A tyro desoldering question.

[duncan webster 1Participant @duncanwebster1]

I think you could do it with a rotary wafer switch, not sure how many poles. If you're interested I'll think some more. Something like this. Certainly easier to mount

[Robin GrahamParticipant @robingraham42208]

Posted by duncan webster on 10/05/2022 00:27:21:

I think you could do it with a rotary wafer switch, not sure how many poles. If you're interested I'll think some more. Something like this. Certainly easier to mount

Thanks Duncan, I had wondered about a rotary switch but I'm obviously out of my depth with this – I had no idea how many different types of switch there are. A rotary switch would be better for this application than a slider from the operator's point of view, so any further input would be welcome.

I got involved with this project because someone else in my town gave up on it and suggested to the 'creatives' that I was the man for the job. The 'creatives' of course see only the effect and are oblivious to the complexities of the mechanisms which underpin their performances . I'm in a grumpy mood!

Robin

[Robin GrahamParticipant @robingraham42208]

Should have said that if it goes to stage I'll insist that ME gets a credit in the programme!

R.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Robin, there are numerous types and styles of rotary switches from a single wafer and upwards. Some are fixed to the number of ways they will do, but others have the choice of restricting the number of ways needed. This 2 to 6 way Rotary switch (Cricklewood Electronics) has a user installation adjustable stop to limit the rotation between two and six positions.

Hope this helps you understand there use.

Regards Nick.

P.S. there are a few here you might be able to choose from Rotary switches (CPC)

Edited By Nicholas Farr on 10/05/2022 08:03:07

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Robin, the only other thing to consider, with whatever switch you use, is that they very often will be stated as make before break (MBB) or break before make (BBM). It might not be obvious what this means or why. A MBB switch means that each contact will make the next one before it breaks the one that it is currently on, this can be a disaster in some circuits as it could short out some components a destroy them, in which case you need a BBM switch which will break the contact it's currently on, before it makes the contact that it's switching too and thus no short circuit takes place. I can't tell you which type you need for your circuit board though, so you may have to see if you can work out which type the switch you have is, but if unsure, I'd go for a BBM switch, but in some circuits it makes no difference, but a MBB switch can stop arcing in the switch taking place in some circuits.

Regards Nick.

Edited By Nicholas Farr on 10/05/2022 08:58:12

[duncan webster 1Participant @duncanwebster1]

I think this works, but it would be good if someone checked it, we don't want to release the magic smoke on something difficult to replace. The switch is this, break before make. If you need make before break you'll fond one easy enough. I'm not sure which you need (see Nicholas above) you might be able to tell by connecting a resistance meter between pins 1 and 3 and very slowly sliding the switch across. If it is MBB you will get momentary connection, but it might be hard to spot with a digital meter. If you'r edestroying the switch you might be able to see what's going on. I must admit I'm always wary of prodding about with a resistance meter in a circuit like this, could you reverse bias something and kill it? Someone who knows what he's talking about will advise.

[Robin GrahamParticipant @robingraham42208]

Thanks Duncan, and apologies for delay replying – reply notification got swamped in my inbox. That looks like it should do what I want. A rotary switch would be actually be even better than a toggle for this application.

I'm confident that the existing switch is break-before-make just from visual inspection of the innards.

Robin

Edited By Robin Graham on 13/05/2022 22:09:09

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