How Much Current Are You Drawing From Your DCC
[see DCC Accessories
If you are like most DCC users, you haven't got
a clue. But you should. The current demands of an average DCC layout
vary widely during operating sessions depending upon the number
of locos in use, loco speed and load, and the number and type of
other accessories that draw power from the DCC booster (eg loco
lights, passenger car lights, integrated sound systems, etc.). How
close are you to exceeding the capacity of your current DCC booster
? Are you contemplating dividing your layout into power districts
and adding additional boosters when, in fact, your present layout
has adequate reserves? Or, if you must divide your layout into separate
power districts, what is the best way to do it to achieve a balanced
DCC booster load?
You'll never know unless you can accurately measure
the current your booster is putting out at any given point in time.
Unfortunately, most DCC boosters manufactured today that have a
capacity of less than 10 amps do not have a current meter built
in or even a pair of terminals to connect to your own meter.
The problem is in the DCC signal itself. It is a
complicated, high frequency AC signal that cannot be measured accurately
with conventional AC ammeters. Extra circuitry is needed to smooth
the signal into one that can be measured by inexpensive conventional
meters without disturbing the DCC signal that goes to the tracks.
Another Tony's Train Exchange exclusive!
We have manufactured just a device and are offering it for $15.00!
The CMC (Current Measuring Circuit) comes complete
with a wiring diagram and can be installed on your layout in about
10 minutes. Order one today!
Informational note for CMCs using Digital
I have the following setup using the CMCs with P30756 Digital Multimeters
from Harbor Freight. Meters were chosen because of quality and low
cost ($5-10) on sale. The setup is as follows:
Digitrax DCS100 and two boosters. CMCs used to read
current for each booster section. One CVC connected to each booster
connected to each meter. DC to DC converters used in the meters
to get rid of the batteries and so meters could be mounted without
further fussing with.
Now came the problem, I used a single wallwart
to supply the power for the DC to DC converters to all three meters.
Meters did not work and after discussions with Don Crano and hours
of testing it became clear that some kind of feedback was at work.
The solution and everything will work fine is to use a separate
wallwart for each meter.
I am sure this problem would probably exist with
all DCC systems but I
only own Digitrax so have not tested with other systems. Also note
this situation would not happen with mechanical meters!
For me time has stopped in 1941
Digitrax DCC owner, Chief system
NMRA Life member #2623
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