Lazy whistle on electronic tender

[toolmandan]

I have an 8'x8' O27 layout.  I'm having problems with the "newer" electronic whistling tenders.  Because I have a small track,  I can not run the throttle fast enough to spin the whistle motor.   I can activate them on a bench test an they work well, but they are very "lazy" on the track.  Is there a way to boost the voltage to the whistle to get the "kick" I need to spin the motor at low speeds?

[TrainLarry]

 It sounds like you have a motor driven air whistle with an electronic relay. If that is so, then the motor speed is dependent on track voltage. Since you are running slowly, track voltage is low, thus the weak whistle. The easiest solution is to add more weight to the train so you can boost the voltage a bit. Add more cars to your train, or weight your existing ones down.

  If you have a straight electronic whistle with a speaker, then the problem is the same, low actuating voltage, and the solution is the same.

Larry

[servoguy]

Add some post war cars to your train.  They have significantly more friction than the new cars with the high angle wheels.  This will raise the track voltage as the loco will be working harder.

[toolmandan]

Thanks for the advise!  I'll give it a try and report back.

 

[lionelsoni]

You can also wire anti-parallel diode pairs in series with your locomotive motor to boost the track voltage.

[toolmandan]

Hello Bob,

This sounds more like what I was lookig for.  Do you have a diagram on how this is done.  I've added more cars but my engine is staring at my caboose!  :)

[lionelsoni]

The simplest way to do it is to use bridge-rectifier modules, like this one from Radio Shack:  http://www.radioshack.com/product/index.jsp?productId=2062580&filterName=Type&filterValue=Rectifiers

You will not be using it as a rectifier, but just as a handy source of the four diodes inside it.  Connect the + and - terminals together (and insulate them from touching anything else).  Then, using the two ~ terminals, connect it in series with the motor.  That will reduce the motor voltage by about 1 volt, which means that you will have to turn up the track voltage by that amount for the same train speed, thereby giving an extra 1 volt to the whistle.

If that's not enough, you can connect more of these modules in series to get whatever voltage is needed.  You can also get 1/2 volt by connecting between the +- terminals and one of the ~ terminals instead of using both ~ terminals.