This board lives in the CCD footlocker interface box. It is a rework of Terrance Ricketts' original Ilex shutter controller. The rework is mostly a new layout of the board, and the addition of two new connectors, J4 and J5, the two front panel LEDs, and the 74LS540 driver IC.

In the upper right hand corner of the diagram is the input connector J5. This connector carries the input signal for operating the shutter and the output signal SHUTTER_OPEN. To ensure compatibility, the BNC connector J3 is wired in parallel to allow use in older systems. Connector J4 brings in the +5v and ground connections from the Footlocker Power Supply board EL-1348. The +5V is used for the logic circuit and to power the COMMAND and SENCE LEDs. Also, the +5V power is wired to J5 to provide power to the opto-isolator that receives the shutter signal.
The input signal is pulled high through R4 which actuates the solid-state relay RY1. When actuated, the shutter will be in the open state. The signal from the CCD Controller will pull this line low to close the shutter. The sense line, SHUTTER_OPEN, is generated by a small magnet attached to the moving ring of the shutter mechanism. When the shutter is fully open, the magnet is positioned next to a small reed switch which closes connecting the output to ground. This line is pulled up to +5V by R5. The signal then goes to a set of inverters that drive the output connector and turn on the SENSE LED.
The diagram shows 110VAC entering the board on pins 1 and 3 of connector J1. The solid-state relay contact is used to apply the 110VAC-H to relay RY2, which in turn, applies voltage to the Ilex shutter. Note that the capacitors C1 and C2 will charge up when relay RY2 is relaxed. This charge is dumped into the coil of the shutter when the relay is closed resulting in a high initial voltage being applied to the shutter. This spike contains enough energy to actuate the shutter solenoid but once the capacitors have discharged, the voltage across the shutter coil is the much lower ~12-24 volts required to continue to hold the shutter open without over heating the coil.