9
Tension Sensor
The BIG SKY P-Series platters are all equipped with a tension sensor on the
pay-out film path. This sensor will stop the platter and sound an alarm, put the
console s automation and projector in stop mode (if connected via the fail-safe),
and provide extra film for projector wind-down should a brain wrap occur.
The Tension Sensor is a sliding roller that is normally at rest in it s bottom
position. Should a wrap or problem occur where the film stops feeding from the
pay-out head, the roller assembly is pulled up on it s slider by the film tension. As
the roller rises from it s rest position, it closes a switch which is connected to the
platter speed control, and should also be wired to the fail-safe connection on the
console s automation. When the switch closes, the control system stops the
motor(s), and sounds an audio and visible alarm(marked FILM TENSION
WARNING on power panel of mast). By stopping the platter, no more film is
allowed to be fed into the developing problem. By also shutting down the
console(via the fail-safe), no system or film damage can occur since the whole
system is halted. The travel of the slider provides extra film needed for the time
period needed by the projector to stop turning.
Electrical connections and details of this sensor are depicted in the drawing,
Film wrap Switch Wiring in the drawing section of this manual.
