The Track Wiring section shows several useful tools. I have built the short detector and would like to build the DCC to DC circuit converter but cannot tell the parts required. I know its a rectifier and capacitor, but not the specifics for each. Can someone give me the details and/or Radio Shack part numbers for these? I am just getting into DCC (actually my system isn't here yet) and am thankful for this resource.

-- Christopher Treloar (christopher.treloar@wcom.com), April 03, 2002

Answers

This is a good question to remind everyone that when referring to my web page, PLEASE mention specifically the section and topic header number you are referring to. This question is good because the circuit referred to here occurrs in my web page many times each tweaked to the specific situation it was used.

I can't always remember what's in my page or is waiting on the wishlist to add. I don't think I have a general DCC to DC converter anywhere, but it's on the wishlist for lighting - someday!

There is a DCC to DC converter (power supply circuit) in the Track Wiring section that I think is referred to here.

IN GENERAL, if you want to convert DCC to DC, use a 1N4001 or higher diode which will give you 1A at 50V. A 1N4002 is rated at 100V. The higher voltage rating simply means the diode will withstand higher voltages (in super simple layman's terms). You can pretty much use any voltage rating of 50V or higher with DCC.

If you need more amperage, there are higher amperage diode available.

For the GENERAL DCC to DC converter, you can use a bridge rectifier instead of the diodes as long as the bridge has the amperage and voltage rating you need. Bridges are a little more compact.

As for the capacitor, I have to admit I have yet to get around to determining what the minimum capacitance value required. At 60 Hz, 1000uF/amp was good for power supplies that weren't sophisticated. At DCC frequencies, I would think 100uF/amp would be overkill. It's better to go over in capacitance if you really want DC. Try a smaller value if you are space limited. I'm sure it will work.

If anyone has made this determination, please let me know. Thank you! I'll certainly get around to it when I have the need for it! :)

The other key thing about capacitors, is like the diodes, is their voltage rating. Use one rated at least 35V, and IN GENERAL, you will be safe from explosion - that will keep you from using one that is too small! For HO or smaller, one rated for 25V would be adequate.

A discussion covering DCC to DC conversion could easily fill a section of my web page for all scales! One of these days, it will.

Lastly, if I should omit a part description, check my section on Parts. Besides listing parts, it describes why you would use a particular part. So you might find what you are looking for there. Normally, I mention to look there if I intentionally don't mention a specific part. But sometimes it simply gets left out of the text. Sorry.

The Parts section does not have parts listed for every distributor. Trying to keep this section up to date is hopeless. Still, it serves as a good shopping list. I'm always printing it out, highlighting what I want to buy, and place an order - followed by updating the changes I discovered while trying to order! :)

So the parts listed are generally who I bought them from. Parts are only listed for Radio Shack if I bought them there and only needed a few or in a hurry. If you haven't tried Mouser or Digikey, you really need to. You will find them friendly, fast, and much less expensive than a retailer like Radio Shack could ever hope to be. But if you need more than just a few, try one of the mail order places. Mouser has no minimum order in the US. In the end, I probably spend the same because I'm always buying other things, like heat shrink or terminals, to have on hand! :)

-- Allan Gartner (bigboy@WiringForDCC.com), April 08, 2002.