Abstract: A security device including a power supply and a pair of conductors connecting the power supply with a source of alternating current. A switch, associated with the first conductors, selectively breaks the connection between the power supply and current source. An outlet is connected by a pair of second conductors to the first conductors such that the switch also breaks the connection between the outlet and current source. A power cutoff relay is connected to the power supply so as to be energized by direct current from it. A normally open contact set is closed by the power cutoff relay to connect the alternating current source with the outlet through the second conductors. An alarm emits an audible signal when energized by direct current from the power supply. A current sensor senses the flow of alternating current from the outlet and operates a switch to permit the flow of direct current to the alarm when alternating current flow is sensed.

Abstract: A security device including a power supply and a pair of conductors connecting the power supply with a source of alternating current. A switch, associated with the first conductors, selectively breaks the connection between the power supply and current source. An outlet is connected by a pair of second conductors to the first conductors such that the switch also breaks the connection between the outlet and current source. A power cutoff relay is connected to the power supply so as to be energized by direct current from it. A normally open contact set is closed by the power cutoff relay to connect the alternating current source with the outlet through the second conductors. An alarm emits an audible signal when energized by direct current from the power supply. A current sensor senses the flow of alternating current from the outlet and operates a switch to permit the flow of direct current to the alarm when alternating current flow is sensed.