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Count 1ns pulse
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Bill Sloman
electronics forum Guru


Joined: 12 May 2005
Posts: 1080

PostPosted: Thu Jul 20, 2006 2:54 pm    Post subject: Re: Count 1ns Pulse Reply with quote

"Paul Taylor" <paul.taylor@uea.ac.uk> schreef in bericht
news:e9o3r9$9$1@cpca14.uea.ac.uk...
Quote:
"John Fields" <jfields@austininstruments.com> wrote in message
Why don't you get ahold of the guy again and ask him what the width
of the output pulse is? I'd almost bet that it'll be about half of
the pulse-pair resolution, or about 12ns, which should get you over
the hump.


--
John Fields
Professional Circuit Designer

Just emailed him, mind you when i spoke to him on the phone i explained my
problem and mention about stretching the pulses because the counter wasn't
recognising them he said it is feasible as they do this also, he even
emailed the circuit they use. Anyway lets see what the email brings back.

What sort of photomultiplier tube are you using to drive the AD7 amplifier
discriminator?

Photomultiplier data sheets usually list the typical single photon output
pulse width - it depends on the spread of the electron trajectories through
the dynode chain, and it is pretty reproducible.

Using the wrong voltage distribution down the dynodes can mess up the pulse
width - with fast focussed high gain tubes yo can need a lot of voltage
across the last few dynode to prevent the space chage associated with the
electrons from messing up the electric field and spreading out the
electrons.

--
Bill Sloman, Nijmegen
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Phil Allison
electronics forum Guru


Joined: 20 May 2005
Posts: 1368

PostPosted: Thu Jul 20, 2006 3:10 pm    Post subject: Re: Count 1ns pulse Reply with quote

"Bill Slowman Autistic Cunt "

Quote:

** He is a science grad who has faked his way into a job he has no clue
how to do.

He isn't the first.


** Asinine...........


Quote:
It took a while before I started performing to my potential.


** Wot - as the biggest faker out ???

LOL ....



Quote:
It looks as if he can learn,


** Looks to whom ??????????

Only to a criminal pile of autism fucked wog s**t.






.......... Phil
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Phil Allison
electronics forum Guru


Joined: 20 May 2005
Posts: 1368

PostPosted: Thu Jul 20, 2006 3:23 pm    Post subject: Re: Count 1ns Pulse Reply with quote

"Bill Slowman Autistic Cunt "


** Geeez, you do like *sucking* this fuckwit pommy charlatan's tiny cock
in public.

Don't ya - Billy boy ??

Says it all about where YOU are coming from.





........ Phil
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Michael A. Terrell
electronics forum Guru


Joined: 24 Mar 2005
Posts: 2291

PostPosted: Thu Jul 20, 2006 3:39 pm    Post subject: Re: Count 1ns Pulse Reply with quote

Phil Allison wrote:
Quote:

"Bill Slowman Autistic Cunt "

** Geeez, you do like *sucking* this fuckwit pommy charlatan's tiny cock
in public.

Don't ya - Billy boy ??

Says it all about where YOU are coming from.

....... Phil


Here you go, Phillys:

<http://www.harborfreight.com> Item 34923 is one toy you won't wear
out. Not only that, but you won't run out of batteries. Buy it and a
step down transformer, use it on yourself and STFU. The sailors and
drunks will thank you.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
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Bill Sloman
electronics forum Guru


Joined: 12 May 2005
Posts: 1080

PostPosted: Thu Jul 20, 2006 5:00 pm    Post subject: Re: Count 1ns pulse Reply with quote

Phil Allison wrote:

<snipped usual rubbish>

We have to be kind to Phil. He lives in Sydney, and can't get refugee
status anywhere else.

--
Bill Sloman, Nijmegen
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Bill Sloman
electronics forum Guru


Joined: 12 May 2005
Posts: 1080

PostPosted: Thu Jul 20, 2006 5:21 pm    Post subject: Re: Count 1ns Pulse Reply with quote

Phil Allison wrote:
Quote:
"Bill Slowman Autistic Cunt "


** Geeez, you do like *sucking* this fuckwit pommy charlatan's tiny cock
in public.

Don't ya - Billy boy ??

Says it all about where YOU are coming from.

Don't be a bigger idiot than you have to be.

I spent a couple of years working on single photon counting electronics
and I've got two papers in the Journal of Physics E: Scientific
Instruments covering aspects of that work.

The electronics is much the same as we used in the version of the
Everhart-Thornley secondary electron detector we developed for the
Cambrdige Instruments Electron Beam Tester in 1989-91.

In short, I'm advertising my expertise (such as it is) and cultivating
potential customers - knowing full well that the University of East
Anglia doesn't have any money, and would spend it on hiring more
graduate students if they did.

Or are you just generalising your own obvious enthusiasm for verbal
abuse to include oral abuse as well?

--
Bill Sloman, Nijmegen
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I.F.
electronics forum Guru


Joined: 30 Mar 2006
Posts: 407

PostPosted: Thu Jul 20, 2006 7:28 pm    Post subject: Re: Count 1ns pulse Reply with quote

<bill.sloman@ieee.org> wrote in message
news:1153414810.930979.13180@m79g2000cwm.googlegroups.com...
Quote:

Phil Allison wrote:

snipped usual rubbish

We have to be kind to Phil. He lives in Sydney, and can't get refugee
status anywhere else.

--
Bill Sloman, Nijmegen


He'll burst a vessel if he keeps on like that!!!!!
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I.F.
electronics forum Guru


Joined: 30 Mar 2006
Posts: 407

PostPosted: Thu Jul 20, 2006 7:35 pm    Post subject: Re: Count 1ns pulse Reply with quote

"Paul Taylor" <paul.taylor@uea.ac.uk> wrote in message
news:e9noms$qsb$1@cpca14.uea.ac.uk...
Quote:
"David L. Jones" <altzone@gmail.com> wrote in message
news:1153391411.204205.200970@m79g2000cwm.googlegroups.com...
Paul Taylor wrote:
"David L. Jones" <altzone@gmail.com> wrote in message
How are you generating a 1ns pulse with a generator that is only
capable of generating a 25ns pulse at best?
http://www.amplifierrentals.com/Equipment/HP/8011A.htm

Dave :)

Derhhh sorry Dave you are right i misread the scope it is in fact 1usec
timebase not as i previously thought 1ns must get my eyes tested.

Thread closed!

Dave :)


I have know got a BNC model 555 pulse delay generator and a more powerful
scope LECROY 9361C which is more than capable, im going to stretch the 5ns
TTL pulse from the pad to 10ns and see if the counter will except this?


All the gear - no idea!!!
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cs_posting@hotmail.com
electronics forum Guru Wannabe


Joined: 26 Sep 2005
Posts: 250

PostPosted: Thu Jul 20, 2006 7:43 pm    Post subject: Re: Count 1ns pulse Reply with quote

Paul Taylor wrote:
Quote:
"David L. Jones" <altzone@gmail.com> wrote in message
How are you generating a 1ns pulse with a generator that is only
capable of generating a 25ns pulse at best?
http://www.amplifierrentals.com/Equipment/HP/8011A.htm

Dave :)

Derhhh sorry Dave you are right i misread the scope it is in fact 1usec
timebase not as i previously thought 1ns must get my eyes tested.

The problem is not misreading the scope, but failure to sanity check
the reading.

You need to develop a sense of "that (probably) can't be right" based
on knowledge of what might reasonably be happening.
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martin griffith
electronics forum Guru


Joined: 06 May 2005
Posts: 1098

PostPosted: Thu Jul 20, 2006 8:11 pm    Post subject: Re: Count 1ns pulse Reply with quote

On Thu, 20 Jul 2006 19:35:13 GMT, in sci.electronics.design "ian
field" <dai.ode@ntlworld.com> wrote:

Quote:

"Paul Taylor" <paul.taylor@uea.ac.uk> wrote in message
news:e9noms$qsb$1@cpca14.uea.ac.uk...
"David L. Jones" <altzone@gmail.com> wrote in message
news:1153391411.204205.200970@m79g2000cwm.googlegroups.com...
Paul Taylor wrote:
"David L. Jones" <altzone@gmail.com> wrote in message
How are you generating a 1ns pulse with a generator that is only
capable of generating a 25ns pulse at best?
http://www.amplifierrentals.com/Equipment/HP/8011A.htm

Dave :)

Derhhh sorry Dave you are right i misread the scope it is in fact 1usec
timebase not as i previously thought 1ns must get my eyes tested.

Thread closed!

Dave :)


I have know got a BNC model 555 pulse delay generator and a more powerful
scope LECROY 9361C which is more than capable, im going to stretch the 5ns
TTL pulse from the pad to 10ns and see if the counter will except this?


All the gear - no idea!!!

Yep, poor sod, but he has come to the right place, wonder if Paul has

a copy of AoE?


martin
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Bill Sloman
electronics forum Guru


Joined: 12 May 2005
Posts: 1080

PostPosted: Thu Jul 20, 2006 9:44 pm    Post subject: Re: Count 1ns pulse Reply with quote

ian field wrote:
Quote:
bill.sloman@ieee.org> wrote in message
news:1153414810.930979.13180@m79g2000cwm.googlegroups.com...

Phil Allison wrote:

snipped usual rubbish

We have to be kind to Phil. He lives in Sydney, and can't get refugee
status anywhere else.

--
Bill Sloman, Nijmegen


He'll burst a vessel if he keeps on like that!!!!!

We can hope, but he's survived long periods of mouth-frothing rage
before, so one can't be too optimistic.

--
Bill Sloman, Nijmegen
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David L. Jones
electronics forum Guru Wannabe


Joined: 07 Jun 2005
Posts: 286

PostPosted: Fri Jul 21, 2006 12:18 am    Post subject: Re: Count 1ns pulse Reply with quote

Phil Allison wrote:
Quote:
"David L. Jones"
Paul Taylor wrote:

Derhhh sorry Dave you are right i misread the scope it is in fact 1usec
timebase not as i previously thought 1ns must get my eyes tested.

Thread closed!

Dave :)



** That penny just made ONE HELL of a clang !!!!

No toasters to fix today Phil?

Dave Smile
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Paul Taylor
electronics forum beginner


Joined: 10 Feb 2005
Posts: 45

PostPosted: Fri Jul 21, 2006 8:07 am    Post subject: Re: Count 1ns Pulse Reply with quote

"Bill Sloman" <bill.sloman@ieee.org> wrote in message
news:44bf9ea5$0$2017$ba620dc5@text.nova.planet.nl...
Quote:
What sort of photomultiplier tube are you using to drive the AD7 amplifier
discriminator?

Photomultiplier data sheets usually list the typical single photon output
pulse width - it depends on the spread of the electron trajectories
through the dynode chain, and it is pretty reproducible.

Using the wrong voltage distribution down the dynodes can mess up the
pulse width - with fast focussed high gain tubes yo can need a lot of
voltage across the last few dynode to prevent the space chage associated
with the electrons from messing up the electric field and spreading out
the electrons.

--
Bill Sloman, Nijmegen

Hi bill the photomultiplier is supplied by Stockholm university which they

now have back, I don't have no data sheet on it as it is a old type one, I
heard back from the guy at electron tubes and basically he has said the same
as you! dependant on photomultiplier tube speed and biasing of the tube ect,
Im trying to pin him down on the minimum pulse width, he has said between
3ns and 15ns so if I work with 3ns then any type of photomultiplier tube
will work.
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Paul Taylor
electronics forum beginner


Joined: 10 Feb 2005
Posts: 45

PostPosted: Fri Jul 21, 2006 8:16 am    Post subject: Re: Count 1ns pulse Reply with quote

<bill.sloman@ieee.org> wrote in message
news:1153431871.396180.99330@m73g2000cwd.googlegroups.com...
Quote:

ian field wrote:
bill.sloman@ieee.org> wrote in message
news:1153414810.930979.13180@m79g2000cwm.googlegroups.com...

Phil Allison wrote:

snipped usual rubbish

We have to be kind to Phil. He lives in Sydney, and can't get refugee
status anywhere else.

--
Bill Sloman, Nijmegen


He'll burst a vessel if he keeps on like that!!!!!

We can hope, but he's survived long periods of mouth-frothing rage
before, so one can't be too optimistic.

--
Bill Sloman, Nijmegen


Isn't it a shame that a certain individual trying to ruin the thread, I
reckon Phil must lead such a sad and boring existence that he has to try and
insult every one else to make himself feel better!

Phil seek some help mate as Im sure that under all that bitter and twisted
attitude is a nice helpful guy waiting to get out and into the real world of
existence with normal people.
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Paul Taylor
electronics forum beginner


Joined: 10 Feb 2005
Posts: 45

PostPosted: Fri Jul 21, 2006 8:34 am    Post subject: Re: Count 1ns pulse Reply with quote

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:44bf9381$0$9932>
Quote:
The 74F579 has tristate outputs, which means that it can fit an 8-bit
counter into a 20-pin pacakage. Not quite as fast as the ACT163, and
probably eats more current, but it might be interesting, if you can find
someone willing to sell you a few. Fairchild will probably send you free
samples if you ask nicely, but maybe not enough.

If board space really is a problem, go for a biggish programmable logic
device. My guess is that the smallest of the CoolRunner 2 IC's, with 32
logic cells could accomodate two 12-bit synchronous counters and most of
the rest of your glue logic in a single 44-pin package

http://direct.xilinx.com/bvdocs/publications/ds090.pdf

http://direct.xilinx.com/bvdocs/packages/pc44.pdf

If you went for the next step up, with 64 logic cells in the same package,
you could probably accomodate all the logic on the board ...

And I'm pretty sure that the parts are fast enough to make your counter
...

--
Bill Sloman, Nijmegen

I would like to get into using Xilinx but time is a little bit tight for me

on this job at the moment. I did think to start with about using FPGA? this
is another area i need to get into more.
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