At least one problem was obvious: the plastic gears were crumbling (this being a common failure mode).
We remarked how they would fit our décor, but thought it was silly to buy a fake camera when there are plenty of affordable real ones out there. Accordingly, I picked up an old folding Polaroid 100 on eBay on the cheap. Reading up on it, I discovered that Polaroid originally made roll film cameræ for a few years, then went to the wildly successful "pack film" format. These were made for a long time, and in huge numbers. My Model 100 was the first, and probably well over a million of them were produced. The Model 100 was also quite capable with quality glass lenses, a range of film speeds, and an automatic electronic shutter capable of producing correct exposures at speeds from 1/1200 to 10 seconds.
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 light 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.
It's a nice old farmhouse on 5 acres in Lovettsville, with a nice little creek running through the property. It's out on the edge of town, and they're planning on building a park in some land out behind the neighboring farmer's fields. The previous owners have done some beautiful work on the house, bringing the second floor bathroom up into the attic, giving it a higher ceiling and more light. They've added on a spacious kitchen/breakfast nook with a vaulted ceiling and skylights. There's a deck out back, surrounding a tree. There's a nice little sun porch, lots of built-in shelves, a finished basement, a cedar closet, and a fire pit. The yard has plenty of plantings of native plants, and is a Certified Wildlife Habitat and a Certified Bird Friendly Habitat. Fizzygeek will get to indulge her green thumb.
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. Originally posted at Dreamwidth.org comments
So why are they so useful? It's the "hollow shaft" part that does the trick. Rather like deep sockets can do some things that ordinary sockets can't, they'll let you loosen/tighten a nut that's threaded way down on a long bolt. And the hollow shafts on these extend the entire length of the shaft.
If you look up the shaft, you can see all the way up to the handle. It's not just a 2cm recess, the entire shaft is hollow, accomodating anything up to that length. For example, using these tools, it's easy to install long-shaft controls in panels and neatly tighten the nut without fighting with pliers, trying to keep a box-end wrench in position on a thin part, or running the risk of marring the panel.
That's one, on the right, in position to tighten the retaining nut, quickly and easily.
Recently, I realized that a metric set of these would be a very useful thing to have as well, so I went out to see what the offerings were. I was pleased to find out that the original Xcelite HS618 set is still available, as well as the individual drivers. It's nice when useful things are still in production, after all these years. Unfortunately, they don't seem to offer a metric version. Originally posted at Dreamwidth.org comments
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.