Well someone asked how to reduce voltage from a trasnformer. Webenda replied with a nice drawing or photo. I thought the last set of bridge rectifires I purchased from Radio Shack had them reversed. Well, I post my picture of the soldering of the + and -. I suddenly realized that I had soldered the ~'s together on Lionel smoke unit on a diesel [the smoke unit was acting up and probably needed a new board]. No wonder it did not work right. Well, went back and corrected my mistake and now it really smokes. It took three bridge rectifiers for this smoke unit to “calm down”. Direct track voltage [I had rewired the unit bypassing the board and using direct track voltage] is too hot for it. The + and - on the Radio Shack bridge rectifiers are all over the place. You really can not tell which is which. Bob [lionelsoni] had set me straight in the beginning so the MTH dummy ones were correct. Wanted to post his so others would not make this mistake. [:(] [:I]