|Producing prints with tight sensitometric specifications requires
precision light valves and a precision light source. The Precision Lamp
Controller (PLC) is a constant current lamp driver designed to work with
TFS Light Valve Controllers (LVC). Working together, these units allow the
operator to accurately set the picture light value and maintain constant
The PLC consists of a power supply, current feedback power amplifier
and interface to the LVC. The power supply and amplifier deliver up to 10
amps at 120 Volts DC. The amplifier feedback is connected to the LVC so
the lamp current can be monitored and changed using the LVC interface.
Changes in line voltage or in lamp contact resistance will not affect the
lamp brightness due to the constant current. If a fault occurs in the
system and the lamp current does not match the command setting, an error
message is displayed on the LVC.