# Speed Matching with DCS-51 (Zepher)



## DAvid.Corbin (Apr 12, 2021)

Consider, I set the speed using the rotary throttle to some position for loco #2.... Then I switch to other things and move the throttle while dealing with other engines.

Now I want to switch back to Loco #2, but as soon as I do, the speed will jump to the current throttle position....so the throttle control must be in the exact right position - and there is no feedback for this....

Am I missing something, or is this a limitation of the DCS-51?


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## ncrc5315 (Jan 25, 2014)

It is a limitation of the DCS-51, as they use a pot for speed control, rather than a encoder. As a suggestion, add a Digitrax DTthrottle to your DCS-51, and now you will have a throttle with an encoder; end of problem.


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## MichaelE (Mar 7, 2018)

A problem that shouldn't exist for a DCC system. IMO.


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## ncrc5315 (Jan 25, 2014)

The DCS51 was meant as an inexpensive starter DCC system, to allow for easy entry into DCC. Thinings like pots vs encoders helped keep the cost down. I believe the latest version, (DCS52) does have an encoder.


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## Steve Rothstein (Jan 1, 2021)

ncrc5315 said:


> The DCS51 was meant as an inexpensive starter DCC system, to allow for easy entry into DCC. Thinings like pots vs encoders helped keep the cost down. I believe the latest version, (DCS52) does have an encoder.


The DCS-52 still has a pot for the throttle. That is what I am running now and found the same problem as the OP. And I also solved it by adding extra throttles.

I think that a second part of why they did this, besides cost, might have been because it makes the DCC system behave just like the DC power pack did. It might be easier for beginners to use that way, though they find this problem the first time they try to use DCC for what it was designed for, controlling two trains on one track.


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## DAvid.Corbin (Apr 12, 2021)

Thanks for all the replies, I was aware of the difference between Potentiometers and Encoders (or even synchro/resolvers where the handle could be physically driven...

There is a pretty standard solution that is used in other (non Model RR) that is common... The pot has no effect until it is moved to one end-point, and then moved to cross the current setting. As it crosses the setting a simple LED (or other display indicator)illuminates.

This can be done with ZERO additional hardware just a tiny bit of software...

I am planning on getting a wireless throttle (that is another discussion to make sure I get the optimal one).

Since I do a lot of automation, I have an Arduino which provides the functionality described above.. For example, I set the DCS for Loco 14, the Arduino monitors, adjusts and then sends the commands to Loco #4 (a simple offset of 10 works for me). As am about otbe making some changes to he entire system, I really wanted to confirm that I had not missed some functionallity, and am happy to get the confirmation.


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## Steve Rothstein (Jan 1, 2021)

DAvid.Corbin said:


> Since I do a lot of automation, I have an Arduino which provides the functionality described above.. For example, I set the DCS for Loco 14, the Arduino monitors, adjusts and then sends the commands to Loco #4 (a simple offset of 10 works for me). As am about otbe making some changes to he entire system, I really wanted to confirm that I had not missed some functionallity, and am happy to get the confirmation.


Don't forget that the direction switch is also hard wired and acts the same way. Otherwise, you could be suddenly putting the brakes on a train you did not expect to.

I like your solution. Your automation knowledge is well beyond mine.


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## Stejones82 (Dec 22, 2020)

Me, too. I also went with a DT602 throttle to resolve this issue. The DT602 is wired and Infrared wireless only. The DT602D is wired, IR, and RF wireless. If wireless operation is your end goal, make sure you match the correct receiver: UR90 for IR only, and UR 93 for RF wireless plus IR.


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## DAvid.Corbin (Apr 12, 2021)

Steve Rothstein said:


> Don't forget that the direction switch is also hard wired and acts the same way. Otherwise, you could be suddenly putting the brakes on a train you did not expect to.
> 
> I like your solution. Your automation knowledge is well beyond mine.


Yup, made that mistake a few years ago


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## DAvid.Corbin (Apr 12, 2021)

Stejones82 said:


> Me, too. I also went with a DT602 throttle to resolve this issue. The DT602 is wired and Infrared wireless only. The DT602D is wired, IR, and RF wireless. If wireless operation is your end goal, make sure you match the correct receiver: UR90 for IR only, and UR 93 for RF wireless plus IR.


Tyhat is the way I want to go, but with a price tag of about $400...it is a little hard to budget for...


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## Lemonhawk (Sep 24, 2013)

Yankee Dabbler has the Digitrax EVOX set (controller and handheld DT602 throttle for $345. It will serve you for years! Even plugs into a computer so you can use JMRI Decoder Pro for programming decoders. Far better than their older 51 -52 controllers that have all the pot/revers switch confusion.


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