ok, another transformer question.........

[Anonymous]

I may have asked this already, but here it goes again. Can I use a common ground for both a a/c transformer and a d/c transformer?
What I want to do is use a d/c transformer to power my switches. can I just hook the positive of the d/c to the switch plug, and the negitive to the common ground from the track? or would i be better using another a/c for the switchs? I would like to buy a new zw but I have other stuff I would like to buy first.

[chuck]

Why would you want to try and use the track return as the negative side for the DC power supply?  You could use the dc supply with it's own paired feeds (ak postive and negative).   If you try to put a DC power source that can tie into the AC track circuits, you might get some unexpected horn/whistle/bell action as these circuits are activated by DC spikes.

[lionelsoni]

Yes, you can connect the returns of both the transformer and the DC supply to the outside rails and use the DC for the switches.  In fact, it is the simplest way to combine the anti-derailing feature, diode turnout-throwing logic, and capacitive-discharge turnout throwing.  The whistles should never see the DC that you use in this way.

[Anonymous]

Next question, has anyone ever used a low voltage transformer from a yard lighting kit (malibo lights)? I see them around pretty cheap and most have around 100watts.
The only problem is see, there in either 12v, or 24v, not sure if 12 is enuff, and if 24 is to much.
thoughts anyone?

[wrmcclellan]

c-burke,

Our club uses them on our club layout. We use the 12 vdc units which produce a nice warm glow from typical toy train lamps designed for 12-18 volts. These are nice cheap power supplies (for the wattages available) with a lot of power. They do have a very low but noticable high frequency "whine" due to the switching technology used to produce and regulate the output voltage.