37. MRH13-03-Mar2013-P - page 80

of the programming track issues and created a new market in
Programming Track Boosters(mrdccu.com/curriculum/ptb.
htm)to interface older command stations with decoders that
meet the new RP.
Some boosters see the increased in-rush current drawn by the
larger capacitors in the sound decoders as a short and shut
down, sometimes refusing to restart until the loco is removed.
The use of circuit breakers designed for sound locos, such as
the PSx series, can frequently fix this.
But modelers continue to demand smoother operation. So,
let’s look at how to get additional energy storage in your locos.
Like other things in life, there is no single answer that fits all
and changes have consequences.
Do I need special decoders?
The basic answer is “no”. However there are some issues.
To add any form of electronic energy storage, you need
access to both the decoder positive and negative leads.
Positive is easy, as it will be the function common. This is the
blue lead, assuming the decoder meets NMRA Recommended
Practices in color selection.
Most non-sound (and even some sound) decoders don’t bring
out the power supply negative lead, as I discussed last month
(mrhmag.com/magazine/mrh-2013-02-feb/di_anatomy-of-a-
decoder). If you are intent upon adding electronic energy stor-
age to one of these decoders, you will need to bring out that
negative lead yourself. Please understand that these modifica-
tions will void your warranty. Marcus Ammann has a wonder-
ful page on his web site dedicated to finding the negative lead
(members.optusnet.com.au/mainnorth/alive.htm). The nega-
tive lead is shown in green in figure 4.
DCC Impulses Column - 3
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MRH-Mar 2013