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Contents
  • A cheap and simple DCC Decoder
  • Suppression capacitor - To remove or
    not to remove
  • Fitting the decoder to a loco that is
    not 'DCC Ready'
  • Testing the decoder installation
  • Programming the decoder for optimal
    running



Lenz LE1014W Ultra-Thin Drive-Select DCC Decoder
(LE1014W product
manual
)
$18.95 per decoder from Tony's Trains.

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Feature Set:

  • Selectable Silent Drive or Precision Glide
    Control
  • Selectable for operation with 14/27, 28/55
    or 128/256 speed steps.
  • Operation on conventional DC layouts is
    possible or can be disabled.
  • Provides 1A continuous motor current.
  • Four function outputs, one rated at 500 mA
    and three rated at 150 mA each.
  • Special lighting effects including
    directional, independent, adjustable dimming, Mars light, Gyro light, single
    Strobe, double Strobe, adjustable blinking and ditchlights.
  • Support for Advanced Consist Control and
    Extended Addressing
  • Support for programming on the mainline
  • Support for all forms of programming as
    described in NMRA RP-9.2.3
  • Programmable locomotive address,
    acceleration and brake momentum, speed curve and much more.
  • Size: L 1.3" x W 0.63"x H
    0.14" L 31.7mm x W 16mm x H 3.6 mm

This decoder is used because it works well, it
is cheap and simple.

Update: Initially I had installed a Lenz
LE1000 decoder, but the LE1000 does not support CV5 (Max speed) and CV6 (Mid
point speed) neither does it support Speed tables. It didn't perform well and
was erratic on my Layout. Notably when it came to managing the top-speed of the
loco. Tony's Trains swapped these decodes for LE1014W ones that do support a
speed table. So the loco now runs much better. Smoother acceleration and a much
more realistic top speed. See the speed table settings below. The photos
below show the LE100 being installed, but the wiring is exactly the same with
the LE1014W.




Train Wheel Vehicle Rolling stock Window




For this article, we have here a Hornby Streamlined West Country class 4-6-2 34041 "Wilton" & tender in BR green.
Reference number: R2218.

Built at the Brighton Works and originally numbered 21C41, 'Wilton' first appeared on the rails in October 1946 and was renumbered 34041 and liveried in BR green at the beginning of 1949. The Hornby model is liveried as 'Wilton' in its later days, complete with a cut down tender and the later BR emblem.

The model has no NEM socket so the
decoder has to be installed directly to the pick-up wires and motor
connections. There are no lights or other functions on this loco, so the
function circuits of the decoder will not be used.





Train Wheel Vehicle Rolling stock Toy




To remove or not to remove the
suppression capacitor


European locomotives are equipped with a
RFI (Radio Frequency Interference) suppression circuit, usually consisting
of a capacitor and mini ferrites across the motor brushes. This is because
of the high frequency signals that egress from the motors, can cause
interference with household television and radio equipment.

Virtually all DCC decoders use a form of
PWM (Pulse-Width-Modulation) to control motor speed.

Since the super sonic or high frequency
decoders operate such that the high frequency PWM output is approaching
RFI range, the suppression capacitor will start to act as a short, or
suppress the decoders output to the motor.



Remove the capacitor. This will result in
less current being drawn from the decoder, and improved performance from
it. Again note, this is only applicable with high frequency PWM output
decoders, normal PWM decoders will not be effected by RFI suppression
circuits.

European and certain other
telecommunication agencies require that RFI suppression circuits be
installed, in the USA this is currently not a requirement. But note by
removing the capacitor or disabling it, should cause no problems with RFI
as long as a decoder is installed. The decoder's output will take care of
RFI suppression on it's own.





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At this point, certain locomotive
manufacturers [Bachmann] have stated the removal of the suppression
capacitor will not void the manufacturer's warranty when a DCC decoder is
installed in it's place. Some decoder manufacturers [Lenz] also recommend
the removal of suppression capacitors. Some manufacturers don't advocate
removing the suppression capacitors [ZTC], but this is when using their
decoders as they are designed to work with the original suppression
capacitor in place.



The suppression of interference is what
it's all about. I have had no instances where RFI caused any disruption to
appliances in my place or for any of my neighbors.

At the end of the day, you can decide. If
anything blows up, give your product manufacturer a call and see what they
have to say. Please feel free to contribute your opinions or expert advice
on our forums here.





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Fitting the decoder


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First connect the decoder to the pick-ups
from the wheels of the locomotive:

  • Red cable to the wheels, which in
    relation to the direction of travel, are on the right-hand side of the
    locomotive
  • Black cable to the wheels, which in
    relation to the direction of travel, are on the left-hand side of the
    locomotive

Then connect the decoder to the motor
connections:

  • Orange cable to the motor connection
    previously connected to the
    right-hand locomotive wheels
  • Grey cable to the motor connection
    previously connected to the
    left-hand locomotive wheels
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Now connect the function, if required:

  • Function output (white cable) to the
    bulb of the locomotive.
  • If the function inside the locomotive
    (e.g. the bulbs of the light) is not
    electrically connected to the chassis of the locomotive (i.e; if they are, "potential free")
    then connect the other pole of the function
    to the blue cable.

Note: When using LEDs with the function
output, note that the blue cable is the positive pole (longer anode side of the LED) and the function output the
negative pole (shorter cathode
side of the LED). The voltage at the function output is
approximately 16 V. Please do not forget the necessary protective resistor
on the anode side of the LED. The value of the resistor can be calculated by
the
formula R = V/I where I is current rating of the LED and I is the difference
between the DCC track voltage and the voltage ratting of
the LED.


Train Wheel Vehicle Rolling Motor vehicle



For example:
If the supply voltage VS = 16V, and you have a 3mm red LED (VL = 2.8V), requiring a current I =
15mA = 0.015A, R = (16V - 2.8V) / 0.015A = 880
Font Tints and shades Monochrome photography Monochrome Darkness
, so choose a
1K
Font Tints and shades Monochrome photography Monochrome Darkness
resistor (the nearest standard value which is greater).

Secure the decoder in a suitable place
with double sided tape. If there is any chance of the components on the
decoder touching anything, protect the decoder with an insulating sleeve.

Shield the soldered wires with electrical
tape to prevent any shorts. Secure the excess wires with black tape
to finish-off the installation. Coloured tape could show from under the
body.


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Testing the installation

Place the locomotive on the programming
track (without its body on) and read
the loco address (CV1). If you have installed the decoder correctly,
you should now be able to read the address
(3= factory default for the LE1014W). If you
are not able to do so, it is possible that you have made a mistake
when connecting the cables. Do not
subject the loco to full running track power until you
obtain
the correct "03" address read-out.


If there is a problem, recheck your
cables and connections.



Programming the decoder


This aspect of the installation is very
important and often not looked at hard enough by the modeler. To get the
best out of DCC, try and program you locomotives so that when they all run
together on your layout, they look in harmony with one another and to the
scale and feel of the layout. There is no point in all you locos running
around at top speed, screeching off from a stop and then also stopping
dead when the operator presses the stop button. It is much more pleasing
to the eye of the operator knowing that the Gresley A4 is the fastest
steam loco on the layout, the Merchant Navy class following behind, but
still hold their own on the main lines. The shunting and branch line locos
clatter along at a more sedate pace even when the controller is set to
'Max'. The Class 08 locos had a maximum speed of 27.5mph. For 00 gauge
models, that scales down to just over 6 inches per second. Not that fast
really.

Note: The default settings of the decoder
will work fine and even if you use a Bachmann EZ Command these decoders
will work out-of-the-box and you can still set the loco address and
direction of travel. Bachmann users: If you have access to a decoder
programmer or if you can visit someone with a programming controller, you can tailor your locomotive and use it with those settings on EZ Command.
Once programmed, the settings in the decoder registers are stored permanently and will determine how the decoder controls the locomotive.
We use the configuration variables of the decoder or "CV’s" to set up various operating characteristics
of the decoder.

We simulate weight of the loco and
resistance of the load by setting the Acceleration delay (CV3). Steam
locos ease off and then build up speed as they pick up rhythm and
momentum. We simulate inertia of the moving train by setting the Brake Delay
(CV4)

The speed of the loco is governed by the
voltage sent to the motor - starting out with it's initial starting
voltage (CV2) and peaking with it's maximum voltage.

On most decoders, the speed curve is shaped by modifying
maximum voltage setting (CV5) and the mid point voltage (CV6).
The Lenz decoders don't use CV5 and CV6 so to modify the speed parameters
of the loco, we must use a speed table. This is a series of voltages that
are applied at the 28 speed steps enabling the loco to perform more
prototypically. In 128 speed step mode the decoder internally averages the
speed curve table to obtain the correct speed step value.


DCC CV Settings
for the Streamlined West Country class Locomotive
using the LE1014W decoder
CV141Address (The loco
number)
CV28Minimum Speed (V Min at
step 1)
CV34Acceleration delay
(0-15)
CV44Brake Delay (0-15)
CV2922Default = 6,
but to enable Speed curve selection, use a value of 22
CV67Speed
Curve Table (See below


to

CV94


The rest of the CV's are left
untouched (factory default).



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So there you have it. All should
be working well. Please feel free to ask questions. You will find an
immense amount of pleasure when you operate your locos on the same tracks independently
from each other without having to worry about isolating the current to
specific sections of your layout. Using this method to install and program
your decoders, you can get the oldest locos from your collection to run
alongside your most recent 'DCC Ready' locos. Have fun.

- September 2005

Train Rolling stock Vehicle Track Railway


All text, photos & graphics ©2005
Doug Teggin - All rights reserved.

 

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