Author Topic: EEVblog #756 - Mailbag  (Read 12514 times)

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Offline SeanB

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Re: EEVblog #756 - Mailbag
« Reply #25 on: June 26, 2015, 01:45:04 am »
Just a small note about those inverters. The inputs and outputs are opto isolated, using a small 24VDC SMPS fed from the main DC bus derived from the mains. However, the controller IC's, displays and push buttons are all running on a 5v rail derived by a non isolated SMPS also driven by the same main DC bus. This makes the driving of the IGBT stage easier, but has the small side effect of having the whole control circuit effectively being connected to the mains, and this can lead to issues if you are using the remote display options on the controllers that have them. There you need to have the entire cable be rated for mains voltage, even though you may only think they are 5V signals.

Also be aware that the inverters have the main DC bus voltage on the terminals, for use as either energy recovery to other drives during braking, or for larger drives if energy recovery is not in use ( or there is too much being fed back) for dissipation in a brake resistor. Some drives may also need an input inductor, there both to improve power factor ( I have not yet seen a drive with active PFC, the mains in industrial plant is a little rough for that at times) and to increase supply inductance, so as to keep the inverter from blowing up, especially in a plant with it's own dedicated supply transformer, where the mains supply impedance can be close to zero.
 

Offline Stonent

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Re: EEVblog #756 - Mailbag
« Reply #26 on: June 26, 2015, 08:35:22 am »
A note about the Fluke and the modular design.  Where I work we have the modern version of the One Touch called the One Touch AT.  It is based on the Fluke Versiv platform (which the display and interface module is named) and the back of the unit has little wings that pop out that disengage the back side of it so you can pull the back off and swap out the module.

You can convert it into a network analyzer (One Touch AT), or a fiber inspector or a variety of other devices built on the Versiv platform by purchasing a different backpack module.


Once nice feature is the passthrough mode where you can capture traffic inline as well as pass through PoE and power up a VoIP phone and capture the traffic.  You can the copy the file and inspect it with Wireshark.
« Last Edit: June 26, 2015, 08:38:32 am by Stonent »
The larger the government, the smaller the citizen.
 

Offline sony mavica

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Re: EEVblog #756 - Mailbag
« Reply #27 on: June 29, 2015, 09:46:55 pm »
that dinosaur looks creepy
MORE POWER!
 

Offline ketil b

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Re: EEVblog #756 - Mailbag
« Reply #28 on: June 30, 2015, 07:47:53 am »
 

Offline bitwelder

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Re: EEVblog #756 - Mailbag
« Reply #29 on: June 30, 2015, 03:30:35 pm »
BTW: has anyone measured how long is the PCB trace line from Port A to Port B in that cable simulator?
 

Offline Smokey

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Re: EEVblog #756 - Mailbag
« Reply #30 on: July 01, 2015, 01:42:17 pm »
So I'm a dickhead... sue me... but...

Is that guy seriously going to school to be a video blogger?  Is that really even an option, or did the guy make that up to get on camera?  No wonder he doesn't want to name is school.  Where does that rank on this illustrious list of majors including Ancient Philosophy, Art History, Religious Studies, Communications....

And watching him try his best to cut his hand off was cringe-worthy.

see... I told you I was a dickhead.


ok.. I assumed freshman in college... . so I just got to the part where he said he was a sophomore in high school.... Maybe I was a little harsh on a sophomore in high school.. but still... highschool youtube work study......  I guess they had to replace "home ec" with something.
« Last Edit: July 01, 2015, 02:11:11 pm by Smokey »
 

Offline EEVblog

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Re: EEVblog #756 - Mailbag
« Reply #31 on: July 01, 2015, 02:47:01 pm »
So I'm a dickhead... sue me... but...
Is that guy seriously going to school to be a video blogger? 

No. He's a high school kid in year 10 who is interested in video.

Quote
Is that really even an option, or did the guy make that up to get on camera?  No wonder he doesn't want to name is school.

It would not be kosher to name his school for obvious reasons, and he's smart enough to know that, perhaps more savvy than you in this case it seems.

Quote
  Where does that rank on this illustrious list of majors including Ancient Philosophy, Art History, Religious Studies, Communications....

Err, it's 2015. The internet and media and video is a big thing in case you haven't noticed.

Quote
ok.. I assumed freshman in college... . so I just got to the part where he said he was a sophomore in high school.... Maybe I was a little harsh on a sophomore in high school.. but still... highschool youtube work study......  I guess they had to replace "home ec" with something.

What do you want him to do? Something he has no interest in?
I appeared at their school careers day and spoke to the kids, Ryan was interested in video so asked if he could join me for work experience week.
That's what they try to do on work experience week, match kids up with employers in the field they have an interest in.
Majority of kids there didn't give a toss, so Ryan is away ahead of the curve.
 

Offline nitro2k01

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Re: EEVblog #756 - Mailbag
« Reply #32 on: July 01, 2015, 07:15:49 pm »
Is that guy seriously going to school to be a video blogger?  Is that really even an option, or did the guy make that up to get on camera? 
I misinterpreted that too and thought it was weird. In particular the sentence "You know nothing about engineering. You're here for video blogging" at about 10:49 and onward. Of course, that refers to the lab, not his school. The way work experience works, in case it wasn't around when you were young, or perhaps doesn't exist in US culture, is that high school kids are supposed to spend one week at a workplace to be able to experience a workplace firsthand. It's generally a mandatory thing for everyone, and not everyone is lucky enough to get to go to a "fun" workplace.

But like Dave said, ahead of the curve. The ambition is there. Becoming a video blogger is just one click away. Becoming a successful blogger is something else entirely. But even so, there are a number of more professional (employable) lines of work related to video, like editing, CG effects and so on. But formal education can never replace a genuine interest in the subject.
Whoa! How the hell did Dave know that Bob is my uncle? Amazing!
 

Offline EEVblog

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Re: EEVblog #756 - Mailbag
« Reply #33 on: July 01, 2015, 09:13:32 pm »
But like Dave said, ahead of the curve. The ambition is there. Becoming a video blogger is just one click away. Becoming a successful blogger is something else entirely. But even so, there are a number of more professional (employable) lines of work related to video, like editing, CG effects and so on.

Yes, and he's talking about doing some sort of media type degree, game development, graphics, that kind of stuff.
But he's keen on just video in general and wants to have a shot at being in front of camera doing various stuff.
 


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