6pin on-on-on switch: a DP3T or a DPDT?

[k4rlhp]

Hi!

I'm building a project and came across something unexpected (to me).
It's advertised as DP3T switch on farnell...
Drawing: http://www.farnell.com/cad/2291354.pdf
Alcoswitch, part no. 3-1825139-9

It connects center pins (the common pin) to opposite pole sides in a Z pattern when in middle position, otherwise it works like a standard DPDT switch.
Would you call this a  DPDT on-on-on or a DP3T?
If you call it DP3T, why not call a DPDT on-off-on a DP3T since the mid position is a discreet position?

Seems to me that there is some ambiguity in terminology, or maybe it's just me.

Thanks.
Karl

[ajb]

DP3T implies that there are two SP3T switches, and SP3T implies one common contact that can be connected to any of three other contacts.

The switch itself is a three-position DPDT switch.  In options 3, 5, and 7, the center position is off.  In options 11, 13, and 15 the center position is a 'staggered' on, with one side in one position and the other side in the opposite position. 

The notes for the diagram say "SP3T function achieved with functions 11, 13 & 15 by customer applied jumper between terminals 3 and 5", so they're showing that with external wiring you can convert the staggered DPDT switch to a SP3T (not DP3T!) switch.  The diagonal line in the schematic between pins 3 and 5 is an external wire that you have to install.

[tecman]

In my years of experience, this was called a DPDT-Center Off switch.
DP3T implies a 3 active, unique positions,m which the switch is not.

paul

[ConKbot]

Decoding the PN with the table, shows that the switch specified is a SP3T not a DP3T switch.  Look at the "function 11" on the operation chart to see how the SP3T operation is done.

AJB is correct in that it's a staggered operation DPDT switch, not a normal DPDT switch, and the external jumper gives you SP3T functionality.

Definitely not DP3T, but about par for the course in SP3T toggle switches, sometimes you have to add a jumper, sometimes one comes pre-attached.

[macboy]

This switch could be wired as a forward-brake-reverse for a small brushed motor.
Motor across 2,5
V+ to both 1,6
V- to both 3,4

Or as mentioned in the datsheet, add the 3 to 5 jumper and it becomes SP3T (not DP3T) using 2 as the IN and 1,4,6 as the 3 OUTs.

[k4rlhp]

I see that I'm generally right, labelling this as dp3t is incorrect. The rest is on the schematic/datasheet and sure, the switch can be used for many useful purposes just not for a dp3t. Farnell listing it as a dp3t was the unexpected part for me.