Neat video on power dist transformers

[paulca]

https://youtu.be/96Vekm8Ws4U

[schmitt trigger]

The other day I came across a railroad intersection where the gates had already closed.
Turned off the engine while waiting the lumbering train to pass.
It was a short train, and it carried an absolutely massive transformer in a special rail car known as the Schnabel car.
 Something similar to this;