Re: tsunami 2


Mark Kasprowicz
 
Edited

I've not heard of this happening though perhaps putting the qjuestion to the Soundtraxx list might shed more light.

As for inrush that's a current thing, not voltage. I am not sure how your  RRAMP meter is connected Dale, but you do not mention the current reading because that's the one that shows the initial inrush on start up, the difference of 0.2 volts is insignificant. Inrush is created by a number of stay alive devices starting to charge their capacitors at the same time which tricks the system into thinking it's seeing a short because the demand is so high and so sudden. That said stay alive units have a simple circuit to slow the charge current going into them but which allows the stay alive to discharge fully when track power is not detected.

If you wire the RRAMP meter in series with the NCE output and not just across it, the inrush will be very apparent and much more than magnitudes of 0.2 in 14.

The stay alive is connected to the decoders' +ve and -ve DC rails. I think some of the early sound decoders seperated the motor circuit from the lights and sound but that no longer holds true.

Mark K

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