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Topic: What types of capacitors are these? (Read 3055 times) previous topic - next topic

allanhurst

#30
Feb 06, 2018, 05:04 am Last Edit: Feb 06, 2018, 05:05 am by allanhurst
I did some work a long time ago for a firm called Oxford instruments in Cambridge, who modified a SEM with an extra deflection plate, which they could synchronise with an external clock.

With this gadget they could look at the propagation of signals across the surface of a working silicon chip at many MHz.

Neat.

Allan

ChrisTenone

I did some work a long time ago or a firm called Oxford instruments in Cambridge, who modified a SEM with an extra deflection plate, which they could synchronise with an external clock.

With this gadget they could look at the propagation of signals across the surface of a working silicon chip at many MHz.

Neat.

Allan
That sounds really cool! What did it look like?
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allanhurst

#32
Feb 06, 2018, 08:28 am Last Edit: Feb 06, 2018, 09:39 am by allanhurst
It wasn't my project - but they showed me it working. A clock generator drove the chip, and via something like a nS 555, the plate. You could see the lines on the chip change as you tweaked the pot. Great for diagnosing eg race problems.

I think Intel were the client.

I was impressed.

Perhaps you could mod your SEM? - perhaps by modulating an existing  deflection plate rather than adding a new one? All you have to do is effectively turn the beam off synchronously - easier by momentarily deflecting it well off target than directly switching the beam . Couple a fast 'spike' in to do this ?

 I think they added an extra plate to do this as a collector before the main deflector plates, but it might work without.  And the detector would have to be seriously wideband, ... .

If it works, let me know.....  that'd be something to show your students.....

I bet it's all patented, but who's to know?

Allan

Grumpy_Mike

Quote
I bet it's all patented, but who's to know?
Patents run out in 25 years, which at my age isn't as long as it used to be.

ChrisTenone

Sounds like a fun project! I'll walk in with a bunch of tools, and announce I'm gonna do an Arduino project on the inside of the SEM. -Ha!

It's not like SEMs of yesteryear, where you could get at the innards easily. In fact it more closely resembles a coffee maker than an electron microscope!



Seriously though, I might try observing a live chip if I get the opportunity. The sample chamber is about an inch in diameter. That would be quite the educational opportunity.

Mike, I think patents are even shorter these days. My youngest child reminded me this weekend that she'll turn 18 this year. Now I'm feelin' old.
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allanhurst

#35
Feb 07, 2018, 11:44 am Last Edit: Feb 07, 2018, 11:50 am by allanhurst
My daughter's 35, so I know what you mean.

My work with  OI  must have been pre-2000, so the patent clock is ticking.....

If you changed the chip clock such that it or a sub harmonic  sync'ed  with the SEM  scan, you might  get some interesting pictures without touching the SEM at all except (possibly) to pick up the scan ....

I dare you! This is, after  all, a hacking sort of forum.....  perhaps a shift to 'Bar Sport'?


Allan

ChrisTenone

My daughter's 35, so I know what you mean.

My work with  OI  must have been pre-2000, so the patent clock is ticking.....

If you changed the chip clock such that it or a sub harmonic  sync'ed  with the SEM  scan, you might  get some interesting pictures without touching the SEM at all except (possibly) to pick up the scan ....

I dare you! This is, after  all, a hacking sort of forum.....  perhaps a shift to 'Bar Sport'?


Allan
Hmmm, I'm moving the microscopy lab to new dedicated and bigger facilities at the end of the summer. The transition would be an ideal time to mess with the instrument, as it's insured/warrantied. I might just try that. Of course I'll start a new thread ... ;)

Moving to barsport would be cool. The only downside is that my post count will go down.

Before we go though, I wanna add something for the folks who came looking for information about capacitors. In my (semi)finalized project, I chose the blue rectangular ceramic capacitor because it looks good in the circuit and it works. It couples the output of the reverse junction (random) oscillator to the amplifying transistor, comparator, opamp, and ultimately the microcontroller (a Trinket M0.) In the picture below, the oled shows a stream of moving dots that represents whitened random numbers being pushed out of the micro usb socket (on the left) at 25Kbits/sec or so. The stream would be faster, but it also plays all sorts of games of chance, such as dice, I Ching, Magic 8 Ball, password generator, cards, coin flip, roulette and stock market prediction.


The box is shown here in it's simplest mode:

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allanhurst

Stock market prediction  !?

Probably no worse than any other method......

Allan

Coding Badly

#38
Mar 31, 2018, 08:39 pm Last Edit: Mar 31, 2018, 08:39 pm by Coding Badly

@ChrisTenone, I have a question: Are you running the data streams through an analysis tool like Diehard, Dieharder, TestU01, or ENT?


ChrisTenone

Hiya CB, I started installing ENT onto my mac a few weeks ago. After four hours, I needed the computer for something else and put it off for now. I'll get back to it when I have a day off, or perhaps on a pc from work.

I lent the device to a collegue who plays d&d. He complained that it doesn't give him all high rolls (like his special dice do ;) ) which I think is a good thing. He said it does increase his nerd factor, which in that crowd is not an easy task.

In the meantime I've built a couple more generators, first a miniturized version of the PN type that fits in an Altoids can and throws the I Ching. And then I made a second generation generator:


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Coding Badly


ChrisTenone

I'll post again once I do an analysis.
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