TTi Power Supply Output Terminal Stud Size - Page 1
Forum section: electronics / testgear

author: Ohm_My
author_rank: Contributor
timestamp: June 05, 2020, 03:43:32 am
content: I'm looking for the stud size on the TTi model PL303 power supply output terminals. I have a need for a spade or fork connector to the outputs but I cannot be sure of the correct size connector.I wrote to TTi directly about this but have not had a reply over a few days. Any help is appreciated.

author: voltsandjolts
author_rank: Unknown
timestamp: June 05, 2020, 08:15:50 am
content: Erm, did you try measuring it?

author: Ohm_My
author_rank: Contributor
timestamp: June 05, 2020, 04:38:51 pm
content: The outer collar that threads on to the shaft does not have enough exposed area to make a measurement of the shaft diameter.

author: AVGresponding
author_rank: Super Contributor
timestamp: June 05, 2020, 05:15:40 pm
content: All my TTi psu's use standard binding posts.A diameter of 5mm may be regarded as default.

author: Gregg
author_rank: Super Contributor
timestamp: June 05, 2020, 05:28:35 pm
content: Take some fairly stiff paper such as card stock and cut a narrow V groove such that you can slip it over the binding post shaft. Mark where it fits the shaft and then measure the gap where marked.

author: Cerebus
author_rank: Super Contributor
timestamp: June 05, 2020, 05:35:17 pm
content: Quote from: AVGresponding on June 05, 2020, 05:15:40 pmMight be a bit risky to take 5mm as nominal, I've come across a lot of binding posts that use an M6 fine thread (i.e. 6 mm major diameter).As for not being able to measure that binding post - just use a bit of ingenuity. Wrap a bit of solid core wire into a U shape over it, take it out and measure that. Or cut some slots of varying width into some thin card and use them as gauges.

author: AVGresponding
author_rank: Super Contributor
timestamp: June 06, 2020, 08:17:54 am
content: Quote from: Cerebus on June 05, 2020, 05:35:17 pmMy bad, I should have been more clear.The threaded section is indeed M6 x 0.75, the clean section where you'd put your fork terminal is the 5mm diameter part(well, 4.8mm, but what's a couple of tenths of a mm between friends?).

author: Hydron
author_rank: Super Contributor
timestamp: June 06, 2020, 02:52:53 pm
content: Looks like the OP's TTi is using the newer shrouded-banana-plug compatible binding posts, so they may not be the same diameter as the standard posts.I've got some spares of these special posts handy at work that normally would be easy to measure, but thanks to covid i'm stuck at home and can't sorry.

author: Cerebus
author_rank: Super Contributor
timestamp: June 06, 2020, 03:31:31 pm
content: Quote from: Hydron on June 06, 2020, 02:52:53 pmDid you get those from TTi as official spares, or from an independent source?I've been looking for a stock "safety" binding post that:1) Doesn't cost the earth - I'm looking at you Multicontact.2) Will accept spade connectors. (The Multicontact [now Staubli] ones just have a hole you poke a wire through and come in at more than £9 a piece.)

author: AVGresponding
author_rank: Super Contributor
timestamp: June 06, 2020, 05:10:24 pm
content: Quote from: Hydron on June 06, 2020, 02:52:53 pmThe plastic molding is bigger, but my guess is the metal post is the same size. Wouldn't really make sense to make one a different size and render all existing fork terminal leads obsolete.As Cerebus says, easy enough to wrap some solid core around it to get a measurement.£9 each?!? Are they carved out of solid gold by grey-bearded virgins in a mountain cave?

author: Hydron
author_rank: Super Contributor
timestamp: June 06, 2020, 07:49:13 pm
content: Quote from: Cerebus on June 06, 2020, 03:31:31 pmSpares direct from TTi. This was 3 years ago but they cost 2.50 GBP each then (probably plus VAT), and came with a kit so they could be retrofitted to any of their PSUs, even the ones that originally came with the older posts (all the binding post options have M4 fixing bolts at the back). I suspect they're just trying to cover costs with the spares (was free P&P too), so may not want to sell anyone a large quantity.