JST Series Type - Page 1
Forum section: electronics / projects

author: bostonman
author_rank: Super Contributor
timestamp: July 07, 2021, 02:24:40 pm
content: Does anyone know what series JST connector this is?I'm measuring 8.2mm wide and 4mm height (not including the two plastic guides that protrude out). From looking at different series, I can't find any that are 8.2mm wide. The closest I've come are 7.9mm.

author: Monkeh
author_rank: Super Contributor
timestamp: July 07, 2021, 02:37:49 pm
content: Just your every day XH.

author: ajb
author_rank: Super Contributor
timestamp: July 07, 2021, 07:41:10 pm
content: Yeah, looks like an XH. It's a lot easier to go by the connector pitch, since that's a spec that's more commonly used and can usually be filtered on at distributors.

author: bostonman
author_rank: Super Contributor
timestamp: July 08, 2021, 12:56:31 am
content: It looks like a pitch of 3.30mm.I had looked on Wikipedia prior to my post, and didn't see what fit mine.

author: sleemanj
author_rank: Super Contributor
timestamp: July 08, 2021, 01:27:55 am
content: Quote from: bostonmanPitch is between the centers of two adjacent pins (or in your case, the center of one end pin and the center of the middle space where a pin would be).Since you measured the 3 pin plug to be 8.2mm wide, then a pitch of 3.3mm is impossible :-)XH is 2.5mm pitch, and your plug looks like XH to me

author: bostonman
author_rank: Super Contributor
timestamp: July 08, 2021, 01:52:39 am
content: QuoteIt wouldn't be impossible, it would just leave very little between the edges and side pins - but you're correct, it's an impossible design to have.This is hard to measure. Placing the calipers in the holes, and I get over 3mm, holding it aside of the holes and manually centering it does place me in the 2.5mm range. I can't fit the calipers in the female end.I'll go with the majority input of 2.5mm.

author: sleemanj
author_rank: Super Contributor
timestamp: July 08, 2021, 02:21:42 am
content: If using a digital caliper, an easier way to measure pitch than eyeballing centers is usually to set your caliper to the width of 1 pin and then zero it, then measure the outside distance from one pin to the next, this will get you the pitch between two consecutive pins (outer distance minus 1 pin width).

author: Siwastaja
author_rank: Super Contributor
timestamp: July 08, 2021, 01:56:30 pm
content: Obviously, to obtain the pitch of an n-pin connector, measure between the far end pins and divide by (n-1), this reduces any measuring error by factor (n-1).2.5mm is easy to verify, with just 3 pins it should align pretty well on a standard 2.54mm pin header.

author: ajb
author_rank: Super Contributor
timestamp: July 08, 2021, 03:11:52 pm
content: Another way to get a more accurate pitch measurement is to measure from one edge of the pin/hole to the same edge of the next pin/hole. Lining up to edges is easier than trying to eyeball a center position. A lot of connector pitches are going to be either a nice round metric measurement (0.5, 0.7, 1, 1.5, 2, 2.5, etc) or a multiple or half-multiple of 100mil/2.54mm, although there are some popular oddball sizes like 3.96mm.

author: xavier60
author_rank: Super Contributor
timestamp: July 08, 2021, 11:28:49 pm
content: Quote from: sleemanj on July 08, 2021, 02:21:42 amThat's how I do it also. It works well in other situations like measuring the pitch of screw holes or studs. Taking the measurement over a larger number of pins then dividing, would reduce the error.

author: viperidae
author_rank: Frequent Contributor
timestamp: July 09, 2021, 10:37:15 am
content: Isn't 3.96mm 5/32 of an inch? I'm a native metric speaker, but I always assume things that don't make nice round numbers in metric are based on imperial.

author: phil from seattle
author_rank: Super Contributor
timestamp: July 10, 2021, 04:42:33 pm
content: Quote from: viperidae on July 09, 2021, 10:37:15 amYes but there aren't a lot of possibilities. 3.81mm springs to mind - 150 mils/.15". And let us not forget the most common pitch out there 2.54mm (0.1"). I think it more likely to be measurement error that gets an odd pitch value. Realistically, there are only a few likely pitch values.