I am a very capable individual. I have 1.4 million readers in 155 nations! I must remain anonymous, because I've experienced 15 murder attempts in the last 3 years, all because of what I write.
Care to share with us what you have written that garnered 1.4m readers and 15 murder attempts?
After all, it is public, right?
Perhaps you'll even gain some more readers...
there are many places in a design of this sort to shave off slivers of noise, jitter, instability and drift, if you know where to look.
The price has been raised to $157
@ TunerSandwich RE Fluke refs -- do you mean the 731A or B? Very nice if cleaned up and working well. I've had two 343A (I still have one) and two 332s -- an A and a D -- all of those proved to have both short and long term jumps and spikes. They all had/have the Fluke/Motorola buried zener refs; in the 332s, these are in ovens, while they are naked in the 343s. So as transfer standards, they would work, but as references, not so much. I believe the basic problems come from the chopper amp circuits, so I have a plan to build a different chopper amp for the 343 I have now.
I have had two Fluke 732As with really good experiences -- really wish I had those back now. They would hold better than 0.5ppm from a cold start to fully hot on the 10V output, but the 1V and 1.018V outs were much less good, which was maybe why I had them and some cal lab didn't. I couldn't see any reason to keep them hot all the time, though i suppose that's good long term -- the 732A also uses the Fluke/Moto buried zener ref and puts it and all the divider resistors in a foam box with 4 plate-type heaters.
I have a digital image of the cal certificate for the 732A. but I found it confused eBay buyers. I had much less sales, so I took it out of the listing. You can see it if you want, though.
Hi Awesome14,
YES! Please post the calibration certificate from Fluke here in this forum
I have some suggestions for improving your reference:I think if you did all of these things, you would notice a great improvement in stability of your reference. I didn't mention accelerated burn-in procedures, as I am sure you are already doing that. There is no reason why you could not raise the price of your product to cover the costs of doing all of this.
- Consider moving the TempCo adjustment to the "noise reduction" pin. This will reduce the influence the TempCo fine-trim has on voltage fine-trim.
- Consider using better quality resistors in the divider chain [and for the trim-pot]. The resistors I have in mind are the Vishay UXB-0207 series, which you can buy at 2ppm/K. The Vishay Precision Group 1285G trim-pot has 5ppm TCR [for the total resistance]. Texas Components, Digi-Key, and Mouser stock these, but they are more expensive in small quantities.
- I know you stated that the AD587 is not as good as the REF102, and that may be true for the REF102 in a hermetic "can" [which they don't sell anymore], but it is *not* correct for the hermetic AD587 in a ceramic package vs. the REF102 in a plastic package. Humidity causes the plastic [epoxy] IC packages to expand, and this [in turn] causes stress on the IC's die, and this [in turn] causes a shift in the voltage output. Inside the package, the buried Zener is probably not affected by this phenomenon very much, but the REF102 also has a current source for the Zener and a boost op-amp with gain setting resistors that *will* be affected.
- If you don't want to switch to the ceramic AD587, then consider encapsulating the entire circuit board in dual-wall PTFE/FEP heat-shrink tubing. PTFE and FEP are from the fluorocarbon family, and the strong fluorine bonds in the material make it [chemically] very stable. When you shrink this over the entire PC board, the PTFE has a higher melt point than the FEP, and so the FEP will melt and "fuse" to the thing that you are encapsulating. To prevent damaging the components, place a silicone-foam weather strip on top of them and on the bottom of the board before applying the heat-shrink. This provides a 100% stop to water vapor infusion-- [in essence, it is a "poor man's hermetic package"]. Naturally, you will have wires exiting the heat-shrink for the power [(+), (-) in], the reference [(+), (-) out], and 4 more wires to attach the external trim-pots.
- Consider using a metal enclosure inside of a plastic enclosure. The metal enclosure would only be attached to the reference (-) output, and would act as a "guard", as well as would reduce temperature gradients. The metal box could be placed inside of the plastic box, with wires brought out for power in, reference out, and trim-pots. Then the inside of the plastic box is filled with closed-cell polyurethane expanding foam [you have probably seen this in your hardware store in a small can-- it is used to seal the cracks in your house from the wind]. The foam [together with the internal metal box] will act as a "thermal lag" type of system, keeping the temperature very stable inside.
- Please consider switching to Tellurium Copper binding posts on the output (+) and (-) terminals to reduce thermal EMF's.
-Ken
I want you to wait 24 hours after reading this message. Then, return to this board--if you are able--and try spouting your arrogant diatribe against me words. Behold, The Lord God Almighty!
Seriously? And you are calling others arrogant?
I'm sorry but I simply don't see where you have done anything "remarkable".....in fact I see a rather un-remarkable attempt at self marketing an average "voltage standard"....with claims that you have somehow cracked some great physics mystery....
If you keep experiencing hostility from others....throughout your life....maybe it's time to take a step back and realize the problem isn't everyone else
P.S. "sealed" is a total embellishment....your package is NOT hermetically sealed, nor is the inside of the enclosure a vacuum....I'm sorry, but your claims are very over the top....there is nothing remarkable or special about your device....although I think the REF102C is an excellent and inexpensive ref IC chip....+/- 2ppm (which is totally unfounded over time) is not "remarkable"
Why do these guys always have to sound crazy? Unverifiable anecdotes, pleas to authority, and meaningless technobabble just make you look defensive and uneducated.
Provide logical rationale for the design decisions that have been made and everyone is happy.
I don't see how following a simple applications schematic is in any way cutting edge.....I simply don't see anything out of the ordinary (other than somewhat shoddy construction), and when confronted with that issue, the maker says "it's a big secret". Really? What is so special or secretive about a monolithic REF IC?
Hell we have all seen the guts of a Fluke standard....and it's a far far far cry above and beyond the $100 ebay special....and even that isn't "remarkable" or "ground breaking"......nor is it "magic" nor does it do anything that can't be significantly bettered......it simply follows an accepted standard for producing reasonably low drift/stable transfer standards.....it's not magic, and it's not super science.....it's basic electronics engineering....given Flukes resources and engineering prowess, i highly doubt any of us here, acting independently are going to best their efforts and "revolutionize" any facet of their already acceptable design.....and it's surer than shit not going to happen at a $100 per unit cost basis.....
I found this whole topic quite amusing at first, but now it has crossed the line into complete and total insanity....conspiracy theories about death threats.....claiming mental superiority over other engineers....claims of cracking mystical boundaries of physics the rest of us are "too dumb to understand"....etc etc etc.....
this shit is just plain bonkers.....but wonderfully entertaining.....I can't wait to hear all about the death threats and "assassination attempts"
The design was a gift to me, and I'm passing it on.
uhhhhhh, I thought you invented it. Or was it given to you as a gift? Or do you mean a gift from on high?
I am a very capable individual. I have 1.4 million readers in 155 nations! I must remain anonymous, because I've experienced 15 murder attempts in the last 3 years, all because of what I write.
Care to share with us what you have written that garnered 1.4m readers and 15 murder attempts?
After all, it is public, right?
Perhaps you'll even gain some more readers...
I am a very capable individual. I have 1.4 million readers in 155 nations! I must remain anonymous, because I've experienced 15 murder attempts in the last 3 years, all because of what I write.
Care to share with us what you have written that garnered 1.4m readers and 15 murder attempts?
After all, it is public, right?
Perhaps you'll even gain some more readers...
I made the greatest scientific discovery of all time. So, I published it. It's the holy grail: the key to immortality and absolute power; or perhaps I should phrase it: extremely extended lifespan and the ability to manipulate the physical laws of nature. I've demonstrated that it is the means by which God conceived the Christ Child in the womb of Mary Most Holy. I've also done a thesis that the same principle when mixed with murder produces vampire fetuses.
No one has ever argued the points I have made regarding immortality, absolute power, or vampires. So, now you'll have a bit of google fodder. But I'm not tying myself to any certain published material, because I don't desire to be linked to it.
The price has been raised to $157
The price has been raised to $157
Thankfully the market dictates "value". I can buy a half way decent Fluke ref (older model) for around $200 (I foolishly let one go the other day on the ole eBAY), with broad voltage ranges....proper compensation and cal features and don't have to pay 30% of the value in shipping.....
I say best of luck fetching $157 + shipping from a potential customer.....but it won't be coming from my bank account.....but again the seller doesn't care about money, because he's already set-up, in that respect....
Curious that he has all the money he needs though, and is so accomplished, but then feels the need to raise the price, so he can "help the EE community out".....give me a break
@ TunerSandwich RE Fluke refs -- do you mean the 731A or B? Very nice if cleaned up and working well. I've had two 343A (I still have one) and two 332s -- an A and a D -- all of those proved to have both short and long term jumps and spikes. They all had/have the Fluke/Motorola buried zener refs; in the 332s, these are in ovens, while they are naked in the 343s. So as transfer standards, they would work, but as references, not so much. I believe the basic problems come from the chopper amp circuits, so I have a plan to build a different chopper amp for the 343 I have now./quote] Those are +-10ppm refs. I have buyers purchasing my standard to calibrate 731s. Sheesh!QuoteI have had two Fluke 732As with really good experiences -- really wish I had those back now. They would hold better than 0.5ppm from a cold start to fully hot on the 10V output, but the 1V and 1.018V outs were much less good, which was maybe why I had them and some cal lab didn't. I couldn't see any reason to keep them hot all the time, though i suppose that's good long term -- the 732A also uses the Fluke/Moto buried zener ref and puts it and all the divider resistors in a foam box with 4 plate-type heaters.
The 732A is not meant to be powered off, ever!Quote731B. They are obviously nothing compared to a 734A (loaded with a few 732B).....but you can get them all day on eBAY for under $200.....I let one go a couple weeks ago for $135....figured i have too many transfer standards already, but I would like to have a nice 731B to clean up, cal and refurb (battery pack etc). I always thought they were cool (in a funky retro gear kind of way) and they were/are certainly well engineered product, with the assurance and confidence that Fluke doesn't partake in any "magic".The older Flukes are nice for nostalgia.QuoteSo options given....$157 + shipping for Mr. "Awesome14" "standard" or $135 + shipping for a genuine Fluke standard....which has pretty solid range capability...and doesn't "lose it's precious vacuum, hermetic, magical seal" when you open it up to re-cal or service it?So, then you want a standard that's less accurate, 10ppm vs. 2ppm. The D-105 DC doesn't require opening of the chassis for any reason.QuoteSeems like a no-brainer to me....oh and of course lets not forget the Fluke has mains power into it (no additional investment in tying up a nice PSU to let Awesome14 standard cook 24/7). Also the brilliant capability to remove AC mains and move the unit around......and further gain confidence in your measurement, by running completely isolated from any nasty service flaws....The D-105 DC will run for weeks on (2) 9V batteries, isolated from mains. But it is repeatable over power cycles, so you don't need to run it for weeks. The D-105 DC is the most accurate standard behind the Fluke 732A, 732B, Josephson effect reference, and a Daytron reference. You can't touch those for under 500.00! Let's make fair comparisons.