Model Railway Forum banner
1 - 1 of 8 Posts

· Administrator
10,744 Posts
>what does this PCB *actually* do?
At a guess it directs the power from the rails into the decoder and connects the output from the decoder to the motor. That's apart from providing a steady state DC voltage for powering the decoder chip itself with maybe a few capacitors as well.

It makes sense for a manufacturer who is providing a "DCC on board" locomotive to do it this way. On the production line they just drop the PCB into the slot made specially for it, hook up the wires from the wheels and the wires to the motor and they're done. No need to pay extra for the 8 pin NMRA connector plug.

Of course this arrangement is not good for those who want to fit their own decoder, since they have to chuck the PCB and hope that the space left behind matches the decoder of their choice. They also have to make their own connections. For popular models fitted with a PCB, the after market decoder manufacturers will often make an indentical PCB which plugs instead. So far this is restricted to American models and some Kato units.

I hope this gives you some background

1 - 1 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.