PCB Libraries Forum Homepage
Forum Home Forum Home > PCB Footprint Expert > Questions & Answers
  New Posts New Posts RSS Feed - Molded body polarity marking
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Molded body polarity marking
 Post Reply Post Reply
Author
Message
  Topic Search Topic Search  Topic Options Topic Options
Tempest View Drop Down
Active User
Active User


Joined: 20 Jun 2012
Location: Oregon
Status: Offline
Points: 20 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Tempest Quote  Post ReplyReply Direct Link To This Post Topic: Molded body polarity marking
    Posted: 25 Jun 2019 at 8:16am
On a 3D step model, wondering why I'm not seeing a polarity mark on a molded body inductor, is the 3d step just not supporting this?It's been like this for a while just curious.

Thanks,
Paul
Back to Top
Back to Top
Tom H View Drop Down
Admin Group
Admin Group
Avatar

Joined: 05 Jan 2012
Location: San Diego, CA
Status: Offline
Points: 5719 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 25 Jun 2019 at 9:30am
The Molded Body Inductor is bi-directional. 

It can be inverted during assembly. 

Can you provide the URL link to a datasheet that has a Polarized Inductor? 
Stay connected - follow us! X - LinkedIn
Back to Top
Tempest View Drop Down
Active User
Active User


Joined: 20 Jun 2012
Location: Oregon
Status: Offline
Points: 20 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Tempest Quote  Post ReplyReply Direct Link To This Post Posted: 25 Jun 2019 at 9:46am
Hi Tom,

Some indicate polarity like the Panasonic part number ETQP4M220YFP, regardless as to if that is true or not.

The software does give the option for polarized inductor so I'd kinda expect a pin 1 indicator.

Thanks,
Paul
Back to Top
Tom H View Drop Down
Admin Group
Admin Group
Avatar

Joined: 05 Jan 2012
Location: San Diego, CA
Status: Offline
Points: 5719 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 25 Jun 2019 at 10:01am
Here is the Panasonic ETQP4M220YFP Molded Body Inductor. 

Download it here (much more Terminal Lead Detail) - 3D STEP

Here is what it looks like and I don't see any Polarity Marking - 
Stay connected - follow us! X - LinkedIn
Back to Top
Tempest View Drop Down
Active User
Active User


Joined: 20 Jun 2012
Location: Oregon
Status: Offline
Points: 20 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Tempest Quote  Post ReplyReply Direct Link To This Post Posted: 25 Jun 2019 at 10:10am
Thank you Tom for looking this up, nice model.

I'm still wondering though, is Lib expert not supporting inductor polar marking and if not is it going to be.  If not maybe consider removing the option. 

Thank you
Back to Top
Tom H View Drop Down
Admin Group
Admin Group
Avatar

Joined: 05 Jan 2012
Location: San Diego, CA
Status: Offline
Points: 5719 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 25 Jun 2019 at 10:16am
We only add Polarity Markings to packages that are polarized. 

Show me a polarized inductor and we'll add it. 

Otherwise, all inductors like all resistors, can be inverted during assembly. 

We do not want to confuse the assembly process with unnecessary polarity markings. 
Stay connected - follow us! X - LinkedIn
Back to Top
Ian S View Drop Down
Advanced User
Advanced User


Joined: 21 Aug 2014
Status: Offline
Points: 67 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Ian S Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jun 2019 at 1:24am
Following up on this subject here's some inductor polarity-related reading:


Ian
Back to Top
Tom H View Drop Down
Admin Group
Admin Group
Avatar

Joined: 05 Jan 2012
Location: San Diego, CA
Status: Offline
Points: 5719 		Post Options Post Options   Thanks (1) Thanks(1)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 26 Jun 2019 at 6:48am
Ian - These are good articles. I wonder why the manufacturer's 3D models do't have a polarity marking. 

I've been involved in over 2,000 PCB layouts since 1974 and I've never added Polarity Marking on Inductors on the silkscreen Legend. 

I'm going to rethink this for the future. 

Thanks!
Stay connected - follow us! X - LinkedIn
Back to Top
5not4 View Drop Down
Active User
Active User


Joined: 09 Jul 2013
Status: Offline
Points: 40 		Post Options Post Options   Thanks (0) Thanks(0)   Quote 5not4 Quote  Post ReplyReply Direct Link To This Post Posted: 01 Jul 2019 at 6:53am
We've been including a Pin 1 indicator on inductors when the manufacturer supplies it for the past few years. 

It was discovered during EMC testing that the polarity (a term I find inaccurate, should be more related to Pin 1 or the winding start pin) could be critical during PCB layout. 
Back to Top
Tom H View Drop Down
Admin Group
Admin Group
Avatar

Joined: 05 Jan 2012
Location: San Diego, CA
Status: Offline
Points: 5719 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 01 Jul 2019 at 7:35am
You should add a Pin 1 polarity marking on the silkscreen legend and the assembly drawing. 

This would help the assembly process, but also increase the performance of the PCB layout. 

I haven't seen a Pin 1 polarity marking on the mfr. provided 3D STEP models. 

If you have inductors lined up side by side, it's a good idea to point all Pin 1's in the same direction so that all the coil starting points are in the same direction. 
Stay connected - follow us! X - LinkedIn
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.422 seconds.