LGB 10345 shuttle is short cycling

[bmartinpe]

I installed the LGB 10345 shuttle unit and it short cycles. The loco starts up, then reverses before it reaches the break at the first diode. After it passes the diode, it does not reverse, but continues in the same direction to run off the track. Checked to see that the track break sections are on the same rail. Checked to see that the diodes are pointed in the same direction. Double checked the wiring diagram to be sure that the power supply and the track power connections are correct. Please help. Bill Martin, Nashville, Tennessee

 

[LVT]

I installed the LGB 10345 shuttle unit and it short cycles. The loco starts up, then reverses before it reaches the break at the first diode. After it passes the diode, it does not reverse, but continues in the same direction to run off the track. Checked to see that the track break sections are on the same rail. Checked to see that the diodes are pointed in the same direction. Double checked the wiring diagram to be sure that the power supply and the track power connections are correct. Please help. Bill Martin, Nashville, Tennessee

Bill,
Try reversing the diode that the engine runs past on its way to running off the track. For the shuttle to work, each diode must cut the power to its respective isolated section, and then restore it when the unit reverses polarity on the main section. A remote possibility could be a faulty diode.

You can check that the diodes are correct by connecting your power supply directly to the main section and then manually use the direction switch to confirm the diodes’ orientation and functionality. Good luck on achieving the reliable and entertaining operation that a shuttle unit can provide.

 

[Greg Elmassian]

Reversing the diode would explain running past the "break", but what explains it reversing before the first diode?

But the op's post indicates it reverses before the first diode, but next he says it goes past the diode and runs off the track, is this after it prematurely reverses, and heads off to the OTHER end?

Something is not quite clear here.

Greg

 

[Dan]

The LGB reversing units have a X1 and X10 switch/jumper connection for the timer circuit. I assume yours is set to X1 (times 1) not X10 (times 10).

 

[Greg Elmassian]

But is that timer the pause before reversing?

 

[Neil Robinson]

I think some shuttle units are activated by the short circuit that occurs as the rail gap adjacent to a diode is traversed. If this is the case and the loco reverses before it reaches the first diode there may be an intermittent short in the loco. I suggest using a different loco.

 

[mmts]

Would anyone know the details of a replacement diode for the lgb set as it might be an idea to have a spare or two just in case...... ( I’m hatching plans...)

 

[Gavin Sowry]

Checked to see that the diodes are pointed in the same direction.

That's the problem..... the two diodes should be in directions opposite to each other.

 

[Gizzy]

Would anyone know the details of a replacement diode for the lgb set as it might be an idea to have a spare or two just in case...... ( I’m hatching plans...)

I may have one or two here....