[sdiy] cure my ignorance..

[James Husted]

on 2/8/02 2:00 PM, ElmacacoX at aol.com at ElmacacoX at aol.com wrote:

> I am looking to buy some toggle switches that have a center position, and I
> see two different types that I don;t know the difference of.
> 
> On-Off-On

Three positions. The center position has the center contacts connected to
nothing.
 
> and 
> 
> On-NONE-ON

Two positions. The center contacts are connected to either the  other sets
but is never off.
 
Another switch wording of interest is MBB and BBM which stand for Make
before break and break before make. This means the contacts to the old
position  are still connected for a very short time when the switch is
engaged (MBB) leaving the switch always connected to something (for circuits
that don't want to be floating, connected to nothing, however for how short
a time). In the other type the old connection is broken before the new one
is made (BBM) giving a time while switching when nothing is connected.

-James