Allan Bennett Posted June 21, 2022 Share Posted June 21, 2022 I would like to replace one of the 3-way switches on my Taranis X9D+2019 transmitter with one that is spring-loaded either side of centre -- i.e. hands-off it will return to centre. I can't see any on T9's Taranis spares site, nor on RS Components site. Any ideas, please? Come to think of it, is there such a thing, for achieving a positive contact in the centre position might be problematic? Quote Link to comment Share on other sites More sharing options...
PatMc Posted June 21, 2022 Share Posted June 21, 2022 (edited) Here's the list of Taranis switches at T9. There's a couple of 3 position but I don't think there is a centre biased one. Edited June 21, 2022 by PatMc Quote Link to comment Share on other sites More sharing options...
RottenRow Posted June 21, 2022 Share Posted June 21, 2022 Allan You can get the type of switch that you describe, the positions from which the switch returns to the centre are called 'momentary'. The T9 link provided by PatMc above has one (the third one down) described as 'momentary long lever', though none in the photo next to the list is of that type, probably just a generic photo. There are only three terminals; the centre one is a common and the outer ones connect to the common in the two momentary positions of the switch. In the centre position, neither connects. The radio interprets this open-circuit condition as the switch being in the middle position. RS have a very large selection of small toggle switches but their website descriptions are confusing and in some cases contradictory, and although their datasheets provide the information required for a range of switches they are not specific. They used to be much better in this respect. T9 appears to be the obvious choice in this instance. Brian. Quote Link to comment Share on other sites More sharing options...
Mike T Posted June 21, 2022 Share Posted June 21, 2022 In the absence of a proper description, I suspect the 'momentary' switch from T9 is a single action - like a trainer switch. They don't look too pretty but there are these: https://www.amazon.co.uk/Mini-Momentary-Toggle-Switch-Miniature/dp/B00WZDJF9M Quote Link to comment Share on other sites More sharing options...
RottenRow Posted June 21, 2022 Share Posted June 21, 2022 6 minutes ago, Mike T said: In the absence of a proper description, I suspect the 'momentary' switch from T9 is a single action - like a trainer switch. Good point... Another source would be a supplier of model railway components, as these are used to operate electric point solenoids. Brian. Quote Link to comment Share on other sites More sharing options...
Mike T Posted June 21, 2022 Share Posted June 21, 2022 LOL! The reviews of the Amazon switches are mostly by Railway bods who've used them to control their points! ? Quote Link to comment Share on other sites More sharing options...
Caveman Posted June 22, 2022 Share Posted June 22, 2022 This looks like another source here GDB Quote Link to comment Share on other sites More sharing options...
Allan Bennett Posted June 22, 2022 Author Share Posted June 22, 2022 Thanks for the suggestions guys. The problem, I think, is that the standard Taranis 3-way switch actually has 3 contacts, doesn't it? The two switches referenced by Mike T and Caveman are both SPDT -- i.e. contacts only at the two end positions, and nothing at centre. Quote Link to comment Share on other sites More sharing options...
Sparks Posted June 22, 2022 Share Posted June 22, 2022 Just for info, the brackets of a switch description indicate the momentry positions ie (ON)-OFF-(ON) is a center-biased three position switch. ON-OFF-ON is a three position switch with no bias. 2 Quote Link to comment Share on other sites More sharing options...
RottenRow Posted June 22, 2022 Share Posted June 22, 2022 8 minutes ago, Allan Bennett said: The problem, I think, is that the standard Taranis 3-way switch actually has 3 contacts, doesn't it? Allan, No probably not. I haven't looked at a Taranis switch but the types used by Futaba and others only have contacts at the two end positions, and nothing at the centre. The transmitter then interprets this accordingly; if contacts 'A' are closed, the switch is one way, if contacts 'B' are closed it is the opposite way, and if neither is closed then it is in the middle. If you actually look at your switch terminals (inside the transmitter) if it only has three terminals then that will be how it works. That will almost certainly be the case. Sparks is exactly right in his post immediately above this one; it's a pity whoever wrote the descriptions on RS' website didn't adhere to this as some of the descriptions don't match. Some of the switches with brackets in the description are also described as latching... which they can't be. Brian. Quote Link to comment Share on other sites More sharing options...
Allan Bennett Posted June 22, 2022 Author Share Posted June 22, 2022 Thanks, I'll be looking inside my trannie this afternoon, and will report back. Quote Link to comment Share on other sites More sharing options...
Allan Bennett Posted June 22, 2022 Author Share Posted June 22, 2022 Yes, the 3-way switches in my Taranis have three leads, so they're SPDT. So I'll check my usual sources for (ON)-OFF-(ON) switches with of similar size. Quote Link to comment Share on other sites More sharing options...
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