Yes, one track has a passenger train with a dozen lighted cars, two are LED and the rest incandescent. To make matters worse, that train is also pulled by a pair of Athearn Genesis w/Tsunami which to my understanding are relative power hogs.
At some later date (TBD when dealer sale occurs) I'll get a second booster (Digitrax DB150) for the inside mainline which will have double reversing sections.
In the meantime Digitrax support offered an alternative solution. Change option switch 18 on the DCS100 to Close. It changes the booster short circuit shutdown time from 1/8 second to 1/2 second, enough additional time to let the inital track power-on surge current pass without tripping the circuit breaker. For the time being this works.
Yeah, I think it's the incandescent lighted cars causing the issues more so than the number of locos. You have the same issue with an incandescent headlight. Even if the bulb is rated for 14-16 volts, meaning it can work fine off the direct decoder output, it is recommended to use a small value resistor just to limit the inrush - the inrush can easily be enough to fry the decoder's function line, even though steady state conditions are well within the limitations.
ANother option is the SoftStart module from Tam Valley. It is a time delay and relay that puts a small resistence in line with the track power and after the delay expires, the relay closes and puts a direct connection between the track bus and booster. That way locos and lighted cars can start up without exceeding the booster power and then once up and running there is nothing left in the circuit to interfere with track power.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
cuyama Lake 5 amps is a lot of power. It's the start-up inrush current, not the ongoing operating current, that is causing his problems. Lake What with 50 or more sound engines? 5 amps likely wouldn't be enough to operate "50" typical HO sound engines, in any case.
Lake 5 amps is a lot of power.
It's the start-up inrush current, not the ongoing operating current, that is causing his problems.
Lake What with 50 or more sound engines?
5 amps likely wouldn't be enough to operate "50" typical HO sound engines, in any case.
Based on a post by the OP in another thread, I believe he also has lighted passenger cars on the layout. If that's the case, and they're lighted with incandescent bulbs, he's getting inrush not only from the sound decoders but also from those lighted cars.
According to the PDF available here (A Primer on Driving Incandescent Lamps), a cold incandescent bulb's inrush can be 10 to 12 times it's nominal current.
In a string of lighted cars, that can add up to a LOT of initial inrush current that needs to be taken into consideration when the layout gets powered up.
EDIT: Corrected spelling
Lake5 amps is a lot of power.
LakeWhat with 50 or more sound engines?
Layout Design GalleryLayout Design Special Interest Group
ArtoI now exceed the 5 amp capacity of my command station/booster on start-up current surge
You must have a really humongus layout. What with 50 or more sound engines? There are club layouts that use what you have with no problems. 5 amps is a lot of power.
Ken G Price My N-Scale Layout
Digitrax Super Empire Builder Radio System. South Valley Texas Railroad. SVTRR
N-Scale out west. 1996-1998 or so! UP, SP, Missouri Pacific, C&NW.
If you're that close to hitting your booster's limit, you might want to consider adding a second booster. Since your layout is already blocked, it probably wouldn't be difficult to do.
Yeah, after giving this more thought, the power has to be on in order to be able to turn track power on.
The layout is all blocked, as it was built before DCC. I only have one short siding that already has a toggle switch on it but just turning off that one loco isn't enough. The two mainlines are isolated from each other so I could just put a toggle on each of those and turn them on separately. In the meantime I guess I'll just have to have a couple locos removed from the track and carefully put them on after everything else is on.
Artocan I use a Variac to slowly turn up voltage to the PS2012 power supply & DCS100 command station/booster
Unlikely. Digital logic isn't like tubes and capacitors. "Brownout" voltage will probably damage the circuitry (if it operates at all until you reach near normal voltage).
ArtoI'm consider this so I can postpone the purchase of an additional booster a few months or a year.
If the inrush current is the issue, the solution is very easy. Just set up one or a few sidings on your layout that can be turned off with an SPST switch. If some of your engines are parked on those sidings and the sidings switched off, when you restart the layout the next time, they won't be part of the start-up current draw. And then you can switch them on as needed.
Or don't store all the locomotives on the layout at once.
No need to make this more difficult than it is.
Since I've discovered that I now exceed the 5 amp capacity of my command station/booster on start-up current surge (pulling 3.5 amps running conditions), can I use a Variac to slowly turn up voltage to the PS2012 power supply & DCS100 command station/booster?
I use the variac to reform capacitors on vacuum tube amps that haven't been turned on for a while. I'm not sure if this few seconds of zero to 100% voltage would harm the digital electronics in the command station or decoders.
I'm consider this so I can postpone the purchase of an additional booster a few months or a year.