[KLC F7.2] THT Relay coil at middle pins

[Knochi]

I have a footprint of a relay where the A1 pin of the coil is at one of the middle pins.
Should i still place the anchor on A1 or is it not considered as pin1?

So I try to use the standard “Relay SPDT” symbol with A1, A2 (coil), 11(COM), 12(NC) and 14(NO) pin numbering.

The part in question is a relay from lcsc NBC BS4

From the datasheet:

My current footprint(with top left pin as anchor):

Thanks in advance
David

[paulvdh]

For a personal project there is not much benefit to adhere to KLC compliance. There also does not seem to be any pin numbers in that chinese datasheet. It is common to number the pins, as if they were a DIP-14 (and skipping the missing pins / numbers). but it really is not very important.

The important thing is that the pin “numbers” in the schematic match that of the footprint, and when you use multiple pins with the same number, then KiCad wants you to connect them all together with tracks on the PCB.

[Knochi]

Hi Paul,

thanks for the quick reply. I’m planning to commit the footprint and a 3D model to the repo. And I always adhere to the KLC, because i think it’s a good thing to have everything nice and consistent and some of the rules even have technical reasons or resemble some industry standards.

So still the question is if it would be compliant with KLC to have just the upper left pin (11 in this case) at the anchor.

[paulvdh]

Instead of reading the KLC, I browsed a bit though the relays in KiCad’s libraries.

There are a few with the relay coil on the top side, but most have the relay coil on the left side.
Your relay is also very similar to: Relay_THT:Relay_SPDT_HsinDa_Y14,

The most notable differences I see are:

• 180 degree rotation.
• Pin numbering.
• Round versus oval pads
• Small differences in pin pitch.

Another noticeable difference is that when pad order is marked with a square pad, it is always a pad in the corner in KiCad’s own libraries, regardless of whether that pin is from a coil or a switch. The HsinDa is an example, but also the Relay_SPDT_Omron_G5V-1 (Which is same form factor as HsinDa, but has the square pad in another location).

[Knochi]

That’s good reference. I will look this up