Name for type of toggle sw. that is Mom. Off On?

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
I have been looking for a small toggle switch for a test box
that is momentary on, off, and on, but can't find one and
don't know if there is a special name for these switches.  I
have seen them, but of course can't find them when needed
(yea, what else is knew!).  Any help will be appreciated.

Electrically, this switch is like a momentary switch in
parallel with a regular on/off toggle switch.  This is one
option, but more work also.

____|____
|        |
---------
  M Off On


Dave,


Re: Name for type of toggle sw. that is Mom. Off On?

Quoted text here. Click to load it

Do you mean "normally open momentary" where "off" means the switch is open
an thus passes no current? I would be surprised if www.digikey.com didn't
have them.

--
- Mark

Re: Name for type of toggle sw. that is Mom. Off On?
On Wed, 29 Jun 2005 14:53:37 GMT, Dave Boland

Quoted text here. Click to load it

---
They're called (are you ready???)

"On - Off - Momentary" toggle switches

We've slightly trimmed the long signature. Click to see the full one.
Re: Name for type of toggle sw. that is Mom. Off On?
Sometimes the momentary action is denoted on data sheets with th
parenthesis e.g. on-off-(on)



Quoted text here. Click to load it


        
This message was sent using the comp.arch.embedded web interface o
www.EmbeddedRelated.com

Re: Name for type of toggle sw. that is Mom. Off On?
$ snipped-for-privacy@twister.nyroc.rr.com:

Quoted text here. Click to load it

In major electronics catalogs they are usually designated as:

ON-OFF-(ON)

The parinthesies indicates momentary.

But sometimes:

ON-OFF-MOM.

I just went though search for a ON-NONE-(ON), and got a ON-OFF-(ON) by
mistake.  Typed in the wrong part number from Mouser. So, I know they have
them.

Re: Name for type of toggle sw. that is Mom. Off On?



Quoted text here. Click to load it

Digikey has them also.
ALCO, C&K and others



Re: Name for type of toggle sw. that is Mom. Off On?
Another odd duck to watch out for is on-on-on.
It's a spdt, but in the middle position, the arm is connected to BOTH
sides.  Tough to figure out what's wroing with your creation if you
install one of these by mistake!


Re: Name for type of toggle sw. that is Mom. Off On?


Quoted text here. Click to load it

Sounds like the toggle switch equivalent to the old "shorting" rotary
switch, where the next contact makes before the current one breaks.

While we are on the subject, anyone know a source for momentary contact
pushbutton switches.  I want one that makes and breaks in one press.
[I.e. press and it makes and breaks the contact, release does nothing
(except re-arm it for the next press).  Years ago I took one apart -
basically it's just a little roller under a slider.  Goes down one
path, and back up the other.  One path it makes contact, the other it
doesn't.

Can't seem to find one in the catalogs now.  Just need a modest sized
one that will handle an amp or two.  [If I can't find it, I'm going to
have to cobble some circuitry together, in a tight space in the
housing.]
                        tnx, jmk


Re: Name for type of toggle sw. that is Mom. Off On?

Quoted text here. Click to load it

I think it's not exactly shorting, but the two sections have different
detent points:

        o   o             o   o               o   o
                              |               |   |
        o   o             o   o               o   o
        |   |             |    
        o   o             o   o               o   o

Quoted text here. Click to load it

Actually, it sounds like something's broken. How long of a pulse are
you looking for?

Good Luck!
Rich


Re: Name for type of toggle sw. that is Mom. Off On?
Quoted text here. Click to load it

You are right, that's different from what I thought was being
described.

Quoted text here. Click to load it

One man's broken is another man's specification requirement. <G>

These things are mechanical and the pulse length is usually pretty
variable... around  100 ms or so.  Unfortunately, my ASCII art isn't as
good as yours, so I hesitate to even try to draw one.  They used to be
fairly common, back when "control logic" meant stepper relays and the
like.  Now I guess it's so much easier to do everything with
electronics rather than electromechanical, that pulsing a relay
mechanically just isn't much of a market.

                            jmk


Site Timeline