I have installed a Tsunami sound decoder in a Bachmann 4-6-0. I had to remove the tender DCC ready board to gain room for the decoder and speaker.
All wires are soldered and insulated and match the coding as specified. Everything works correctly including motor control, front and rear lights direction sensitive, dimming, firebox flicker (using an LED and separate 680 Ohm resister) and all sounds. However, the front headlight, an LED with a 680 Ohm resister, never goes completely off even with F0 set to off. It is more dim than the dim level. The rear light is a 16Volt incadescent which does go off as it should. I am using a Lenz Set 100 with input voltage at 16 - 16.5 volts.
CV 49 is set at 129 - 1 for dim and 128 for LED inhancement. I asked Soundtraxx for help several weeks ago and have not received an answer.
Any one got any ideas before I just put the boiler back together and live with a constant glow?
Thanks, Tarp
Hello Tarp,
I am not familiar with your decoder but (being an electrical engineer) I will venture a guess.
I would test it by swapping the LED&Resistor pair with the light bulb.
If the problem moves then follow step two below. If it doesn’t it may be a bad decoder.
#2 Your resistor value seems to be a bit low. The reasons are technical but basically any source has an internal resistance. There may be some leakage current from the decoder and with a very low internal resistance this is sufficient to dimly light the LED. I would try a resistor in the range of 1000 ohms and see if it helps. It should drop the current and thus the voltage available to the LED below it’s turn on point. Make sure that the LED achieves sufficient brightness when it should be on. You may have to play around a bit with values.
Hopefully someone more knowledgable can give you a more definitive answer.
Thank you larak. Makes sense. I’ll try that.
tarp
I would probalbly have to say get a new light bulb or change the decoder.