Installation guide, 'Pickle Fork' Back-and-Forth Model Train Controller
Azatrax model PFRR-3W
This controller can automate a 'back-and-forth' model train layout
with optional siding at either or both ends of the layout -- or, one
train can travel continuously around a loop, making stops at
predetermined locations.
Requirements:
Trains must be DC powered
, not DCC or AC, because train
direction is controlled by the polarity of the track power.
Maximum track current: 2 amps (2.5 amps for acceleration).
If turnouts (track switches) are used, the turnouts must be operated
by
switch machines with 3-wire control cables
. These are 'snap'
type switch machines with twin coils such as Atlas, Bachmann or
Peco.
If your turnouts have switch machines with 2-wire control cables,
use the Azatrax PFRR-2W control circuit.
An accessory power supply, 12 to 17 volts AC or DC is required to run the PFRR circuit. This is separate from the track
power.
This power supply must have sufficient current capacity to operate the switch machines -- typically 2 amps or more.
Train sensors:
One train sensor must be installed at each track location where a train is to stop. One sensor is needed at each track end
point. Additional sensors or external detectors may be added for station stops where a train will momentarily stop, then
continue in the same direction.
The PFRR controller has connections for up to four train sensors. They are numbered W1, W2, E1 and E2.
The operating mode of the PFRR is determined by the combination of sensors that are connected.
So be careful to connect your sensors to the correct terminals on the PFRR controller. The wrong
combination will result in unexpected operation.
Back and forth, no turnouts
Connect sensors:
Do not connect W2
W1 at west end
E1 at east end
E2 may be used as a station stop between W1 & E1.
External detectors may also be used for station stops.
see
page
2
Back and forth, one turnout
Connect sensors:
Do not connect E2
W1 at west end, track 1
W2 at west end, track 2
E1 at east end
Use external detectors for station stops if desired.
see
page
2
Back and forth, two turnouts
Connect sensors:
W1 at west end, track 1
W2 at west end, track 2
E1 at east end, track 1
E2 at east end, track 2
Use external detectors for station stops if desired.
see
page
2
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Azatrax Pickle Fork RR Installation, 3-wire switch machines
rev. C1 pg. 1 of 7