How to reduce mth brick voltage

I'd just use the PW transformer, it already has the the capability.

I would use one of the methods suggested by the above forum members, much easier.  With the post war transformers no new purchases would be needed.

If you don't have a variable output transformer/controller and your source is a fixed output (18V AC) brick, another option is to consider running the accessories on DC voltage.  Many (most) accessories run just fine on DC voltage and if one of your applications is lighting, many guys are making the conversion from bulbs to LEDs which require DC voltage.

Soldering and messing with wiring is not for everyone but one alternative is to use AC-to-DC converter modules.  They are adjustable (albeit not large knobs like on a Z-Controller) and run about $3 each (free shipping) on eBay.  You can connect multiple modules to a single brick output to generate multiple, independent DC voltage outputs to fine-tune individual accessories.

Separately, you will see threads describing a rheostat or string-of-diodes to reduce AC voltage.  But when dropping from 18VAC to 12VAC, these methods waste a lot of power as heat.  That is, while rheostats or string-of-diodes can effect a 6V drop, it expels it as heat.  So if running full-tilt, of the 54 Watts of power from the brick, 18 Watts (1/3rd) would be wasted and you are left with 36 Watts to drive the accessories.  Using the converter modules above, you'd pick up at least 10 Watts of useable power.

stan2004,

Dumb question, but if you absolutely had to have AC, what would happen if you put another bridge rectifier on the output end to convert back to AC after reducing the DC? 

I should just try this myself instead of asking, but if it did work I would not be aware of any potential problems or side effects I might be causing like you guys would and don't want to create something that shouldn't be created.

Rectifiers don't convert back to AC, how convenient it would be if they did.

I warned it was a dumb question! I was thinking of something I believe Dale H had posted a while back that was using the AC connections on the bridge rectifiers, don't remember what it was on? I was too lazy to try and find it, but now I am going to have to look to see what it was.  

I don't remember what Dale had posted, but I'm pretty sure that converting DC to AC with a bridge rectifier wasn't it.

One thing that a bridge will do for you is make your power input polarity insensitive, you can connect the bridge either way on a DC supply, and you'll always get the same polarity out of the bridge.  However, the output will be DC.

That might have been what he was doing? All I remember is there were multiple bridge rectifiers and he was using all four leads somehow. He has some really interesting things for conventional operation and relay logic. Maybe I will look at his blog tomorrow, weather here is supposed to tank again for the next few days.

Thanks for the suggestions guys!  I think for now using the LW is the way to go.  Plenty of power and i can use the track posts to get wp12 volts.  Plus, that's a beauty of a transformer!  Thanks again!