----- Original Message ----- 
From: "Eric Smith" <[email protected]>
Sent: Sunday, April 24, 2016 1:38 AM


> On Sat, Apr 23, 2016 at 8:18 PM, dwight <[email protected]> wrote:
>> You'd need to decide, LOAD is switch up or
>> LOAD is switch down.
> 
> Which still doesn't explain how a toggle (not momentary) can be said
> to have NC and NO pins.------------

It kinda does, if you think of 'normal' not as a fixed function of the switch 
but its logically inactive state, usually relative to its (possibly implied) 
label and function. If a push button is labelled 'RUN' then the 'normal' state 
is opposite and away from that label, i.e. out or up; similarly, when a toggle 
switch is labelled 'RUN' then its 'normal' position will be opposite that label 
and like the momentary switch in that NORMAL state it can be either OPEN or 
CLOSED (with a complementary contact if it's a DT switch).


Schematics will usually determine and indicate the 'normal' state and the 
switch should be mounted, labelled and connected accordingly.

The on/off light switches in your house would be considered NO; by convention 
toggles (if any) should be UP to CLOSE and turn on the light  and the 'normal' 
state would be OPEN and pointing DOWN.


m

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