@geepboy posted:OK, I'll bite. What are TVS diodes and why do I need them?
Dan
Transient Voltage Suppression. They help protect sensitive electronics from voltage spikes when you have a derailment. Circuit Breakers are not fast enough and really only protect the transformer. TVS Diodes should be placed as close to the electronics you want to be protected as possible. They are cheap and usually pretty easy to install. This one from Digikey is perfect for the job: 1500W 36V TVS at Digikey.