Need some help. I just set up my DCS50. I have the programming track connected properly, I have checked it several times to be sure. When programming it seems to talk to the DH123D I have installed in my UP 0-8-8-0. I wired in the decoder and have checked the diagram several times to make sure it is installed correctly correctly. I am using this as my testbed to learn all I can. I have installed the decoder and replaced it with one straight out of the package. This way I am using the factory defaults. Place the engine on a cold track(no Power). Made sure I had good continuity all around. Next made sure the trottle at "STOP". Hit the power button. I watch the display cycle through until it found the address 03. The light on the engine came on and the engine began to run.It moved less than 1 inch and quit. This is where I am now. I have checked the AC voltage at the DCS50 and it reads a constant 14.3 VAC, no matter what setting the trottle is at. Evidently it is the Ampage that varies not the voltage as in a DC system. I have 2 decoders which acted the same. Now I can not get the engine to move at all, or to come on but both decoders respond on the programing track. Any suggestions? I am lost at this point.:thumbs_down:
Hi Buck - I can't help you much, but maybe I can help with understanding DCC. First, it is normal for the track voltage to be constant with a DCC system. Track voltage is always present, and it is the decoder that controls how much of that voltage gets to the motor. Speed control is NOT achieved by varying the current. The decoder responds to digital signals (the "D" in "DCC") that you send from the controller. Those digital signals tell the decoder what to do, such as allowing a certain amount of voltage to go to the motor. Now hopefully someone with knowledge of your gear will step in here and offer some practical advice, instead of useless theory! - Jeff
I don't believe there is a tether to connect between loco and tender, as there is in BLI, Bachmann, and other engines. I would have suggested reseating the tether because that connection accounts for a lot of intermittent behaviour. I would guess, if the track meters an indication that it is getting the full voltage, that there is a broken wire someplace inside the engine or your a joiners nearby are not connecting properly so that there is continuity from rail to rail. No other solders to be checked on the layout, key one, or key wires, say from the power pack to the terminal at the rails? A meter will show if the output terminals show juice, and if the rails just after the connection there show juice. If you know there is power to the engine, then the engine must be the culprit, and it may be several things...dirt, corrosion, broken wire, wiper not properly installed so that it actually makes contact with the metal it is to wipe, a faulty decoder. Can you verify output voltage from the decoder's motor leads with partial throttle?
Crandell, I have checked all solder connections on the harness. I do not believe I have any cold solder joints. I checked voltage at the track it is 14.3VAC, which I think is normal. I checked the voltage at the wiper pick up and it is 14.3 VAC. I then checked the input voltage at the connection of the red and blue input leads that are connected to the red and black leads to the decoder. again 14.3VAC. at the motor I have 0.00VAC, I believe at this point the voltage should be a DC voltage? The measured DC voltage at the motor input is 0.1 VDC. What gets me is I tested this loco before putting the decoder in on the track using address 00 and it ran fine. I have also checked 2 other locos on address 00 and they both operate fine. Being an electronic tech most of my life I am puzzled because the wiring is as diagramed on the DH123d Hand out. I have an idea something is blowing the decoder, but can't find anything it could be. The reason I say this is I have used 2 different decoders and had the engine run for a very short time, and then it quits. I just did another test on my DC track. when applied power to the engine. the light came on and it attempted to run, but quit very quickly. It is my understanding the the decoder comes from the factory so that you can run in on DC or AC. need some more ideas.
You won't get measurable DC current, I don't think, because it is pulsed...I could be wrong, but I know for sure you don't get an accurate measurement on the AC setting when you use a simple multimeter to measure track current, and that is due to the square wave nature of the DCC. But, say I am wrong, and that you should get at least a solid approximation of the DC current out the decoder and to the motor. You wouldn't get any significant DC voltage unless you had directed the controller to tell the decoder to do that via dialing up the speed on your throttle. Had you dialled in some speed before you measured? It would probably mean inverting the engine and hooking up some wires with alligator clips to the non-rotating tires...if there are any, and dialling in some speed. Or, just block the engine while it sits on the rails and spins...but it can't spin unless the motor is receiving voltage. That is when you would know if the decoder is working...if it receives voltage but issues none to the motor.
OK, Just for grins, I cut the decoder out, and using alligator clips I put the loco back to ground zero. On address 00 all works just fine. Then I took the decoder and hooked it up to LT1 and the DCS 50 to check out the decoder. Darn thing checked perfect. I will try wiring it again and maybe it was my connections. Just as an aside. Measured the voltage out and with the throttle wide open the voltage was 10VDC on the leads that go to the motor. Like you said I'm going to work with some alligator clips until I get it working. I will publish all I find.:tb-biggrin:
He he... Well, you can't say you aren't getting somewhere. About the voltage at the highest throttle setting...it sounds low to me. I would feel much better if, even with the error due to square wave current and using the multimeter, you were getting an indication much closer to 13 volts.
I assume that you had the loco on the main track (Rail A/Rail B) and not the programming track at this point. The programming track does not provide enough power to actually run a loco. I am perplexed about watching the display cycle until it "found" address 03. It doesn't work that way. You must actively SELECT address 03 by presseing LOCO-03-LOCO as described in section 9.2 of the Zephyr manual. The fact that the loco traveled an inch before stopping may mean it was responding to some DC on the rails(which can happen when power is first turned on) until it recognizes the DCC signal,then, seeing no speed command, it stops. If you follow the sequences descried in Section 9 of the manual, you should have no trouble.
One other thing to consider is the current (Amps) the motor pulls when moving the engine. If it is more than the decoder rating the decoder may shut down after a few seconds to protect itself. Various things could cause that, but checking with a meter should quickly show if it is a problem to pursue.
Did you test the decoder installation by putting it on the programming track and trying to read a couple CVs before you connected it to full DCC power? If you cannot read a Digitrax decoder on the programming track, it almost always means there is something miswired. Even if I am going to try and run it using the default address, I always read and program a couple CVs to check it. The current supplied on the programming track is not enough to damage the decoder if it is not wired properly, but you will get an "nA" or "nD" indication on the DCS50 display if there is something wrong. Putting an untested decoder on the full power DCC track is an invitation for the magic blue smoke to come out of the chips. Have you used a VOM to make sure the motor circuit is isolated from the rail power pickup? You must have no continuity between the red/black wires and the grey/orange wires. That also means no continuity between the motor brushes and the locomotive chassis. That might mean taping the chassis or connections with Kapton tape to make sure no shorts occur.
First thanks Jim for the sage advice. I did as you directed of reading the device on the programing track before trying to put it on a track. The one thing I seemed to miss was the way the light was wired into the circuit. Power and ground for the light came directly off the motor +/- terminals respectively. After I ruined 2 decoders I cut the light out of the circuit, added a third decoder and everything worked as advertised. The way Life-Like(their suppliers) wired the ground lead directly to ground did not allow the motor to be isolated from the chaise. Cutting the light both leads did this. Now the light does not work, but that is a problem for another day. I have tried wiring the light to the decoder directly, by-passing the motor completely but that does not work. So it is back to the drawing boards and manuals until I figure it out. Guys, I am grateful for all of the good advise and have used it to my advantage. Now I have 2 decoders to return to the factory and hopefully replaced. Thanks again.:tb-biggrin::tb-biggrin:
