AC voltage reading but no response from a locomotive?

S

Sarah Winfield

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Did I understand from a recent post that it is possible to see an AC voltage reading on my analogue meter from the track but not have the digital signal to operate a locomotive, please?

Thanks,

SW
 
Yes. The AC voltage will be there all the time, regardless of whether your central station is sending any DCC commands to the loco(s). The command signal is created by stretching and compressing the square wave of the AC voltage (in other words, by Arcane Magicks.....) and (I think) won't in any way show up as any changes on your meter reading.

Jon.
 
So, am I correct please, the AC voltage can be on the rails which is what my meter is reading but my controller isn't sending the command (in this case) for my locomotive to move forwards? Or the locomotive isn't recognising that command?

This DCC "stuff" is a real tester when you can't actually see anything on a meter? I find that quite frustrating.

SW
 
There exist devices to decode the DCC packets, but they are more expensive than a decoder.

Again, disconnect the wires from your layout, connect to a short piece of track and validate with a locomotive.

You can then determine if you are not sending a signal, or you have some other issue (track).

Greg
 
This may be a silly question, but are you sure you're sending commands to the correct loco address? You haven't pushed any of the buttons on your Bachmann controller to select a different address, perhaps in an effort to get something to happen?

I would suggest getting one of your other DCC locos out (either of your other two Stainzes or the black diesel), check what loco address it uses (I assume you were told that when you bought them, or maybe it's written on a label somewhere?), put it on the track and press the corresponding address button.

Jon.
 
Thanks Greg.

I think what I'll do is to secure 5' of track on a gravel boards and use this as my tester. There won't be any rail joiners and it'll be fairly easy to keep clean. Then if I hook it up to my controller with a switch so the AC voltage and DCC signal can go to this or my layout.

SW
 
Jon, I can sense some frustration in your post, and who can blame you!

But no, I always check I've got it on the correct address before asking my question.

Tomorrow I'm going to have all my locomotives out and play around with addresses (and I do know which each is). It'll be a bit of fun if nothing else.

In addition I shall continue revamping my layout to give me an end to end and also a roundy-roundy circuit.

Thanks again to those who have the patience, understanding and knowledge to help.

SW
 
A good idea... check all the locos on the "test track", and when you are confident of operation, then on the layout. If it runs well on the test track, then you can be assured problems on the layout are layout issues, not locomotive issues.

Also, don't try to run more than one loco, with the voltage and current limitations you have that will be an issue for sure. Another thing you can do, is check for a short on the layout with the power disconnected and the meter set for ohms, measure across the rails... a "small" short could distort the DCC signal.

Regards, Greg
 
Sarah, for reliable DCC operation of a garden railway, it is recommended that your system can supply at least 20 Volts @ 5 Amps or 100 VA. If it doesn't, it is quite likely that problems you have described here and in other threads will occur. Trying to use a DCC system designed for use on smaller scales is bound to end in tears!
 
Here's a pic of the "portable" board I use as a test bed, Sarah - a 4-foot contiboard shelf with two lengths of track screwed to it, both with the screw-on power connectors we've been talking about. The front track is connected to the "programming" output of my central station (when the green plug is fitted to my Massoth CS), while the rear (longer) track can be switched between DCC power and basic analogue DC via the little LGB 1-amp power pack fixed to the board. using the big DPDT toggle switch on the black box. The Massoth rolling-road section on the rear track is movable to the front one when necessary, and can be adjusted to take almost any size of loco. The four feet of track is just enough to test locos on either DC or DCC, allowing them to crawl a short distance - for longer running-in I use the rollers.

Test track board.jpg

If you built yourself something similar, if a little simpler, you'd have the ideal setup to test any of your locos.

In the meantime, at the risk of repeating myself (and maybe showing just a little frustration!!), please, please, PLEASE buy yourself some proper track power connectors like the ones shown in the pic....! ;)

Jon.
 
Zerogee said:
In the meantime, at the risk of repeating myself (and maybe showing just a little frustration!!), please, please, PLEASE buy yourself some proper track power connectors like the ones shown in the pic....!
Click to expand...

Sarah,
Have you worked-out how to have a 'conversation' with another Forum member? - If so, start one with me, and I will send you a set of the above connectors. :)
PhilP.
 
PhilP said:
Sarah,
Have you worked-out how to have a 'conversation' with another Forum member? - If so, start one with me, and I will send you a set of the above connectors. :)
PhilP.
Click to expand...

A very kind offer, Phil - I'd have offered some myself if I had an extra pair I wasn't otherwise using!

Jon.
 
Gentlemen, I need no charity. I do have a couple of the LGB rail connectors but preferred to use the croclips until my wiring does what I want it to

I'll use them tomorrow on my test track.

Tonight I've enjoyed myself running a passenger train from one end of my layout to the other and then marshalling the stock ready for the next departure.

The last train of the day will leave after it is dark tonight hence the front light is illuminated. (Thank you JohnS)

SW
 
Hi Sarah,

I just want to encourage you to keep trying!

If you followed my "CS3 Trials and Tribulations" thread at all you will know that I had been beating my head against the DCC wall for about 18 months trying to chase down an intermittent control problem. And, to somewhat mix metaphors, I finally broke through. My problem turned out to be very simple - I refused to believe that a brand new Central Station could be faulty. I spent hours combing DCC forums, web sites like Greg's (by the way ,thanks Greg, for your site), and manufacturer web sites and tried just about any DCC voodoo out there in an attempt to solve my problem. Once I finally admitted to myself that my brand new CS3 could be at fault - voila! All was solved. I've been enjoying the wonders of fully functioning DCC for past 10 days! Now the only faults are debris on the track and human error and it's wonderful.

I would strongly encourage you to beg, borrow, or steal a known good DCC controller just to eliminate your controller as the problem source.

Phil S.
 
Zerogee said:
Here's a pic of the "portable" board I use as a test bed, Sarah - a 4-foot contiboard shelf with two lengths of track screwed to it, both with the screw-on power connectors we've been talking about. The front track is connected to the "programming" output of my central station (when the green plug is fitted to my Massoth CS), while the rear (longer) track can be switched between DCC power and basic analogue DC via the little LGB 1-amp power pack fixed to the board. using the big DPDT toggle switch on the black box. The Massoth rolling-road section on the rear track is movable to the front one when necessary, and can be adjusted to take almost any size of loco. The four feet of track is just enough to test locos on either DC or DCC, allowing them to crawl a short distance - for longer running-in I use the rollers.

View attachment 239860

If you built yourself something similar, if a little simpler, you'd have the ideal setup to test any of your locos.

In the meantime, at the risk of repeating myself (and maybe showing just a little frustration!!), please, please, PLEASE buy yourself some proper track power connectors like the ones shown in the pic....! ;)

Jon.
Click to expand...
I see no Crocodile Clips here!
 
Sarah Winfield said:
I'll let you know the results.

Thanks,

SW
Click to expand...
When you know what number each loco has it is well worth while putting that number underneath the loco with a small sticker if you have one. Memories being what they are!
 
Thank you Phil S.

My encouragement comes from the friendly and helpful members of this forum. In addition I get it from a day like today and an evening like tonight. I've just put my stock away after watching my locomotive pulling 3 carriages and a parcel van round my layout without virtually any problems.

The only aspect which I would like to know more about is, does the light on my locomotive give any indication as to an issue? When the locomotive is sitting stationary on the track the light is on and steady. Once I set the locomotive off I occasionally get the light flickering and sometimes the locomotive will stop. When in this instance it stops the light now goes out.

I just wondered why sometimes the light stays on when the locomotive is stationary but other times when the locomotive stops the light goes out?

SW

I had responded to Phil S's post before reading Dunnyrail's message. The locomotive's are identified but I'll still put a sticker on to remind me.
 
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The light going out whilst running would usually indicate a loss of power to the loco - dirty track or wheels, or a dodgy section of track. If you run in the late evening you sometimes get condensation on the rails as they cool down after a hot day, and this can cause loss of contact.
 
When the loco is stopped deliberately, under control, then the power is still being picked up from the track so the light will stay on; if the loco stops when you haven't told it to, and the light goes out, that strongly indicates a loss of power pickup from the track, as Nick says.

Jon.
 
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