250A - 500A "analog" pulser, rev a2.3

Winfield Hill

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Mar 27, 2020, 3:04:38 PM3/27/20

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I've finished a 3rd rev of my RIS-796A "analog"
fast pulsed current source. This beast can be
programmed with all kinds of waveforms, over a
100:1 range of currents, up to 500 amps, and
turned on or off in about 1us. After a rapid
shutoff, an instantaneous junction temp can be
measured with a 10mA current source. If the
test is repeated with varying ON durations, a
plot of Tj vs time can be made.

Before ordering a batch of PCBs, I'm posting
the design info, looking for your comments.

Schematic:
https://www.dropbox.com/s/uj18eqqaq7urles/RIS-796A_2a_a2.3.pdf?dl=1

PCB views:
https://www.dropbox.com/s/sn8cit9nhlkbgox/RIS-796A_2a_3D.PDF?dl=1
https://www.dropbox.com/s/1vcebcceeuegaq8/RIS-796A_2a_assembly.pdf?dl=1

background info, folder of various files:
https://www.dropbox.com/sh/tcmiahzzughadfk/AABtgFDy01cuTDWDRjujP6jva?dl=0

--
Thanks,
- Win

jla...@highlandsniptechnology.com

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Mar 27, 2020, 4:37:32 PM3/27/20

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On 27 Mar 2020 12:04:22 -0700, Winfield Hill <winfie...@yahoo.com>
wrote:

Another way to get a lot of current is to use a transformer.

https://www.dropbox.com/s/s6ji5ifsatqi24p/AM_Transformer.jpg?raw=1

That's rated 190 amps, but it's good for a lot more at low duty cycle.
I think it's from an old AM station, filaments. I paid $15 for it at a
surplus place in San Carlos, back when there were surplus places.

--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

Winfield Hill

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Mar 27, 2020, 4:42:15 PM3/27/20

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Winfield Hill wrote...

I've added an updated writeup on version a2.3
https://www.dropbox.com/s/pvfshfo2fojz64w/RIS-796A_a2.3_writeup.pdf?dl=1

--
Thanks,
- Win

bitrex

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Mar 27, 2020, 5:45:44 PM3/27/20

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You could mount bike handles to each side and probably get a great
upper-body workout huffing that piece up and down.

jla...@highlandsniptechnology.com

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Mar 27, 2020, 6:20:52 PM3/27/20

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I have a young engineer who works out. He does my heavy lifting.

Like my 11802 scope. Damned thing must weigh 70 pounds. Miguel muscles
that one for me.

bitrex

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Mar 27, 2020, 7:00:28 PM3/27/20

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Is that still a valuable instrument in 2020? its sampling memory must be
tiny.

jla...@highlandsniptechnology.com

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Mar 27, 2020, 10:57:13 PM3/27/20

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It's fabulous. The 20 GHz TDR is wonderful, and I have a 50 GHz
sampling head. And a dual-channel probe sampler: 3 GHz, 0.25 pF at the
probe tips.

The memory is whatever's on the screen.

Winfield Hill

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Mar 28, 2020, 10:20:39 AM3/28/20

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Winfield Hill wrote...
>

> I've added an updated writeup on version a2.3
>https://www.dropbox.com/s/pvfshfo2fojz64w/RIS-796A_a2.3_writeup.pdf?dl=1

OK, I learned that although Word won't accept .eps
files, showing it as blank, you can convert them to
.eml files, and thereby retain vector resolution in
your final .pdf file. Good to know.

So I've replaced the writeup with a new copy having
an embedded readable expandable schematic. Same link.

Clifford Heath

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Apr 4, 2020, 12:59:04 AM4/4/20

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I lucked into a cheap Tek 7904 with the 7S12 (S-53 & S-6) TDR plugin.
It's supposed to be about 25/30ps. Not as good as the 11802 at <20ps,
but still, I'm pretty pleased. I'd long been planning to build a TDR,
but this is better than anything I could make.

I have to learn to use it now... any good resources (that I might not
have already found)?

CH