are long thin tubes that are lit by (aha!) high voltage. Since they're so common, the associated high voltage power supplies and the parts they're built from are also common.

I found a nice design at tubetime that used a CCFL transformer in a lashup using a voltage divider to sample the high voltage, a voltage reference for comparison, an operational amplifer (op-amp) to compare them, and a power transistor to control the CCFL circuitry. I figured I'd breadboard it and see how it performed. The CCFL transformer itself, while common, is still a specialty part. However, complete CCFL modules are, inexplicably, cheaper. Eyeballing the schematic showed that the core of the design was the same lashup used in the CCFL supply. All I had to do was add a rectifier and reservoir capacitor to convert the high voltage AC output to the high voltage DC I wanted, just as was done in the tubetime design. A quick breadboard showed that it worked as desired.

However, the tubetime documentation explained that the design was derived from a Jim Williams application note, so I read it and saw that Williams' original design didn't use an linear analog feedback loop like the tubetime version, but employed a switching voltage regulator chip instead. This was appealing, as it would be both more efficient and have a smaller parts count. The switching regulator chip replaced the voltage reference, op-amp, and power transistor with a single part, and added some nice protection circuitry as a bonus. I decided to build that version. In the process, I modified the CCFL supply slightly by cutting a trace to separate the low voltage ground from the high voltage ground. I did this because the low voltage "ground" wasn't actually ground, but the switching transistor, and I didn't want to ground an 800 volt signal through the low voltage switching power supply transistor.

( The rest of the writeup (with pictures)... )

fizzygeek

( picture )

It turns out it’s a weirdie plastic twist-on bulb that apparently uses a notched hole in a printed circuit board as the “socket”.

I don’t have anything like that in stock. So I walked down to the brand new Advance Auto Parts here in town to buy one. They looked it up and said those don’t normally burn out in a car only a few years old, and in any case, they don’t stock them and I’d have to get one from the dealer.

This did not exactly thrill me, so it occurred to me that I could probably find the bulb elsewhere, probably cheaper. But what was it? I didn’t have a type number or anything. Some research on the web revealed that there were a lot of people looking for this bulb, and that it was a Ford part number F5VY-13B765-AA (or perhaps F5VF-13B765-A or maybe E83Z-13466-A). There were a few mentions in the pages I found to this being an 80mA bulb, and that’s a believable current for a bulb like that. The existing bulb is marked “2W”, which might mean that it’s a two-watt bulb or it might not. There’s a chance that the E83Z bulb mentioned above is a 1.2 watt version. There’s also a chance that one of those isn’t a green painted bulb like the original. I don’t know.

I decided to try out the parametric search for light bulbs available on the Don’s Bulbs site. I could make good guesses at the glass type (T-1½), voltage (12-14V) and current (.08A), but what was that base? Happily, Don’s Bulbs has pages where you can search for bases by drawings. After peering at the “automotive” category for a while, I decided it was probably a “neowedge” of some sort, but couldn’t figure out which variant. No problem, the site lets you search on broad base categories, and even a vague type of base narrows down the huge pile of results nicely. The closest match I could find was a GE type 91646, which doesn’t seem to be available much any more. It does sport a B8.4D base, but I wasn't at all sure it was the right one.

I went back to searching the web, adding “neowedge” to my search terms. I found many more pages of people trying to find this bulb, and a bunch of pointers to LED bulb vendors. However, many people had bought the LED replacements, only to have them not work.

This gave me an idea - I could convert the existing one to LED myself and have it fixed the same day! I rounded up a blue LED and calculated that an appropriate voltage dropping resistor would be about 525Ω. Some rummaging around produced some 560Ω resistors, which should run the LED at slightly lower current, for a little less brightness and longer life. I crushed the burned-out bulb so I could solder the new parts to the resulting leads.

I then assembled the parts into something that should fit into the space occupied by the original bulb.

I remembered the LED bulbs I had made for my pinball machine, which runs its bulbs on AC, so the polarity doesn’t matter. But my car uses DC, so any way I assemble it is likely to be backwards. Then I realized the base was symmetrical, so if it didn’t light, I could just install it the other way. I hooked it up to a power supply to make sure it worked.

Then I went to install it in the car. Unfortunately, it didn’t light. I pulled it back out to turn around, and saw that I had broken one of the fine wires. Rats!

I took it back inside, and attempted to solder the wire directly to the terminal, but without success. I tried every flux and solder I own, slowly melting the plastic base, but it was beyond me. I considered finishing building my tack welder, but that’s a biggish project and there’s a pretty good chance I would fry the LED in the attempt anyway.

Greatly annoyed, I called the dealer to see if they had the right bulb in stock. Naturally, they didn’t — and they wanted more than fourteen dollars for the stinking bulb! I reluctantly told them to order one and call me when it got in. They said it would be in by Saturday morning.

Back to the web. I noticed a lot of the references to LED replacements were to the same place, superbrightleds.com so I figured I’d have a look. They have a facility to look up bulbs by car make and model, but didn’t list anything for my clock. So I looked at their “automobile, instrument cluster and gauge, T1.5 Base - New-Wedge, B8 Type” page. After clicking around for a while, I saw they had some nice big clear mechanical drawings of the various bases, complete with 3D renderings. From this, it seemed that I had a B8.4D based bulb. They offer LED bulbs with this base in two brightnesses, and six colors, and they don’t cost much at all ($1.59 for the regular brightness). The original bulb had a green coating, but I thought red would be nice looking, and avoid impairing my night vision. I ordered one each of the red and green, in both regular and high power.

I went by the dealership on the way to Balticon on Saturday, but they had closed early for Memorial Day weekend. Fie on them.

The LED lights showed up in today’s mail.

I popped the regular brightness red one in, it fit perfectly, and lit on the first try. I’m looking forward to seeing it at night. As for the dealer, I still haven’t heard back from them, and at this point, I no longer care about their overpriced bulb.

So I elected to buy a Canon Selphy ES-30 which is a compact dye sublimation photo printer that can also print gold and silver foil. It was listed as having Macintosh support, which is good because I don't do windows. It's a cute little thing, and takes its printing supplies as little cartridges that contain both the paper and the dye sub ink sheets. This makes it easy to switch between different media, and ensures that the ink and paper stay in synch and are compatible. They're specialized enough that they'll only ever be available from Canon, and they're not particularly cheap. But that's fine, it's cost effective for my occasional use.

But then it turns out that the Macintosh support is only partial - you can print color or black and white, but no gold or silver foil. It is my opinion that if you claim to "support" a computer for a product, that you support all the product's capabilities. Otherwise, it's partial support at best, and this should be stated clearly in all sales literature. Otherwise, you are lying to me, and I do not appreciate being lied to.

I waited a while to see if there would be an update that would add foil support, but none was forthcoming. Then I wrote Canon and asked if they would send me the protocol, so I could implement this myself.

They refused, saying the information was proprietary. What? Why? You're not selling printer drivers, you're selling printers, or more to the point, you're selling printer supplies. The more people who can use your printers, the more printers and supplies you will sell. Keeping the protocol a secret is nonsense. I offered to sign an NDA, but no reply at all. I realize that companies avoid giving out technical information because it might lead to more support questions. I explained that I would not ask for further support, nor use the information in a way that would cause this to happen.

Do you know what would have happened, if you had furnished the interface specification? I would have extended the existing Gutenprint Canon Selphy support to include the ES-30, including its metal foil printing capabilities. I would have provided my changes back to the Gutenprint project for inclusion in their core software. This would have given Canon ES-30 support to Linux and BSD users, and since Apple uses Gutenprint to provide their third-party printer drivers, you would have gotten Macintosh support for free. Better yet, customer support for this driver would have come from the Gutenprint project and Apple — saving you support money. I would have written a positive review of the printer, and all my adoring readers would have gone out and bought them. The underserved Macintosh, Linux, and BSD communities would have bought the now-supported printer, and supplies for it. As the cartridges are not easy to replicate (unlike refilling inkjet cartridges), you would have had a solid revenue stream for years to come, that no one could take away from you. You would have enjoyed a positive mindshare in a large, geeky customer base - and their friends, families, and employers.

But no. You decided to take the low road, keep things secret for no reason, and now you're stuck with unpreferred vendor status. I'll buy my cameræ from Nikon, Fuji, and Olympus. I'll buy my printers from Epson and HP. And I'll tell all my friends how you refused to play nice.

Your pointless corporate decision will end up costing you a surprising amount of lost revenue over the years.

Really? We've had decades of absent-minded professors, mad scientists, and nerds complaining about their childhood treatment and taking their revenge on the world. Now that is something we might complain about.

But Big Bang Theory? Please. Most folks focus on Sheldon, so I will too. Sheldon is portrayed as a good guy. That's right, he's shown very positively. Yes, he has difficulties with social niceties. But he tries. He really wants to learn how to interact with people properly. It's not his fault he isn't very good about it, but instead of making excuses ("I can't act nicer, I'm an assburger"), he tries to learn from his mistakes, learn how to recognize sadness and sarcasm, and react appropriately. When someone needs a large amount of money, he offers to lend it to them, for whatever amount of time they need it, interest free. When someone's feeling down, he tries to comfort them, even though he doesn't really know how. It's tough to attempt something you don't know how to do. But it's the right thing to do, and he tries. Even when it involves touching other people, he does so, overcoming his aversion to doing so. That sort of thing makes the character a good one, in my opinion.

"But they portray Sheldon as a buffoon!", I hear people whine. Really? Granted, Sheldon is often portrayed as a buffoon. But so is everybody else on the series, including most of the guest stars! Everybody's a little off in this show, it's part of the show, not an insult to anybody in particular. That was part of what I liked about In Living Color: they were evenhanded, making fun of everybody. I really can't object to that, as long as it isn't mean-spirited. And if there's mean-spiritedness in Big Bang Theory, I simply don't see it.

That's a subtle difference, and hard to point to, but it's important. Anybody remember The Man Show - the original one with Adam Carolla and Jimmy Kimmel? Lots of folks objected to that, saying it mocked women and objectified them, treating them as nothing more than sex symbols. There were a lot of such shows before, during, and after it that did exactly that (and I include the reboot of The Man Show with Doug Stanhope and Joe Rogan). But the original Man Show wasn't like that. The hosts (Adam and Jimmy) love and respect women, and I can see it in the show. A lot of their gags boil down to "I don't completely understand women, but I adore them". That's why I liked that show, and didn't really enjoy any of the others of that sort.

It's the same way with The Big Bang Theory. While the jokes necessarily revolve around the characters and their personalities, they're not mockery, they're poking gentle fun. And many of the gags are simply standard sitcom fodder - they're laughing at what it is to be human. And that's always going to be funny. If you've read Alison Bechdel's Dykes To Watch Out For, it has a similar feel. Yeah, a bunch of the characters are lesbians, and a lot of the story lines hinge on things lesbians do, say, and are - including some stereotypes. But the main message I get from the comics is "we're all human, and we all have the same sorts of fun, problems, and laughs." The same with The Big Bang theory - it's a show about being human, with the wrinkle that not all humans are alike. As someone who's "not alike", it's nice to see that explored, whether it's in a humorous vein or not.

And yes, sometimes I'll do or say something nerdy (like "I like to turn the plates so they face the sprayer in the dishwisher"), my sweetie will smirk at me and say "Okay, Sheldon!" It's not mean, it just reminds me that I can be picky about minutiæ. And it makes us both smile.

( graphic description and pictures of bugs )

Then I read it again, noticing that the first word was really "outsmart".

However, it's apparently possible to outsource worry! A. J. Jacobs mentions this in his article on outsourcing his life.

Then, in his new book "Drop Dead Healthy", he mentions an episode where a reader offered to trade worries with him. Apparently it worked out nicely for both of them. The idea seems to be catching on.

Presently, someone wandered by and asked if I had been at the iCarly event last night. I said I had, and he shook my hand and said he thought he recognized me as a big bidder for the day on the set. It turns out he was the winning bidder, but didn't really have any friends or family who enjoyed iCarly. He said he'd try to find out if I could come with him, as I was obviously interested enough to be willing to put down major money. We exchanged contact info.

Finally the ticket windows opened up, and I went to the USAir window to try again to get my flight changed to terminate in Charlotte (where I would be catching my flight to Florida) instead of Dulles. It was still impossible. So I asked if I could just have my luggage marked to come off at Charlotte. The agent looked very flustered and asked why I would want to do such a thing. I explained that I'd be abandoning the Charlotte-Dulles segment and catching some other plane. She snapped "I don't want to hear about that!" and turned away. Hopefully there won't be anything in my luggage that I can't carry on the plane.

( more (with pictures) )