Z Scale Decoders

rray Nov 18, 2006

  1. SJ Z-man

    SJ Z-man TrainBoard Member

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    No worry Tim, it's only 4 wires you have to hook up. And two don't have any polarity. If you do the dual zener diode thing, you shouldn't have to do anything else other than program an address (but it will run as-is on the default address 3).

    Buy a PowerCab and live life ! AC wall adapter, 2 wires to the track, plug the Cab in and press "select loco", 3, Increase. Note: "Dir" will change directions. :)
     
  2. Cleantex

    Cleantex TrainBoard Member

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    Hi,

    I got today the new commercial version of Oliver Passmann's
    DECPROG. And it has apart from the programming also connection
    for the motor wires, so you wont need to use additional resistor
    or motor. The beeper is optional and plugged into own socket.
    And for bigger scale, or if you receive decoder with Nem'S
    (not with nog yam sauce) 651 and 652. A must have.
     

    Attached Files:

  3. Silverexpress

    Silverexpress TrainBoard Member

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    Hello,

    Interesting thread! Especially the info on the CT Electroniks decoders. Has anyone tried the sound decoders for steam from this company, and if so are the sounds anything close to USA steam engines?
     
  4. Lownen

    Lownen TrainBoard Member

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    I noticed that this is an old thread. A couple months back Digitrax released the DZ125 decoder. It replaces the DZ123 with a smaller footprint. You serious Z decoder people probably already knew, but I thought it was worth adding to the thread.

    By the way, this thread is great. I'd never heard of the Lenz Power 1 module. I have a vintage N scale loco with spring loaded wipers that press down on the tracks for pickups instead of wheel wipers. The loco doesn't have any flywheel. It stops dead sometimes, but just a slight tap gets it going again. Maybe the Power 1 module will make it practical to run. I'm sort of sentimentally attached to it.
     
  5. Garth-H

    Garth-H TrainBoard Supporter

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    Reviving an older topic
    Did you ever order a group of DCX74zD with lower voltage ratings like 7 - 14 v and is there anyone interested in getting a group order to-gether. I want to try an put this decoder into the D51 Japanese steamers.
     
  6. shamoo737

    shamoo737 Staff Member TrainBoard Supporter

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    Garth, I have a DX75zd. Its narrower and little bit longer then the DX74, and I am looking to sell it. I am asking $35 plus shipping.
     
  7. SJ Z-man

    SJ Z-man TrainBoard Member

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    Garth, the NMRA standards say that an NMRA decoder has to work down to 7V so any decoder from CT Elektonik should work in Z since they claim "Fully NMRA compatible". However, their DCX74, their first small one, is rated document rated at 12-18 volts, a crazy range: http://www.tran.at/Dokumentation/DCX74_en%20long.pdf but the DCX74Z has one document saying 12-21 volts and other formatted version of the document says 7-21V: http://www.tran.at/Dokumentation/DCX74z_1.pdf. I have run them all with no problems.

    The newer DCX75 is not only narrower (9mm Vs 7.2) and also thinner (1.4mm Vs 2.1mm) by using a single sided board. Compare to the TCS Z2 6.7mm wide by 2.8mm thick or Digitrax DZ125 (8.7x2.9mm), similar to Lenz Silver Mini (9mmx2.8mm)

    All of the CT Elektronik decoders are 2 function but support 4 via CV and flash memory. One bonus of the DCX75 series is that the decoder will stay alive for up to 10 seconds without resetting. This is great for dirty track, meaning that as soon as electrical contact is restored, the motor should see the voltage 'similataneously' where as other decoders must 'initiallize' (which is pretty quick, but not 'instant' like the CT's). Lenz does it one better with their USP (only available with the Gold decoders), additionally supplying power too for a few seconds for perfect continuous running on the crappiest of track.

    The Recommend Practice for Z is 10 volts, but several of us have had issues with all manufacturers decoders runnign at this lower voltage (reliable decoder restarts on dirty track and programming consistancy). Since most all starter sets are 13volts +/- and high power systems are 14 volts, the BAZ BoyZ (and others) run at 12V, the N scale Recommended Practice.

    The decoders loose a volt or two internally in the track power rectification and motor drive circuit so no harm is really done. At least statistically.
    .
     
  8. Garth-H

    Garth-H TrainBoard Supporter

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    Hi Jeff

    I want to put this thing in the D51 so thickness is not the problem length and width are. The 74 would fit with out modification the 75 won't fit even on the angle and I am trying to do this with out modifying the coal bunker.

    Otherwise I guess the Z2 is the other option but you definitely have modify the bunker to fit it.
     
  9. animek

    animek TrainBoard Member

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    Sorry to insert myself in between the discussion here. but I have 3 questions.

    I've read quite all of the post here since 2006, and this answers more my questioning I had about about the power cab PCP being too high in voltage


    1. is this quote here from Robert’s is still relevant today ? meaning installing diodes like this to lower voltage from the PCP on a power cab?


    2.Is the RRampMeter very much recommended to protect your engine motors? (meaning to follow voltage and amps to make sure to not go to high?)
    Can it work connected to a PCP only ? (no booster) on a system where I would have put 10 diode to reduce the voltage?


    3. Ok here’s a very Green Green Green question, look under noobster in dictionary:
    Function in decoders:
    If you take for instance 2 decoders:
    The first one has some characteristics (speed control, light, sound etc.. ) but is a 2 functions only.
    The second one has exactly the same amount of characteristics (speed control, light, sound etc... ) but is a 4 functions decoder.

    Does functions number means it can operation this quantities of characteristics at the same time? (If this is not the answers, then I’m lost!)

    Thanks
    Ben
     
  10. Garth-H

    Garth-H TrainBoard Supporter

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    Hi Ben;

    4 function decoder means it can control 4 items usually lighting effects like ditch lights or gyro lights or rotating beacon or combination of these things plus control the motor.

    Your diode bridge was first proposed by Atlas with their DCC system which had a 15 vac to the track and to protect our Z scale engines which don't want more than 10vdc to the motor. Since the power cab is using 2.5 volts less to start with you only need half the diode bridge. There is another factor to consider that some decoders will not work below 10vac to the track. Yes the NMRA standard is 7vac to 21vac for decoder input from track but not all manufacturers meet this standard.

    Many of us using the power cab have not put a diode bridge in place but have instead limited the power output from the chip to the motor and have found this works. Some have said they have had runaway problems and I am not sure if this related to too low a track voltage ie below 10vac or not. Runaway is not something I have experienced.

    Some people have experienced trouble with programming a loco on track voltages below 12vac, but I have not experienced this with NCE system I use.

    It does not matter what the track voltage is if you have a short circuit and the engine is unattended at the time of the indecent then blue smoke is a definite possibility.

    Use of a 1 amp lamp in one leg of track power will usually save most of us from a blue smoke event. This means the filament is in series with the lead. The light comes on with a short and since the lamp is limited to 1 amp by design it lights up and the max current in the loop is 1 amp and so the engine which created the short causes the lamp to light up and so your engine does not heat up as it just passes the voltage to the lamp rather than becoming a resistor if the light was not present.

    The RRampmeter is a good tool but not the total answer unless you watch it continually.


     
  11. SJ Z-man

    SJ Z-man TrainBoard Member

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    Ben, with the Power Cab, don't worry about using the diodes. The Power Pack is 13.5 volts with very small losses in the Power Cab and some loss in the Decoder's internal diodes and motor control transistors results in about 13V maxium to as low as 12V to the motor in some decoder designs. So many of us do not care about the voltage and have no issues. 2 volts more is NOT going to blow anything up. Besides, you CANNOT use those low power 1N4148 signal diodes anyway, they are not rated for the current ! They are only good for 0.2A continuous, more than an MTL F7 or most any Märklin draws ! (MTL GP's or AZL's are OK). You would need any 1N4000 series diode (e.g. 1N4002, etc.). Again, don't bother. BUT, as Garth says, DCC can certainly smoke. Now, that does not mean the decoder, it means wheels and the pickups that transfer power from the wheels. DCC is a "full Power" system: voltage always on and up to 2 amps with a Power Cab power supply. So 20 watts of power. WATCH YOUR TRAINS !

    The RR Amp meter will only indicate the Voltage and Current, it will NOT limit or stop it it ! To limit, you need an Electronic Circuit breaker or crude light bulb. The Electronic Circuit Breaker is built into the Power Cab. You can also buy them but many do not go to low currents for Z scale. Light bulbs are a subsitute but introduce uncontrolled voltage loss so adding more locomotives will noticeably slow down locos. The only light bulb that works for Z is NCE's CP6 http://www.ncedcc.com/component/vir...lypage=flypage.tpl&product_id=9&category_id=1 or any light bulb that is rated about 5 Watts, maybe 10 at the most. If you watch (and listen for your trains to unexpectedly stop), you should not have any serious problems !

    Functions: to be clear, 2 functions are common: F0F and F0R (that is Function-zero-Forward and F-0-Reverse). These can be reprogrammed in any decoder to standard Forward light (F0F) and then F0R to Firebox flicker in a steam or, a second light up front (MARS light) or yard beacon on a switcher. The 4 function just makes it easier with 2 addtional functions, typically Ditch Lights. ALL have the defaults of only F0F and F0R for forward and reverse lights. Digitrax will drive you crazy with their 6 billion combinations of programming. NCE's Z14 is brainer. TCS is pretty easy too.

    And again about the motor voltage: the Speed Tables (Speed Steps) do not in any way change the voltage to the motor ! Only how long it is on. The same track voltage (less a little loss in the decoder) will always be applied to the motor ! At Speed Step 0, no applied voltage. At Speed Step 1, track voltage is applied for 1/28 of the time. Drummer: 1 beat on, 27 beats tapping your foot, 1 beat, 27 tapping your foot. Same full impact to the drum. Not like a loud or soft roll :) Below are waverforms that might just help you understand:

    [​IMG]

    Note in the middle picture, Speed Step 64 (of 128 Speed Steps but the same as Speed Step 14 of 28), that the voltage to the motor is on 1/2 of the time and Speed Step 125 is on almost all the time.

    If your loco runs too fast at Speed Step 28, change CV5 to a lower number than 255 (the Power Cab will show you 0 when programming - many decoder manufacturs do this for CV5 [Max Speed] and CV6 {Mid Speed} for ease of initial default programming). Set CV6 to one half of CV5. For most of us running "prototype" speeds, CV5= 80 to 120. CV6= 40 to 60 (half of CV5).

    Skype me @ merrill-man (Santa Clara) if you want to chat and share beats.
    .
     
  12. animek

    animek TrainBoard Member

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    Oye! A lot of info, thanks Jeff and Garth, I'll do some more reading, since I only understood 80% of your answers.

    But coming back to the functions question, I will reformulated my sentence since both did not pinpoint what I was trying to understand.


    Let's take for instance 2 different decoders, same brand.
    Digitrax (Dz123) & the Digitrax (Dz143)

    Both decoders have the same characteristics, reading theirs specifications, I see that they can both do the same thing , lights effect, speed, etc "all their characteristics are the same". so in the end they look the same.
    Only differences: one is 2 functions (Dz123) & the other is 4 functions (Dz143).
    Again, does this mean one decoder can operate 4 characteristics at the same time and the other can only operate 2 characteristic at the same time?


    Ben
     
  13. Garth-H

    Garth-H TrainBoard Supporter

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    Two function decoder can operate the motor and one forward headlight and one rear headlight if connected to decoder if you don't hook up the headlights then 2 other lights can be connected.
    Four function decoder can operate the motor plus front and rear decoder plus ditch light left and ditch light right so they can me made to flash alternatively or some other combinations of light features like rotating beacon and none flashing ditch lights, marker lights etc.

    So TCS MZA4 is 4 function and I have ditch lights left and right plus headlights front and back and that is 4 functions.
     
  14. Garth-H

    Garth-H TrainBoard Supporter

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    Found a source for the DCX74zD decoders in Europe and it seems they are no longer being made so while supplies last. I purchased 5

    cheerz Garth
     
  15. SJ Z-man

    SJ Z-man TrainBoard Member

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    Ben, the Functions outputs are always independent. The are all programmable as Garth says. The default is Forward (white wire) and Reverse (yellow wire) lighting for 2, 3, 4, 6 or whatever number of outputs. As in our examples, if you only have one Forward light (steam, F loco, etc), the Reverse light or other function wires can do whatever. If you miswire it, you can make any Function wire the Front, etc. This is called Mapping.

    Most all decoders support Phase. The Ditch lite is an example (each output out of phase, e.g. 1 is on, the other is off). So, to make a better Firebox flicker on a steamer, you can make 2 outputs Firebox flicker but set one to Phase A (or whatever the manufacturer calls it) and the other to Phase B. Put two Gyro lights on top of the cab and do the same, looks like they are both rotating differently.

    Those DZ123 are ancient. Same with the 143 but, if you have them, why not use them :) The DZ125 is better (smaller, updated electronics) -2 function. NCE's Z14 is a four function the size of your DZ123/143 and SO simple to program. E V E R Y T H I N G you need to program it is on 2 pages. You don't need the 82 page Digitrax Decoder Manual to program it (plus it is still full of typos).

    Hope to hear your cheers from your new loco this weekend !
    .
     
  16. animek

    animek TrainBoard Member

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    Ok thanks for the info!

    Ben
     
  17. animek

    animek TrainBoard Member

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    Hi Garth, did you put your CT electronics decoder in your Tenshodo steamer yet? If so how did it went?

    Also curious, were in Europe did you get your CT decoders ?

    Ben
     
  18. Garth-H

    Garth-H TrainBoard Supporter

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    Hi Ben;

    I got them from Oliver Passman in Germany.

    Just got back from a long long weekend in Houston.

    I have the first one wired and have it working but have not finished getting it inside the tender yet. There are some problems for first time DCC types with this decoder as it requires direct programming which is not a default function on most controllers. Once you have conquered the decoder programming the engine runs fine. I found I could not remove the weight from the rear of the tender as I lost pick-up from the rear truck of the tender. I also wired the headlight direct and got much better lighting that way. I will let you know more in a week or two. I will try one with modified rear weight and board inside tender between floor and weight and one with modified tender top to put decoder under tank top of oil bunker instead of coal and I may try extending the coal bunker sides a bit to get decoder on top of motor where it will be easier to service if needed. Anyway when I have it all worked out and photographed I will document my progress and results.

    I am really pleased with the engine performance. I limited the max. voltage CV5 I think to 110 and with 28 steps the speed acceleration is great and it really can run slow. The top end speed is still too fast so I will lower that number a bit more and I figure I will end up with about 90. That is based on 255 representing 12.5volts as max available if your track voltage is higher than mine you will have to lower that number some more.

    cheerz Garth
     
  19. Cleantex

    Cleantex TrainBoard Member

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    Hi Garth,

    Where do you found this information ?
    As I know, it is always produced and disponible in Shop of CT-Electronic.
    But perhaps your have fresher news.
     
  20. Garth-H

    Garth-H TrainBoard Supporter

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    Hi Armand

    Mr Oli Passman told me this when he answered my e-mail. He said he could get me the five I wanted but that when the current stock is gone there will be no more. He ordered them from CT Elektronik for me.

    cheerz Garth
     

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