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DCC unit functions?

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  • Member since
    September 2006
  • From: Buellton,CA.
  • 97 posts
DCC unit functions?
Posted by cliffsrr on Wednesday, December 17, 2008 9:49 AM

I evidently have a bent side rod in my brain as I read every post on DCC but still in the dark about what each component does. What is actually taking place in the base unit? The hand held Unit?

I read that some systems allow the hand held to be unplugged and moved to another outlet while the train movement continues. I first bought a Bachmann because of price on E-Bay and found the draw backs to that system. Next I bought Roco (again for price) Better operations but still not what I wanted. Last purchase was a MRC Advance2 and also a wireless unit. I now can consist and most anything I want to do but would like to know what takes place in each just to get the coal dust out of my brain.

Can any of you very capable guys and gals set me straight.

Thanks

Cliffsrr

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Wednesday, December 17, 2008 10:01 AM

This might be a good place to start:

Tony's Trains - DCC Basic Principles

Stix
  • Member since
    July 2008
  • 1,206 posts
Posted by mfm37 on Thursday, December 18, 2008 4:40 AM

 What's happening in the base unit really depends on the system. There are some basics.

Every DCC system has a command station, booster, and some type of throttle or controller. All of them need a power supply which just sends raw voltage to the booster and command station.

The command station is the brains of the system. It makes up the packets that control each decoder on the layout and keeps track of them. The packets it sends out are low current pulses that would not be able to actually run a train motor. These low current pulses are sent to the booster where they are "boosted" to current levels that can actually run trains and power lights. The pulses remain the same as those sent out by the command station. These pulses are the packets that actually mean something to the decoder.

Your throttle or controller just sends changes to the command station where the appropriate packets are sent to the booster.

How these three components are assembles depends on the system. Some have separate components, some combine all three into one box. Some combine the command station and booster with the throttle being a separate device.

Martin Myers
 

  • Member since
    September 2006
  • From: Buellton,CA.
  • 97 posts
Posted by cliffsrr on Thursday, December 18, 2008 9:43 AM

Thanks Martin!   The info from Tony's Trains is great but still not quite what I wanted to learn. It would seem that different systems could be classified as to what type packaging they are. For example units like Bachmann (like my first DCC) could be type "A"  One piece that has everything in one box. Digitrak Zypher would also fit that category. Type "B" could be units that have a base unit that makes the Pulse Width Modulation but the handheld makes the packet. If the handheld is disconnected everything stops. My Roco system is this type.  Type "C" could be a base unit that not only makes the track power but stores the packet information and that would let  the handheld to be removed and hooked into another receptacle. With some sort of common terminology it would seem simpler to match booster with systems. My MRC system is type "C" . I can start a train and unplug the handheld and in my case go into a shed where I have two loops, plug in and control the train. I don't think this unplug and move capability is mentioned in any of the procures. When I bought my first Roco at a good price I decided I needed another controller for a second operator. I bought another set and decide to try using the second base unit as a booster. WRONG! Smoke!   I then wound up with one controller that worked as a "Master" and one that would only work as a slave. Each unit that I have acquired has some feature I like. The Bachmann has the smoothest control movement but the 1 to 10 decoder address is a not good. The Roco is a small handheld control with "Yard" system dial movement. Clockwise is forward and counterclockwise is reverse. One drawback is the center point has not much of a click feel and its very easy to go from forward to reverse by accident. The other drawback to the Roco is the lack of "Consisting"  I have a grade that requires a helper and this is a problem. I have a DPDT switch that allows me to use Roco or MRC and I find I use the Roco about as much as I use the MRC. I bought the MRC over NCE because I still had the Round knob feeling instilled in to me from many years of Rheostat type controllers. I like the MRC but there are little things I would like different. I guess I am wishing for a perfect world. Thanks again! I love this forum!

cliffsrr

I guess what I am trying to say is

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