Powering Woodland Scenics Buildings: AC or DC, does it matter?

I’m sure the experts will help further, but the three older woodland scenic buildings I have use a bridge rectifier to convert AC to DC on a small pcb which also controls the brightness of the leds.  So you certainly should be able to use your DC power supply for the buildings.

Thanks for that info. Ted. I checked my buildings and none have that black thing on the circuit board. I wouldn't think it would matter whether AC or DC, but I don't know why the instructions would state AC.

Update: Last night I tried powering my buildings with by DC, one building's LEDs came on, and one did not. Then, I switched to AC and both worked. My conclusion: they say AC for a reason, so AC is it.

Most any item with LEDs runs on DC, either directly or rectified AC. Your second one might have worked if you reversed polarity. Obviously you have them working, so that's what counts.

I believe most commercial power packs...e.g., MRC's...have AC powered "Accessory" terminals, even when the variable output ("Track") is DC (HO, N, G, et al 2-rail).  Woodland Scenics items are typically thought of as accessories, thereby accommodating an AC power hook-up as the most common .

John H. is right, though.  LED's are polarity sensitive.   Simply switching the leads to that one LED probably would have solved the discrepancy.   If the power pack's Accessory terminals were DC powered, it's easy to imagine the frustration many inexperienced hobbyists would have with some LED's on, others unlit.

And, BTW, we all learn these simple lessons in the School of Hard Knocks.  I know I did!   (And have occasional memory lapses thereafter!)

KD

LED is an acronym for Light Emitting Diode.  A diode only conducts current in one direction. Which means the LED only lights up when the current is flowing in one direction, and not the other.  If  you apply DC to the LED and it does not light up, then simply reverse the wires as pointed out above