Last week a commenter asked me why the whistle button makes a Lionel train speed up. This behavior may seem unusual but it’s normal and solves a problem.
Traditional Lionel whistles work by blowing a fan into an air whistle. This fan needs a motor. The motor has a relay in front of it that only responds to DC. The transformer has a DC rectifier in it to activate the motor. This rectifier is what activates when you push the whistle button on your transformer. The motor and all this circuitry require extra power, so the transformer outputs an extra volt or two.
This extra voltage is usually a bit more than all of the circuitry needs, so the train speeds up a bit.
The alternative would be to let the train slow down, but if you’re running the train at low speed, a slight drop in voltage could cause it to stall. A stalled electric motor can overheat and damage the sensitive windings inside, requiring a costly repair. So it’s definitely better to let the train run a bit faster while the whistle blows than to risk stalling it out.
So while it may be a bit disturbing to see the train speed up unexpectedly, this is normal. It’s not a sign of a problem. It’s just how Lionel worked around an unintended side effect of a new feature.