Bottled! 10K Resistor - Page 1
Forum section: electronics / general

author: zhtoor
author_rank: Frequent Contributor
timestamp: May 07, 2018, 07:32:30 pm
content: -

author: BNElecEng
author_rank: Regular Contributor
timestamp: May 07, 2018, 07:49:52 pm
content: What is your end goal with this?

author: kj7e
author_rank: Frequent Contributor
timestamp: May 07, 2018, 07:53:50 pm
content: This one $26 resistor will far outperform the the 10 parts in parallel your proposing;https://www.digikey.com/product-detail/en/vishay-foil-resistors-division-of-vishay-precision-group/Y145310K0000V9L/Y1453-10KA-ND/2609894Edit: I just pulled one out and put it on my 34465A. When trying to obtain precision, the least expensive option will never yield the best results.

author: eurofox
author_rank: Unknown
timestamp: May 07, 2018, 08:07:52 pm
content: Quote from: kj7e on May 07, 2018, 07:53:50 pmI got one like that, build it into an hermetic enclosure with 4 decent binding post and 2 packet of silica gel.This way I build a quite cheap 10K reference.eurofox

author: pigrew
author_rank: Frequent Contributor
timestamp: May 07, 2018, 08:19:49 pm
content: I like the idea of soaking the resistor in oil to help it maintain a constant temperature. You could add an RTD (Pt100?) in the bottle to get a better idea of the resistor's temperature. It'll certainly help with humidity, but my gut instinct is that it wouldn't help (much) with aging. You may be able to fix the TC by selecting components with complementary TC in some range.

author: rhb
author_rank: Super Contributor
timestamp: May 07, 2018, 10:43:42 pm
content: The composite aging should be readily determinable by measuring the resistance and temperature during initial operation. The aging curve is almost certainly an exponential decline to a constant value. This is based on basic mechanics of materials considerations, stress, strain and visco-plastic deformation. That curve can be solved to ~1% for a period in the future equal to the length of time for which you have prior data. If the part changes by 40 ppm in a year, with 6 months data one should be able to predict the change to under 1ppm over the course of the next 6 months.The TC presents some interesting problems. It would be nice to have histograms of the coefficients for a third order polynomial fit to a bunch of resistors and run some Monte Carlo simulations of the composite TC for various topologies.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: May 09, 2018, 01:53:28 am
content: yeah, had play this way, relatively cheap resistors in par, seq but metal film only .....it doesn't has to be 100k to make 10k, it can be 4.99 or 5.11. or better some variations where you can find it cheapthe most important are tempco, so ....get as much as you can, resistors diff value ...measure each one for tempco, it may be positive or negative even in one batchcalculate connection in sequence parallel , to compensate tempco and get in summary a close to target value but should be below it....burn it at 150-170 C for a few days; that would be oxidation ageing processconstruct it togetherthen adjust a final resistance value by altering a metal surface, increasing a resistance use a scalpel or something sharp , you may consider a high nominal in parallel, if screw it up trow it and start again. then coating a few layers of conformal ....then you can dump a final product in the bottlethat would be a week of fun and stable, low tempco product , with some patient and good source you may outperform $26 resistorbtw, 25ppm usually possible to find for .05-.1 ; 0.50 - kinda expensive to play with .. bought 5ppm for $.11

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: May 09, 2018, 04:34:20 am
content: Lets just state the obvious: for over $100 time investment you may, perhaps, do better than buying a $26 resistor....

author: eurofox
author_rank: Unknown
timestamp: May 09, 2018, 04:42:48 am
content: Quote from: GigaJoe on May 09, 2018, 01:53:28 amoutperform $26 resistorResistance 10 kOhmsTolerance ±0.005%Power (Watts) 0.6WComposition Metal FoilFeatures Moisture Resistant, Non-InductiveTemperature Coefficient ±0.2ppm/°COperating Temperature -55°C ~ 125°CAnd you need an instrument able to measure the resistance up to 0.005%

author: GigaJoe
author_rank: Frequent Contributor
timestamp: May 09, 2018, 05:04:56 pm
content: eurofox, As I said, it matter of source material and time spend, for tempco and value - how precisely you compensate and measure. and environment stable temperature and humidity, and equipment. for example: HP3478A (5.5) pretty amazing in accuracy, for a last year 2 my units drift to 1 and 2 LSB. means it possible to measure .005%, consider to match with some reference , or use a bridge, if again, you have reference ....

author: eurofox
author_rank: Unknown
timestamp: May 09, 2018, 08:58:52 pm
content: Quote from: GigaJoe on May 09, 2018, 05:04:56 pmI never said that it is not possible but imagine checking a bunch of resistor the PPM + and PPM - and put them together the way they compensate each other and finally you need a "meter" that is calibrated and that is very precise. You stil need to solve the humidity influence.I prefer to pay 27$, put it in an hermetical enclosure and know that I have a good reference.eurofox

author: kj7e
author_rank: Frequent Contributor
timestamp: May 09, 2018, 09:00:32 pm
content: Quote from: zhtoor on May 09, 2018, 04:52:42 amYour original idea was to just simply take 10, 100K parts and wire then in parallel then encase it in rosin, not to combing neg and pos TC parts to cancel out TC.While you may be able to cancel out some or even most of the TC within a given window, you still end up a host of other issues. Load life, self heating, aging rate which all lead to a drifty standard. Now instead of one, you have many parts to account for and none will act or age exactly the same as the rest.It would take a nice TEC box, at least one high end DMM (you will need more resolution and stability than a 3468 or 3478), and weeks of TC testing and component selection to save just a few bucks. Not a very good trade off if your intent is to make a usable and stable reference vs academic.

author: tszaboo
author_rank: Super Contributor
timestamp: May 09, 2018, 10:26:35 pm
content: Quote from: eurofox on May 09, 2018, 04:42:48 amYou aren't reading the datasheet right. For 10K, the tempco is "±0.2 ±0.6", AKA 0.8PPM/K. Welcome to the world of "bulshitting on the front page" by Vishay Precision group. Oh dont get me wrong this is still probably one of the best resistor money can buy.

author: kj7e
author_rank: Frequent Contributor
timestamp: May 09, 2018, 10:36:02 pm
content: I wish I didn't see they had these in stock;https://www.digikey.com/product-detail/en/vishay-foil-resistors-division-of-vishay-precision-group/Y407810K0000V9L/804-1059-ND/4233065Oh well, also picked up a Hammond 1594RABK copper lined RFI/EMI shielded heavy duty plastic case that will be perfect for this.https://www.hammfg.com/electronics/small-case/plastic/1594rI already have some Pomona 3770 posts. It will give me something to play with over the weekend while I'm grounded.

author: rhb
author_rank: Super Contributor
timestamp: May 09, 2018, 10:56:16 pm
content: Quote from: kj7e on May 09, 2018, 10:36:02 pmDid you go for the 50 or the 100 unit price break?

author: CalMachine
author_rank: Frequent Contributor
timestamp: May 09, 2018, 11:06:16 pm
content: Perhaps this is a good place for a sneak peek

author: GigaJoe
author_rank: Frequent Contributor
timestamp: May 09, 2018, 11:57:56 pm
content: http://www.buy-components.com/components/vishay-foil-resistors/Y0078100R000V0L.htmlhttp://www.buy-components.com/components/vishay-foil-resistors/Y00781K00000V9L.htmlhttp://www.buy-components.com/components/vishay-foil-resistors/Y007810K0000V0L.htmlhttp://www.buy-components.com/components/vishay-foil-resistors/Y0078100K000V0L.htmlfedex shipping around $40 (i think), make sense for a few nominal or group buy

author: kj7e
author_rank: Frequent Contributor
timestamp: May 10, 2018, 12:37:22 am
content: Quote from: GigaJoe on May 09, 2018, 11:57:56 pmYou know that's a scam site right?

author: Vgkid
author_rank: Super Contributor
timestamp: May 10, 2018, 12:44:55 am
content: Quote from: kj7e on May 10, 2018, 12:37:22 amPrices looked a bit too low

author: kj7e
author_rank: Frequent Contributor
timestamp: May 10, 2018, 01:43:26 am
content: Quote from: CalMachine on May 09, 2018, 11:06:16 pm

author: CalMachine
author_rank: Frequent Contributor
timestamp: May 10, 2018, 02:36:25 am
content: Quote from: kj7e on May 10, 2018, 01:43:26 amSecret magic sauceQuote from: zhtoor on May 10, 2018, 02:20:41 amYes it is the 2nd 10k prototype! Preliminary measurement logging is showing roughly -0.1 ppm/ºC TCR.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: May 10, 2018, 04:37:55 am
content: Quote from: kj7e on May 10, 2018, 12:37:22 amFrankly , had no idea ...But, google the thing found at least 4 websites with the same design , same resistors, same price as above .... *&^$*&$ ...HK inventory has 0 (NULL) such items, seems whatever you find it , it a scam, or a pure luck of old stock, if it so ...

author: kj7e
author_rank: Frequent Contributor
timestamp: May 10, 2018, 05:06:24 am
content: Once I saw the price, I did some searching and found many references to fraud. You cant even buy VHP's used off eBay from China for those prices.

author: CalMachine
author_rank: Frequent Contributor
timestamp: May 10, 2018, 12:12:15 pm
content: Quote from: zhtoor on May 10, 2018, 02:39:09 amThe current prototypes employ a 2 wire connection on the side of the box to a 10 kOhm NTC thermistor.

author: HighVoltage
author_rank: Super Contributor
timestamp: May 10, 2018, 02:03:36 pm
content: Quote from: CalMachine on May 09, 2018, 11:06:16 pmWhat brand is blue banana plug for the guard cable ?Or is this an original Fluke low emf cable?

author: CalMachine
author_rank: Frequent Contributor
timestamp: May 10, 2018, 02:38:31 pm
content: Quote from: HighVoltage on May 10, 2018, 02:03:36 pmIt's a Pomona!https://www.pomonaelectronics.com/products/hardware/banana-plug-safety-collar-solderless

author: TiN
author_rank: Super Contributor
timestamp: May 10, 2018, 04:29:12 pm
content: Quote from: kj7e on May 10, 2018, 01:43:26 amBoxes? I have some boxes...With extra touch of blue tape

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: May 10, 2018, 04:33:14 pm
content: CalMachine,Are you copying xDevs designs? Shame on you.

author: CalMachine
author_rank: Frequent Contributor
timestamp: May 10, 2018, 05:00:15 pm
content: Quote from: ManateeMafia on May 10, 2018, 04:33:14 pm

author: kj7e
author_rank: Frequent Contributor
timestamp: May 10, 2018, 05:32:31 pm
content: Love the blue color. My build wont be able to compete with yours, but I suspect it will still perform quite well.

author: hwj-d
author_rank: Frequent Contributor
timestamp: May 13, 2018, 08:22:17 pm
content: I know someone around here in the forum, who have probably a demand to the "all rights reserved" for the colour of "blue"...

author: TiN
author_rank: Super Contributor
timestamp: May 14, 2018, 04:58:32 am
content: It's not yellow, so we are safe.

author: Pipelie
author_rank: Regular Contributor
timestamp: May 14, 2018, 06:02:40 am
content: Quote from: TiN on May 14, 2018, 04:58:32 amIt's not grey, so we are safe.

author: kj7e
author_rank: Frequent Contributor
timestamp: May 14, 2018, 11:56:30 pm
content: $22 at Mouser;https://www.mouser.com/ProductDetail/Vishay-Precision-Group-Foil-Resistors/Y145310K0000V9L?qs=adduyb8LSTE261AZJo232w%3d%3d