EEVblog Electronics Community Forum

EEVblog => EEVblog Specific => Topic started by: EEVblog on January 18, 2019, 09:15:35 am

Title: EEVblog #1170 - Mystery Teardown
Post by: EEVblog on January 18, 2019, 09:15:35 am
Mystery Teardown from the dumpster!
Even Dave had no idea what this was until he tore it down.

http://www.youtube.com/watch?v=xo4sojpJIBI (http://www.youtube.com/watch?v=xo4sojpJIBI)


Title: Re: EEVblog #1170 - Mystery Teardown
Post by: elliottveares on January 18, 2019, 09:30:34 am
Dave, no audio on right channel.  ::) Can you please fix and re-upload.
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: darik on January 18, 2019, 09:30:47 am
It must suck to have a video uploaded and get a bunch of views and _then_ find out the audio is buggered.
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: HwAoRrDk on January 18, 2019, 09:34:29 am
Could try plugging the USB (whichever is the non-charging one) in to a PC and see if it enumerates, perhaps as some kind of serial device (i.e. COM port)?
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: rsjsouza on January 18, 2019, 09:36:34 am
oh, c'mon! Just adjust appropriately the mono/stereo switch of your headphone...  :-DD
(https://www.electrosupplies.co.uk/images/products/expanded/100616_CO1.jpg)
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: johnlsenchak on January 18, 2019, 10:11:59 am


Can that platypus   fix the  audio  ? As  Dave would say   "Bloody hell "
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: chris_leyson on January 18, 2019, 10:22:55 am
Damn, video has disappeared. Looks like a nice well thought out design. Wurth 750817841 datasheet here https://katalog.we-online.de/icref/datasheet/750817841.pdf (https://katalog.we-online.de/icref/datasheet/750817841.pdf) They probably use the AUX winding for the H-bridge driver supply, neat.
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: mihaibr on January 18, 2019, 10:43:21 am
"This video is unavailable."  :( :( :(
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: aqarwaen on January 18, 2019, 11:17:23 am
"This video is unavailable."  :( :( :(

same here video unavailable.
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: Brumby on January 18, 2019, 11:31:23 am
Dave has likely taken it down and is fixing it.

Be patient, it'll be back up.
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: elliottveares on January 19, 2019, 03:38:57 am
Still not back up on YouTube  :( , so here it is below. I have also fixed the Audio issues.

http://www.grottotree.com/EEVblog-1170-Mystery-Teardown.mp4 (http://www.grottotree.com/EEVblog-1170-Mystery-Teardown.mp4)

Regards: Elliott
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: macboy on January 19, 2019, 07:24:53 am
Dave may have had greater success with the test at end of video if he had supplied the nominal 11.1 V of the battery pack (it was 3 cell, not 2 cell), and if he had flipped the switch to ON.  >:D
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: rsjsouza on January 19, 2019, 09:13:14 am
Still not back up on YouTube  :( , so here it is below. I have also fixed the Audio issues.

http://www.grottotree.com/EEVblog-1170-Mystery-Teardown.mp4 (http://www.grottotree.com/EEVblog-1170-Mystery-Teardown.mp4)

Regards: Elliott
I could almost swear that there was a tool on Youtube to correct single-channel issues like these without having to re-post the video. However, with the recent changes to their interface I think this is either gone or never existed.  :(
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: NiHaoMike on January 19, 2019, 02:09:03 pm
There are a few portable battery packs with built in AC outputs available.
https://thewirecutter.com/reviews/the-best-portable-ac-power-supply-so-far/
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: EEVblog on January 22, 2019, 07:26:08 pm
Back home, new video uploaded:
http://www.youtube.com/watch?v=xo4sojpJIBI (http://www.youtube.com/watch?v=xo4sojpJIBI)
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: EEVblog on January 22, 2019, 07:26:47 pm
I could almost swear that there was a tool on Youtube to correct single-channel issues like these without having to re-post the video. However, with the recent changes to their interface I think this is either gone or never existed.  :(

I'm pretty sure you used to be able to replace the audio with your own upload once upon a time
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: Phoenix on January 22, 2019, 09:31:20 pm
I think it's not designed to test the PAT itself but as an alternative to needing mains power for RCD testing. I.e. for testing RCD trip you need to supply power to the RCD.

His description of a normal scenario:
Mains power/Extension cord -> Isolation transformer -> RCD -> RCD Tester

What I think he means with his box:
Platypus Box -> RCD -> RCD Tester

So you no longer need to drag power over and you eliminate the high power hazard of mains.
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: KeithBrown on January 23, 2019, 08:46:24 am
Wait a minute! Nobody seems to have noticed the perpetual motion aspect! 850 mAhr at 11.1 V is about 9.4 Whr...how does it deliver 20 W "indefinitely"??
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: johnlsenchak on January 24, 2019, 12:48:46 am

Thanks for fixing the audio  !
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: rsjsouza on January 24, 2019, 01:19:26 am
I could almost swear that there was a tool on Youtube to correct single-channel issues like these without having to re-post the video. However, with the recent changes to their interface I think this is either gone or never existed.  :(

I'm pretty sure you used to be able to replace the audio with your own upload once upon a time
I had this impression too - however, in these days of "fake news" and hacking, I wonder if Youtube was concerned with a PR disaster if a personality/commentator had his videos hacked and replaced with an entirely opposite audio. Oh well, I can only speculate.
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: thylacine1975 on January 24, 2019, 02:49:12 am
Firstly, let me say thankyou Dave for your open, unprompted and enthusiastic tear down of our inverter! It was wonderful to hear a fellow engineer explore his way through something you've spent *so many* hours working on.  Your intuition of the various functions of each of the sections of circuitry was pretty much spot on too :)

I'm James (Webb), the balding chap in the blue shirt who features at 10:11 in the video. I'm the design engineer - Trevor is the business development guy and CEO, and together we are Platypus Instruments.  You are correct Dave - the idea of the PI3 inverter was Trevor's, driven by the difficulty of obtaining power on remote worksites to conduct appliance tests in his day job as a test-and-tagger.  I suggested we could make something, a prototype was created and the company was formed!

The unit you pulled apart was v3.3 - we're on to v3.4 now as we've been marching towards readying the design for production.. which has been (frustratingly) non-trivial!  The main difficulties have been the multitudes of things that people have insisted on plugging into it during our (years) of field testing - and the unexpected results (read: learning opportunities).  As some of the forum/youtube comments have suggested, the inclination is to plug the biggest, heaviest 15A load into it to see what it does.  The first versions' output voltages sagged badly as a result of high output impedances. Fixing that caused the next versions to destroy themselves trying to drive a short circuit. Later versions brought better protection mechanisms, thermal management, transient capability, capacitive load stability, inductive load protection, battery management, creepage distances, lower THD etc etc.

And this is why no-one knows about us or our product yet - we've wanted to ensure it was bulletproof before offering them for sale.  Product safety is an aspect we are paranoid about - as there's a lot of potential heat energy stored within that battery and a large amount of electrical energy stored within that capacitor for a device that we've seen many people drop and throw around.  The microswitch that caught your attention just after opening the case is for exactly this reason - if the case is cracked/comes apart, the main capacitor is dumped into the pulse resistor standing up under the (cute) platypus logo.  The same resistor takes the heat (literally) if the overvoltage crowbar triggers too.

Unfortunately, while a long time to market might be good for our consciences, it isn't good for business cashflow!  We were most  fortunate to receive an ACT government grant in 2014 to assist us with taking our prototype to production - and we mainly used the funds to pay for the creation of injection moulding tooling (to replace the 3D printed case your prototype has), patenting (which was a disappointing educational experience) and EMC/electrical safety testing - which is a process yet to conclude.  I must admit, I'm most curious to know how a prototype that looks remarkably like the one I submitted for testing ended up in a dumpster a couple of years later...

I'm very happy you found it though - and stoked that we could present you with a puzzle to ponder.  We'll have to send you a 'real' one when we finally make it to production!

In the meantime though, Trevor and my emails certainly work - even if our website doesn't.  Please feel free to say hi or drop us a line at trevor@... and james@platypusinstruments.com.
Cheers!


[I'm dying to ask though: How on earth did you get a platypus to sit in a box for the title frame of the video??]
Title: Re: EEVblog #1170 - Mystery Teardown
Post by: BU508A on January 24, 2019, 04:08:26 am

[I'm dying to ask though: How on earth did you get a platypus to sit in a box for the title frame of the video??]

Because it is Perry the Platypus.    ;D    (without the hat, of course)

(https://upload.wikimedia.org/wikipedia/en/d/dc/Perry_the_Platypus.png)