Re: DCC HO DC Question

Marcus Ammann
 

Hi Blair

Further more on your question about 13.8 or 12 volts.

My NCE system outputs 13.8. I have an ammeter fitted fulltime that uses
a bridge rectifier in series with one track feeder so the voltage at the
output of the ammeter is 12.4 and I use 21 watt lamps for power division
which further drops the voltage to the track.

For a test, I consisted 4 sound equipped locos two Soundtraxx and two
Loksound, and run all with lights on and drawing .6 Amp and with the 21
watt lamp just starting to glow. The track voltage was 10.3 volts. Sound
decoders were all operating with sound. The Soundtraxx units on a
previous test for using 12 volt lamps for power division, do start to
play up at about 9 volts.

Operating with 12 volts DCC at the track, allows successful operation.
Obviously the top speed will be reduced at this voltage but all locos
were working.

Some operators on my NCE group have lowered the track voltage to 12
volts and have said that some problems they were experiencing, have
disappeared.

Hope this answers your question.

Marcus

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...]
On Behalf Of Rasa and Blair Smith
Sent: Tuesday, 12 July 2005 8:27 PM
To: WiringForDCC@...
Subject: RE: [WiringForDCC] DCC HO DC Question

Marcus
Yes, we know that the input may be AC or DC, and that regardless of that
input signal, in at least the Digitrax case, the input is rectified.
Yes,
we know that any system that produces AC from DC from AC is going to
need
what we generally refer to as "headroom". Digitrax specs 12 to 28 as
input
DC, what I am more or less questioning is whether 13.8, or even 12,
provided
sufficient voltage "at the track" for satisfactory operation. The
latter is
a very subjective consideration, so I guess the upshot is I should just
try
it.

The double battery suggestion is a fine one; I'll need yet a third, I
guess,
for all the PS12 and other electronics. Alternatively, I guess an
inverter
might be a better idea, with the layout wired for 110 VAC. Then I won't
need to make these decisions at all, off-the-shelf equipment will
suffice.
Thanks
Blair


-----Original Message-----
From: WiringForDCC@...
[mailto:WiringForDCC@...]On
Behalf Of Marcus Ammann
Sent: July 12, 2005 04:45
To: WiringForDCC@...
Subject: RE: [WiringForDCC] DCC HO DC Question


Hi Blair

You can power your DCC systems with DC.
NCE - 18 to 28 volts DC
Lenz - 15 to 18 Volts DC
Digitrax - 12 to 28 volts DC

DCC power at the track is produced from DC that is made from rectifying
the normal AC voltage from your transformer by a bridge rectifier in the
booster. Supplying the bridge rectifier with DC instead of AC will still
provide DC to the booster circuits. It just uses 2 diodes to pass the
DC, instead of the 4 that are used for rectifying the AC.

The bridge rectifier and the electronics that produce the DCC voltage
will require some "extra" volts. For example if you supply the DCC
system 12 volts from a car battery you will only at maximum get say 10
volts. All decoder will work on 10 volts DCC but top speed will
certainly be affected. Sound decoders will start dropping out at 9
volts.

So for a DCC system to provide the recommended HO voltage of 14.25
volts, it will require at least 16 to 18 volts DC.

So if you go off the "grid" and have to supply your system with DC then
I would check your system requirements. From the above if you were
operating either the NCE or Digitrax, you could supply them with two 12
volt batteries connected in series to give you 24 volts. You will have
to separate the batteries to charge them with a 14 volt car alternator.

Hope this helps

Marcus



-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...]
On Behalf Of Rasa and Blair Smith
Sent: Tuesday, 12 July 2005 11:34 AM
To: WiringForDCC@...
Subject: [WiringForDCC] DCC HO DC Question

Hi
For those with a lot more experience. I keep reading comments about
13.8
VDC not being enough to power DCC systems for HO, because you "dont get
enough speed out of the locos". Now, when I think about it for not very
long, it seems to me that that implys running the units at full throttle
and
being unsatisfied with performance. So what voltage DC is required to
achieve full performance? Yes, I realize that we have to assume a few
things, like the voltage drop to the farthest corner of the layout, etc.
etc, but ignoring those factors for a moment, what input voltage DC
should
we strive for to get satisfactory DCC performance?

If 13.8 VDC is satisfactory as long as we aren't looking for slotcar
performance, then the next question becomes will a DCC system perform
satisfactorily from an automobile electrical system? With and without
alternator charging system, or only when the car is running?
12 VDC is the minimum input, right? Or is that optimistic?

I ask all of this because there is a significant chance I am going to
want
to go off-grid in my next abode, and I expect 12 Volts will be part of
my
life at that point.

Blair Smith




http://www.WiringForDCC.com
Yahoo! Groups Links






--
No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.323 / Virus Database: 267.8.11/45 - Release Date: 9/07/2005


--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.323 / Virus Database: 267.8.11/45 - Release Date: 9/07/2005




http://www.WiringForDCC.com
Yahoo! Groups Links










http://www.WiringForDCC.com
Yahoo! Groups Links






--
No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.323 / Virus Database: 267.8.11/45 - Release Date: 9/07/2005


--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.323 / Virus Database: 267.8.11/45 - Release Date: 9/07/2005

Join w4dccqa@groups.io to automatically receive all group messages.