Common LED display of crossover turnout route

[Steve Smith]

Hi guys,

I am looking at using LED's to display route indication through a crossover. and am looking for a wiring diagram that will allow 1 common LED indicating the crossover route to be lit only when both turnouts are aligned for the crossover.

Schematic :       ------------------0-----------
                                     \
                                       \
                                         0
                                           \
                                             \
                       -----------0------------------ 

The O in the crossover is the LED to be lit only when both turnours are thrown for the diverging routes.

I am using manual turnout controls, each with a double pole slide switch with one set of contacts powering the frog, and want to use the second set of contacts to indicate the turnout position on a control panel.

I have searched the web but not had any success.

Any ideas ?   

Regards,
Steve Smith
Wellington
South Africa

[RBrodzinsky]

Steve,

The simplest way is to have one of the DPDT switches connect to power when in divergent position, and the other connect to ground.  Then wire your LED (and resistors appropriately).   That way, their is no flow through the LED unless both switches are in the position you desire.

[railnerd]

Fun morning brain puzzle. Using a few resistors and transistors, you build a discrete "NAND" gate for controlling the middle LED.

Normal Case:


One Turnout Thrown:


Both Turnouts Thrown:

[RBrodzinsky]

Dave, wouldn't this work just as well? 

[peteski]

Interesting setup.

[railnerd]

Dave, wouldn't this work just as well? 

Seems like it, and fewer parts, too.

[mighalpern]

Hello, New to railwire
I have done the same but using tortosie machines and 1 DPDT switch on the main to actuate the cross over. Since you are doing it the mechanical way  If you connect both switches to a single linkage then you can designate one DPDT switch to run the LED's while each switch still controls its own frog
I can always send a picture of my wiring.
good luck
Miguel

[Steve Smith]

Hi guys,

Many thanks for the suggestions to solve my dilemma.  Being a technologically challenged individual, I will give Rick Brodzinsky's suggestion a try out this week-end.

Cheers,
Steve