GB2286475A

GB2286475A - Theft alarm system

Info

Publication number: GB2286475A
Application number: GB9402465A
Authority: GB
Inventors: Winston Paul Rose
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-02-09
Filing date: 1994-02-09
Publication date: 1995-08-16
Also published as: GB9402465D0

Abstract

An electrical means of detecting whether item(s) of equipment situated locally or remotely is/are removed. The system uses cables and connectors, which may have the same appearance as those required for the normal operation of the equipment. A signal source is connected to the cable and disconnection of this cable breaks a circuit and raises an alarm either locally or remotely. <IMAGE>

Description

ROSE UNIVERSAL INSTRUMENT SECURITY SYSTEM (ROSECURE) This invention relates to a method of raising an alarm when an electrical circuit between a signal source and a piece of equipment to be protected is broken by an unauthorised person.

Portable electrical equipment, especially computers and laboratory instruments, are vulnerable to removal by unauthorised persons. Such equipment is often left unattended, connected by cables, either to other electrical equipment or to fixed sockets nearby.

According to the present invention there is provided a system which will raise an alarm if equipment is disconnected by an unauthorised person. An essential feature of the system is that it does not have the appearance of a security system. The system consists of two main components.

The first is the source of an electrical signal. This electrical signal is communicated to the item(s) to be protected by cable(s). The cable and its connectors have the same appearance as those required for the normal operation of the equipment, so that an unauthorised person may not recognise that they are part of a security system.

The second main component of the system is an electrical circuit within the item to be protected. When the cable from the signal source is connected to this circuit and the source is energised, the system is in the normal protected state. If the cable from the source is disconnected from the circuit in the item to be protected, while it is carrying the signal, an alarm is initiated immediately. This may, for example, be an audible signal, a lamp or an automatic telephone dialling system, activated by the signal source.

There is no limit to the length of the cable(s) between the signal source and the protected item(s), so the alarm can be located either locally, or remotely where it will not be seen or heard by an unauthorised person disconnecting the item(s) protected by the system.

An authorised person wishing to remove the equipment will arrange for the signal source to be switched off before disconnecting the cable.

The system may be used with cables connected either in parallel (star configuration - Figure 3) or in series (daisy-chain configuration - Figure 4) between the signal source(s) and the protected equipment.

There is no limit in principle to the number of items that can be protected by the system, as the circuit to the item to be protected can be designed to take a very small amount of power from the signal source.

The system may also have, for example: a separate warning indicator, circuit in normal operation indicator and enable/disable switch for each item protected by it.

an indicator which shows whether circuits are functioning correctly and whether protected items are connected.

a cancel switch to stop the operation of an alarm and to return the circuit to normal operation.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows a schematic diagram of the system, in which a single item is protected, using an out and return connecting cable.

Figure 2 shows a schematic diagram of the system, in which a single item is protected, using a single wire between the source and the protected item, and earth connections to provide the return route for the current.

Figure 3 shows a schematic diagram of a system in which several items are protected by a single signal source connected in parallel.

Figure 4 shows a schematic diagram of a system in which several items are protected by a single signal source connected in series.

Figure 5 shows a schematic diagram of a system used to protect many items at a large number of different locations on one or more sites.

Figures 6,7 and 8 shows are schematic diagrams of electrical circuits which can be used to realise the system described above.

Claims

1. A security system which uses a cable which does not have the appearance of traditional protection equipment. It comprises a signal source connected, locally or remotely, to one or more pieces of equipment to be protected, using one or more circuits such that the breaking of the electrical connection raises an alarm.

2. A security system as claimed in Claim 1 which uses a cable containing two separate conductors, one for the current to the equipment to be protected, the other for the return current.

3. A security system as claimed in Claim 1 which uses a cable containing one conductor for the current to the equipment to be protected and uses the earth return to complete the circuit.

4. A security system as claimed in Claim 1 and Claim 2 or Claim 3 used to protect several items, by connecting them to the current source either in series or in parallel.

5. A security system as claimed in Claim 4, used to protect any number of items located on separate sites.