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Analog Faceplate Design Decisions: Art or Science?

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mhrackin
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What about the WORST CASE?
mhrackin   10/30/2014 12:50:50 PM
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You have based the "blue moon" display using the AVERAGE time between blue moons of 2.7 years. But you have set the maximum time dispayed to the next blue moon as 3.0 years. What is the MAXIMUM time to the next blue moon? If it's more than 3.0 years, you can't display it accurately!

Max The Magnificent
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Re: What about the WORST CASE?
Max The Magnificent   10/30/2014 1:48:58 PM
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@mhrackin: You have based the "blue moon" display using the AVERAGE time between blue moons of 2.7 years. But you have set the maximum time dispayed to the next blue moon as 3.0 years. What is the MAXIMUM time to the next blue moon? If it's more than 3.0 years, you can't display it accurately!

That's a great question. I'm glad to see someone is paying attention LOL. Actually, I didn't say I had based the display using the average time between blue moons -- I just happened to note that "...a blue moon occurs about once every 2.7 years."

What I should have also noted is the minimum and maximum number of days between blue moons. I've nit actually found those values referenced anywhere, but here's the way I worked them out by hand...

Neglecting leap years (only for the purposes of these discussions -- I do account for leap years in my algorithms used in the Inamorata Prognostication Engine), three years equates to 3 x 365 = 1095 days.

Today's Julian Day (JD) number (Oct 30th 2014) is 2456961

Julian day numbers for blue moons (JD-BM) 2016 thru 2100 are shown below -- to the right of each JD-BM value is the number of days (ND) between this blue moon and the preceeding one. (In the case of the first entry, the ND value is the number of days between the forthcominh blue moon and today -- i.e., Oct 30th 2014):

             JD-BM    ND
2016 May 21 2457530  569
2019 May 18 2458622 1092
2021 Aug 22 2459449  827
2024 Aug 19 2460542 1093

2027 May 20 2461546 1004
2029 Aug 24 2462373  827
2032 Aug 21 2463466 1093
2035 May 22 2464470 1004

2038 May 18 2465562 1092
2040 Aug 22 2466389  827
2043 Aug 20 2467482 1093
2046 May 20 2468486 1004

2048 Aug 23 2469312  826
2051 Aug 22 2470406 1094
2054 May 21 2471409 1003
2057 May 18 2472502 1093

2059 Aug 23 2473329  827
2062 Aug 20 2474422 1093
2065 May 20 2475426 1004
2067 Nov 20 2476340  914

2070 Aug 21 2477345 1005
2073 May 21 2478349 1004
2076 May 18 2479442 1093
2078 Aug 23 2480269  827

2081 Aug 19 2481361 1092
2084 May 20 2482366 1005
2086 Nov 20 2483280  914
2089 Aug 21 2484285 1005

2092 May 21 2485289 1004
2095 May 19 2486382 1093
2097 Aug 22 2487208  826
2100 Aug 19 2488300 1092


To be honest, I'm not really concerned with what happens after 2100, because that's when I'm scheduled to be picked up and taken back to the home world (ooops, forget I said that).

If we take the average of the NDs above (neglecting the first one which isn't really part of the series), we get 992.5806 days, which equates to 2.7194 years if we assume 365 days a year (this is close enough to the 2.7145 value given by Google -- which I'm sure has accounted for leap years -- as to make me a happy camper).

The main thing is that the maximum number of days between the blue moons shown above is 1094, which means my display is hot-to-trot and good-to-go.

mhrackin
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Re: What about the WORST CASE?
mhrackin   10/30/2014 1:55:58 PM
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Well, I'm glad you're not projecting the useful life of your design to be absurdly long! After all, once all the great tidal pools (e.g. Bay of Fundy) have been equipped to generate electrical power by tapping the angular momentum of the moon, it would eventually render all your calculations useless....

Max The Magnificent
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Re: What about the WORST CASE?
Max The Magnificent   10/30/2014 1:59:25 PM
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@mhrackin: ...tapping the angular momentum of the moon, it would eventually render all your calculations useless....

I will leave it to my descendants to modify the code to accomodate such occurances :-)

mhrackin
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Re: What about the WORST CASE?
mhrackin   10/30/2014 2:13:26 PM
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@max: As you may appreciate, I have spent a large portion of my career as an active participant in the ancient hazing ritual known to the Cognoscenti as the "Engineering Design review." The guiding principle for such is, as I'm sure you know, "No nit is too small to be picked!"

Max The Magnificent
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Re: What about the WORST CASE?
Max The Magnificent   10/30/2014 2:17:50 PM
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@mhrackin: ...the "Engineering Design review." The guiding principle for such is, as I'm sure you know, "No nit is too small to be picked!"

A thorough design review is the only way to have any chance of getting a working product, as far as I'm concerned.

zeeglen
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Re: What about the WORST CASE?
zeeglen   10/30/2014 2:49:09 PM
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@max "No nit is too small to be picked!"

A thorough design review is the only way to have any chance of getting a working product, as far as I'm concerned.

Agree, just so long as the reviewers are technically competent and not themselves nitwits looking to squeeze a penny here and a penny there to add up to 2 pennies saved per unit to get their annual bonus...

I've been nitpicked many times about the the most brainless things by managers of digital design teams who knew just enough to be dangerous.  ("Do you really need that many decoupling capacitors?  Why can't you use our standard value resistor like everyone else does?" ) But when the meetings progressed to the analog portions of the schematic everybody shut up and moved on to the next page.

Max The Magnificent
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Re: What about the WORST CASE?
Max The Magnificent   10/30/2014 2:51:12 PM
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@zeeglen: Agree, just so long as the reviewers are technically competent and not themselves nitwits looking to...

OMG yes -- I totally meant a design review involving real engineers, not drongo managers...

Max The Magnificent
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Re: What about the WORST CASE?
Max The Magnificent   10/30/2014 2:52:15 PM
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@zeeglan: But when the meetings progressed to the analog portions of the schematic everybody shut up and moved on to the next page.

So true ... so scary!!!

mhrackin
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Re: What about the WORST CASE?
mhrackin   10/30/2014 2:49:24 PM
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@max: "I will leave it to my descendants to modify the code..." Are you implying that in the few decades you have left you won't be able to leave the world a legacy of robotic debuggers? There will be much weeping and wailing....

Max The Magnificent
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Re: What about the WORST CASE?
Max The Magnificent   10/30/2014 2:54:09 PM
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@mhrackin: Are you implying that in the few decades you have left you won't be able to...

Few decades? I'm aiming at another 50 years!!!

mhrackin
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Re: What about the WORST CASE?
mhrackin   10/30/2014 3:02:24 PM
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Well, that qualifies as a few in MY book!

David Ashton
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Re: What about the WORST CASE?
David Ashton   10/30/2014 6:39:14 PM
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@mhrackin.... "After all, once all the great tidal pools (e.g. Bay of Fundy) have been equipped to generate electrical power.....  "

You don't need to worry about that.  Our Prime Minister assures us that we have tons of high grade coal in Australia, and that it is the best way to generate electricity.  Tidal pools....schmools......

GSKrasle
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Industrial Design for Engineers
GSKrasle   10/30/2014 3:20:46 PM
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‘Out of all of the things I wish I'd been exposed to, one that is right up there at the top of the list is Industrial Design. I would love to know some of the underlying principles of this discipline.’ Max, you need to peruse the Sacred Book! It’s full of engineering-oriented examples of bad and good design, and you’ll probably want it on your ‘close’ bookcase forever. The Design of Everyday Things: by Donald Norman: h t t p : / / w w w .amazon.com/The-Design-Everyday-Things-Expanded/dp/0465050654 The book inspired a lot of people, including this web-site (which, regrettably, had been neglected for some time): h t t p : / / goodexperience.com/tib/

kfield
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Re: Industrial Design for Engineers
kfield   10/30/2014 4:07:50 PM
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@GSKrasle "Out of all of the things I wish I'd been exposed to, one that is right up there at the top of the list is Industrial Design"

I am with you on wishing that I knew more about industrial design - particularly given the rise of products now that have great design.

Max The Magnificent
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Re: Industrial Design for Engineers
Max The Magnificent   10/30/2014 4:17:19 PM
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@GSKrasle: Max, you need to peruse the Sacred Book! It's full of engineering-oriented examples of bad and good design...

I just added it to my Amazon wish list (I'll order it along with a couple of other books sometime in the next couple of days)

FYI -- you can specify URLs in your posts -- just miss out the http:// part

David Ashton
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Reticule?
David Ashton   10/30/2014 3:58:35 PM
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Max: "...presented in an arc above the reticule..."

Reticule didn't sound right, so I looked it up:

reticule   rɛtɪkjuːl/   noun

 1.     historical

a woman's small handbag, typically having a drawstring and decorated with embroidery or beading.

2.     variant spelling of reticle.

Now apart from having nothing to do with meters, the idea of Max with a small embroidered or beaded handbag reticule would expose him to ridicule, so that was obviously not the right definition.  I moved on to Reticle.

reticle   rɛtɪk(ə)l/ noun

 1. North American term for graticule.

Ah, North America!  Max lives there! we must be getting close.....

 graticule   ɡratɪkjuːl/   noun technical

1.  a network of lines representing meridians and parallels, on which a map or plan can be represented.

2. a series of fine lines or fibres in the eyepiece of an optical device, such as a microscope, or on the screen of an oscilloscope, used as a measuring scale or an aid in locating objects.

2 is getting close, but not quite right.  I think the best word is the good old "Scale"?

In my meanderings I found this interesting meter scale drawing program.

www.tonnesoftware.com/meter2.html

Max The Magnificent
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Re: Reticule?
Max The Magnificent   10/30/2014 4:28:21 PM
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@David: Reticule didn't sound right, so I looked it up...

Arrggghh -- I read the beginning of your comment -- skimmed to the end -- and just went into the article to change all instances of "reticule" to "reticle" -- then I came back and re-read your comment in more detail to see that "'reticule' is a variant spelling of 'reticle'" -- so I was OK in the first place.

I'll get you for this, Red Baron! :-)

David Ashton
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Re: Reticule?
David Ashton   10/30/2014 5:09:50 PM
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@Max... "I'll get you for this, Red Baron! :-)"

Well, at least you didn't tell me to shove it up my reticule.... :-)

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