Building your own Power Pak or Current Keeper

[fishbelly]

I have to build my own current keeper. I am in no way an electronics expert, but I know how to read a schematic and build a circuit.

So I wanted to ask for a little guidance here. 

I am using the Soundtraxx Blunami decoder. I bought one of their CurrentKeeperII capacitor products and it will not fit anywhere under the hood. My thought now is to build my own current keeper to fit the space I have. I can go to Digikey and purchase all the components necessary. The Soundtraxx current keeper has five capacitors. I was planning on using two or three larger ones. The part I do not understand is the resistor. What is the function of the resistor and how do I know what size and wattage resistor to use? 

I can reverse engineer the routing of everything. I know all the capacitor + wires need to be connected and all the - wires need to be connected. Then I can reverse engineer what each side of the resistor connects to. I just need to understand what the resistor is for and how to size it.

Thanks for any guidance here.

[Colin 't Hart]

Google "DIY DCC keep alive" and you'll get lots of hits.

[fishbelly]

Thank you Colin. This is perfect. I really appreciate it.

[fishbelly]

Now I know how to do it and can build my own to fit the area that I have. I do really appreciate the help Colin. Thanks!

I designed a board that will piggyback on top of the Blunami PNP8 board in a nice compact package and fit beautifully right over the motor.