What rating of resistor across motor leads?

[CSX Robert]

I would just leave the resistor off.

Gerome

Actually the decoder functions on the main after programing even with the resistor disconnected....all sounds etc., but won't take programing that way, of course.

Actually, the resistor is not required for programming either.  The decoder will not acknowledge the programming(well, it will, but the command station won't see it - the decoder acknowledges the write by momentarily powering the motor leads but with no load the command station does not detect it), so the command station may report an error, but the programming will take.  This can be an issue with progamming extended(4 digit) addresses, because the command station may stop writing after not seeing an acknowledgement after the first byte, but the extended address can stil be programmed by programming the individual CV's manually.

[rrinker]

Couple of YEARS too soon with Tsunami. The current ad in MR hints that something is coming, it does not actually mention Econami.

                               --Randy

[richg1998]

SoundTraxx will release info when they are ready. They got into trouble some years ago by announcing too soon.

I have been watching the Yahoo SoundTraxx DCC Group for some time. Love the opinions.

Rich

[Mark R.]

richg1998

.... SoundTraxx is going to be releasing another new sound decoder series so we shall see.

Rich

 

Where has it actually been announced by Soundtraxx they are bringing out a new decoder ? All I've seen is rumors and spectulations from the multitudes .... nothing from the source. (?)

Mark.

[richg1998]

I got the resistor idea from this guy maybe three or four years ago. I use to buy from him before he sold Litchfield Station.

http://mrdccu.com/curriculum/soundtraxx/tsunami.html

Scroll down to near the bottom of the page.

Store the link in Favorites. He has loads of good DCC info which is useful for other brands of systems and decoders.

He is very active in the MRH forums and a couple Yahoo DCC Groups.. Doubt he will ever come here.

With the new Econami decoder and the present Tsunami line stopped, I am sure he will have a lot more info soo. SoundTraxx is going to be releasing another new sound decoder series so we shall see.

Rich

[DigitalGriffin]

(V*V)/R = power

so...in worst case (HO)

(14V*14V)/R = 5 Watts

R= 39.2

But as some of us point out, you rarely want to run at the limit.  So I would run 60-80Ohms at least.

If you want 1/4 Watt

(14*14)/R = .25
R = 784Ohm

However I would use a nice 1kOhm to help keep the resister cool.

You can also adjust the max speed setting to lower the overall average output to something really low.

[Gerome]

Great, thanks, fellows.

It is the CV motor settings that are probably boosting the heat, of course. I should have thought of that.  That is why I appreciate this forum so much.  Great help.

[richg1998]

I have used a 100 ohm, 1/2 watt resistor with a Micro Tsunami decoder and adjusted the CV's.

Rich

[Mark R.]

Set CVs 2, 5 and 6 to a value of 0. This will prevent any motor voltage flowing through the resistor. A 100 ohm 1/2 watt should be fine with those CVs set.

Mark. 

[Gerome]

I am using a mobile decoder just for its sound functions in a rail car.  I am not asking about the resistor to program on the programing track.  I have had the decoder operating with a 39 ohm 5 watt resistor and a 1000 ohm 5 watt resistor I had on hand.

Both heated to the extent that the solder connection comes undone.

I do have 1 watt 100, 220 and 300 ohm resistors.  Would these produce less heat?  Of course I also have the little 1/4 and 1/8 watt resistors for LEDs too. I think these work on the programming track....maybe even on the main.  I will try.

Actually the decoder functions on the main after programing even with the resistor disconnected....all sounds etc., but won't take programing that way, of course.

You can tell I am not conversent in electronics.  Only know enough to get into trouble.  Thanks.