DIY power supplies for your model railroad.
The first three links give you different views on how to power your model railroad using a computer power supply.
How to use a computer power supply for a model railroad.
Using a computer power supply for a model railroad.
Organizing the wires on a computer power supply.
This next video shows how to build your own power pack.
How to build a power controller using a discarded laptop computer or other appliance power supply.