Project 21
Use of a Power Distribution Board for operating Accessories
 A Power Distribution Board (PDB) can come in handy to distribute power from a single power source to multiple accessories used on model railroads. Such accessories include  switches, lighting projects, railroad crossing operation, reversing boards, turntables motors or sound devices. The board can receive its power from a  plug in wall  transformer that converts household AC current to 6- 12V DC current. Also many train controllers have an accessory 12-20 V AC power source  which can also be used as a power source for the PCB. However in this latter case it is necessary to convert the AC (alternating current) to DC (Direct current) for many of the accessories to work.