DC to DCC Conversion

[jward]

my thoughts on those throttles are that you could wire receptacles around the layout for them, and have a simple form of walkaround control, by plugging them into audio jacks. this would also be a much stronger system than the telephone jacks most walkarounds use.

[Jim Banner]

Digitrax throttles really only need 3 wires but use 6 wire cables for increased reliability.  And the flat telephone plugs are cheap and easy to replace.

However, the round phone plugs are more robust and stand up better when the throttles are being used by people who are not responsible for the repairs.  That is why some clubs use phone plugs, particularly the 1/4" diameter stereo kind.  No worries about putting them in upside down.  No problem if people pull them out by the cord.  But can be a real headache if visitors want to bring their own throttles.

For jump throttles, by all means use a plug that is different from the LocoNet throttle plugs.  Then they cannot get mixed up.  If you use a four pin plug, you can use two of the pins for the jump throttle output and the other two for picking up power from a wall wart.  No wall wart?  No problem.  You can use track power as long as you treat the rails as a split supply and the Zephyr's ground as a neutral or center tap.  You still only need a four pin plug because one side of each jump port is the Zephyr's ground terminal.

For a minimal center stop throttle, you could use a bridge rectifier, ~ terminals to the rails, + terminal to one end of the speed control pot, - terminal to the other end of the speed control pot, and the center of the pot to the jump port input.  Just 3 wires and 2 components - a 1k pot and a bridge rectifier.  I almost don't believe it myself.

Jim   

[jward]

my thoughts are to use the 9 volt battery throttles, with the audio plugs so they plug right into the fascia without cords. since there will be two jump throttles, my idea is to run a seperate bus for each, with one throttle using a female plug, the other a male, so they won't get mixed up. i will probably build some sort of bracket to support the throttle while it is plugged in.

there will be multiple ports for each of the throttles, so that whoever is running that throttle can move anywhere on the layout....

i estimate that with all materials i could build each throttle for under $15. beats the $100 or so for a commercial throttle.


i like when others think outside of "recommended practice" to come up with inexpensive and ingenius solutions.......that's the way i've always done things in this hobby, and i've had alot of fun to show for it no matter how much the "purists" maay cringe......lol

[Jim Banner]

Jeffery, your scheme sounds good.  The only down side compared to commercial throttles is that when you unplug a jump throttle to move it from one place to another, the train will stop.  With a commercial throttle, it will keep going in the same direction at the same speed.  This is not a problem if you can make the move while the train is stopped in a station or stopped on a passing siding waiting for another train to pass.

It is possible to design a jump throttle without this limitation but it would require some electronics jiggery-pokery. (let the spell checker choke on that!)

Jim

[Yampa Bob]

Jim,
If a club is set up for 1/4" phone plugs, they should make up several short adapter cables for the visitors. 

Speaking of "short", I would greatly appreciate it if forum members would shorten those looooong urls, they are really stressing my MSIE. The problem is compounded by the fact that many of us old geezers with lousy eyes have to use large text to read the posts.

http://tinyurl.com/

Thanks.

[Jim Banner]

Bob, that is a good idea.

I assume that "phono" was a typo.  Phono plugs would be a poor choice for repeated insertions/withdrawls.  But phone plugs were originally made with that in mind.

Jim

[Yampa Bob]

Yep, typo. I was referring to the 1/4" TRS (tip, ring, shank) phone plug, not the RCA plug.

http://en.wikipedia.org/wiki/TRS_connector

Scroll down for other configurations and standard wiring convention.

(I edited my post)
Thanks

[MathewWorley]

Im back everybody. I apologize ive been missing in action but just got back home off the road. I now have everything (almost) to attempt to convert my DC GP50 to DCC. I managed to aquire a MRC Prodigy Express  DCC System, 3 used Digitrax DH123 decoders and a airbrush kit (a whole new adventure awaits). Now I just have to aquire the proper tools for the decoder installation and go from there. so hopfully I will have a better update within the week. From the looks of the post, Ive missed quite a bit but with a few days home Ill have time to catch up.