> > By showing phase instead of actual clocking, we avoid the need to
> > have <60Hz frequencies. The LEDs would show the beat between them
> > due to component tolerances, not the actual clocks.
>
>Now THAT is a fun idea!
Ok, I prototyped this (yay radio shack electronics labs :) with two
DJ Delorie wrote:
Hmmm... make two free-running oscillators with the same parts, and
hook two LEDS up between the outputs (one red, one green, in opposite
directions) so the LEDs indicate phase. Or have one clock the D-FF,
and the other provide the D input, use the Q and ~Q outputs to
indicate p
Has anyone here ever done any work with cryogenic circuits?
The application is some ultra low noise amplifiers.
Does anyone know of which houses can make
PCB's based on Ceramic Substrate Material?
Would there be something better material to use
in Liquid Nitrogen than Ceramic?
http://www.interf
Yesterday I posted a message regarding a failure in gsch2pcb when the footprint
contained the string "SO-28". It seems that any footprint beginning with "SO-"
will fail.
Attached are my test schematic and project files. I would appreciate feedback.
George
schematics so28.sch
output-name so2
gene glick wrote:
>> Sometimes it adds linearly. Sometimes it cancels. Good designs
>> will use this cancellation to advantage.
>>
> How does that work?
Take an opamp that is wired to amplify the difference of two signals. If
both signals are affected by the same noise source, the noise will b
al davis wrote:
On Saturday 05 August 2006 09:46, gene glick wrote:
Hey, I am curious, noise adds as the root of the sum of the
squares, right?
..because it is uncorrelated.
Yep, that's how I remember it :-)
How does distortion accumulate? Seems to me
that it just adds linearly.
Somet
> Panasonic NP061A500A dual PNP with built in bias resistors is in a
> package with a 0.35 mm pin pitch. $0.51 in 100's at Digikey. Is 350
> µm fine enough? ;-)
I have down to 0.40mm pitch so far (the tvsop). The problem becomes
finding cheap FABs at that pitch - 0.40mm is 7.89 mils, so we m
On 8/5/06, COMINT <[EMAIL PROTECTED]> wrote:
Is it possible to output a schematic in pdf in colour?This will get you a .ps in color:http://www.geda.seul.org/wiki/geda:faq-gschem#how_can_i_get_color_postscript_png_output
Then you can use gs to convert and merge multiple .ps files into one .pdf like
On Thu, 03 Aug 2006 22:38:25 +
gene glick <[EMAIL PROTECTED]> wrote:
> Any ideas?
You might take a look on AD8110. I used them, and found very good. However it
goues up till 200MHz, and it was designed for video.
Levente
--
http://web.interware.hu/lekovacs
pgpYAlH9YOuNX.pgp
Description:
Is it possible to output a schematic in pdf in colour?
Cheers
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> Does a Schmidt input inverter cost too much?
www.digikey.com ;-)
The tvsop is a hex buffer; if we swap that with a hex inverter it will
be much more useful, and we'd have six gates to play with. The D flip
flop can be set up as a divide by two.
Hmmm... make two free-running oscillators with
On Aug 5, 2006, at 12:56 PM, DJ Delorie wrote:
If we did multiple transistors, they'd have to be different sizes (not
a big deal) and you don't get the fine-pitch challenge with them, like
you do with the mini-gates (SOT-323-5 and TVSOP).
Panasonic NP061A500A dual PNP with built in bias resi
Hi,
On Sat, 2006-08-05 at 14:56 -0400, DJ Delorie wrote:
> > The success of this circuit depends on what `low' valued means here. To
> > get visual frequencies, for a couple of Hertz we might need between 0.1
> > and 1 microfarad or so. We would have to breadboard the circuit to find
> > out app
I have made the following additions and changes to my footprint
library which is at http://www.luciani.org/geda/pcb/pcb-footprint-list.html
* Added Johnson Component shielded test jacks (129-0701-20x and 129-0701-30x)
* Added Tyco Micro-Match Connectors (series 215079)
* Added footprints for C&K
> Yes - and think about being able instantly identify if the soldering was
> successful or not by seeing the LED blink. 'Built-in diagnostics'...
> That's at least worth another $.02?
Definitely worth $0.02. Not worth $2.00. The trick isn't the
circuit, it's the budget.
__
> The success of this circuit depends on what `low' valued means here. To
> get visual frequencies, for a couple of Hertz we might need between 0.1
> and 1 microfarad or so. We would have to breadboard the circuit to find
> out appropriate values for the cross coupling capacitors. (Although
> p
On Sat, 5 Aug 2006 09:34:20 -0400
DJ Delorie <[EMAIL PROTECTED]> wrote:
> >Even just a little 555-based LED blinker or something would count
> > as "functional" in this case, I think.
>
> 0603 cap = 1 cent
> 0603 led = 7 cents
>
> Even the venerable 555 is too expensive in the small sizes ap
Hi,
Perhaps a bit more low-tech, how about an astable multivibrator? This
circuit needs 2 transistors, 6 (or 7) resistors, and two caps. Add two
LED's and you have a blinker. We used to build these out of leaded
components on a 1.5 x 1.5 inch piece of perfboard. We had students who
wer
On Saturday 05 August 2006 09:46, gene glick wrote:
> Hey, I am curious, noise adds as the root of the sum of the
> squares, right?
..because it is uncorrelated.
> How does distortion accumulate? Seems to me
> that it just adds linearly.
Sometimes it adds linearly. Sometimes it cancels. Good
>Even just a little 555-based LED blinker or something would count as
> "functional" in this case, I think.
0603 cap = 1 cent
0603 led = 7 cents
Even the venerable 555 is too expensive in the small sizes appropriate
to this project (about $0.60).
Now, if you can think of a circuit that use
Noise and distortion are my main concerns. The more stuff that gets in
the way, the more it gets worse. Having said that, maybe the ADC
distortion and noise is the worst - maybe not, have to look into that.
I think I need to come up with a good noise budget and work from that.
But it is hard
I created a footprint called SO-28. I then ran g2ch2pcb on a small test.sch file and it goes into
an finite loop generating pads with the following error messages:
stdin:5: /usr/bin/m4: Bad _expression_ in eval: (1028* - /2)/100
stdin:5: /usr/bin/m4: Bad _expression_ in eval: (1028* - /2)/100
Dan McMahill wrote:
I think we should pester Dave to fire up his SEM for some super close up
photos!
You know...My fiance' and I are hunting for a new house...one of the
biggest requirements is enough space for not only my big iron, but for
the SEM. It hasn't even had its vacuum system pum
DJ Delorie wrote:
I think there ought to be a functional test... so how about a simple
surface mount amplifier and input/output jacks.
Again, if you can come up with a working circuit that (1) uses all the
different footprints, (2) costs less than $2, and (3) fits in about
half a square inch, I
DJ Delorie wrote:
> Again, if you can come up with a working circuit that (1) uses all the
> different footprints, (2) costs less than $2, and (3) fits in about
> half a square inch, I'm all for it.
My former employer did a little pcb as a christmas gift for well known
customers. It is dual use:
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