Large Scale Central

Engine not coming to a full stop with ABC

Electronics DCC
#21

7809 center pin (ground) goes to decoder ground, input pin to decoder + (22 volts).

So regulator has input pin and ground pin tied to decoder.

Smoke unit has one wire to a function (F6) and the other wire to regulator plus output.

If using the LGB smoke unit, 7809 needs for you to modify cv 137, 138, 139 for different smoke loads and cv 132 (if using F6) to 72 for steam or 80 for diesel.

Just remember the higher the number the higher the voltage to the smoke unit. I like small smoke at standing, medium for running and lots for accelerating.

#22

thank you. Where do I put the small caps you mention?

#23

Who the heck is Derailed anyway? It’s hard to care about someone you can’t even name…

#24

I’ve provided my first name twice in this thread. Providing your full name on a publicly viewable site is not wise in this day and age. I’ve already had to deal with stolen identity once and I don’t want to go through with that again.

#25

Derailed = Dan from Kansas City, Kansas.

Dan Kansas. Got it. - Johnny Toronto

#26

Another thought, are all your Zimo engine decoders at the same revision? Latest is 39.0 which means CV 7 = 39, CV 65 =0

#27

I would assume so since they were all purchased and loaded at the same time by the same person. But I will have to check.

#28

Do I need this hooked up to JMRI to get the code? because the value doesn’t display in my nce pro cab when I select those CVs.

#29

I can not help as my system will read any cv location at any time and I have not used JMRI.

#30

Things can never be easy. :slight_smile:

I need to learn how to use JMRI. Summer isn’t a good time for indoor things, though.

#31

installed the LM7809 and moved the lights and smoke off the 10v power. Lamps and smoke work. But it did fix the problem. The ABC still won’t work if either lights or smoke are on. I did notice that the loco is not drawing power from the track. Only thru the tender. so have to fix that. I won’t rule out if that is causing the issue but I don’t see why it would. the Power is still being supplied thru the diode array when in the block. And why would that only affect when the lamps and smoke are on? I’ve just been too busy to focus on it Properly.
lol. I feel like CPT Kirk doing his starship log.

#32

Derailed said:

Power is still being supplied thru the diode array when in the block. And why would that only affect when the lamps and smoke are on? I’ve just been too busy to focus on it Properly.

I know absolutely nothing about the system you are using, but that last statement may be key. If the diode array is not big enough to supply the current needed to run everything, then something will not operate properly. Might be that the lights and smoke are pulling all available current not leaving enough for other things.

#33

True. But none of my other engines have this problem. And they use similar decoders (Zimo), same lamps (LGB 5v) and smoke stacks (LGB 5v). Plus the Diodes are pretty beafy.

#34

But this isn’t your other decoder(s). Can you measure the voltage in the block with the problem loco running lights and smoke? It may be dropping just enough to cause the decoder to get wonky.

#35

The decoder only needs 5 volts to work. ZImo programs the decoder to have decoder, lights and sound to turn on first, and motors last. These are done via voltage steps and work on DC as well as dcc. When power is removed, motor stops first , and then it is lights and sound in the MX699 series with supercaps or a slow speed down in DC.

#36

I will try and focus on this during the weekend. Been busy with kids practice and studying for my securities license exam. The next textbook won’t get here until next week so I have some free time. Maybe try and figure out how to get a decoder reading with JMRI. I just ordered a RRAmpmeter for future troubleshooting.

#37

Took the engine apart and cleaned every part along the electrical path from the wheels to the decoder. There are several potential electrical continuity failure points through the loco’s power path. Track to wheels/sliders, wheel to wiper, wiper to leaf, axle to leaf, slider to leaf, leaf to post, post to connector. I added Piko conductive paste to all but the wheels and track (obviously). The Engine stopped with the ABC with no issues for 4 hours straight with lights, sound and smoke running. The only thing I can think of is maybe enough current wasn’t getting through the tender’s wheel path for the decoder to properly process the ABC request. When the engine was getting continuity, it would work, driving me batty.

At any rate, I probably never would have found the problem without using my new rolling road. If you don’t have one, I highly recommend getting a set.

Thanks for everyone’s assistance.

Dan

#38

Ok, what is a rolling road?

#39

MIKE PATERSON said:

Ok, what is a rolling road?

Something you drink after success ?

#40

Derailed said:

Took the engine apart and cleaned every part along the electrical path from the wheels to the decoder. There are several potential electrical continuity failure points through the loco’s power path. Track to wheels/sliders, wheel to wiper, wiper to leaf, axle to leaf, slider to leaf, leaf to post, post to connector. I added Piko conductive paste to all but the wheels and track (obviously). The Engine stopped with the ABC with no issues for 4 hours straight with lights, sound and smoke running. The only thing I can think of is maybe enough current wasn’t getting through the tender’s wheel path for the decoder to properly process the ABC request. When the engine was getting continuity, it would work, driving me batty.

At any rate, I probably never would have found the problem without using my new rolling road. If you don’t have one, I highly recommend getting a set.

Thanks for everyone’s assistance.

Dan

Dan,

Piko makes a conductive paste ?