Matt Miller

Wednesday, June 8 What I've been doing recently is here.

Well, that and reading Ayn Rand. Fountainhead, good stuff. Will not give you the warm and fuzzies.

Sunday, April 16

A complete writeup of the diagnostic of the box is here.

Thursday, February 17, 2005

Still debugging away. There are pictures of the the signal trace all the way through a channel below.

Pure ECL signal

ECL signal as seen by the 'scope on wires to board. Purple trace is the signal itself.

Just the ECL signal Channel 1

TTL signal immediately after the 10_125 board. Channel 1

Signal out of U3/13. Channel 1

Final output to LED U3/5 Channel 1

Final output to LED U3/13 Channel 2

Final output to LED U5/13 Channel 3

Final outpus to LED U5/5 Channel 4

Obviously in this test the first four channels are working decently. Since previously none of the channels were conducting signals, the problem remains.

Depending on the number of 10_125 chips in the board, the signals can have difficulty.

There seems to be problems if more than two chips are one the board. Signals do come through on all channels, but the chips get very hot very quickly. Maybe if I left the board on, the channels would start to fail?

As to what is actually wrong with the board and why, I don't know.

P.S. If you want to see the first image as a waveform, it is here. The format only seems to be supported by the 'scope.

Wednesday, February 9, 2005

Figured out how to export images. I'll put some up here when I have time. I followed a signal all the way through the four channels of the board that I could test. There were no problems. Since the board previously had not been passing any signals, this implies to me that the error is something on one of the missing chips. They had been acting strangely, and my next order of business is to muck around with them.

That oscilloscope is one of the most user friendly pieces of machinery I've worked with. It has something of a learning curve, but the manual is great and there's a very consistent internal logic.

Tuesday, February 8, 2005

Been working on debugging one of the boards that we took back from Switzerland. I use a really nifty digital oscilloscope, and I'll probably put some screen shots up eventually. Rebecca has at least one, so go see that. The board is a wee and tricky beastie, but the first two channels seem to be transmitting.

The manual is actually very readable.

Summer, 2004

Currently helping to construct boards for the MULAN pulser.

Assembling termination cables for the MULAN drivers.