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What's inside a vintage Fluke 5450A Resistance Calibrator used in cal labs to calibrate multimeters?
Schematic: assets.fluke.com/manuals/5450A...
Coto reed relay: www.farnell.com/datasheets/148...
High Resistance measurement with a relay matrix:
• EEVblog #38 - LCR Mete...
• EEVblog #38 2of2 - Sei...
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Опубликовано:

4 ноя 2013

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Комментарии : 181

@crisdodds1864 10 лет назад

I enjoyed your video alot. Especially the accent. I started working at Fluke almost 40 years ago next month. My Boss was one of the 5 original employees. My favorite part of my job has been the math, used to match resistors per drawings in order to make these instruments so precise. Thanks for admiring the dedication that I still put into all my jobs that I do here. Cris Dodds

@rsattahip 5 лет назад

Wish I could afford your equipment. I have to settle for the best Chinese equipment I can find like Rigol.

@vishalpatil7974 2 года назад

You deserve respect 👏

@pezikon 7 лет назад

I had my Fluke 5700A calibrated by Fluke just last year (2015). The cal cert includes a 5450A. So you could say it's still a relevant unit.

@RobertBardos 10 лет назад

I loved how u talked it down to a box of resistors in the beginning but it actually ended up being quite a work of art at the end. Good video pretty neat stuff.

@mushroomsamba82 10 лет назад

One of the best teardowns yet, this thing is like a piece of art.

@Psychlist1972 10 лет назад

Test equipment doesn't do a whole lot for me, but I really enjoy seeing what people go through to achieve high precision. Another great teardown, Dave.

@EEVblog 10 лет назад

Even if you used modern $20 resistors, you'd still need the special relays and careful design shown in this design to give the same functionality. The product may be vintage, but the design rules are not!

@NathonDalton 10 лет назад

I love your videos. I'm new to the EEVBlog and have already learned so much! Thank you very much for taking time out of what I'm sure is a busy schedule to make these videos!

@kevincozens6837 5 лет назад

My cat and I both enjoyed the video although the cat was more interested in pawing at the screen trying to catch the black pointer you were waving around. :) I also noticed at the 25 minute mark the schematic mentioned the use of special "telfon" standoffs.

@KenYOW Год назад

Those solder joints are beautiful.

@strangersound 8 лет назад

"Each manufactured and hand assembled by nude virgins in Utopialand. Tested by graybeards. Beautiful." :D

@ryankelzenberg3453 10 лет назад

Some of the "early" gear was sure built to last. Some great history and finds for the teardown tuesdays.

@MarkShannonroad_videos 10 лет назад

Sprague is still around. Lots of people use them to restore old televisions and radios because they tend to last. Great video as always!

@wetwingnut 10 лет назад

"All the electrons are going to fall out." LOL Dave, you know why you're successful? Because even when I'm not particularly interested in the topic I still make time to watch you because I know I'll always be entertained. Thanks mate!

@vmiguel1988 5 лет назад

Dave the plate in the 1ohm resistor is Mica not plastic.

@theoryof9 10 лет назад

The shielded wound resistors are wound on mica insulators that were also used in HV vacuum tubes, great insulation values.

@pigpenpete 10 лет назад

In our lab we're still using a vintage Wavetek 4808 multifunction calibrator but we've characterized it over a fair few years and we can get fairly good uncertainties exceeding the original specification, good enough for most 8.5 digit long scale DMMs anyway.

@crocellian2972 9 лет назад

Maybe your best ever. I will never have a chance to see this tech. Many thanks.

@gglovato 10 лет назад

lol @25:10 "telfon", 1979 original typo!

@Damien.D 7 лет назад

This thing is a serious piece of art.

@edherdman9973 10 лет назад

So, about that linear regulator, two ideas: 1) To keep the heat from bothering other parts? 2) To make sure that it was conducting heat out into the chassis, but they didn't want any stresses on the chassis being transferred into the linear regulator's soldering points, so they used the flexible cable for a standoff? I like the second idea better, could it be something else though?

@excavatoree 10 лет назад

The bus company I worked for used them for the chassis power circuits. P&B "ice cube" relays were rated at 40 Amperes, while the rest were 30A or 20A. We only used P&B and Bosch. Now, my current company uses Tyco relays that I believe are no longer made in the USA.

@MrocznyTechnik 10 лет назад

25nA half of a bee's dick - cannot stop from laughing :D

@materialsguy2002 7 лет назад

MrocznyTechnik i

@smbrob 10 лет назад

One hot peace of electronics Dave.

@WooShell 9 лет назад

Re 12:30 - Sprague joined Vishay a decade or two ago.. and I wouldn't be surprised if they were still behind their power elcap series.

@scottgfx 10 лет назад

I'm not sure why they exist, but they do make GPIB 488 to USB adapters! 25 years ago we had a Tek plotter with a GPIB interface donated to the art lab at my college. Sadly, we didn't have anything that would talk to it. Didn't have the internet back then to look up Microchannel GPIB cards! :)

@Eman2000 10 лет назад

i have heard of Potter and Burmfield (P&B) i have a 4PDT relay from them in the original box. the box says that they make electromechanical relays, solid state relays, time delay relays, specialty sensors, circuit breakers, solenoids, contactors, sockets and accessories at least at the time this was made, the box also says made in the USA

@treborrrrr 10 лет назад

I always find it hilarious how Dave just can't quite resist poking at things. Not saying that the little taps with the plastic spudger would actually do anything but with all the talk prior to popping the lid off... :P

@anachrocomputer 8 лет назад

Not only are the relay poles in parallel, they're in inverse parallel. The wiper end on one pole connects to the fixed contact on the other pole. I wonder if that's for easier PCB layout? Or is it done that way to minimise the effects of the metal-to-metal contact in the relay? Thermal EMFs? Differences in contact resistance with polarity?

@johantoftling5518 6 месяцев назад

One of those should be nice to have in my collection 😊

@Avionics1958 10 лет назад

ah good old Zilog, Z-80 how much fun we had with these in 80's :-)

@bazathemanyoungG0SCI 10 лет назад

Hi Dave the Screened area is a ribbon wound resistor on a mica former

@AmirHakimiRezaei 10 лет назад

your screwdrivers still amaze me

@johnclawed 6 лет назад

Never heard of Potter Brumfield? They were huge in relays.

@twomorestars 10 лет назад

Awesome video!

@TheHuesSciTech 7 лет назад

The relays do NOT have to have ultra low or ultra consistent contact resistance in 4-wire mode. The inherent advantages of 4-wire mode apply to relay contacts as well, as long as you invest in double the number of relays, or dual-throw relays (since you need to switch both sense and force).

@douro20 10 лет назад

It's probably a silver-tin alloy with high silver content, and I would imagine that it was soldered without flux, in a glove box under an argon atmosphere.

@JosefdeJoanelli 10 лет назад

14:55 Potter and Brumfield also make LOTS of resetable circuit breakers and switch breakers for aircraft.

@paulbendel 10 лет назад

I didn't know boards had care factors! Awesome :)

@rsutherland76 10 лет назад

Yes it is, good catch!

@topxe. 10 лет назад

Very cool. I would love to see the inside of those various relays and resistors. Obviously this would be destructive but hey... :)

@whitcwa 10 лет назад

I worked on pro VTRs and one maker abbreviated "Record Tally" as "rectally".

@mtravnik84 2 года назад

We have 4 of these still in use at the NASA Marshall Space Flight Center. They still serve their purpose.

@MarkShannonroad_videos 10 лет назад

I stand corrected. A lot has changed in the world of component makers over the last 25 years. At least the name hasn't been bastardized like some in the industry. Thank you for the correction.

@antonioferraoneto6681 7 лет назад

Very nice video! Thanks!

@matthewrichardson828 6 лет назад

This thing is beautiful

@martinda7446 9 лет назад

That was wonderful stuff.

@robber576 6 лет назад

I wonder if you would need to use a special high conductivity solder for such a unit? , and what would that be? , high in silver?

@cemx86 10 лет назад

The spare fuses was a nice touch. I also noticed next to the huge blue Sprague cap (look at the size of the bracket!) something held in what looks like a fuse clips but it has leads and is soldered in place. What was that? Why the clips?

@CoolMusicToMyEars 2 года назад

I always wanted the Fluke 5450A resistance standard, but what a cost in those days & these days, I like it, but 4 Terminal Resistors in oil bath are far better

@digital4282 10 лет назад

Dave, Does the amount of dust on that board cause any issues with the resistors? Thanks!

@LawrenceDuffy477 10 лет назад

Always a fun time

@skonkfactory 10 лет назад

The resistance wire used is probably constantan or manganin or something like that. Low tempco alloy.

@crisdodds1864 10 лет назад

PS- I'm not a nude virgin.

@baroque_engineer 10 лет назад

And there was none of them involved in assembly process? I'm kinda disappointed... :D

@MaxKoschuh 9 лет назад

Cris Dodds Hahahaha. Great work, Chris.

@kcasc_hd 2 года назад

19:42 I found a website that could give informations concerning the electrol relays

@rsnilssen 10 лет назад

considering its a ten year old design at the guesstimated date of production maybe the flatflex was added to accomodate some change in production at some point during the lifetime of the design

@TomStorey96 3 года назад

Is there a reason they would use 162 ohm resistors in parallel when that results in 81 ohm? 81+10+10=101 but on the board it had 100 written?

@TestTubeBabySpy 6 лет назад

would have been cool to hear the relays

@djscottdog1 10 лет назад

what was that calc with the parallel button i want one

@SergeiKotikov 6 лет назад

Aren't those mica sheets at 27:17?

@ericsbuds 9 лет назад

whats a moldymeter?? sounds nasty!

@anuragsaha9641 7 лет назад

ericsbuds This accent is one of the may rsns i watch eevblog regularly😂😂😂

@ericsbuds 7 лет назад

agreed. I was trying to make a joke but I am no comedian.

@Razor2048 10 лет назад

Can those resistors and other parts be re purposed for other devices? eg repairing cheap electronics :) One thing I wonder, how do they get the initial calibration for the first ever device, eg who made the first ever resistance standard and how did they know when that was accurate when there is no other calibration device to compare it to?

@TheOriginalEviltech 10 лет назад

Those 1 and 1.9 ohm resistors are wound on mica sheets. Same as normal heating elements.

@rustyrebar9647 4 года назад

That 'plastic see through former' is mica sheeting!

@oetken007 7 лет назад

28:00 I think it's Glimmer. It is a very good insulator and can handle temperatures around 600°C (soldering).

@bur1t0 7 лет назад

TIL: "Glimmer" is the German word for "Mica".

@williamsquires3070 10 лет назад

Okay, but what I didn't see are the back-EMF protection diodes for the relay coils... or, for that matter, driver transistors. Dave, did you note any ULN-series driver ICs for these things?!?

@alpcns 10 лет назад

Now THAT's a horrible thought:-) Thanks for another great video, Dave! How is that impressive back-to-the-future display doing? I would love to see it working!

@friedmule5403 6 лет назад

I am afraid of asking, but how many arms and legs do you have to pay for such a thing, new?

@bain5872 10 лет назад

As always enjoyed it. Do you think the clear 10 ohm former cards could have been Mica?

@cryptsys 10 лет назад

What EEVblog means is "if someone would kindly loan/donate an extender card, i could go further" :]

@Boerje69 9 лет назад

Moldy meter?

@echen1024 10 лет назад

Is your calculator RPN?

@petersage5157 6 лет назад

28:00 With the solder connections to those resistors, I doubt they're nicrhome. Basic metallurgy - solder takes to nichrome about as well as it does to aluminum. Of course Dave probably realized this moments after he said "nichrome".

@BAMBAM5476 10 лет назад

Where do you get this stuff man

@EEVblog 10 лет назад

I need an extender card before I can further do anything useful

@travisbigelow823 10 лет назад

@10:57-"you're only talking ten nanoamps... it's naff all, half a bees dick" HAHAHA! I love Aussie slang. Thanks for the video Dave. You're just as entertaining as you are informative, as usual :D

@matthew3p 6 лет назад

Travis Bigelow 10:57

@douro20 10 лет назад

The Coto equivalent for that is 1240-0177, according to NSN Now.

@lef149 7 лет назад

where did you get that shirt at?

@EEVblog 10 лет назад

Yes, ULN2003 drivers.

@NickMoore 10 лет назад

Tohms? Where i work we just call that "open"

@Bubu567 3 года назад

What is that, the resistance of 1 foot of vaccuum on the moon?

@wetwingnut 10 лет назад

That's a really good idea. What brand do you use? ;)

@StrapMerf 6 лет назад

Schrodinger's resistors under the can, looking at them changes their value...

@ve2zzz 10 лет назад

27:00.... Now you know where the zig-zagged resistor symbol comes from...

@matthew3p 6 лет назад

ve2zzz 27:00

@calmarcalmar 10 лет назад

not sure guessing: 0.1 + 0.9 = 1 1 + 9 = 10 10 + 90 = 100 100 + 900 = 1000 So when you connect all the small ohm together with the bigger ones, .you get 1.. stuff.

@chrisandcarleen 10 лет назад

potter and brumfeild some of the best relays you can get.

@GeorgeTsiros 10 лет назад

is that fx61f actually *programmable* ?

@simoncrabb 10 лет назад

Fascinating! Telfon!

@whitcwa 10 лет назад

Unlike modern DMMs, most meters at that time read up to 2, 20, 200, etc. I guess 1.9 was near full scale.

@ScramblerUSA 10 лет назад

It's probably a mica, not acrylic boards (on which 1 and 1.9 resistors are wound).

@berni8k 10 лет назад

While it is nice to see the guts of modern gear, those teardowns are usually not as fun since its alaways some BGA SOC processor, meaby a FPGA and varius tiny SMD bits around. While in vintage gear you always see some neat tricks they used to get around the limitations of technology back then(I absolutely loved the vintage high speed camera teardowns that tesla500 did)