Author Topic: EEVblog #643 - Mailbag  (Read 22141 times)

0 Members and 1 Guest are viewing this topic.

Online EEVblog

  • Administrator
  • *****
  • Posts: 32742
  • Country: au
    • EEVblog
EEVblog #643 - Mailbag
« on: July 22, 2014, 12:39:38 pm »
 

Offline Simon123

  • Regular Contributor
  • *
  • Posts: 203
  • Country: si
    • Youtube channel
Re: EEVblog #643 - Mailbag
« Reply #1 on: July 22, 2014, 01:54:44 pm »
Did u used 3V on meter to power it on or 1.5V.
2R10 is 3V battery.
 

Offline Mark Hennessy

  • Frequent Contributor
  • **
  • Posts: 305
  • Country: gb
    • My electronics and audio website
Re: EEVblog #643 - Mailbag
« Reply #2 on: July 22, 2014, 02:24:19 pm »
I bought my fx7000G in 1989 for my A-levels, and still use it daily. I have tried many newer Casio calculators, but keep going back to the 7000. I guess that after 25 years, I'm used to it. Recognising that it's getting old, I bought a couple second-hand, and they are in pretty mint condition. Good job I did, as no-doubt the prices will shoot up now :-DD
 

Offline kcs

  • Regular Contributor
  • *
  • Posts: 160
Re: EEVblog #643 - Mailbag
« Reply #3 on: July 22, 2014, 02:32:04 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.
 

Offline nathanpc

  • Supporter
  • ****
  • Posts: 138
  • Country: br
    • Innove Workshop
Re: EEVblog #643 - Mailbag
« Reply #4 on: July 22, 2014, 02:42:12 pm »
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.
 

Offline rob77

  • Super Contributor
  • ***
  • Posts: 1850
  • Country: sk
Re: EEVblog #643 - Mailbag
« Reply #5 on: July 22, 2014, 03:36:38 pm »
the new format is great !  :-+ :-+ :-+
 

Offline Dr. Frank

  • Super Contributor
  • ***
  • Posts: 2007
  • Country: de
Re: EEVblog #643 - Mailbag
« Reply #6 on: July 22, 2014, 03:46:07 pm »
Hi Dave,

The new location and perspective (angle) of your videos is really very nice.

The background now is very pleasant (not so uneasy any more, as in the foregoing video), as you cleaned up the racks neatly.

On Long Shots, the picture pane should be a little bit bigger (more wide angled), as your head is cut off periodically. That's quite distracting, during watching your video.

The sound is quite ok, but could be better. I think it sounds a bit hollow now, maybe you had more trebly (?) sound in other videos.

Frank
« Last Edit: July 22, 2014, 03:55:12 pm by Dr. Frank »
 

Offline Laertes

  • Regular Contributor
  • *
  • Posts: 58
  • Country: de
Re: EEVblog #643 - Mailbag
« Reply #7 on: July 22, 2014, 03:52:01 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.
These boards were made by OSHPark, apparently. They don't really specify minimum soldermask width but I'd venture a guess it's going to be 4mils. Make the soldermask expansion only 2 mils and there you go.
In my experience, soldermask expansion specs are pretty loose by the manufacturers, with OSHPark or my local source here, I've never run into an issue with 2 mils or occasionally just 1 mil. My local manufacturer actually recommends going for 4mils.
 

Offline Laertes

  • Regular Contributor
  • *
  • Posts: 58
  • Country: de
Re: EEVblog #643 - Mailbag
« Reply #8 on: July 22, 2014, 03:52:38 pm »
Oh and I forgot: The new format is great!  :-+
 

Offline kcs

  • Regular Contributor
  • *
  • Posts: 160
Re: EEVblog #643 - Mailbag
« Reply #9 on: July 22, 2014, 04:22:26 pm »
Laertes, yes, I know it is OSH Park. And yes, they do specify min solder mask expansion, just load DRC file they provide.
My points was, if I follow the DRC rules, I cannot put solder mask between those pins. Of course I can choose not to follow them and accept the risk.
 

Offline Alexei.Polkhanov

  • Frequent Contributor
  • **
  • Posts: 683
  • Country: ca
Re: EEVblog #643 - Mailbag
« Reply #10 on: July 22, 2014, 04:53:49 pm »
Those MOSFETs are impressive but 0.19 ohm RDS On won't put them into "world best in TO220 package" category. I recently ordered IRFB41110 ($6 on Digikey) - RDS ON is 3.7 mOhm - that is milliohm. http://www.irf.com/product-info/datasheets/data/irfb4110pbf.pdf
 

Offline rob77

  • Super Contributor
  • ***
  • Posts: 1850
  • Country: sk
Re: EEVblog #643 - Mailbag
« Reply #11 on: July 22, 2014, 05:00:07 pm »
Those MOSFETs are impressive but 0.19 ohm RDS On won't put them into "world best in TO220 package" category. I recently ordered IRFB41110 ($6 on Digikey) - RDS ON is 3.7 mOhm - that is milliohm. http://www.irf.com/product-info/datasheets/data/irfb4110pbf.pdf

i bet those 3.7mOhm are not rated for 600V , are they ? ;)
 

Offline