LEDs on a parallel circuit: CONCLUSION

[CSX_road_slug]

I'm installing a decoder in a P2K SW-9, and I want to wire the front and rear headlights so they are both on at the same time, regardless of direction. [That's how I've always seen them operating in steel mills.]  If I was using regular filament bulbs, wiring them in parallel wouldn't be a problem.  But I want to use LEDs, since they're cooler and won't melt the cab roof.  Can LEDs be wired in parallel?

 

T.I.A.

-ken 

[river_eagle]

yes, you can wire them in parallel, but your decoder can also be set up to do the same thing, or for light in direction of travel to be bright, while the other is dim, or purely directional.

check decoder manual for specs.

[CSX_road_slug]

yes, you can wire them in parallel, but your decoder can also be set up to do the same thing, or for light in direction of travel to be bright, while the other is dim, or purely directional.  ...

OK - thanks! 

[betamax]

You can wire them in parallel, but you must sum all the currents passing through the LEDs to calculate the series resistor.

Which is not really that much of a problem. The real problem will be: Can the decoder output handle the current that will be needed? Some may be very limited in that aspect.

[CSX_road_slug]

There's already a 1K resistor built into the decoder for installing LEDs, on a separate circuit from where I would solder the bulb wires.  It's an NCE SW9SR.

[CSX_road_slug]

... The real problem will be: Can the decoder output handle the current that will be needed? Some may be very limited in that aspect. ...

It appears that it can! I wired up both LEDs and ran a chassis-only test, forward and reverse - both light up simultaneously.  I also set CV120=0 so the 'headlight' circuit is always either ON or OFF[controlled by the f0 button], regardless of direction.

My major concern now is, Will I be able to squeeze the shell back on top of this mess...?