I have on several occasions used such switches for speaker switching, in one
case the old ready made ones and also some made by me. Always they seem to
fail with dodgy contacts, some work if you squirt them others not. Is this
because the actual contacts clean themselves on mains voltages, but do not
on the lower voltage speaker lines?
Brian

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Brian Gaff wrote:

====================
> I have on several occasions used such switches for speaker switching, in one
> case the old ready made ones and also some made by me. Always they seem to
> fail with dodgy contacts, some work if you squirt them others not.

** Ones with plain brass contacts will fail, brass tarnishes and becomes non conducting at low voltages.

However nearly ALL mains rocker switches sold use plated contacts - silver or silver alloy - so there is no such issue.

Maybe you have trouble telling the difference ....

....... Phil

On Thu, 1 Sep 2022 10:09:07 +0100, "Brian Gaff" <brian1gaff@gmail.com>
wrote:

>I have on several occasions used such switches for speaker switching, in one
>case the old ready made ones and also some made by me. Always they seem to
>fail with dodgy contacts, some work if you squirt them others not. Is this
>because the actual contacts clean themselves on mains voltages, but do not
>on the lower voltage speaker lines?
> Brian

Mains voltage has a way of fixing poor contact switches. You need
specific low voltage high current ones. They will have contacts that
wipe, not simply touch. The big old blade switches you used for
electrifying corpses for doctor Fran\enstein will do nicely.

d

In article <6310afbf.19882218@news.eternal-september.org>,
Don Pearce <spam@spam.com> wrote:
> On Thu, 1 Sep 2022 10:09:07 +0100, "Brian Gaff" <brian1gaff@gmail.com>
> wrote:

> >I have on several occasions used such switches for speaker switching, in one
> >case the old ready made ones and also some made by me. Always they seem to
> >fail with dodgy contacts, some work if you squirt them others not. Is this
> >because the actual contacts clean themselves on mains voltages, but do not
> >on the lower voltage speaker lines?
> > Brian

> Mains voltage has a way of fixing poor contact switches. You need
> specific low voltage high current ones. They will have contacts that
> wipe, not simply touch. The big old blade switches you used for
> electrifying corpses for doctor Fran\enstein will do nicely.

On my old car, Lucas decided to use relays switched by the same high
current ones used on other versions and makes. Contacts are plain touch
copper. When used to only switch a relay, go 'dirty' quite quickly and
need cleaning. On high current use, pretty well never. Did wonder about
silver or whatever plating the contacts.

--
*He who dies with the most toys is, nonetheless, dead.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

You would think QED would not use rubbish and one of them is made by them.
Brian

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"Phil Allison" <pallison49@gmail.com> wrote in message
news:2c776b6f-ff2f-4f5f-b44b-3efebad03f36n@googlegroups.com...
> Brian Gaff wrote:
>
> ====================
>> I have on several occasions used such switches for speaker switching, in
>> one
>> case the old ready made ones and also some made by me. Always they seem
>> to
>> fail with dodgy contacts, some work if you squirt them others not.
>
> ** Ones with plain brass contacts will fail, brass tarnishes and becomes
> non conducting at low voltages.
>
> However nearly ALL mains rocker switches sold use plated contacts - silver
> or silver alloy - so there is no such issue.
>
> Maybe you have trouble telling the difference ....
>
>
> ...... Phil
>
>
>
>

Well, the rocker types big small or whatever have all given problems. Pity,
since they look nice in a panel!

In many cases those miniature toggles are far more reliable I find but it
kind of looks cheap.

Still, I guess nothing is quite so bad as jack plugs for grotty contacts!
Brian

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"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:5a2127c123dave@davenoise.co.uk...
> In article <6310afbf.19882218@news.eternal-september.org>,
> Don Pearce <spam@spam.com> wrote:
>> On Thu, 1 Sep 2022 10:09:07 +0100, "Brian Gaff" <brian1gaff@gmail.com>
>> wrote:
>
>> >I have on several occasions used such switches for speaker switching, in
>> >one
>> >case the old ready made ones and also some made by me. Always they seem
>> >to
>> >fail with dodgy contacts, some work if you squirt them others not. Is
>> >this
>> >because the actual contacts clean themselves on mains voltages, but do
>> >not
>> >on the lower voltage speaker lines?
>> > Brian
>
>> Mains voltage has a way of fixing poor contact switches. You need
>> specific low voltage high current ones. They will have contacts that
>> wipe, not simply touch. The big old blade switches you used for
>> electrifying corpses for doctor Fran\enstein will do nicely.
>
> On my old car, Lucas decided to use relays switched by the same high
> current ones used on other versions and makes. Contacts are plain touch
> copper. When used to only switch a relay, go 'dirty' quite quickly and
> need cleaning. On high current use, pretty well never. Did wonder about
> silver or whatever plating the contacts.
>
> --
> *He who dies with the most toys is, nonetheless, dead.
>
> Dave Plowman dave@davenoise.co.uk London SW
> To e-mail, change noise into sound.

On Thu, 1 Sep 2022 18:09:49 +0100, "Brian Gaff" <brian1gaff@gmail.com>
wrote:

>Well, the rocker types big small or whatever have all given problems. Pity,
>since they look nice in a panel!
>
>In many cases those miniature toggles are far more reliable I find but it
>kind of looks cheap.
>
>Still, I guess nothing is quite so bad as jack plugs for grotty contacts!
> Brian

The miniature toggle has the advantage that the contacts close with a
snap, which will break through corrosion to an extent.

d

Brian Gaff wrote:
==================

> You would think QED would not use rubbish

** ????? Better think again.

Made in Taiwan by the cheapest contractor ......
Just one step removed from a total scam.

....... Phil

> > ====================
> >> I have on several occasions used such switches for speaker switching, in
> >> one
> >> case the old ready made ones and also some made by me. Always they seem
> >> to
> >> fail with dodgy contacts, some work if you squirt them others not.
> >
> > ** Ones with plain brass contacts will fail, brass tarnishes and becomes
> > non conducting at low voltages.
> >
> > However nearly ALL mains rocker switches sold use plated contacts - silver
> > or silver alloy - so there is no such issue.
> >
> > Maybe you have trouble telling the difference ....
> >

Don Pearce wrote:
================
>
> The miniature toggle has the advantage that the contacts close with a
> snap, which will break through corrosion to an extent.
>

** Mini toggles do well at signal ( ie dry) switching, so are OK for speakers too.

All carry markings ( ie 250VAC, 5A) that suggest they are suitable for mains power but very few meet safety standards.
Creapage and clearance distances are not met and they do not "fail safe".
Should always be used mounted on an *earthed* metal panel.
None will accept push on ( ie QC) connectors so factories hate them.

Not really mains switches at all.

..... Phil

On 2/09/2022 7:28 am, Phil Allison wrote:
> Brian Gaff wrote:
> ==================
>
>> You would think QED would not use rubbish
>
> ** ????? Better think again.
>
> Made in Taiwan by the cheapest contractor ......
> Just one step removed from a total scam.
>
>

**Yep. QED is nothing special. I well recall their RCA leads, which were
OK, but the RCA connectors were horribly designed. Almost impossible to
remove with human fingers.

--
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www.avast.com

You would think though, having taken a rocker apart in my youth, that there
is also a toggle element in those as well, its kind of sprung knee thing, so
in effect its a toggle inside, not simply a bit of bent brass like you might
find on an old torch.
Brian

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"Don Pearce" <spam@spam.com> wrote in message
news:6310f59c.37766609@news.eternal-september.org...
> On Thu, 1 Sep 2022 18:09:49 +0100, "Brian Gaff" <brian1gaff@gmail.com>
> wrote:
>
>>Well, the rocker types big small or whatever have all given problems.
>>Pity,
>>since they look nice in a panel!
>>
>>In many cases those miniature toggles are far more reliable I find but it
>>kind of looks cheap.
>>
>>Still, I guess nothing is quite so bad as jack plugs for grotty contacts!
>> Brian
>
> The miniature toggle has the advantage that the contacts close with a
> snap, which will break through corrosion to an extent.
>
> d

Yes, However back in the day I fitted one to a Sinclair PSU case and it is
on the mains side. It has a plastic lever and has given me no trouble.
Meanwhile those multi voltage psus with the slide switch get truly awful as
the are I assume only handling low voltages and currents.

Brian

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"Phil Allison" <pallison49@gmail.com> wrote in message
news:82de170f-ba22-4110-810e-349bd814ca07n@googlegroups.com...
> Don Pearce wrote:
> ================
>>
>> The miniature toggle has the advantage that the contacts close with a
>> snap, which will break through corrosion to an extent.
>>
>
> ** Mini toggles do well at signal ( ie dry) switching, so are OK for
> speakers too.
>
> All carry markings ( ie 250VAC, 5A) that suggest they are suitable for
> mains power but very few meet safety standards.
> Creapage and clearance distances are not met and they do not "fail safe".
> Should always be used mounted on an *earthed* metal panel.
> None will accept push on ( ie QC) connectors so factories hate them.
>
> Not really mains switches at all.
>
> .... Phil