K27 does not move with Titan Quantum large scale decoder

[krinor62]

Hi,

I recently bought a Bachman K27. I tested it with DC and the Dummy PC board installed. In this mode the engine runs fine, changes direction, head lights, marker light and cabin lights work. Only the smoke unit does not work (smoke set to smoke DC on, fan under smoke stack does not run, no smoke).

I now installed a Quantum Titan DCC Sound Decoder and tried to run it in DC mode. The lights work, the fire box flicker and the smoke unit are working fine (I can also hear the fan). However the engine does not move and I do not hear any sounds. The Quantum Titan should also work in DC (with limited functionality).

I have to say that I currently only have an old DC transformer which generates 17 V 7VAC maximum. This transformer works if I run the engine with the Dummy PC board installed. Is the transformer output too low for the engine to run with a Quantum Titan or is this a faulty decoder?

Best regards

Krinor

[Chuck N]

Krinor:

That is a very low voltage/power unit to run the K.  My guess is that there isn't enough power to heat the smoke unit.  Also many have said that the fan is in there to cool the motor, not drive the smoke.  Therefore, it pulls the air down the stack rather that pushing the smoke up.  I never run mine with smoke so I can't officially confirm.  Also there may not be enough power to run the decoder.  Try turning off the smoke and see if that helps with the sound.

Chuck

[GG1onFordsDTandI]

Many of the old DC power packs don't produce nice clean, even power either. A solid state supply would likely produce better conventional results.

[David]

As far as voltage goes; I run my four large scale (all Bachmann) locomotives with 14.4 vDC feeding Aristo Train Engineers. These probably drop another volt or so. So running at about 13 volts the engines and the Phoenix sound works fine.

[Kevin Strong]

If you're running the loco on DC through a DCC decoder, you almost invariably need a filtered DC power supply. If the decoder sees unfiltered DC or pulse-width-modulation, it thinks it's just getting a really bad DCC signal, and doesn't kick over to DC mode.

Aristo-Craft makes a PWM - Linear filter that may work on the DC output of an unfiltered DC power supply. I haven't tried it in that environment, but I know it works to convert the PWM output to filtered so that a DCC decoder will behave properly.

Later,

K

[krinor62]

Thanks a lot for your replies,

This is what I suspected, but it is always good to get confirmation from the experts. I plan on buying  a Digitrax Superchief 8 A Duplex (radio controlled) DCC system for my garden railroad. I hope this will solve the problem. Any experience with this DCC system?

Best regards

Krinor