I have a diode controlled hidden staging yard. Train enters and stops when reaches diode controled track. then i back it thru a reverted loop into one of 4 staging tracks and the loco stops again when it reaches the diode controled section.

when i convert to DCC what will have to be changed.

-- phil sifers (stjocbrr@AOL.com), June 13, 1999

Answers

Phil,

DCC is an AC like power (really more - but that's for latter) and using diodes for direction control won't work. Direction is in the form of the signal packet for the specific locomotive under control and the signal rides along on the track which also supplies the power.

You have several options for controlling a reverting loop - semi automatically to your present state. Take the diode control sections and make them drive a current sensing device (real cheap and good information is available on the WEB). Have the current sensing drive an LED to state that you've hit the control section and drive a relay to turn off the power. Now change the direction from your DCC cab and hold a button down to overcome (cancel) the power relay and apply the signal for the reversing direction. When the train backs into the staging track the same process occurs. There will be an LED showing that that track has a train on it. When you're ready to run that train, select the engine - place in forward and hold down a canceling button until the staging track goes off (train is on the main now). Another way is to use the fact that the decoders can cause automatic stop when a DC section is crosssed into. You'd then have to have a DPDT to switch between DC and DCC for those sections you want to control. There's probably several other ways to wire it up, depending on how much control you what or need. Seems like a nice project!

-- Ed McCamey (emccamey@cheerful.com), June 13, 1999.