Author Topic: EEVblog #643 - Mailbag  (Read 22210 times)

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Offline MouseBiteFever

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Re: EEVblog #643 - Mailbag
« Reply #25 on: July 22, 2014, 08:29:53 pm »
I am very curious how did he got solder mask between those pins. I have used IC in the same package recently and I was not able to get solder mask because of the small pitch. I have used the same PCB manufacturing service as that guy.

Datasheet for IC recommends:
 - Distance between pads - 8 mils
 - Pad width - 17,5 mils

PCB manufacturer's rules:
 - Min solder mask expansion - 3 mils

So we are left only with 2 mils for solder mask.

I don't think I did anything special. I just loaded up the OSHPark DRC and put the board together.
I'm adding a close up pic of the pads and tstop. The spacing is 5mil/div
digikey lists the package as "Package / Case   8-TSSOP (0.173", 4.40mm Width)"
I'm also adding the dimensions from the data sheet
 

Offline RupertGo

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Re: EEVblog #643 - Mailbag
« Reply #26 on: July 22, 2014, 09:41:07 pm »
The new format is a definite improvement, although Dave now looks a bit like a TV anchorman. Perhaps some portentous music and pointlessly swoopy glittery animation at the front? As for the shelves behind - if a bunch of scopes can be wired up to show key metrics in real time (hits/sec, comments/min, Dave's blood pressure, swear index, etc) then it'll be much more Star Trek and thus much more to my taste.

I do hope someone has the circ for the dimmer, or something like that. In a past life, I was part of a team doing comparative testing of UPSs, which is a seriously hard job and one we really did have to stop working on rather than finish. I learned (well, was exposed to) a ton of stuff on that project, including just how mad mains electricity looks in a large building filled with mid-90s vintage IT running off second-generation SMPSUs. It's a very hard environment to properly appreciate, let alone design for, especially for a chap whose previous PSU knowledge stopped at four diodes, a centre-tapped transformer, a couple of caps and an excuse-me.

Designing a half-kilowatt universal dimmer that isn't going to do something impolite seems to me to be a long-trousered job and a half. Some insight would be much appreciated.

R
 

Offline deth502

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Re: EEVblog #643 - Mailbag
« Reply #27 on: July 22, 2014, 10:03:19 pm »
gold guilding is fairly easy if you can manage to not mangle the gold.

you coat the edge with an adhesive, then just place the thin, thin THIN, VERY THIN gold sheets over the adhesive and press on. the un glued portions will easily just wipe off since the sheet is so thin.

it is so thin, its even easily eaten. heres some guilding sheets, these happen to say they are designed for food. the same as if you have ever seen/drank goldschlager vodka.

http://www.deandeluca.com/pantry/baking-ingredients/giusto-manetti-23k-gold-leaves.aspx?ref_code=GoogleMerchant&gclid=COOy88302b8CFQwV7AodGX4AIg

a common thing done with large guilded areas (like letters on a sign) is to use a small sponge on a stick to swirl an engine turned finish into the guilding.

 

Offline deth502

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Re: EEVblog #643 - Mailbag
« Reply #28 on: July 22, 2014, 10:07:26 pm »
a videos worth a thousand words.



and turning

 

Offline synapsis

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Re: EEVblog #643 - Mailbag
« Reply #29 on: July 23, 2014, 12:37:04 am »
Quick question:

On the German ohmmeter, the meter face has a line of symbols (looks like Egyptian hieroglyphs ;) ). What do these symbols mean? I've purchased a couple of OneHungLo analog meters off eBay in the past that also had symbols, so I assume they mean *something.*
 

Offline Simon123

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Re: EEVblog #643 - Mailbag
« Reply #30 on: July 23, 2014, 01:09:26 am »
It tells you type of moving coil or iron, input protection, accurecy, orientation ...
If i find picture defining it il post ti.
https://www.eevblog.com/forum/testgear/exploring-the-symbols-on-a-analog-multimeter-quiz/
« Last Edit: July 23, 2014, 01:21:20 am by Simon123 »
 

Online djacobow

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Re: EEVblog #643 - Mailbag
« Reply #31 on: July 23, 2014, 02:33:00 am »
Designing a half-kilowatt universal dimmer that isn't going to do something impolite seems to me to be a long-trousered job and a half. Some insight would be much appreciated.

Well, I think with dimmers sold into residential and light commercial settings, nobody is making much in the way of promises. That is, if you go to all the lighting dimmer websites you will see scant descriptions of what constitutes a CFL-friendly dimmer, and LED-friendly dimmer, a "universal" dimmer, etc. It's actually pretty embarassing. As far as the quality of the waveform, well, garbage in and even more garbage out appears to be the watchword. Good filtering requires non-trivial inductors and those are components that NOT in evidence in your typical dimmer. These things are built to be as cheap as possible.

All that said, this gentleman (Rod Elliott) has torn down the CLIPSAL in the video and claims that it basically is a FET-based dimmer that can operate in either forward- or reverse-phase mode, and will make the determination itself:

http://sound.westhost.com/lamps/dimmers.html

I have built a similar dimmer myself. It can do forward or reverse phase control, driven by a uC. (It could also do PWM which works nicely with incandescents and a good LPF and on the input AND output.) However, unlike the CLIPSAL people, I was not clever enough to have the dimmer determine which mode it should best operate in! Anyway, my project has been useful for experimenting with the topology.

Also, the CLIPSAL unit is obviously driving two FETS in half waves rather than one in a full bridge.

-- dave j

 

Offline Tek_TDS220

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Re: EEVblog #643 - Mailbag
« Reply #32 on: July 23, 2014, 02:42:38 am »
Fancy format - I can remember when Dave did these videos in his garage.   Next he needs a female co-host, some informal banter, and a teleprompter.
 

Offline 99tito99

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Re: EEVblog #643 - Mailbag
« Reply #33 on: July 23, 2014, 04:57:08 am »
Hi Dave: Like the new format (2 thumbs up).  The back-and-forth between the “full frontal” view and the close-up seems to work well.  The background porn is not a problem, I just paused and got my eye-full and then continued.  Although, some said it is distracting, I say keep it and in fact swap out a new gadget every so often.  Besides, if someone is listening that closely to what you are actually saying they may have an issue (joke?).  Cheers, Mark * * *
 

Offline SmalltimePrankster

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Re: EEVblog #643 - Mailbag
« Reply #34 on: July 23, 2014, 05:08:03 am »
Many years ago part of my job was to repair those Sharp IQs.  Really all that went wrong with them was the flat cable between the two halves and it was a real PITA to replace.  The post repair test process, as directed by the service book, was hilarious.

Test one was check that it powers up (so far so good).

Test two was to grip either end with it turned on and twist the case to see if the display stayed normal (ok, this test makes sense).

The final test, and you may not believe this, was to hold the unit 20cm above a flat hard surface and drop it so it (hopefully) landed flat and then check that it still worked.

A drop test.  Part of the standard service process.  Really.
 

Offline Juun

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Re: EEVblog #643 - Mailbag
« Reply #35 on: July 23, 2014, 05:08:27 am »
Next he needs a female co-host, some informal banter, and a teleprompter.

This would be the end of it!  :--
 

Offline Stonent

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Re: EEVblog #643 - Mailbag
« Reply #36 on: July 23, 2014, 05:15:20 am »
The new format is a definite improvement, although Dave now looks a bit like a TV anchorman. Perhaps some portentous music and pointlessly swoopy glittery animation at the front? As for the shelves behind - if a bunch of scopes can be wired up to show key metrics in real time (hits/sec, comments/min, Dave's blood pressure, swear index, etc) then it'll be much more Star Trek and thus much more to my taste.

I do hope someone has the circ for the dimmer, or something like that. In a past life, I was part of a team doing comparative testing of UPSs, which is a seriously hard job and one we really did have to stop working on rather than finish. I learned (well, was exposed to) a ton of stuff on that project, including just how mad mains electricity looks in a large building filled with mid-90s vintage IT running off second-generation SMPSUs. It's a very hard environment to properly appreciate, let alone design for, especially for a chap whose previous PSU knowledge stopped at four diodes, a centre-tapped transformer, a couple of caps and an excuse-me.

Designing a half-kilowatt universal dimmer that isn't going to do something impolite seems to me to be a long-trousered job and a half. Some insight would be much appreciated.

R

With the background and facing the camera, I think Dave now needs a red vest with company logos on it and subtitles if anyone catches the reference...  ;)
The larger the government, the smaller the citizen.
 

Offline steve30

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Re: EEVblog #643 - Mailbag
« Reply #37 on: July 23, 2014, 07:42:23 am »
I don't really care much for the idea of Dave sitting behind the desk. But it did work fine for the mailbag since we can see him while the mail is being opened.

It would be cool to get that Sharp organiser working :).

Can the LCD on the calculator be improved at all?
 

Offline 84GKSIG

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Re: EEVblog #643 - Mailbag
« Reply #38 on: July 23, 2014, 02:44:57 pm »
hey Dave I :-+ like the new video format for the mail bag. im gonna try send something to you for your mail bag if you like hopefully in the next couple of weeks.
 

Offline kcs

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Re: EEVblog #643 - Mailbag
« Reply #39 on: July 23, 2014, 05:02:42 pm »
MouseBiteFever, I took a closer look at your PCB. Your pads are smaller in width (14 mils instead of mine 17.5 mils). With those extra 3 mils (5 mils total), you can use solder mask between pins. I was following manufacturer recommendations for PCB layout and it seems that TI does not offer that for its package.
Well, we will see how hard it will be to solder that tiny IC when no solder mask is used. I should receive my boards very soon.
 

Offline timelessbeing

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Re: EEVblog #643 - Mailbag
« Reply #40 on: July 23, 2014, 05:27:10 pm »
I like the new mailbag format. Keep doing that.  :-+
 

Offline 99tito99

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Re: EEVblog #643 - Mailbag
« Reply #41 on: July 23, 2014, 06:48:57 pm »
Fancy format - I can remember when Dave did these videos in his garage.   Next he needs a female co-host, some informal banter, and a teleprompter.

Yeah, and a bow tie.  Cheers, Mark


 

Offline Laertes

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Re: EEVblog #643 - Mailbag
« Reply #42 on: July 23, 2014, 07:54:03 pm »
if a bunch of scopes can be wired up to show key metrics in real time (hits/sec, comments/min, Dave's blood pressure, swear index, etc) then it'll be much more Star Trek and thus much more to my taste.

Much better idea than a female co-host.  :-+ :-+
 

Offline nixfu

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Re: EEVblog #643 - Mailbag
« Reply #43 on: July 23, 2014, 09:31:48 pm »
Fancy format - I can remember when Dave did these videos in his garage.   Next he needs a female co-host, some informal banter, and a teleprompter.

And an official "announcer" that says "Heeeeeeers Dave" and also a  band....don't forget a band.  They have to play the "mailbag jingle" or the "Teardown tune" whenever appropriate.   
 

Online Monkeh

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Re: EEVblog #643 - Mailbag
« Reply #44 on: July 23, 2014, 09:33:47 pm »
Well, we will see how hard it will be to solder that tiny IC when no solder mask is used.

Piece of cake.
 

Offline silicon_ghost

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Re: EEVblog #643 - Mailbag
« Reply #45 on: July 26, 2014, 03:29:40 pm »
+1 on the new format. I like how it breaks up the video into segments.
 

Offline lapm

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Re: EEVblog #643 - Mailbag
« Reply #46 on: July 26, 2014, 04:45:53 pm »
Hey Dave, i like the new mailbag format... Big  :-+ for that...
Electronics, Linux, Programming, Science... im interested all of it...
 

Offline kolbep

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Re: EEVblog #643 - Mailbag
« Reply #47 on: July 26, 2014, 06:15:45 pm »
Quote
With the background and facing the camera, I think Dave now needs a red vest with company logos on it and subtitles if anyone catches the reference...  ;)

What, you want him to join the EFF (A South African political party - The Economic Freedom Fighters - Who wear red Jumpsuits/Overalls with Red Berets even at Parliament mettings, Apparently to associate themselves with the hardworking, underpaid miners, etc in RSA)

?
====================================
www.ShoutingElectronics.com Don't just talk about Electronics, SHOUT ABOUT IT! Electronics Blog Site and Youtube Channel
 

Offline SeanB

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Re: EEVblog #643 - Mailbag
« Reply #48 on: July 26, 2014, 06:51:59 pm »
No Peter, he does a little more work than lifting up a Breitling and shouting slogans while eating. I think the reference is to a more American talking head.....
 

Offline electrolux

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Re: EEVblog #643 - Mailbag
« Reply #49 on: July 27, 2014, 11:38:56 am »
I like the new format, it looks a lot better since the camera isn't too close to the box you're trying to open and you have more room to show the contents before changing to the usual angle.
I like it too, Keep it
The funniest thing about this signature is that by the time you realize it doesn't say anything its too late to stop reading it.
 


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