EEVblog #894 - Keysight U1461A Insulation Resistance Multimeter Teardown - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: June 28, 2016, 11:13:47 pm
content: Inside the Keysight U1461A Insulation Resistance Multimeter

author: Muttley Snickers
author_rank: Unknown
timestamp: June 28, 2016, 11:47:49 pm
content: Once again a great video on a very nice product.The blue on the terminal could perhaps be a new elaborate form of tamper detection, who the hell would have access to a blue marker pen or sharpie anyhow ?, I'd be screwed with plenty of Loctite about the place but not a blue marker anywhere to be seen.

author: Cliff Matthews
author_rank: Unknown
timestamp: June 28, 2016, 11:59:28 pm
content: Love that soldering by the HV transfo, but what happened to C130 and C131? For a new product, I guess they didn't need the extra multiplier stage. Wah wah wah... Anyway, on the absence of a 10amp internal shunt, with all those adapters why couldn't they have rigged something external for current?

author: Someone
author_rank: Super Contributor
timestamp: June 29, 2016, 01:01:11 am
content: Shutter speed, not the frame rate was being varied to observe the scanning of the display. It can be done with frame rate too but requires fine increments.

author: iloveelectronics
author_rank: Frequent Contributor
timestamp: June 29, 2016, 03:44:24 am
content: In the video you mention only Fluke has a similar product but it's not exactly correct. Brymen has a new BM870 series which seems fairly comparable too, at much more affordable prices.

author: Muttley Snickers
author_rank: Unknown
timestamp: June 29, 2016, 08:12:44 am
content: I just noticed that the remote switch probe is slightly different on this meter when compared to the similar probe on the U1280 series, The U1461A uses the U5403A lead and the U1282A uses the U5404A as linked below, looks like you could use the U5404A on the U1461A but not the other way around with the jointed input jack, thought it was worth mentioning, don't get your wires crossed.U5403A Switch probe for the U1461A.http://www.keysight.com/en/pd-2422444-pn-U5403A/remote-test-probeU5404A Switch probe for the U1282A.http://www.keysight.com/en/pd-2615346-pn-U5404A/remote-switch-probe

author: bktemp
author_rank: Super Contributor
timestamp: June 29, 2016, 08:42:18 am
content: What's the purpose of the two villard cascades?I doubt they generate anything near 1000V, because there is almost no clearance around the traces.The spacing around the transformer is much larger, so my guess would be it generates the 1kV directly using 2 windings in series with each having its own rectifier (C153, C154, D38, D39) with R135 being part of the voltage divider for the voltage regulation.

author: Fungus
author_rank: Super Contributor
timestamp: June 29, 2016, 08:58:50 am
content: Quote from: bktemp on June 29, 2016, 08:42:18 amThat doesn't matter. It's not going to arc so long as there's an easier path to go down.

author: bktemp
author_rank: Super Contributor
timestamp: June 29, 2016, 09:11:09 am
content: Quote from: Fungus on June 29, 2016, 08:58:50 amIf it arcs over, the arc will be the easiest path to ground. And if you have an easy path to ground somewhere else, it will load the supply and you don't have 1kV anymore.So no, your argument is totally wrong.

author: Fungus
author_rank: Super Contributor
timestamp: June 29, 2016, 09:18:57 am
content: Quote from: bktemp on June 29, 2016, 09:11:09 amNot as wrong as this: "It's not arcing so therefore itcan'tbe 1000V"You really think they'd release a $900 meter that can't measure voltage?

author: tszaboo
author_rank: Super Contributor
timestamp: June 29, 2016, 12:54:53 pm
content: The reason they dont build in the Bluetooth module: It needs to be FCC (and TÜV and who knows what else) certified, and that takes time, money... Doing that for every meter is a lot of trouble. I would not want to respin a multimeter because some RF stuff refuses to behave.

author: Monkeh
author_rank: Super Contributor
timestamp: June 29, 2016, 01:29:41 pm
content: Quote from: NANDBlog on June 29, 2016, 12:54:53 pmThe same reason the wifi and bluetooth in laptops is (almost) always on a card.

author: bitwelder
author_rank: Super Contributor
timestamp: June 29, 2016, 06:01:43 pm
content: Curious, the transformer placement seems to be a teeny tiny bit skewed from the main PCB axis.

author: AF6LJ
author_rank: Unknown
timestamp: June 29, 2016, 08:17:33 pm
content: That was a good teardown....Nicely built.....Thank You again for the good videos Dave.

author: TheAmmoniacal
author_rank: Unknown
timestamp: June 29, 2016, 08:22:14 pm
content: Quote from: iloveelectronics on June 29, 2016, 03:44:24 amYep, Dave should get his hands on this for comparison.

author: Hydrawerk
author_rank: Super Contributor
timestamp: June 29, 2016, 11:47:03 pm
content: What is the point of an OLED display? It must consume the AA batteries pretty quickly.And where is the high voltage line that goes from transformer to output jacks?

author: Unknown
author_rank: Unknown
timestamp: June 30, 2016, 01:09:52 am
content: Quote from: TheAmmoniacal on June 29, 2016, 08:22:14 pmI'd like to see a brymen review also. There was a US located member on the forum trying to source without luck. Anybody know where to purchase one for US market?

author: Fungus
author_rank: Super Contributor
timestamp: June 30, 2016, 10:00:08 am
content: Quote from: Hydrawerk on June 29, 2016, 11:47:03 pmPeople buy shiny things. Simple as that.I've even seen EEVBLOG members go gaga over those - people who ought to know better.Quote from: Hydrawerk on June 29, 2016, 11:47:03 pmYep, and it has no DC input jack so you can't plug it in when it's on your workbench. You need to constantly stop work to change/charge the batteries.The engineers must have facepalmed when management told them to make a meter that can only be used in dim lighting and you need to charge it every other every day (via the input posts!).Marketing knew best though: There's a whole sector of drooling idiots who only see "color display!!!!"The only thing missing is an Apple logo.PS: The 'drooling idiots' aren'tnecessarilythe meter owners. If I was a consultant I'd buy a huge OLED meterjustso could pull it out in front of clients to show how amazing I am.The other guy has a black and white meter, mine is color. Who you gonna hire...?(And pray the boss leaves before the battery runs out...)

author: EEVblog
author_rank: Unknown
timestamp: June 30, 2016, 11:49:56 am
content: Quote from: TheAmmoniacal on June 29, 2016, 08:22:14 pmHmm, I didn't know about that model.

author: EEVblog
author_rank: Unknown
timestamp: June 30, 2016, 11:54:47 am
content: Quote from: NANDBlog on June 29, 2016, 12:54:53 pmYou simply use a pre-certified module and solder to the board. I'm doing that for my custom meter design.

author: Hydrawerk
author_rank: Super Contributor
timestamp: June 30, 2016, 06:40:08 pm
content: I have no problem with OLED displays on a bench meter, that is not powered from batteries.

author: f4eru
author_rank: Super Contributor
timestamp: June 30, 2016, 08:30:22 pm
content: Hello,The blue glue on the ground post screw is a safety feature : if the screw comes loose, and the ground post is lost, the whole meter "potentially" goes to 1000V, and it can arc over to your fingers at many places (in worst case). So that ground connection is safety relevant.The two cascades are probably for different voltages : the two with the small components and 4 stages are probably for 50V, the one with big component and one stage is for higher voltages.The presence of the 6uA range is easy to explain : that is what is used to measure the very high resistances !

author: Muttley Snickers
author_rank: Unknown
timestamp: July 01, 2016, 03:15:46 am
content: Peter Oakes also did a couple of video reviews on this meter and the common terminal was not blued on his one as shown below, if it was used to lock the thread then I would expect to see remnants of it on the thread itself but this is sometimes not the case in all applications.Peter Oakes U1461A general review.Peter Oakes U1461A chilling review.

author: peteb2
author_rank: Regular Contributor
timestamp: July 02, 2016, 09:34:45 am
content: Yep... great meter and yeah i own one but what i really like is the external software Keysight make available for it, especially the handy-dandy database around insulation testing when you are required to track a whole bunch of different equipment...

author: peteb2
author_rank: Regular Contributor
timestamp: July 02, 2016, 03:30:41 pm
content: ... and here's what is probably Keysight's own produced videos on YouTube explaining this software but i am sorry, the young lass who explains things obviously has English as a second language. I've watched it 10 times... i'm still confused.