so what would cause a motor to turn over it’s armature 1/2 to 1 revolution while just sitting at idle (0 throttle) not enough to turn the wheels? there is a sound decoder installed.
even if there is a minor surge through the rails, the decoder is still responsible for maintaining a steady idle, or am I incorrect?
Too many unanswered questions to be able to hazard a guess on the cause.
What brand and model of DCC system –
What brand and type of decoder – you say ‘sound,’ but there are several sound decoders on the market.
What brand and model number of hand-held controller – radio or tethered?
I was attempting to keep it generic so responses would not be prejudiced by any specific brand names. what difference does it make what brand? should/do decoders in general allow this behavior to happen at times and why? do you know of a specific brand that this occurs?
Is this a Kodak or Polaroid? Oh, you mean armature. So far as I know, there should be no current to the motor if the controller is calling for zero speed.
Was DC operation turned “off”?My guess…
no need to be sarcastic maxman. I am a photographer and sometimes mix up those words.
Jactal, thanks for asking. the decoder is presently at factory reset so CV 29 is at its default value of 6. which means 28/128 speed steps are enabled and analog (DC) operation is enabled.
There have been a few DC operation issues discussed on different forums.When turning DCC power to the track,it happens that the decoder receives full voltage milliseconds before the digital instructions,so react by sending what it sees as DC current directly to the motor,ignoring any throttle setting.In worst cases,locos took off at full speed without any control other than the 0-5-0.
If not running the loco on DC,simply turn DC operation “off” since it’s of no use anyway.
thanks much Jacktal, that’s good information. I’ll turn DC off on 29’s bits and keep an eye on the motor.
Disable BEMF, amd make sure CV2 = 0 (or since this is a TCS decoder, CV2=1 is the default I believe). If there is no way a second throttle could have the same address selected and at non-zero speed, and it still ticks the motor over with speed at 0, no BEMF, no start voltage (and make sure CV29 is not set to use speed tables, either), then there is definitely an issue with the decoder firmware. Or the motor driver is faulty and allowing power to leak through.
–Randy
interesting that folks have opinions about CV values and what they should be but the thing is…this decoder is at factory reset. there have been no changes. when these things like involuntary motor cog/revolution happen all config. values are at their defaults. I’m pretty convinced this is either bad firmware or a defective integrated circuit.
Is the same decoder / engine that you are having the lighting effect issues?
Factory default is BEMF on, DC mode enabled in CV29.
–Randy