[sdiy] illuminated rocker switch confusion

[Julian]

Hello,

Im familiar with single pole illuminated rocker switches that have three terminals -

1 + 2 switched
3 ground for lamp


...however, ive just got double pole versions through with only 4 terminals.

I dont understand these, as i would have expected another terminal for the lamp ground?


The only way i can see that they can work is by grounding the lamp through the live to the load.  And, if the load is disconnected, 
the lamp in the switch will go out - which doesnt seem right?

Also, which side of the switch is the lamp connected to, i wonder?


My intended application for the switches was to switch both mains voltage on one pole, and a 12v DC on the other.  But, like i say, 
the arrangement has me confused.


I must admit, this isnt going into a synth at all, but is for my biodiesel reactor control unit -

http://www.zen9084.zen.co.uk/random_photos/bd_controller_01.jpg
http://www.zen9084.zen.co.uk/random_photos/bd_controller_02.jpg
http://www.zen9084.zen.co.uk/random_photos/bd_controller_03.jpg
http://www.zen9084.zen.co.uk/random_photos/bd_controller_04.jpg

...but the switched are equally relevant for synths, so im hoping i can get away with it ; )

Thank,
Julian