Archive for April, 2010

Names for LED Driver

Wednesday, April 21st, 2010

The LED driver board is nearing its final configuration (I need to convince EAGLE that the mounting hole has a hole in it; and don’t worry, those aren’t really the headers I’m using) and I’m about ready to send it off to be manufactured. But I’d really like to come up with a great name for it, to have silkscreened on the back side.

Rendering of LED driver PC board

I’d like something whimsical but which still relates to its function as an LED driver. Fun hobby electronics names I love: Adafruit, MintyBoost, BlinkM, SparkFun, MakerBot, and CupCake.

I’ve considered Illumerator, Illumifier, and variations Lumerator and Lumifier (which is probably TM and a bad idea). Whatever I settle on will have -3L appended, to distinguish this 3-string linear driver model from the -1S switching model I want to do next.

So I welcome suggestions for great names. I’ll be happy to send you a couple of drivers if you’re the first person to suggest something I end up using.

Warning: I don’t care for variations of my name that feel like they came from the “makin’ copies” sketch.

Glastherm HT: Not So Good for Insulating Hotplates

Monday, April 19th, 2010

Two pieces of Glastherm HT for aluminum hotplates

I got a care package this week from my friend Scott in San Diego. Half of it was two pieces of Glastherm HT that he cut to fit my soldering hotplate and my MakerBot CupCake heated build platform. Scott and his buddy Ben Wynne are building hotplates and were also planning to use Glastherm to insulate them.

Last night I pried the warped acrylic off the underside of my platform, cleaned the surfaces with alcohol to ensure a good stick, and affixed the Glastherm to the heater PCB with kapton tape. I then set the assembly on edge on another piece of Glastherm and ran it up to operating temperature.

Testing Glastherm HT insulation on MakerBot CupCake heated build platform

The Glastherm was not nearly as good an insulator as I expected. The “cold” side of the sandwich lagged only 25°F behind the hot side as I was heating it from room temperature and once it stabilized at 250°F, (at which point the “cold” side reach equilibrium around 225°F).

I’m surprised that the Glastherm provided so little insulation. Perhaps it’s not intended to be used in direct thermally-conductive contact with a hot surface — although the diagram on their web site certainly suggests that it is.

At any rate, the “cold” side of my sandwich is still far too hot to be in contact with my acrylic mounting plate. And since Glastherm is supposed to be pretty good stuff, I think I’m resigned to finding a way to assemble my sandwich that leaves an air gap between the heater and the mounting plate, which I hadn’t wanted to do.

Replacing a Broken Power Jack on a DBX 266XL Compressor

Sunday, April 11th, 2010

I recently bought a DBX 266XL audio compressor/limiter on eBay. The seller described it thus:

Has light scratches, small amount of rack rash, in perfect working condition- no issues whatsoever. Has been used in my guitar rig for the past several years with no problems.

Broken C-14 power jack on DBX 266XL compressor

It arrived oddly but adequately packed and … as you can see, not in perfect condition. I would go so far as to say it had issues. I suspect had I tried to use it, I would have had problems.

Well … I could complain to the seller, who would tell me it was damaged in shipping, and then I could try to deal with the USPS who I don’t think broke it, and I could spend a lot of time and frustration and maybe get some money back and probably end up with no compressor. Or I could just fix it myself and have a little fun in the process.


What Is This Thing?

Sunday, April 11th, 2010

I bought this at a surplus store a long time ago (twenty years?) thinking it was cool.

Front side of mystery plug strip

The front side has what I hoped would be lights but appear to be sockets. Positions 050 and 056 have broken off pins in them.

Back side of mystery plug strip

The back has wire-wrapped pins and Babcock PS-1224 devices, which I can’t identify. Fron context, I assume they’re some kind of matrix scanners.

I can’t decide whether it’s a patchboard (my best guess) or some kind of matrix input device — insert conductive pegs to connect rows to columns and indicate which of a thousand positions should … something.