|Updating the Zimo equipped Class 66 with Yard mode lighting and a speculative super-shunter lighting option.|
The Zimo equipped Class 66 locos are updated once again, to add "Yard Mode" and "Super Shunter" lighting options.
Recent inputs from loco drivers on the RMweb site indicate that when picking up or dropping trains in the yard, headlights are switched off to avoid dazzling the yard staff. This results in "Yard Mode" lighting, with forward markers and rear lights active, but no headlights.
Occasionally, with the demise of dedicated small shunting locos such as the previously ubiquitous Class 8, large freight diesels are used to assemble trains within the yard. When undertaking this task, the preferred lighting arrangement is to display red rear lights and white marker lights simultaneously at both ends of the locomotive. However, if modern dual function LED combined rear / marker lights are in place on the locomotive, this arrangement is not possible. However, a little imagination results in these lights emitting alternate red and white flashes, providing an effective equivalent set of warning lights. Hence "Super Shunter" Mode.
No hardware changes are required for the DB Schenker Class 66/0 locos, which have separate rear lights and lower marker lights.
However, for the later build 66s fitted with dual function combined lower front marker lights with integral rear lights, changes are needed to provide flashing marker/rear lights for shunting:
The previous double strobe headlight warning is clearly far too bright to be a viable lighting regime for yard use. The double strobe output on F4 is therefore sacrificed and replaced with a 1 to 1 mark-space waveform. This waveform is directed at the lower marker lights and in antiphase to the rear lights, via steering diodes.
Revised Circuit diagram for later build Class 66 locomotives with dual lights:
Summarising the lighting requirement:
a) Early Class 66/0
b) Later Class 66/9 etc (with dual function rear/front markers)
Common CV Elements:
CV131=60 to automatically switch off the cab light (FO5) when the loco is on the move.
Early Class 66/0:
Later Class 66/9 etc:
CV130 to zero to remove previous double strobe output.
CV118 defines FO to flash... for FO4, value=32
CV117 defines flashing waveform... for 1/2 sec on and 1/2 sec off, value = 55
Swiss Mapping CVs:
Revised Function Mapping:
Lighting mode Descriptions and key combinations:
Class 66/0 :
Class 66/9 etc (dual
marker/rear lights) :
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