DCC Lighting Flicker Problem

[iallcroft]

Dear All,

 

I'm using a Lenz Silver decoder to control fans and cab lighting in a JLTRT Class 52. The cab lighting will be controlled by the directionals (white and yellow), and I've been reducing the output voltage settings using CV 55 and CV56 on a combined grain of wheat bulb and two yellow LED's (with capacitor), with the LED's wired in parallel with the GoW. The problem I have is that when I reduce the output value to the level I'm after for the lighting in the cab (down to 65 from 255), I'm getting unwanted flickering in both the bulb and the LED's.

 

Does anyone know a workaround for this, or what may be causing the problem?

 

Thanks,

 

ian.

[Suzie]

Decoders do dimming by switching the outputs on and off quickly and it sounds like the switching is not quick enough for your eyes. I would recommend trying a small electrolytic capacitor between the blue and yellow and another between the blue and white as a simple fix. 47uF or 100uF 35V capacitors might be a good start - the negative end should go to the white or yellow wire.

 

The alternative is to not use the decoder's dimming capability and just use resistors, adding one in series with the cab bulb.

[iallcroft]

Decoders do dimming by switching the outputs on and off quickly and it sounds like the switching is not quick enough for your eyes. I would recommend trying a small electrolytic capacitor between the blue and yellow and another between the blue and white as a simple fix. 47uF or 100uF 35V capacitors might be a good start - the negative end should go to the white or yellow wire.

 

The alternative is to not use the decoder's dimming capability and just use resistors, adding one in series with the cab bulb.

 

Thanks Suzie. I hadn't realised that the dimming control was a pulsed feed. I'll go with the resistors option... cheers.