Way back, when I was 7 or 8 years old, (I am 55 now), my dad got me an
electric train set....During that Christmas we were at my Grandparents place
and they were on 25 hz power....At home we were on 60 hz power...

We had to be at home for me to try out my new train set.

What has that got to do with this question?...

This....

I have a number of transformers and would like to experiement using then at
a higher frequency....let say 500 hz and / or higher.....

Would they still work?...I am assuming so...

Would they run cooler?....

Could anyone foresee any negative effects?....

Larry ve3fxq