Hello
I understand that I can't run a DC loco on a DCC setup because the DCC set uses higher voltages. I have a young friend who has a DC setup - if i were to buy him a DCC loco would that loco run on his current layout until he upgrades?
Apologies if this is a really dumb question!
Malc
Normally DCC decoders are designed to also work on DC power. I can't think of any engines that come DCC-equipped from the factory that don't use a 'dual-mode' decoder, or any decoders that aren't OK with running on DC.
However, if it's a sound-equipped engine, it will most likely have a much higher current draw than his DC engines.
Most decoders built in the last 5->8 years have dual mode which allows then to run on both DC and DCC. That said there are several cavaets and warnings...
First, non sound dcc dual mode decoders take a minimum of 3v track voltage just to turn on. Sound dcc decoders take about 6 volts. This means reduced throttle range for speed adjustments. Also your top speed is likely to be reduced. Second steam sound dcc decoders typically dont sync the chuff very well on dc. This can be adjusted with a dcc system but its hit and miss. Third not every dcc decoder is setup to run by default in dual mode...you need a dcc system to program cv29 to allow it on a few oddball decoders. Safe bets for out of the box dcc dc operation are: Bachmann dcc-ready, qsi decoders, and soundtraxx decoders. Im sure others can chime in about loksound and tcs. And you dont have access to a dcc system dont buy used unless its QSI decoders which can be programmed via dc track
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
I have a number of locomotives both diesel and steam made by Broadway Limited that are DCC/DC compatible. They run fine on DC. However if you want to control the basic sounds like horn & bell you'll need an outboard control called DCMaster (also available from Broadway Limited). This device also allows you to do limited programing of the DCC/DC decoder in the locomotive for DC operation.
I also have a few Athearn Genesis DCC locomotives that also run fine on DC. The only quirk here is you can only control the horn by quickly varying the track voltage up & down. Not the most elegant horn control by any means.
Keep in mind that if you want to two or more locomotives together you should use locomotives of the same manufacturer, same (possibly similar) model, and sometimes even year manufactured to ensure some kind of speed consistancy.
The Broadway Limited locomotives can be consisted (multiple unit operation..... MU) to run together at the same speed in DC mode but you will need the fore mentioned DCMaster to program the decoders to do that.
Thanks to all of you for your usual super detailed answers (I must confess I hadn't even considered the "bells and whistles" aspect of DCC - just whether the train would run or not!).
This is a good question I just wondered about, too. I think I'm just going to start with a couple of dc ovals for now, but have a few DCC engines along with a few dc engines. Right now, I don't care about lights, bells, or whistles. This is a good source on information!
Greg Whitehead
Ironically, I live in the only county in Tennessee with no railroad tracks.
Just be aware, the decoder will not wake up until the track voltage is about five volts and maybe seven volts before the loco begins to move. Nature of the beast. Many have reported this.
The loco does not require more power. Same amount of power. Some confuse more voltage with more power.
The digital logic on the decoder runs at about five volts DC.
DC locos with a DC power pack start at a lower voltage.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Just some background for any of the newer folks just tuning in...DC engines run on 0-12 volts DC; the more power on the track, the faster the trains run. DCC has a constant AC 14V or so on the track. The decoder changes the AC into variable DC to power the motor based on the commands sent to the decoder.
Most recent (last 15-20 years) DC engines have a green "light board" that diverts the first 2-3 volts of DC power to the lights; only the power above that goes to the motor. That way you can shut the power down enough to stop the engine but the lights stay on.
Yes, I remember those days.
We used diodes to have constant lighting using 1.5 volt light bulbs. The light bulbs would light before the motor started operating.
Rollins had an online site. It still exist.
Dcc decoders do not run well on pulsed DC. They will run but only when the voltage is turned up high. At lower settings the pulses look like those of DCC signals and since the decoder will only respond to "its unique pulses", it will just sit there. Once the throttle is turned up those pulses smooth out and the decoder figures out that there is analog DC. It then begins to run but with a jackrabbit start and at fast speed.
Smooth DC should be used instead of pulse so if possible to turn pulse off, do so. The trains will be more responsive.
Martin Myers
wjstix Just some background for any of the newer folks just tuning in...DC engines run on 0-12 volts DC; the more power on the track, the faster the trains run. DCC has a constant AC 14V or so on the track. The decoder changes the AC into variable DC to power the motor based on the commands sent to the decoder. Most recent (last 15-20 years) DC engines have a green "light board" that diverts the first 2-3 volts of DC power to the lights; only the power above that goes to the motor. That way you can shut the power down enough to stop the engine but the lights stay on.
Technical aside -
The decoder changes the AC into variable DC to power the motor is a common misconception. However, often used by those who know the following in order to keep things simple for the DCC newbie.
A DCC decoder changes the DCC square AC waveform to DC to power the motor. However, the DCC decoder does not apply a variable DC voltage to the motor. DCC decoder always applies full DC voltage using PWM (Pulse Width Modulation) to control the motor speed.
RR Baron
I have two Intermountain GP10 HO locomotives which are DCC and the instructions say not to run them on DC. They request that either you send them the DCC decorder and they will exchange it for a dummy plug ( even exchange ), or for $5 they will send you a dummy plug. This is the only time I have seen this on newer locomotives.
Ralph
Rapido does not recomment running their engines with the MRC 1300 series because of voltage spikes causing damage to the decoder
Henry
COB Potomac & Northern
Shenandoah Valley
I did measurements some years ago. The decoder chnages the DCC into 5 volts DC to power the IC's and 12 volts DC power the lights. About 12 volts for the IC's to power the motor as was said with PWM. The motor and a meter sees it as DC. My Scope showed 12 volt pulses. The wider the pulse, the faster the loco went. No pulse, no movement. They could be 12 to 14 volts depending on the controller.
I use to have photos but Photo Bucket locked them up. I left PB. Still have the photos.
I have no desire to go thru that again. At over 78, had enough.
I did a bunch of measurements with a test stand.