Anti-theft device

• US 5,089,807 A
• Filed: 10/06/1988
• Issued: 02/18/1992
• Est. Priority Date: 08/13/1987
• Status: Expired due to Fees

• Current Assignee: Henry H. Shim
• Original Assignee: Henry H. Shim
• Inventors: Shim, Henry H.
• Primary Examiner(s): Orsino, Joseph A.
• Assistant Examiner(s): Hofsass, Jeffery A.
• Application Number:
  US07/253,605
• Time in Patent Office: 1,230 Days
• Field of Search: 340/568, 340/571, 340/687, 340/636, 340/540
• US Class Current: 340/568.2
• CPC Class Codes: G08B 13/1409 for removal detection of electrical appliances by detecting their physical disconnection from an electrical system, e.g. using a switch incorporated in the plug connector
• CPC Class Codes: G08B 29/181 due to failing power supply

Abstract

An anti-theft device comprises a circuit which control a relay. The house power is connected to the circuit which energizes the relay. When the relay is energized, the contacts in the relay remain open. A battery and an alarm horn are connected in series with the contacts of the relay. When the power to the circuit is cut off, as during a theft, the relay is de-energized, completing the circuit to the batter and the alarm causing the alarm to sound to warn of a possible theft.

Claims

1. An anti-theft device for use in a motel room comprising a first circuit and a second circuit, said first circuit having a power input from a power outlet in the room, electrical components in said first circuit for reducing and rectifying the voltage coming from the conventional power outlet to prevent electric shock and to reduce the danger of fire, a coil in said first circuit, said reduced and rectified voltage in said first circuit connected across said coil, a plurality of fragile series connected wires attached to the items in the motel room to be protected from theft, said wires connected to said circuit in such a way that as long as the wires to the coil are not broken, the coil is energized by said voltage and a pair of contacts in said second circuit are kept separated from each other, a battery and a first alarm connected in series with said pair of contacts, so that when the voltage to said coil is cut off said pair of contacts come together to close the contacts actuating the alarm to warn the owner that objects in the motel room are being stolen, and an automatic indicator in the first circuit, said automatic indicator connected to the first circuit in such a way that voltage changes in the second circuit which occur when the battery becomes weakened or drained cause a second alarm to be actuated to warn the operators of the anti-theft equipment that the battery needs to be replaced.

2. An anti-theft device for protecting fixtures and electronic equipment comprising an electric circuit, said electric circuit connected to a 100 volt power outlet in parallel with the electronic equipment, a 0.1 uf ac capacitor connected to one side of the power input, a wire connected to the opposite side of the capacitor, said wire connected to various fixtures to be protected, a portion of said wire adjacent each fixture to be protected, the opposite end of said wire connected to the positive side of ecg116 rectifier, the opposite side of said rectifier connected to the opposite side of the power input to reduce the voltage across the rectifier to 6 volts D.C. to reduce the danger of fire and electric shock, a 1.7 K ohm coil connected in parallel with said rectifier in such a way that as long as there is six volts D.C. across the coil, a pair of contacts remain separated, a battery and first alarm connected in series with said contacts in such a way that when an attempt is made to cut off power to the fixtures being protected, the weakened portion of the wire adjacent the fixture being carried away breaks and power across the coil is cut off cause said contacts to come together, whereby the circuit to the first alarm is completed and the first alarm is actuated warning the owners of the property that objects are being taken, and an automatic indicator in said anti-theft device, said anti-theft device connected to said circuit in such a way that changes in the voltage which occur when the battery becomes weakened or drained turn on a second alarm to warn the operator of the anti-theft equipment that the battery needs replacement.