Seminar Night at MITERS

Nancy gives a lecture on how to github:

It’s nail painting night at MITERS!

nancy edits on 2 dec 2011:

for reference, I talked (actually mostly I evangelized open source hardware and mentioned rise of EE but not really meche-oriented version control, then most people already knew how to use git & github) about:

  • upverter, solderpad, circuitbee, openhardwarehub (
  •,, pro git, (then search for git, or embedded hardware, etc.)
  • (his made in china series is interesting too)
  • Here is the video which I decided not to hunt for during the talk: Open source hardware $1m and beyond – foo camp east 2010 by adafruit industries 2 years ago

Direct-to-PCB Laser Printing

This is a cross-post from  muffin’s blog!

Over the weekend, Dan disassembled a laser printer that he found in the trash. He was able to tear it down to the point where he could fit a board in the (quite linear) print path and gave it a go. To his dismay, the board jammed and nicked the heating drum. I came over and we decided that by removing a metal guide and chamfering the edge of the circuit board, we’d have better luck – and we did! The print quality turned out pretty good, but the toner wasn’t fusing to the board. We figured that it was either a heat/pressure issue or a charge issue and called it a night.

The next day, Dan and I went to [miters]( to improve the process. We tried a whole slew of ideas include charge compensation, increasing roller pressure, and pre-heating the boards to get the toner to fuse. The last one did the trick. Although print quality isn’t 100% there yet, we’re certain that we can hammer out those last pixels and get this process rolling. We etched my first lab in 6.331 – a 4MHz 50-ohm line driver with 2 watts of output power.

More to come next weekend!


Induction Heater

Because documentation is good, I hear…so here’s documentation of an old-ish (circa this June) project.

Inverter is a fullbridge of CM400 IGBT modules, matching transformer is something like 20:1. The whole thing resonates at ~65KHz. The driver is a simple fixed-frequency oscillator.

Sorry ’bout the lack of video…seems like I was too busy setting things on fire and forgot to video it =( Remember kiddies, setting a CDE940 film cap on fire=Terrible Idea!