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Counter project complete.

Posted: Mon Oct 18, 2010 11:25 am
by Richard Hull
This relates to a counter suitable for interfacing to any nuclear detection system.

I have been playing with a new counter with giant digits since May of this year and finally had the time to complete the on going effort this past weekend.

I attach some images. All that remains is to get my hands on a suitable sized ruby red filter from a local plastic place. I hold a small piece I have to show the effect in one of the images.

The unit uses large 2" tall LED 7 segment readouts. I decided to go retro and hand wired the 238 connections of 26 TTL ICs in an old school design. This is simple counter and not made to do any frequency counting or necessarily fast work. 10khz is the most any amateur would need but this tracked an HP pro unit count for count up to nearly 5 megahertz. I was stunned the hand wiring worked to that speed. The most I have had need of is about 1000hz in neutron counting. I assembled it in an old discarded 19" rack case that was dumpster bound here at work.

This will replace the cool old HP nixie tube unit that was in the rack seen in the HEAS 2010 images. I opened the lab door, went outside against my neighbor's fence and could easily read the digits from about 40 feet away.

Just an infrastructure item but no one will have trouble in a crowd reading the count.

Richard Hull

Re: Counter project complete.

Posted: Mon Oct 18, 2010 11:40 am
by Mike Beauford
Hi Richard,

Nice package job! Now that's what I call durable construction. It looks like you could roll a truck over it and it would still work.

Mike Beauford

Re: Counter project complete.

Posted: Mon Oct 18, 2010 1:07 pm
by Tyler Christensen
Very nice build. I've done similar things with both 4026 chips cascaded with LED segment displays (although I must say, you certainly beat me in digit size!) as well as 4017 chips with nixie tubes, both count with plenty of speed, up to the mhz range.

I'm curious, what chips did you use? I see you said 26 IC's, that is far more than I used in my designs (one per digit).

Re: Counter project complete.

Posted: Mon Oct 18, 2010 3:39 pm
by Richard Hull
Each digit has 4 IC's 7490, 7475,7447 and a 16 pin dip with 8 X 330 ohm resistors as segment limiters. The other 4 ICs are input shapers and monostables, etc.

Like I noted, an old school effort clubing one's way to a counter. A lot of the older Intersil "ICL" prefix number 40 pin chips were full counters, decoders all in one, but I liked the durability of the ancient, power hungry logic that was pretty static and noise impervious over the modern nmos/cmos stuff or the even more modern roll your own MPU chip stuff. Although, I am currently dipping lightly into the new Parallax Propeller developer board after playing with the basic stamp for years. On most of this modern stuff I am leaving the field to the younger guys so that they can spend their careers learnlearning 20 or 30 codes for this that and the other latest and greatest what-not, like I did back in the day. I figure I'll let the 'prop' be my last gasp at this sort of thing.

At lunch, I just picked up a large chunk of the deep ruby filter plastic and will post an image of the finished beast in the fusor control rack tomorrow.

Richard Hull

Re: Counter project complete.

Posted: Mon Oct 18, 2010 11:09 pm
by Jerry Biehler
Way to be counter productive!




OK, I will go now...

Re: Counter project complete.

Posted: Tue Oct 19, 2010 9:17 am
by Richard Hull
Here are the promised images of the counter integrated into the fusor instrument rack and fully finished with the new filter.

Picture one is a close up of the rack and gear. The top two LED displays (Voltage and Current), are a full 1" display giving an idea of just how large the new counter's digits are.

Next is an overall shot

Finally a shot from about 12 feet back. The other instruments are a blurb in the low res image, but not the new counter.

Richard Hull

Re: Counter project complete.

Posted: Tue Oct 19, 2010 9:31 am
by Mike Beauford
Hi Richard,

Once again, nice work. Very clean.

Mike Beauford

Re: Counter project complete.

Posted: Tue Oct 19, 2010 7:09 pm
by Rich Feldman
Very pretty, Richard, and the retro -implementation- is well appreciated.
Using great big digits emphasizes that among all the instrument displays, this one represents the fusor payout!

Re: Counter project complete.

Posted: Wed Oct 20, 2010 10:10 am
by Richard Hull
Interesting comment about the payout.........So it is a big scoreboard in the game of fusion so that all the spectators can see how the home team is doing during the game.

Richard Hull

Re: Counter project complete.

Posted: Thu Oct 21, 2010 2:33 am
by Richard Hester
I saw it as a counter for us old geezers with bifocals, heh, heh. Can't laugh too hard, though, as I got my bifocals a long time ago... It's a splendid possible use for the TTL that otherwise might as well be shoveled into my coffin (or urn) when I kick it. I have a set of large 5X7 LED matrix displays that have lacked purpose for quite a few years. This might become their purpose in life. It would be nice also if they had something to count, but that's another matter altogether.

Re: Counter project complete.

Posted: Thu Oct 21, 2010 8:14 am
by Starfire
Congrats Richard - a good effort - better than working with SMT SOT-23 or 1206 with tweezers and the need for an inspection microscope

Re: Counter project complete.

Posted: Fri Oct 22, 2010 11:42 am
by Richard Hull
Yes, The large DIPs of old are about the only way someone is going to do electronic hobby work without involving a PCB house or going blind.

The large digits were for large visitor groups, of course, but as Richard notes, our eyesight is bad and I have had bifocals for over 20 years now. I feel I know why too.

When Richard and I were young, there were no computers or computer games, no cell phones, internet,etc and Television was not fully developed and most only broadcast after dark. (no daytime TV) As such, we had to play outdoors with friends or go inside and play with ourselves. I fear the latter has caused the early onset of poor eyesight..........If I might further an old wives tale.

Richard Hull

Re: Counter project complete.

Posted: Fri Oct 22, 2010 1:51 pm
by Richard Hester
I have my eye on some middlin' large Russian vacuum fluorescent displays that would make an attractive display that looks a little out of the ordinary. There's some huge VFDs on Ebay originally meant for clock duty, but the seller wants some really intense folding money for those. The Russian product goes for beer change.

Re: Counter project complete.

Posted: Fri Oct 22, 2010 3:06 pm
by Starfire
Agh! - ( R.Hull ) an honest man