The Niles LS-1 Light Sensor is a device used to monitor the on/off status of almost any component. It is used to provide a 12V "Sync" or status feedback signal to the IntelliControl Home Theater Automation System, IntelliPad Wall-Mounted Keypad; a Niles infrared repeater system, or any other device that requires a 12V DC control voltage. When the source component is powered up, the LS-1 sensor detects the change in brightness of the component's front panel display or on/off indicator. This change in brightness triggers the LS-1 to output a 12V DC "sync" signal. Note: Includes a 12 Volt AC Power Supply.