Difference between DPDT on-off and on-on

[littlegreiger]

Is there a difference between a switch that is labelled DPDT on-off and a switch that is labelled DPDT on-on

[zeta55]

Ehh.. As I remember one of them is momentary, but wich one? :?

[Mark Hammer]

For a switch to have a position where it is "on", and another where it is "off", there have to be two switch positions, right?

Consequently, even though a toggle or footswitch may only have two contacts that can be closed or left open, it is referred to as a *single-pole/single-throw* switch, despite having *two* positions.  In a sense, there can BE no such thing as a DPDT on-off switch because any contacts that become available in the opposite switch position would automatically make it a "double-throw" switch, and if there WERE no such contacts (i.e., only 4 solder lugs on the switch) that would make it a double-pole single-throw (DPST) switch because there is only one dual-set of contacts the signal can be "thrown" to.

It IS possible that somebody might mistakenly label/refer-to a DPST as a DPDT on-off switch.  It is also possible that someone might refer to a 6-solder-lug DPDT switch as "on-off" with respect to how it is *used/wired*.  To the best of my knowledge, though, if there is no "second choice" to direct the signal to (i.e., 2 sets of 3 contacts) it would properly be referred to as a DPST switch.

[littlegreiger]

Thanks for the help guys.  I was just wondering because i need a switch for an amp.  So I could use one that is labelled on-on even if it is for the on-off switch on the amp.

[sir_modulus]

Yuppers!

What you do, is you use half of it. (use it like a normal switch (you know...on - off.....two contacts?)).

Also, since someone mentioned momentary...that's usually written as:
On - (On)
or
On - (Off)

Nish