The TDR-10 timed power relay serves to turn on a standard 120 volt outlet for a preset amount of time. This timed interval is initiated when a contact is made across the Start terminals on the rear panel. This low voltage contact may come from a pushbutton, motion sensor, or other device. Once triggered, the timing cycle starts and the outlet switches on. While timing, any additional start signals force the timing cycle to begin anew. This ensures that there at least one complete cycle after the last start signal. For example, if used with a motion sensor such as the Museum Technology BB-200, the first visitor to approach turn on the AC outlet for the preset time. If no further motion is sensed, the outlet switch off at the end of the preset time. Should another visitor approach while the outlet is on, the TDR-10 start the timing cycle from the beginning. In this way, as long a visitor motion is detected, the outlet remain on, shutting off only after motion has not been sensed for the preset time.