Relay footprint cannot be ascertained? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: May 23, 2022, 05:52:22 pm
content: Hi,Would you agree that the relay J115F11C12VDCSH.9 has a datasheet which makes it impossible to make a PCB footprint for it?I am speaking in relation to the position of the outer case in relation to the location of the drill holes.In making a footprint as best i can, I am guessing that the case is , in any place, at least 4mm from the centre of the nearest drill hole to that point of the case, and then making the case conform to that (as attached)….is this a good conclusion? (ie, to avoid collision with neighbouring components on the PCB)....then i just extended its width to be at least 26.9mm, to accord with the stated width......my initial width from the "method" was 25.8mm, so to be sure, i extended the width 1.1mm in each direction.(my length was more than the stated 31.7mm when using the "method", so i left the length as it was.)Would you agree with this?J115F11C12VDCSH.9 Relayhttps://www.citrelay.com/Catalog%20Pages/RelayCatalog/J115F1.pdf

author: jfiresto
author_rank: Frequent Contributor
timestamp: May 23, 2022, 06:20:26 pm
content: Perhaps it copies a popular part and duplicates its well-known dimensions. If it does, your mission, should you decide to accept it, is to identify that part and use its datasheet.

author: floobydust
author_rank: Super Contributor
timestamp: May 23, 2022, 06:22:05 pm
content: The datasheets are usually missing dimensions. It looks like a commonT9AAKA T90 style relay form-factor.Songle T90so I would use those dimensions.Note the extra pin makes HV clearance hard to meet because it's right by the coil pads. I've even seen it not used and just a hole in the pcb there.edit: also these relays dissipate a few watts and need decent space for cooling. Thick copper pours on the power pins also help to act as heatsinks for the contacts.You can't put parts right next to them and have a tiny cramped product IMHO.

author: Gyro
author_rank: Super Contributor
timestamp: May 23, 2022, 07:13:14 pm
content: Your relay coil is damaged! I would suggest a resistor style rectangle.

author: jpanhalt
author_rank: Super Contributor
timestamp: May 23, 2022, 08:09:47 pm
content: I don't see a problem assuming the upper left two holes are aligned, which seems reasonable.

author: vstrulev
author_rank: Contributor
timestamp: September 01, 2022, 11:14:12 pm
content: Quote from: Faringdon on May 23, 2022, 05:52:22 pmGood day. Measure with calipers, create part, print the component on a piece of paper, put the paper on soft base (mouse mat) allign and press on it and see if matching. If not, move the vias to the desired positon. To decide on the hole diameter, grab each pin with calipers and rotate the relay. The largest number is the hole size, add another 0.5mm or so. Otherwise the datasheet is confusing. I would not choose the part at all for its price/value. Take a look: ACTL3CR3V or CB1AH-P-12V. We used them both. Great choice and super reliable.

author: Warpspeed
author_rank: Contributor
timestamp: September 12, 2022, 06:23:27 am
content: Just be doubly sure the drawing is a top view, and not just a pretty picture of the base.Often it does not matter, as the whole thing may be symmetrical, but not always.So beware...

author: exmadscientist
author_rank: Frequent Contributor
timestamp: September 13, 2022, 12:39:47 am
content: Quote from: jfiresto on May 23, 2022, 06:20:26 pmDing ding ding ding ding!Here have this one. Used in production! The outline's pretty much perfect too, or at least perfect within tolerances.I'd share a picture, but blah blah blah NDAs and all that....

author: Jeroen3
author_rank: Super Contributor
timestamp: September 13, 2022, 06:16:02 am
content: Doesn't the mechanical dimension drawing indicate the position of the pins relative to the bottom left corner?Thus also the drill hole positions?I've seen worsecursed footprints.

author: exmadscientist
author_rank: Frequent Contributor
timestamp: September 13, 2022, 09:12:39 am
content: Quote from: Jeroen3 on September 13, 2022, 06:16:02 amThe main trouble on this footprint is getting the silkscreen outline position correct with respect to the hole pattern. Many vendors are sloppy about providing this information, especially connector vendors, but we all know that connectors are designed by evil bastards anyway. The hole pattern here is easy, though guessing which units were used for the original design was harder than usual. (Turns out it was inches.) This footprint can serve a half-dozen or so vendors' parts, which is both great and kind of a pain in the ass because now you've really got to get it right. I think I decided the original or at least eldest findable was Potter & Brumfield, though it's been a while now since I did this one so my memory might be crap.QuoteHow sad is it that I don't even think half of those are that bad? Hell, I recognize a couple there that I've even built 3D models for because the manufacturer couldn't be arsed to provide them. And the guy who didn't like PLCC pin numbering and called it "cursed" was hilarious. It's probably older than he is! But every PLCC's the same (...I hope....) so at least the buggers are consistent. Not that I'll miss them when they're gone. (Which is probably soon! Many packaging houses seem to have decided that they're not worth making in the current industry climate.)Or, OK, maybe I'm just getting old