KW Transformer Question

[coldironsbound]

I am using a KW transformer on fast trac.  The whistle controller on the KW does not activate the locomotive whistle.  I do notice the lights in the locomotive geta little  brighter when I turn the whistle control. When I connect a new Lionel 80 watt transformer uisng the same track connection the whistle works fine.  Is there any special connection I need to make with the older KW transformer other than connecting to the a and u terminals?  Or is there something that needs to be fixed with the transformer? 

[8ntruck]

Welcome to the Forum.

While I don't own a KW, I do know that the whistle control on some locomotives is sensitive to polarity.

You might try reversing the connections on the KW.  Typically, the 'U' terminal on the KW should go to the outside rail.

This is assuming that you are powering a simple loop of track with your KW.

Good luck.

[phillyreading]

Depends on the age of your KW transformer and how thw whistle output is. Try the locomotive on another track or straight wired to the transformer output to be sure the transformer whistle control works. Another thing to consider, how old is the locomotive; it is brand new or a few years old? Is it the new style electronic whistle board or is it an older motor spun turbine? The new electronic board may not work with the KW because of a compatibility issue with the electrical componants being used, old and new don't always mix.

[gunrunnerjohn]

A trick with the prewar locomotives is to turn the whistle switch only to the first detent which provides 5-6 VDC offset to the track, many times the full activation of the whistle switch will not activate modern electronic whistles.  The full throw parallels the rectifier with a low value resistor to compensate for the power drawn by the old whistle motor in the tender.

[coldironsbound]

thanks for responding.  I've tried reversing connections but no luck.  appreciate the suggestion.

[TrainLarry]

 It is quite possible the whistle rectifier in the KW is bad. The compensating winding seems to be switching in, because the lights are getting brighter.

  As phillyreading asked, how old is your locomotive, and its' number?

Larry

[gunrunnerjohn]

You can use a DC voltmeter to see if the whistle switch is working.  With no whistle switch, you'll see very little DC offset at the output (if any).  When you select the first detent on the whistle switch, you should get a DC offset of 5-7 volts, the second detent output voltage depends on the load on the tracks, but it'll be much less.