Name that Ware November 2011

November 15th, 2011

The Ware for November 2011 is shown below. Click on the image for a much larger version.

To give a sense for the ware’s size, here’s a shot of the business end with my hand as a scale reference.

Have fun!

Winner, Name that Ware October 2011

November 15th, 2011

The Ware for October 2011 is a galvanometer, taken out of an old chinese-made 2-D laser scanner of the type used in dance clubs. As far as I can tell, this is a hand-built prototype unit from an early production run; there are no distinctive markings on the galvanometer’s case, and to my eye there were indications of prototypey-ness, or pilot production-ness, about the surrounding circuitry.

It was very interesting to read the diverse set of guesses for the ware this month, and the winner is marcan for his useful and informative description of how the ware works. For the benefit of those who were stumped by the ware, here is his explanation:

Since nobody has explained how it works yet, I’ll do so: the infrared LED shines on the vane, which partially blocks the light reaching the two photocells on the left. Depending on the angle of the vane, the amount of light falling on each photocell varies. The feedback loop takes the difference between both cells and uses it as input feedback to a servo loop. The output of the loop drives a single-coil stator (the two solder joints to the bottom right are where the coil is soldered from the other side), which applies torque to a thin permanent magnet rotor that is attached to the vane on one end, and to a small front-surface mirror on the other end. This forms a closed loop system, where the angle of the mirror is directly proportional to the input voltage to the servo controller.

Since the rotor is thin, the mass is concentrated near the axis of rotation, and the rotational inertia is very low. This enables it to vibrate at high frequency, scanning a laser beam to draw an image on a target many times per second. Two galvanometers like this one are used for X-Y control. The amplifier has a bunch of adjustments to optimally tune the analog servo loop (servo gain, HF and LF damping, offset, position scale, etc.) which have to be adjusted for each particular galvanometer.

The full assembly, seen mostly from the other side, looks like this:

While there were others who had guessed the type of the ware correctly before him, the competition is judged not only on timeliness but also by depth of response. Congrats to marcan, email me to claim your prize!

Name that Ware October 2011

October 22nd, 2011

The Ware for October 2011 is shown below.

Have fun!

Winner, Name that Ware September 2011

October 22nd, 2011

The Ware for September 2011 is a DEC Alpha 21164A microprocessor board. This is a product from circa 1996: a 64-bit CPU that ran from 366-666 MHz, fabricated in 0.35um technology with a Vdd of 2.5V, and featured a discrete L3 cache with five support chips. Back in the day, having one made you the coolest kid on the block. Chicks would come by just to watch how fast gcc would spit out object files while compiling the kernel (ahem, I did go to a nerd school). Contrast today to an Intel i7-2600k that runs four cores between 3.4-3.8 GHz, fabricated in 0.032um (32nm), a Vdd of ~1.25V, and integrates the memory controller, graphics controller, 8MB of L2 cache, and other goodies. If you could warp one back in time to 1996 it would almost be alien technology.

I’m still fond of the Alpha, it has a very “clean” architecture that was great for learning and teaching. I still remember the headlines about Alpha breaking the 5V barrier and using a 3.3V power supply. There were a lot of articles in the trade magazines (they didn’t have blogs back then!!) trying to explain how and why this is a good thing. When I saw this board laying in a scrap heap, I had to take a photo and share it for old times sake. An easy one to guess, but I have to remember that most college-age students today have never used one, and probably think of it as more an academic curiosity than as a serious machine. Winner is FlorinC for being the first one to guess it. Congrats, email me to claim your prize!

Below is a shot of the board without the redacted part numbers.

Name that Ware September 2011

September 28th, 2011

The Ware for September 2011 is shown below. Click on the image for a much larger version.

Should be a cakewalk to guess, but I couldn’t resist posting this little piece of tech nostalgia after I stumbled upon it during my recent trip to the US.