DCCSA

[davefoxx]

I wonder it it would fit in the speaker recess of the newer Atlas Silver series locos… seems more useful than sound.

Come to HO, and you can have both! 

DFF

[davefoxx]

This is the reply I got for the same question

Most of my decoders are older -- not the fancy new ESUs .. so will have to figure it out .. I also have a BLI with sound -- it might be easier

Be careful with the new fancy ESU (V5.0 LokSound) decoders.  They get three wires to hook up the keep-alive.  In fact, you can void a warranty if you use anything but ESU's keep-alive, because you can fry a decoder, if the keep-alive is not deactivated during programming.  Apparently, the third wire allows this to happen automatically on the ESU keep-alive.

DFF

[peteski]

Be careful with the new fancy ESU (V5.0 LokSound) decoders.  They get three wires to hook up the keep-alive.  In fact, you can void a warranty if you use anything but ESU's keep-alive, because you can fry a decoder, if the keep-alive is not deactivated during programming.  Apparently, the third wire allows this to happen automatically on the ESU keep-alive.

DFF

ESU's own (proprietary) keep-alive (they call it Power Pack) is unique because it has 3 wires. Positive charge/discharge, ground (common), and a control wire. This unit is fairly complex, and since it only uses a small 2.7V rated SuperCap, it is quite compact.  The 3rd wire connects to one of decoders function outputs, and it controls whether the keep-alive is charging or supplying power.   ESU want's customers to use their own keep-alive, so they say that using another brand voids the warranty (but only of the decoder blows up)!  That's how I see it I have reverse engineered the power section of several ESU decoders and I don't see anything there that would warrant using only ESU Power Packs.

Any standard 2-wire keep-alive hooked up to the positive and negative pads (or appropriate components on the board, if there are no pads present) should work on ESU decoders.

[Steveruger45]

Loksound 5 manual page 48 and 49
http://www.esu.eu/en/downloads/instruction-manuals/digital-decoders/?no_cache=1&tx_esudownloads_pi1%5BdownloadItem%5D=11aed2301f38ec395424a7907034d3c6

[CRL]

You might not see it from an electrical circuit standpoint, but if the software sends a signal that has to be read by the ESU keep alive, you could still cause a problem. Like trying to install a modern LS motor into a pre-computer car and not upgrading the wiring harness & electronics… it won’t work.

[peteski]

You might not see it from an electrical circuit standpoint, but if the software sends a signal that has to be read by the ESU keep alive, you could still cause a problem. Like trying to install a modern LS motor into a pre-computer car and not upgrading the wiring harness & electronics… it won’t work.

Well, not quite.  The power section of the ESU decoder is similar to any other decoder.  It is the construction of the "power pack" that is unique (and needs needs the 3rd control wire).

Standard keep alives use an array of 2.5V or 2.7V SuperCaps in-series to make up a single large value capacitor rated at around a standard internal decoder voltage (respectively 12.5V or 13.5V).  The few additional components in those keep-alives limit the charging voltage, allow higher current while discharging, and also protect the SuperCap from over-voltage.  That keep-alive (just like this DCCSA) is a very simple 2-lead device.  This simple keep-alive works well connected to any decoder.  The only possible issue is with uploading the sound file to the decoder. In those cases, simply disconnect one of the keep-alive's leads solves the problem. Some modelers simply install a small switch to disconnect the keep-alive for uploading sound files (which is not very frequently anyway).


ESU Power Pack keep alive is quite different.  It only uses a single 1F 2.7V SuperCap.  That capacitor is still capable of storing energy needed for running the model for few seconds, but at such low voltage it is useless.  ESU's complex design has a DC/DC converter, which during charging converts the incoming 12V to 2.5V to charge the SuperCap.  When the energy is needed to supply power to the decoder, the DC/DC circuit is used in reverse to generate 12V out of the 2.5V supplied by the SuperCap.  That is where the 3rd wire comes into play. It controls whether the Power Pack is charging or supplying 12V power. The decoder's microprocessor monitors the track voltage.  When the DCC signal is present, it puts the Power Pack in charging model.  When it detects absence of DCC track voltage, it puts the Power Pack in power generating mode. Without the control wire the ESU Power Pack would not work. As an added bonus, the third wire is also used to disable to power pack while the decoder is being programmed.

But when a "dumb" standard 2-wire keep alive is being used (in ESU, or any other decoder), there is no need for the 3rd wire.  I hope this clarifies things.

[John]

OK .. now that we have that done .. where do I hook this thing on my digitrax decoders

[CRL]

@peteski - I see what you’re saying… thanks for clarifying.

[mu26aeh]

@GM50 4164 got anything to add to the discussion/questions ?

[GM50 4164]

I've only used them with the Loksound decoders. Worked really well for the brass Yellowstone I did last year.

[peteski]

OK .. now that we have that done .. where do I hook this thing on my digitrax decoders

Digitrax does not provide a common (ground) pad - some reverse engineering would be needed to find the place to attach the negative wire. . And each different size or different shape decoder is slightly different.

I seem to recall that in one previous discussion we had about keep-alives someone posted a link to a website which shows where to hook keep-alive on a whole range of decoders.  Now to find that thread . . .

[John]

Digitrax does not provide a common (ground) pad - some reverse engineering would be needed to find the place to attach the negative wire. . And each different size or different shape decoder is slightly different.

I seem to recall that in one previous discussion we had about keep-alives someone posted a link to a website which shows where to hook keep-alive on a whole range of decoders.  Now to find that thread . . .

I found those .. one is by Mark Guries --- https://sites.google.com/site/markgurries/

I know some have said the 100uf capacitors on the Digitrax N sound decoders are for the speakers, but they state :

3.11  Installing Power XtendersDigitrax Power Xtenders are available for most Series 6 decoders.  They are designed to keep locomotives running and sound from dropping out in situations where power to the locomotive is interrupted due to dirty, dead or bad track.  Hold up time varies based on actual decoder load and track conditions.Most Series 6 mobile decoders include either solder pads, a 2 pin socket or a sound harness replacement for adding a PX module to the decoder.  Some very small Series 6 decoders cannot accommodate power xtenders because there is no room available on the board.  No CV configuration is required to add a power xtender module and most are plug ‘n play installs.  See www.digitrax.com for more information about Digitrax Power Xtenders


So, this would imply that at least on the sound decoders, the capacitor is used for powering the decoder when signal is lost ..

I'm looking to put the DCCSA into a P42 with the SDN144K0A decoder .. 

In the support notes -- they post this:


KB589: SDN144K0A Installation Questions-Capacitor Installation

This article was last updated on Oct. 22, 2013, 6:02 a.m. | Print Article | Leave Feedback

SDN144K0A installation question about the capacitor

Is the 100microF capacitor needed? Or is it only for use in the Kato E8B unit when both LEDs are removed? If it is part of the installation, what size hole doesit need for mounting?

The 100uF capacitor is required for all installations.  The capacitor provides keep alive voltage to the decoder.  This is important when the locomotive runs over a section of dirty track or is traveling through a non powered (insul-frog) turnout.  On non-sound equipped locomotives, typically you will not see the locomotive hesitate or lose power when it encounters dirty track.  With a sound equipped locomotive, you will hear the decoder restart due to the dirty track.

 The capacitor is dipped in a conformal coating to help insulate it when installed in a locomotive.  The nominal size of the capacitor is just over ¼” (.253”).  I would suggest drilling a 9/32” hole. This will allow the capacitor to be easily inserted in the hole.

[John]

[John]

I installed one of the two I received on a Digitrax SDX sound decoder in my P42 .. I simply clipped off the old capacitor, and wired the new one to the red / black wires .. locomotive runs, but I'm not quite sure if it really adds much to the running ability of the engine ..  will have to clean the track first and then see what happens ..

One big advantage .. the body shell does fit back on the frame better ...

[jdcolombo]

FWIW, I have used both home-grown and TCS keep alives (two wires) on ESU LokSound decoders for years - including on the new 5 DCC series.  I do disconnect one of the wires if I'm programming the decoder with the LokProgrammer, but I generally don't do that.  My installation process is to program the decoder with the sound file I want before installation; then I install the decoder, make any tweaks to the programming that I want to make at that point, and THEN connect up the keep alive when I'm done with the LokProgrammer phase.  I've never had a problem using ops mode programming (programming on the main) to then do minor things like speed matching or sound-level adjustment.

Never, ever, had a problem with a LokSound "blowing up" as a result of using a standard 2-wire keep alive.

John C.