Monday, February 24, 2014

PS3 Laser Diode Specs

Recently I brought my posts about building a blue laser pointer (from 2008) back to life on this blog.

PS3s were brand-new tech when I wrote those, but now they're a generation or two (or maybe three) old, and you might have landed here wondering what you can do with the junk you have that used to be a really cool gaming system.

I should have a central place for the technical specifications of the PS3 laser part itself, and the arrangement that worked for us, in a concise text.

Here I'll collate from the four build posts;

  • Diode Pinout
  • Working power settings
  • Brief description of diode component extracting, installing, handling
  • (!!) Full power supply circuits will not be provided here. Sam's Laser FAQ is my usual recommendation for anything laser-related. Better yet, design your own. Make friends with someone smarter than you. All good strategies.

Here we go.

Diode Pinout


Here is the still that you'll find in the video I reference about making a "Laser phaser." It shows the two most important terminals, ground and positive for the blue laser.

If you use this image as a reference, you can see that it matches with the fuller description of the component, which includes pins for the red laser and infra-red laser diodes that are integral to the part. Here is that pinout:

  • Pin 1: (Bottom Left-Hand corner) - Infra-Red Laser +
  • Pin 2: (Left and Center) - Blue Laser +
  • Pin 3: (Top Center) - GROUND -
  • Pin 4: (Right and Center) - Red Laser +
  • Pin 5: (Bottom Right-Hand corner) - Photo diode (used for power regulation when connected)

(Lay the diode on a flat surface in front of you, with the diode's pins facing you. The perimeter of the diode is round, but it has a flat edge. Roll it so that the diode's flat edge meets the flat surface and lays still. Now you're looking at the five pins like a pentagram, with one in the middle at the top. Number the pins 1-5, starting with the bottom left corner and moving around the pins clockwise.)

Finally, keep in mind that the diode component's can is itself grounded (you should verify this yourself by continuity with your meter), and can be easier to solder to than the tiny gold pins on the back of the diode.

Working Power Settings


Close to it, rather. Assume we're using a fresh 9V battery. Following is my friend Eric's description of the power setup:
The final circuit consisted of matched NPN transistors with their bases connected together and emitters tied to ground. On the reference side, there was a 560 ohm resistor between the positive terminal of a 9V battery and the base and collector of one transistor. Four other resistors, valued 470, 1k, 2.2k, and 4.7k ohms were in parallel with switches so that each one could be added parallel with the reference resistor. This allowed for a linearly variable equivalent resistance from 180 to 560 ohms. 
The diode was in series with a 47 ohm resistor between the positive battery terminal and the collector of the second transistor.
Honestly, Eric is awesome, but we just cobbled this thing together. It's probably better if you hit Sam's and get a known good circuit for your project. Your results are not guaranteed, ect.

Diode Component Notes


If your diode arrives and is still part of a laser lens assembly from a disc drive, then you'll need to very carefully extract that diode.

I used jeweler's screwdrivers for some of the extraction, and when I got the thing down to the diode itself and the armature that held it, I had to extract solder from a ribbon cable to free the component from the remaining bit of board before I could work on popping the can free of its bracket.

Your own technique is as likely to work as well as mine, but whatever you do, don't damage that diode can or the pins or the lens!

Anytime the diode is around other electronics, it should rest grounded. We soldered a ground wire to the can rim and used that as our master ground.

If you set the diode in a new collimator, finger-tight pressing (or hot gluing, or both,) will not do. The can must be fully seated in the recess for the diode to sink heat away via the metal contact of the collimator housing. I gently locked the housing in a desk vise and pressed in the diode by the rim edges with needle nose pliers until it popped into place.

I then soldered the rim/collimator interface for better metal-to-metal contact and put on a grounding wire.

Hope this helps! I'll try to answer questions in the comments.

Sunday, February 23, 2014

Violet Blue Laser Pointer Build Part 4

Violet Blue Laser Pointer Build Part 4


Finished Product:

At last, we have a handheld, easily portable, blue/violet laser pointer. It runs on a single nine volt battery, has tunable output, a momentary switch for easy use, an external SPST switch to keep it from lighting up your pocket, an internal master power switch to make extra sure, and it's all in a very attractive black metal case!

Tuning the collimator was both easier and harder than expected. To dial it in, you simply move the threaded lens assembly around until you get the finest dot the optics will allow. Sadly, it's not the best collimator, and beam divergence is quite obvious at a range of fifty feet or so. Better collimation would do wonders for this unit, and might even yield enough light concentration power to pop balloons and light matches.

The blue beam is clearly visible in the night sky, and pointing to stars is easy and fun with this laser. Even with the beam convergence issue, the dot is remarkably bright at several hundred feet, which is plenty far to point out stars, tease animals, and play with at concerts.

When I light it up in public places, it's fun to watch people look around for the source. If the area is dim at all, then the visible beam points right to me, so keeping it on continually is a dead giveaway. In daylight, its source is much harder to find, but it's also a little less noticeable in the first place, with ambient light washing the dot out a little. Green lasers are excellent for this sort of fun as well.

Second Thoughts:

Obviously, I'd like to have been more cautious with our first Blu-Ray laser diode. Doing it right the first time would have saved us at least two weeks and $50. Still, this was a relatively inexpensive project, and if I hadn't been comfortable with the time and monetary investments, I wouldn't have chased it in the first place. If you take my experience in counsel and preserve your own diode because if it, so much the better.

These blue lasers are really, strikingly bright. I feel constrained to warn again that eye safety precautions are a must. Eric and I were careful never to power the laser unexpectedly, and to always indicate to one another where it would be pointed. When even the reflection of the dot on the wall seemed unreasonable to look at, we didn't. We could have been more careful by wearing laser-specific eye protection, and perhaps we should have, but we didn't want to spend more money on goggles that we might never use again. It probably goes without saying; if you build one of these, keep it away from kids and others with poor impulse control.

Eric and I missed out on a big opportunity to make this thing cooler than we had at first imagined. A few days after our Blu-Ray laser project was complete, I was cruising Ebay to see what kinds of blue laser items were available there. I found a seller who apparently orders in PS3 Laser Lens Assemblies, extracts the diode, and then sells the diodes on Ebay as his own product. The photo in his auction exactly matched the appearance of my diodes still in their metal mounts from the PS3 lens assembly, and I was curious. When I emailed him asking if it was a diode from a PS3 Laser Lens Assembly, I must have hit a nerve, because he never answered. I did find his website through his auction page though, and here it is, Indigo Lasers (Defunct Link removed. -Ed).

I'm not linking to Indigo Lasers to shame him in any way. I think that it's great to see the entrepreneurial spirit in action, though he could be a little more forthcoming about his parts sourcing. I'm linking because he's created some interesting technical schematics of the laser diodes. This page in particular (also dead link -Ed) piqued my interest, because it shows the pin outs for all of the lasers in that part; Blue, Red, and Infra-Red!

Had Eric and I realized that our diode was capable of emitting three laser colors, we surely would have incorporated more than one into our circuit, and given at least the red one a switch. As it stands, we can go back and rework it, but it may be wisest to leave this one as is and start a new one for a more integrated laser experience. We can make a better go of it the second time, and then we'll have two!

I would like to post a snippet of Indigo Laser's pin out map, and doing so would surely be within fair use guidelines, but the fellow running that site seems secretive enough and already worried about his documents being stolen. (He's overlaid a clear photo over the real one on the site to discourage people taking a copy. Didn't stop me, shouldn't stop you.)

Instead of posting part of his schematic and sending him into Red Alert mode, I'll simply describe the pin out here. Lay the diode on a flat surface in front of you, with the diode's pins facing you. The perimeter of the diode is round, but it has a flat edge. Roll it so that the diode's flat edge meets the flat surface and lays still. Now you're looking at the five pins like a pentagram, with one in the middle at the top. Number the pins 1-5, starting with the bottom left corner and moving around the pins clockwise.

Pin 1: (Bottom Left-Hand corner) - Infra-Red Laser +
Pin 2: (Left and Center) - Blue Laser +
Pin 3: (Top Center) - GROUND -
Pin 4: (Right and Center) - Red Laser +
Pin 5: (Bottom Right-Hand corner) - Photo diode (used for power regulation when connected)

Final Thoughts:

This was a really fun project. I've known Eric for something like fifteen years now, and I was actually glad that I wouldn't be able to get it done on my own. When we finished the project, we took our wives to a nice dinner. We've both got great wives. (Hi honey!)

Speaking of wives, Crystal was reading through one of my drafts of this write up, and she said that it seemed that not many people would be able to pull this project off. I really have to disagree with her there.

For one thing, Eric and I really made it harder than it had to be, both by designing our own circuit, and also by letting things get out of hand with our first diode. Sam's Laser FAQ is the definitive online resource for all things laser related, and Sam's even got pre-designed circuits you can build straight from given specs there. (There's also a special section at Sam's that's all about Blu-Ray diodes that I seem to have missed when I was researching. Or maybe it's new?) And as for the power snafu, Eric and I really knew better. We even joked while we were doing it that it wouldn't be a surprise if we fried the diode. Sure enough, we did.

If you're thinking about building your own blue laser pointer, I would suggest the following:
  • Know how to solder. This isn't a hard project where soldering is concerned, but you should at least know how first.
  • Don't worry about making yours look like mine, or anyone else's. Focus on the parts and objects around you that could be a case, or a switch, or whatever.
  • Find a friend who's interested and have fun with it. Hopefully, your friend will be able to help out when your skills aren't quite where they could be.
  • Take your time. No need to get sloppy and ruin your hardware.
  • Follow the tips above about not burning out your diode.
  • Don't forget that your safety is paramount. Don't be careless.
Last of all, have fun with this great project.

Thursday, February 20, 2014

Violet Blue Laser Pointer Build Part 3

Violet Blue Laser Pointer Build Part 3


Tragedy Strikes:

We left work on the case for a while to experiment with more power settings for the laser diode.

Rather than stringing you along for a cliffhanger payoff, I'm going to tell you now; we killed our first blue laser diode. The poor thing never had a chance.

Here's what happened. We had already found our lasing range, but we wanted to get the laser really pumping out the light. In the Laser Phaser video, he's got the blue beam clearly visible in the air, in a lit room. When we first got our unit to lase, it put a dot on the wall, but the beam was not visible, even in the dark. So we began ramping the power to see where the sweet spot would be.

We did this experimentation with only the light of my work desk lamp, so that changes in beam visibility would be obvious in the dim room. As we decreased the resistance in the circuit, we found that the laser had a stepping tendency; its output would make sudden, marked increases at what seemed to be consistent power thresholds. Simply tuning the potentiometer up and down made no visible difference, unless the tuning crossed a power threshold, at which the laser's output would suddenly jump, even when we accounted for the logarithmic curve of the potentiometer's range (which made the potentiometer truly effective only in the top 1/5 of its range).

The laser's stepping behavior fascinated us, and it made us eager to see what higher and higher steps would yield. Soon we were seeing not only the beam in the air, but a more and more pronounced beam, and a blue/violet dot on the wall that was so bright that we dared not look at it. These were impressive results, but like Icarus, we didn't know our limits and ended up getting our wings burnt off.

We had become accustomed to being able to predict the step ranges. In our setup, each step seemed to cover 40 Ohms of resistance or so. But now the laser's apparent brightness wasn't changing at the predicted stepping levels. Very soon we found that it wasn't lasing at its former brightness even at higher power settings than previous, and it became obvious that it was damaged. It still lit, but it did little to nothing at our former normal power levels, and it needed more and more power just to keep it lasing within one range of brightness.

During this session, the diode can became notably warm. This is testimony to the fact that even if we had kept it in a reasonable power range, we should have had better thermal management in place. It's possible that if we had done so, that first diode would be happily lasing away today.

Far more quickly than we had expected possible, we had reduced a fine blue laser diode to a very lovely and expensive violet LED. Here are my two tips for not killing your Blu-Ray laser diode. They're very simple, but surprisingly easy to violate:
  1. Mount your diode properly in a metal chassis that will sink heat away from it. Blue lasers are new tech, and they're still quite sensitive. Red, IR, and Green lasers I've worked with have seemed far less delicate to me where thermal dissipation is concerned.
  2. Find a power setting that causes your diode to lase at an acceptable level and use that setting. Ramping the power ever upward to see just how bright a beam you can get is fun, but ends with a dead laser.
That's it. Give your laser an elegant, efficient way to manage (waste) heat, and don't overfeed it.

Eric and I called it a night, and the next day I ordered another PS3 Laser Lens Assembly.

Project Execution, Take 2:

Two weeks later the second PS3 laser assembly arrived, again from Monaco. (What on earth are they doing in Monaco in the first place? Wouldn't China or Taiwan or Hong Kong or Los Angeles make a lot more sense?)

Once I had the new laser diode extracted from its lens assembly, I was determined to seat it correctly in the collimator housing. This is difficult to do, as A.) the diode can is made of thin, crush-able metal, B.) the diode pins are on the side that needs to be pressed from, C.) the back end of the diode has precious little surface area to press on, let alone avoiding the pins, and D.) the whole thing is small, fiddly, and difficult to tool up for properly without purpose-built equipment.

I ended up putting the collimator collar very gingerly (didn't want to crush it) into the desk vise, and using the tips of needle nosed pliers to press down on the disc of the rear end of the diode. I was very relieved when it popped into place.

I figured that soldering the interface ring between the diode housing and collimator would improve heat dissipation through the collimator so much the better, and I realized just in time that the diode's ground pin is in fact grounded to its housing can, so I went ahead and soldered the ground wire along with the ring of solder at the same time. This way, I'd have to only solder one of the delicate little pins on the diode itself.

I now had the two benefits with the new diode that I had forgone with the former; the diode was fully seated and soldered in for improved heat dissipation, and it was properly aligned with the lens in the collimator to maximize light use.

Now that we were truly up and running again, Eric got back to work on the power circuit. After the debacle of losing our first laser diode to carelessness, we decided that overkill for the sake of safety in the power circuit was warranted. Eric's new power supply would be transistor regulated.

There was more work to be done on the case. I still hadn't installed the hard power switch (SPST) yet, and I still needed to template, cut, deburr, and drill holes for the screws in the case. The process is fairly straightforward, so I'm not going to burden this post with too many more photos.

Power Details:

The idea all along had been to install a potentiometer in the case so that the laser's intensity could be tuned up and down. The added benefit to this idea is that when a fresh battery is installed, or the battery is getting weak, the potentiometer can make up the difference in either direction, leaving the laser operating in its 'normal' power range.

An issue we had encountered before burning out our first laser diode and up to this point, is the logarithmic curve exhibited by potentiometers in this kind of circuit. We would install a potentiometer of the proper value and give it power, and we'd only get any real ranging from tuning the potentiometer in the top or bottom 20% of its range. For all the knob turning and sudden effects, it might as well have been a switch.

In addition to that issue, I had a depressingly meager supply of potentiometers on hand. None of these had any obvious and easy method to mount them to the case. One had evenly spaced through-hole pins that we could mount on a circuit board and then attempt to line the board up with a purpose-made hole in the case, but the whole thing just felt too shaky.

After a couple of early iterations of Eric's regulated power circuit, we decided to build in a resistor network instead. A switched resistor network would allow us to put resistors of known value in each of the slots from low to high, and then the resistance could be tuned up and down coarsely and finely, depending on which parts of the network were switched on or off. A five station dip switch block I harvested from an old motherboard would do the trick nicely. (Dip switch number five, colored red in the photo below, is one of the device's three power switches.)

As I said before, I'm not all that strong in electronic theory, so here's Eric's simplified explanation of the power supply we ended up building:
The critical parameter in a driver circuit for an LED is the current. Most circuits provide a voltage, which is not desirable in this case. Therefore, we investigated current mirroring circuits using paired transistors. 
One promising avenue was a Widlar current mirror, which would scale the reference current to provide the load current. It is desirable in this case to have the load current be a multiple (possibly a large multiple) of the reference current since that would reduce the total power consumed in the circuit while allowing us to have a wide, linear dynamic range on a voltage divider that used a 20k potentiometer. 
Unfortunately, the Widlar circuit didn't perform properly and proved to be unusable. 
We ended up with a very straightforward current mirroring circuit. The circuit still passed more current through the diode than through the reference load, but the difference was smaller and more predictable than with the Widlar mirror. 
One problem with the circuit was that the load current would slowly ramp up as the diode (or the transistors?) would heat up. We didn't investigate that effect in any detail. 
The final circuit consisted of matched NPN transistors with their bases connected together and emitters tied to ground. On the reference side, there was a 560 ohm resistor between the positive terminal of a 9V battery and the base and collector of one transistor. Four other resistors, valued 470, 1k, 2.2k, and 4.7k ohms were in parallel with switches so that each one could be added parallel with the reference resistor. This allowed for a linearly variable equivalent resistance from 180 to 560 ohms. 
The diode was in series with a 47 ohm resistor between the positive battery terminal and the collector of the second transistor. 
There is nothing magical about any of these values. They were arrived at experimentally, except for the parallel network resistances which follow a geometric sequence in order to allow the equivalent resistance to vary linearly. 
At least the current mirror circuit helped us reduce the likelihood of burning out the diode.
Thanks Eric!

Next came the soldering, which would be my job. I foolishly didn't have any flux on hand at the time, making the job much more difficult than it had to be.

An issue I had with the soldering was that after we laid all the components on the board, I had to find a way to turn the board upside-down for soldering without all the components falling out. For this, I simply wadded up a face tissue and taped it to the top side of the components. The fluffy nature of the tissue pressed against the components kept them all pressed into place, despite their differing sizes and positions.

Eric created a spreadsheet with a diagram of which wires connected where, and connection by connection, I got the soldering done. When we tested the circuit after soldering, it didn't work at all. Eric carefully checked my work, and found that I had missed one of the ground connections. A quick revisit to the underside of the board with the iron had everything up and running.

Testing confirmed that our wiring was right and our resistor network was functional as designed. I then used the Dremel to cut the circuit board in half, leaving the other half for future projects and saving space in the case of the current one.

We didn't want vibrations wearing on the four soldered wires leading to the board (two for power in from battery, two for power out to diode), so I hot glued everything down. I also glued over all of the exposed solder connections on the bottom of the board so that they'd be well insulated from the surrounding metal case.

Once we had everything wired up and tested, I soldered all of the twisted wire connections and taped them for electrical insulation.

Next was the fun process of hot gluing everything in place, except for the laser collimator and the battery. They both should be movable.

This was also a good time for final tuning of the collimator lens, which simply has threads on the outside of its plastic housing that match threads on the inside of the collimator collar and a spring between them to keep it all under tension.

Finally, I cut up the foam blocks that came in the pen case and hot glued them into positions to hold the battery and collimator in place in the case. This keeps everything quiet and sturdy, but allows for removal and tweaking of each.

Conclusion and Wrap-up will be posted tomorrow!

Wednesday, February 19, 2014

Violet Blue Laser Pointer Build Part 2

Violet Blue Laser Pointer Build Part 2


Oh, one more thing:

Your visual safety is the most important factor to consider when undertaking a project of this kind. Please be cautious around lasers, and never allow a laser beam the remotest possibility of passing near or into an eye. I strongly recommend reading the "Laser Safety" portion of Sam's Laser FAQ. Also, parts of this project involved cutting and grinding metal, both of which create flying metal shards. Eye protection when operating cutting and griding equipment is an absolute imperative. 

Further, the post, posts, documents, text, photos, and any other media that are part of this series documents only my own project, and should not be regarded as advice to you. You undertake any project completely at your own risk. 

That said, here we go.


Project Execution, Take 1:

The PS3 Laser Lens assembly shipped from Monaco, of all places. It took far longer to arrive than I had anticipated, and the company I ordered it from was unresponsive to my requests for updates. I was literally one day from filing a charge back on it with my credit card company when it arrived.

The nondescript white box had me a little nervous at first. How could I know that I actually had a Blu-Ray component here? I would just have to carry on and find out when I power it up. But I couldn't power it up until I had it disassembled.

The lens assembly cover came off easily, and it was neat to see all of the laser lenses arrayed inside. Some of them were mounted on coils that could be moved around with small magnetic braces around them (coincidentally, this is also how the armature in your hard drive moves the read/write heads around on the platters).

The laser diode can be seen on the far left side of this photo, sitting horizontally with its soldered metal brace being the two metal points at the far left of the assembly. The laser is aimed through an initial lens block, and then through a splitter block, where the beam is apparently divided, perhaps by wavelength frequency (beam color).

The sheer number of lenses in this assembly impressed me. I've harvested laser diodes from CD burners and DVD drives, and they usually have very simple lensing compared to this. I suspect that blue lasers being a relatively new technology, the diodes aren't yet advanced enough to give quite the right beam properties straight from the component, and the beam needs a lot of work before it's ready for use in reading media. Thus, the extensive lensing.

It seemed to me that all of those cool lenses might be useful at some point, so when I got the diode free of the assembly chassis, I set the rest aside for more work at some future date.

This is a shot of the laser in its chassis, removed from the main lens assembly. The through hole ribbon cable connector was removed by locking a corner of the diode chassis into the desk vise, and then using copper solder wick to remove the solder and get the pins free so that the connector could slide off of them.

Below is a simple current limiting circuit we built to test things out with. We decided to start with high values of resistance and slowly ramp down to find where the diode would begin to light, and then lase. Once we had our ballpark, we would put a potentiometer on the circuit to help with fine tuning.

This was an early test circuit. I don't know resistor color bars on sight, but it doesn't really matter, because this one got the laser diode to glow like a dim LED, but it was nowhere near lasing. At any rate, it's good to see some of the breadboarding and testing process. You can add up the resistor values for yourself if you like.

This next photo is important to me, because it illustrates our first big mistake. What you'll see here is the laser diode, now removed from its metal housing, and put into the collimator sleeve (also metal, but thick and round). The original red laser was press-fit into the collimator sleeve. It was so snug in the sleeve that pressing it back out damaged the red laser diode can. I was loathe to damage the blue laser diode can by trying to fully press it into the sleeve, so instead I got it in as snug and straight as I could with my thumbnail and then hot glued it down.

Failing to press-fit the diode into the collimator sleeve was a mistake because the diode is intended to use the surrounding metal housing to sink heat away from itself. Without this precious thermal management, the diode is likely to fail even under normal operating power.

Further, the groove in which the diode is seated when it is press-fit is designed to align the diode can so that the beam travels into the collimator lens at as close to the ideal 90 degrees as possible. Simply placing it on the groove, or only pressing it in partway leaves the diode can both misaligned and physically further from the collimator lens than intended, leading to inefficient use of the light source and making beam tuning as intended impossible.

Our first powered tests produced only a dim LED glow from the diode, but as we ramped up power by decreasing resistance in our test circuit, we quickly brought the diode from a dim glow, to a bright glow, to dim lasing, to bright lasing.

We were so excited to see lasing that we turned off the lights in the room and took photos of the blue laser on a wall, but it's a classic "you had to be there" moment; the photos themselves are unspectacular. I won't post photos of a black background with a bright blue dot here for the sake of your sanity.

By this point, Eric had a good idea of the power range needed for the driver circuit, and he grew quiet as he thought about different design options. I left him to it and began work on the case for the laser.

So it's a black metal pen case. I pulled out the foam inserts and stared at it for a while to try to conceptualize the best way of mounting the laser guts inside. Once I felt I had an idea, I took the parts I had at hand and put them into the case to see if they'd fit as visualized. I didn't have a power circuit yet, so I arranged everything, leaving a big gap in the middle and asked Eric if he could commit to his circuit fitting there. He felt that the space provided would be ample, so I got to work on the cutting and drilling that the case would require.

You can see the dot I made on the case with a silver sharpie. To determine the right location for the hole, I simply popped in the collimator and lined it up with the natural front curve of the case. Where the lens ended up is where I needed my hole. I started the hole with a 1/16" drill bit, and then used an Irwin Unibit to step the hole up to 5/16" or so. I then used a Dremel grinding stone to deburr the hole.

Ergonomics are a factor with a laser pointer, so the momentary switch was next. Toward the front of the unit, next to the laser aperture seemed to make sense, so I made an outline for cutting to place the switch. The switch handily came with a collar (which, in a rare moment of brilliance, I had been smart enough to save), so all I needed to install it was the right sized square hole.

I traced the smaller, inner collar size onto the outside of the case with the sharpie and used that as my cutting template. I didn't worry too much about keeping it neat, as the larger, upper collar would cover any small sharpie fudges I made.

Dremel Note 1: Here I'll note that if you don't have a Dremel in your shop, you should really prioritize getting a good one for regular use.

My first "rotary tool" was a Black & Decker Dremel knock off, which I thought would be a good investment rather than a real Dremel because it took a VersaPak battery, along with several other tools I had at the time. Boy, did Black & Decker teach me a lesson. Dust Buster, yes. All other tools, no. They were right to kill off the VersaPak line, but it's too bad that I was suckered into buying any of that garbage in the first place.

Lesson learned. I buy quality tools now. My drills (well, one is an electric screwdriver) are DeWalts, and my Dremels are really Dremels.

Dremel Note 2: If you plan to do any kind of material cutting with Dremel's pressed sand cutting discs, make sure you keep a lot of the discs on hand. They shatter before they flex, and the shattering is just as soon induced by looking at them funny while in use as smashing them with a hammer. This makes eye protection doubly important, as cutting wheel chunks are relatively large, sharp and heavy, and the rotational speed launching them yields incredible velocity in flight. Goggles stop them easily enough, but you don't want your corneas doing that job for sure.

Part 3 Tomorrow!

Tuesday, February 18, 2014

Violet Blue Laser Pointer Build Part 1

(Editor's Note: This appeared on an Entrepreneurship Website that I used to own. It's been at least six years since Eric and I built this (it was posted in 2008), and we remain in touch, and this remains a treasured experience. Since the old entrepreneurship blog no longer exists, I'm posting this technical and fun, but very very long build log here at Phischkneght Extended. Probably with some very light editing. Also, since this post is huge, I'll post it here as three or four parts. Hopefully there are more to come. Cheers. Feb. 2014)

The end of the Blu-Ray/HD-DVD format war (Blu-Ray won, if you haven't been following along) signals the beginning of two changes:
  1. For a very limited time, HD-DVD players will be available at prices far below commodity value. Dead, unsupported tech never fares well in the mass marketplace.
  2. Over the long term, Blu-Ray hardware will follow the natural downward price curve that all consumer commodity tech shows over its life.



When Crystal and I got married in 1999, she wouldn't let me add a DVD player to our gift registry because she couldn't imagine anyone buying us a $500 video player. Today if you watch retail spaces carefully, you can buy a cheap DVD player for $20 or so. It seems extraordinary, but for a tech item, it's a perfectly typical curve. (For a much more radical example, compare 1999's 500MB hard drive for $150 to today's (2008)1TB hard drive for $200. That's 2,000 times the storage space for $50 more, less than ten years later.)
The practical upshot of the two points above is that from here on out, blue lasers are increasingly in the realm of economical hacking projects.

Practicality/Conception:


I make it my general policy not to get involved in the annual Black Friday madness. Once in a while I make an exception, like when I managed to buy The Orange Box at Best Buy for $25 last year (the cake is a lie, Mr. Freeman). 2007's pre-Black Friday hoopla included a press release from Wal-Mart that they'd be offering limited stock of a certain model of HD-DVD player for under $100. I was itching for a project at the time, and my green laser seemed to be getting a bit long in the tooth, so I decided to look into creating a blue laser pointer with an HD-DVD laser diode

The response of my fellow Mefites to the laser question was mediocre, but it did yield a link to this video, which, strangely enough, had been posted the same day I asked my question. It's a very cheesy video, and the creator of the laser pointer in it shows gross disregard for both his own safety and for the health of his laser diode. But the video did serve as an extremely useful idea seeder:

    1. It confirmed to me that a blue laser diode could be harvested and used in a project.
    2. It showed that the diode could be driven by a nine volt battery.
    3. It showed that at its core, the project could involve a very simple power circuit (though the nice tuning regulated circuit we ended up with is much more complex).
    4. It illustrated a source for the laser diode component that I had not (but should have) thought of.
    5. It provided a pin out for the blue laser portion of the laser diode.
    6. I was worried about beam collimation, and this video answered that concern very nicely, with a collimator hacked off of a separately purchased red laser.
    I've criticized the video more than once now, and I should explain why:
    1. The phaser casing isn't as portable as I wanted my final product to be. Oh, and it's tacky. I like Star Trek, but that's just not slick enough for me. 
    2. The video talks about extracting the diode from the laser lens assembly, but does not illustrate how this was done. I found that it's not terribly difficult, but it is a rather delicate process at the point where the diode needs to be extracted from its own little mounting chassis.
    3. The video didn't provide the pin out for the non-blue laser contacts on the diode (more on this later).
    4. The video does not show how the laser diode is secured to the front portion of the collimator assembly. From the video, it looks as if it was done with hot glue, which would negate much of the heat sinking abilities of the collimator assembly, leading to the diode overheating and burning out.
    5. The guy in the video uses one resistor in serial with the nine volt battery to the diode, never mentioning the value of the resistor or why he used that value.
    6. Getting the collimator off of the sacrificial red laser was non-trivial, and it nearly ruined the red laser diode. Not such a big deal, but a mention would have been nice.
    7. The video dialog did not point out that the laser was likely running in the top of its power range, meaning that it would be very sensitive to overheating even with proper heat sinking. My guess is that if his "laser phaser" has had much use at all, the laser diode is in the late stages of progressively burning out by now.
    8. He makes no mention of eye safety where lasers are involved.

    As mentioned in the above list, I realized that buying an entire HD-DVD box would be entirely unnecessary for sourcing a blue laser diode. Those active in the game console modding scene know that parts can be sourced for replacement for just about any current gaming system, including the PlayStation 3 (which of course, uses a Blu-Ray laser as its primary media reader). It seemed like such a no brainer, and I should have thought of it on my own. After heading on over to a couple of my favorite online console parts dealers, I found the PS3 laser lens assembly that I would end up buying.

    Now that I knew that I could source the critical blue laser diode component, I began to get excited. I'd been seeing Sonar Blu-Ray pointers, walkthroughs on building your own (non-blue) laser pointers (Used to have a ref link to Magus Lasers here, but the site is dead and Google offers no replacement -Ed Feb2014), the ThinkGeek blue laser pointers, and even Wicked Lasers, (where, even today at this writing, you can buy the above Sonar Blu-Ray pointer for a ridiculous $2,000) for months by this time.

    Now it was starting to look like my turn.

    But first, I needed to make sure that I could pull off this project. Crystal was unlikely to let me spend $50-$70 on a blue laser diode if the odds weren't good that I could get the project off the ground.

    Late Conceptualization, Preparation:

    I'm mostly a real-world, practical use guy. My electronics theory skills are weak, so my first call was to my good friend, Eric Widdison. Eric walked away from Utah State University a few years back with a Master's degree in Electrical Engineering. Eric isn't that good at basic math, and he can't solder worth a darn, but I knew that he would be my go-to guy for this project. (I should mention here that Eric is a terrific sport, and his advanced math skills are superlative.)

    My main concern for this project at this point was creating the driver circuit to power the laser diode. I knew that this part of the project would be critical to overall success. A bad driver circuit would fail to bring the diode to lasing state, burn it out quickly or slowly, or perhaps a combination of those. I explained the project and the need for help with the power circuit to Eric, he said that he felt confident that he could help me make it work.

    With Eric on board, I ordered the PS3 laser lens assembly and the red laser mentioned in the Laser Phaser video for the collimator. I also spent a week or so thinking about the various components I had on hand and gathering up the ones I felt might be useful to the project.


    Late Preparation, Early Execution:


    Eric and I worked out a good night for him to come over and start the project with me, and on a chilly Tuesday night, we found ourselves at my work bench with all kinds of fun hardware at hand and no idea where to start.

    We quickly decided to pick what our case would be. I had gathered several containers for the purpose, including Altoid tins, some other plastic mint cases, and a pill bottle or two. Most of the potential cases that I had chosen were determined to be too small for this project and had to be eliminated from the running.

    We settled on a metal case with a foam insert...much like a fancy pen would arrive in. In fact, it's the case my green pen laser came in when I ordered it years ago. The case was a little larger than we felt ideal, but better too big than too small in this instance.

    It was good that we settled on our case early, because we needed to begin thinking about component quantity, size, and placement right away. These were our main component criteria:
    • A laser pointer should have a momentary switch. Easy to turn on, but the default state is off.
    • It should also have a hard master switch that will ensure the laser is never accidentally powered on.
    • It would be nice to have the option of tuning output power, possibly via a potentiometer.
    • The power circuit we would build would have to fit inside the case.
    • The battery would have to fit inside the case.
    • The laser collimator housing (with the laser diode inside) would have to fit inside the case.
    With those criteria in mind, we picked through my parts collection and found a momentary switch I harvested from the packaging that a dinosaur toy came in for my son a couple of Christmases ago, an SPST (Single Pole, Single Throw) switch from an ATX power supply, a nine volt battery with a power connector, and the collimator I had already purchased for this project.

    With everything else assembled, I got out the PS3 laser lens assembly box, which had arrived that day, and prepared to begin work on it.

    (Part Two will be posted tomorrow!)

    Monday, August 07, 2006

    High Occupancy Post

    About 5 years ago (just before the Olympics came to town), a massive I-15 construction project was completed that added new traffic lanes and especially a new carpool lane (more correctly known as the High Occupancy Vehicle or HOV lane). At the time, this was a major boon for travelers during rush hour who had more than one person in their vehicles, except when going southbound at around 10600 south (where the HOV lane ended and the merge was a real headache). This was improved recently with the extension of the HOV lane well into Utah County (I don’t know if the merge is still a problem that has just been transplanted to Orem because the lanes are so new, I avoid driving south during rush hour, and I don’t really care what happens in Utah County anyway).

    The new policy allows drivers to purchase an express lane pass for $50 a month that will allow them to travel in the HOV lane (now redubbed the HOV/Toll lane) without any passengers in their car. At the same time, the lane is being repainted so that drivers are not allowed in or out of the lane except in certain areas (15 or so areas are to be included along the 38 miles of express lane, each at least a half mile long).

    Naturally, this has enraged many people. They see the tolls as an elitist policy that some suggest will make less people use the HOV lane (which does defeat the purpose of the lane (which is to alleviate traffic congestion in general and encourage carpooling), but makes the lane better for those who continue to use it, so I’m not sure if they really understand their point). Many people complain about the entrance/exit rules, calling them ridiculous and difficult to use. Some of these people are just whining about change, and some have some good points to make. Without explicitly addressing anyone else’s arguments or complaints, I give my take on the situation.

    First, allowing drivers to use the lane in exchange for paying a fee is a bad idea. I understand that the number of these passes will be limited, and they have to be renewed on a monthly basis, but this will increase congestion in the carpool lane during peak traffic times, reducing the benefit from using it. This reduces the benefit for carpoolers, making driving alone a more attractive option. Of all of the complaints that I hear about Utah drivers, the only one that I feel is truly justified is that we love having our own cars and are unwilling to take measures to reduce traffic congestion (e.g. carpooling or taking public transportation, the latter of which I feel is somewhat justified by the lack of effective public transit, which is in turn driven by the unwillingness to use it, etc.). Having a carpool lane was a good step towards encouraging us to think, if not green then at least cooperatively, about improving the Utah traffic situation, and allowing people to buy the same benefit without going through the trouble of taking on another rider undermines the system.

    Second, the entrance and exit restrictions seem to be the most unpopular part of the new policy. In reality, it is an entirely different issue that is being introduced at the same time. Controlled access to carpool lanes is the standard policy in most places. This improves the flow of traffic in that lane because the cars don’t have to deal with merging except in specific, controlled areas. This will ultimately make the lane work better and it will make apprehending violators easier (if a vehicle is illegally in the HOV lane and sees a cop coming up, they can’t get out without facing a fine for illegal lane change and HOV violation).

    The biggest problem with the controlled access at this point is that drivers don’t know where to get into our out of this lane. It would be good to introduce some signage to say what exits need to be accessed from each egress point so that drivers can plan ahead without first memorizing the entire freeway structure (a feat that many commuters can probably manage, but few others). If amazing feats of memory are required to effectively use the lane, then it will hurt the lane’s effectiveness (at giving incentive for carpooling), especially for visitors to the region.

    It is worth noting that freeway driving during rush hour is a completely different experience than driving during other times. The purpose of an HOV lane is to improve traffic flow (at least for HOV drivers) during peak times. The new access restrictions will benefit this purpose, while allowing people to buy access to the lane will not. Since I am able to (and generally do) avoid driving the freeway during rush hour, I am far more interested in the likely effect that the new policies will have on driving during off-peak hours. I anticipate that the express lane passes will have minimal impact on traffic flow outside of rush hour. The lane access restrictions will make the HOV lane less attractive during those times, since the inevitable slow drivers in that lane will effectively slow you down for miles at a time instead of just until a gap opens up in the left hand traffic lane. I drove along the stretches of I-15 with a carpool lane many times as a single driver during light to moderate traffic and typically found that I could make at least as good of time in the other lanes as in the carpool lane. The only disadvantage was that I often had to change speed (although I didn’t have cruise control at the time, so it didn’t matter then). Since slow traffic in the HOV lane make it difficult to just get over there and hit cruise, this isn’t much of a loss.

    I think it is worth noting that I have been working from several assumptions. I assume that people will choose the lane that they have permission to use that they anticipate will give them the best progress (this is basic economic theory, in that people will likely choose whatever will give them the most gain, although this actually breaks down often in traffic when people merge early into stopped lanes, but that’s another issue). I also assume that most users of the leftward lanes (including the HOV lane) will wish to go faster than the median traffic speed. At the same time, some people who are still traumatized by having unmarried parents will choose to travel in the HOV lane while going much slower than the surrounding traffic. While it is undeniable that they killed Kenny and that the road would be much better without them, they must be recognized just like a force of nature with regards to traffic flow.

    I suppose that I could go into the morality of and possible justifications for introducing traffic policies as a way of increasing revenue. I don’t think that this express pass system will, by itself, raise enough money to consider it a fiscally good decision. The $100 fines for improper lane changes to and from the HOV lane has the potential to raise more money. (This raises the issue of using traffic violations as a source of revenue. I’m sure that the Fruit Heights City Council and I would likely find area to disagree on that one.)

    I anticipate that restricting (physical) access to the HOV lane will be generally beneficial, especially if they can introduce some appropriate signage for it, and will typically be at worst a mild inconvenience. On the other hand, granting paid privileges to access that lane is unlikely to improve the overall traffic system in the long run, even if it does help alleviate congestion in the other lanes without adding undue congestion to the HOV lane.

    Friday, March 31, 2006

    HAPPY BIRTHDAY!

    Today, Phischkneght is two years old, thanks to my good friend Eric.

    I'm happy to report that a silly word I made up in high school has become a weblog, a bit of a technical community, a second, sister weblog for longer stuff, and now...an LLC.

    The new technical company I founded back in January was and is called Phischkneght Works And Services, LLC.

    Now for the good news: Phischkneght is profitable, has clients, has checks coming in, and has what looks to be a bright future. May I humbly wish the same for all Phischkneght participants.

    Saturday, February 25, 2006

    Wikipedia Doesn't Know What A Roof Is

    And I don't really understand it myself. But Eric does.

    I've been watching MIT's Professor Lewin's Physics lecture videos. He's one of the better math instructors I've ever seen, and I'm really enjoying the videos. The funny thing is, Prof. Lewin is a really funny guy, but his students never, never laugh. Ever. So I'm glad I'm not in that class.

    Anyway, MIT is offering the videos to anyone who wants them, anywhere in the world, for free. The problem is, they want you to stream the videos. In Real format. **BARF**

    MIT's pages for these Physics lectures are the following three links, one for each semester:

    Semester 1
    Semester 2
    Semester 3

    Fortunately, MIT themselves provide a way for you to download the videos rather than stream them. The solution, given here, is to change the link to the video from one of Akamai's servers, to one of MIT's servers. There are about 100 video files, so harvesting the links and altering them one at a time is a pretty awful process.

    So, I've done the work, and I don't see any reason that you should have to also. I'm posting the links to the direct downloads on PhischX, if you want them. Again, it's about 100 videos covering three semesters of Physics lectures, and if you download all of them, you'll need about 9.5GB of free space on your hard drive. And a really fast connection to the internet, or several days to waste waiting for downloads.

    So, here are the links:

    Semester 1, Course 880.1

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec1-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec2-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec3-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec4-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec5-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec6-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec7-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec8-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec9-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec10-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec11-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec12-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec13-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec14-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec15-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec16-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec17-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec18-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec19-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec20-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec21-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec22-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec23-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec24-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec25-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec26-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec27-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec28-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec29-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec30-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec31-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec32-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec33-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec34-300k.rm

    http://ocw.mit.edu/ans7870/8/8.01/f99/videolectures/wl99lec35-300k.rm

    Semester 2, Course 880.2

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec1-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec2-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec3-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec4-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec5-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec6-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec7-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec8-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec9-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec10-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec11-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec12-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec13-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec14-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec15-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec16-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec17-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec18-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec19-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec20-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec21-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec22-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec23-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec24-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec25-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec26-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec27-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec28-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec29-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec30-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec31-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec32-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec33-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec34-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec35-220k.rm

    http://ocw.mit.edu/ans7870/8/8.02/videolectures/wl-802-lec36-220k.rm

    Semester 3, Course 880.3

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-09sep2004-0001-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-14sep2004-0002-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-16sep2004-0003-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-21sep2004-0004-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-23sep2004-0005-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-28sep2004-0006-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-30sep2004-0007-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-05oct2004-0008-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-07oct2004-0009-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-12oct2004-0010-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-19oct2004-0011-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-21oct2004-0012-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-26oct2004-0013-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-28oct2004-0014-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-02nov2004-0015-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-04nov2004-0016-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-09nov2004-0017-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-16nov2004-0018-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-18nov2004-0019-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-23nov2004-0020-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-25nov2004-0021-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-01dec2004-0022-220k.rm

    http://ocw.mit.edu/ans7870/8/8.03/f04/video/ocw-8.03-lec-mit-03dec2004-0023-220k.rm

    Sunday, October 02, 2005

    Northern Utah Transportation Problems, or The Davis County Blind Spot

    Today, I passed a stretch of road where the I-15 carpool lane is being extended further into Utah County. It is planned to reach University Parkway in Orem. I think that this is a good thing, since there is a lot of traffic along that route, including a great deal of commuting. At the same time, I noticed that the current carpool lane stretches from exactly downtown Salt Lake through the south end of the valley. It is as though nobody commutes to or from the north.

    This is merely a symptom of a larger blindness that many people have to Davis County. For years, I would hear detailed traffic reports all the way to Provo whether or not anything was happening, but anything short of freeway closure in Davis County failed to register in the traffic reports (they’ve improved since then, by the way). People who work in Salt Lake City won’t bat an eye about living in Cedar Hills or Saratoga Springs (both areas of rapid housing development in the nearly inaccessible east and west sides respectively of the north end of Utah County), but won’t even consider places like Clinton and Syracuse that are much more accessible and much closer to Downtown SLC.

    The blindness extends to public works policy makers. That is why the highway system and public transit both favor southbound traffic, and tend to ignore or actively prevent development of the lands to the north. This is manifest in two areas: the Legacy Highway and express bus routes.

    The Legacy Highway is a planned north-south expressway that is supposed to run parallel to I-15 from Salt Lake City to Farmington and eventually to Ogden. This is critical because I-15 is the only major thoroughfare between Salt Lake and Ogden. If something happens to I-15, there are surface streets that could be taken, but none of them can come close to carrying the traffic load that I-15 carries. Northbound traffic from SLC would be effectively cut off. The Legacy route has been planned for some time, but development has been held back for two reasons, both environmental.

    The first is that the route will pass through the marshes of the Great Salt Lake. This is undeniably true, and does present a real concern for the highway. In fact, during some wet periods (such as the early to mid eighties), the lake has expanded nearly to I-15 in some places, and parts of the Legacy route would certainly be in the lake. The Farmington Bay Bird Refuge is an important breeding ground for many bird species.

    I reject this as a valid reason to block the Legacy Highway for two reasons. The first is that there is a lot of similar areas along the lake that could be used instead, such as in the Willard Bay area. The second is that the Legacy Highway would not likely significantly increase pollution in these wetland areas. Currently, all the traffic that would drive the Legacy Highway travels in I-15, just a few miles to the east. The prevailing winds along the route blow from the east, so any air pollution from traffic is already being blown into the wetland regions near where Legacy would run.

    The second, and in many ways related argument against the Legacy Highway is that it will encourage urban sprawl. This relates to people building homes and business in the wetlands (which, due to lake level fluctuations would be a bad idea anyway), as well as to concerns about development swallowing up all the land everywhere. Urban sprawl, in the second sense, can be a huge issue in many places because there are no constraints to keep the development from continuing indefinitely. For example, Phoenix has spread to cover a huge area almost uniformly.

    In Utah, there are natural constraints on urban sprawl. Population can only spread out so far to the west before they hit the lake, and so far to the east before it becomes infeasible to build on the mountains. In Davis County especially, this region is remarkably narrow. More to the point, development is already spreading farther and farther out to the east and to the west, whether or not the road infrastructure is in place. While there may be some truth to the “If you build it, they will come” argument, the reality is that whether or not we build new roads, people are coming to develop more and more in Davis County. Urban sprawl, in this sense, is happening anyway, so blocking the development of the Legacy highway does nothing to prevent it from happening. It just postpones the inevitable need to expand the roadways, leading to greater transportation crises later.

    In terms of wetland development, it is possible to have a road passing through an area where development is not allowed. Already many roads pass through relatively sensitive areas, but the cars are confined to the road and nothing is built along them. The appropriate authorities can just zone the areas around the highway to make sure that a few critical services (gas stations) are available at appropriate intervals, and otherwise limit commercial and residential development along the route.

    Ultimately, the battle against Legacy is a knee jerk reaction by environmentalists and meddling mayors (Rocky Anderson). The more I think about it, the more I think that Rocky is just trying (unsuccessfully) to discourage development in Davis County, so that more can be kept closer to Salt Lake City (even though Bountiful is only a few miles away from downtown). Anyway, I’d just like to say, “Mind your own city and stay out of our county’s business.”

    Davis County also doesn’t have much in the way of public transit. This is probably because people don’t use it, which in turn is because there isn’t adequate public transit. It’s kind of circular that way. I’ve had some lengthy discussions about this with some people who have lived in places with great public transit systems, and who believe that the same thing can be done everywhere. The problem here is that they’re a long ways away from that in Davis County.

    Right now, there are two kinds of routes in Davis County. The regular routes pass through some of the arterial and collector roads of the county, making regular stops along the way. To travel from most places in the county to downtown Salt Lake City takes well over an hour, with numerous stops along the way. This is hardly a satisfactory substitute for driving, even if it costs a little bit less.

    There are also express routes that make a few stops at parking lots near freeway exits and otherwise take I-15 into downtown. These routes can get you into town in just a little bit longer than driving would take, but they cost twice as much to take. A regular monthly adult bus pass is $47, which is less than the monthly commuting costs for most people in Davis County, but an express pass is $95, which is more than what most people would spend, even now that gas prices have exploded.

    So far, this seems fine. After all, they get to work in half the time, and the routes would primarily be used by business commuters, who can be expected to pay more than Joe Sixpack who wants to get to the library. The problem is one of north-south inequity. For Salt Lake Valley commuters who live the same distances away from downtown SLC as the Davis County commuters, they have their own express routes in the form of the light rail system TRAX. TRAX costs the same to ride as a regular bus route, and transfers can even be made between busses and TRAX for no charge.

    So, people to the south have a convenient way of getting into town, which is faster and more direct than what is available to the people to the north. While it may or may not be cost effective to run a light rail line into Davis County, it is not cost effective to make things more difficult for express commuters. The express routes have less stopping and therefore less gas consumption spent accelerating (except for when they are caught in freeway gridlock, which is a different issue, tied to the Legacy Highway problems addressed earlier), and therefore should cost less to run than the regular routes.

    Bearing in mind that all public transportation in this state is subsidized, we should ask what we should be subsidizing, and for how much. It makes little sense to subsidize business travelers on the relatively expensive TRAX system down to a regular bus fare, but to charge twice as much to the passengers on the operationally least expensive routes.

    As long as they put these kinds of logistical and economic barriers in the way of the potential riders in Davis County and all lands north, there will be a dearth of actual riders, and public transit will continue to fail to accomplish anything useful in these areas. If there are cost effective routes into town that cost enough less than driving, then people will start using them. Once enough people are using them, then they can introduce collector routes that can bring people from the neighborhoods of Davis County to collection points (currently Park & Ride lots), and public transit can actually start making a difference in the area.

    If that can happen, then maybe some of the load on I-15 can be reduced, and if Legacy can be built, then there may be enough options for travelers into town so that the region can grow comfortably. That way, we can build it as they come.

    Monday, August 08, 2005

    PVR Build Log #06 (Final Log)

    OK, how does this posting thing work again? It's been almost a month.

    As you read above, this will be the last PVR Build Log post. The system is done, or at least as done as any system of mine can be. There will be tweaks and adjustments, but I really like where it's at, and I'm happy.

    So here are the details that I forgot to include in that last post, and whatever else I think of. It's the final wrap-up, so pay attention.

    First; Windows. I'm really glad that I gave MythTV a try, and I'm really glad that I finally gave up on making this a Linux-based box. Home theatre PCs, in my humble opinion, are still screaming for Windows simply because it's SOOOO much easier to set up in the first place, and then use.

    And OMG, Linux, can you say "Driver problems," or "WTF Dependencies?" Because I can, as I shake my tiny fist at you. Linux geeks are a bunch of damned masochists. There simply is no other explanation. They don't have the social skills to get some sweet girl to put on leather and whip them, so their computing experiences have to hurt instead. Your secret is out, Linux geeks. Good thing for you, no one reads this blog.

    Here is a brief sampling of things that Windows is doing or allowing and that Linux wouldn't:
    1. Optical audio from my onboard sound card to my Harman Kardon receiver.
    2. Native support for my multimedia keyboard (some of the distros recognized and used the Gyration keyboard ok, but none of them knew what to do with the multimedia buttons).
    3. Windows boot time: ~45 seconds. Fedora Core 3 boot time: Well over 2 minutes.
    4. DeepFreeze. Not available for Linux.
    5. Disable power button from OS. My kids like to press buttons. Now the power button will turn the machine on, but it won't turn it off.
    A note on DeepFreeze. It made this list because it's a big deal to me for the following reason: I don't want to accidentally kill all the work I've done on this machine. Knowing now what I know about Linux, not having something like DeepFreeze, to completely disable the changing of the OS drive, is a deal breaker. What a truly cool product. I, for one, welcome our alien overlords.And Faronics could make a killing if they ported DF to other platforms.

    I've been unfreezing the PVR about once a week and letting AVG update. There is literally no housekeeping to be done on C: as long as DeepFreeze is running. While the system was unfrozen today, I did a registry scan for invalid entries. An average scan on a clean system will turn up fifty or so. I got one invalid entry, and I'm pretty sure it was just from the few minutes that I'd already had the system unfrozen.

    I wanted an elegant screen saver, so I headed on over to Really Slick. This guy programs these as a hobby. You've probably seen his popular SkyRocket screen saver, which puts on a graphics card-killing fireworks show. As I said before, the vid card in this system isn't a fast one, and SkyRocket is too showy for this application anyway. So I used a different Really Slick one called Euphoria (OpenGL). It turns the 19" LCD into a very beautiful 21st century lava lamp, and it takes very little CPU.

    So that's about it. It just works. It now does everything I want it to, except run the picture through a projector, which I can't afford yet. Oh, but I will. So finally, I'll give a complete list of the installed software on my PVR. It's what I consider to be an ideal list.
    • Windows XP Professional, Service Pack 2
    • Other non-stupid Windows updates (I'm choosy about updates)
    • SageTV
    • Nero 6 Ultra Edition
    • SlySoft AnyDVD
    • Elaborate Bytes CloneDVD 2
    • ATI Remote Wonder
    • AVG 7 Free Edition
    • Faronics DeepFreeze
    • Half-Life 1, with updates and High-Def pack
    • Hauppauge WinTV2000 (Just for drivers, I don't use the application)
    • Java 2 Runtime Environment (Required for SageTV, preferred for Firefox)
    • Microsoft .NET Framework, v1.1
    • K-Lite Mega Codec Pack (with Media Player Classic)
    • Motocross Madness 2
    • Mozilla Firefox
    • PowerDVD 5 (Yes, I know there's a newer version)
    • Microsoft TweakUI for XP
    • Farstone VirtualDrive Pro 8
    • WinAmp 5.x
    • WAWI (WinAmp Web Interface - it allows me to control WinAmp from any PC in the house)
    • WinTidy (Remembers desktop icon and window settings)
    • RegCleaner
    • ReallySlick Screen Savers
    • Windows Blue Curve Wallpaper
    • SNES Super Nintendo Emulator
    That's it! My desktop has about five times as much crap installed. But not this system. I want it to stay clean and shiny.

    So the PVR records more TV than I'll ever watch. I go through and delete TV shows that have built up all the time, even though SageTV would do that for me, if I let it. But I rule with an iron fist.

    Cheers!