Patent ID: 6842114

Claim:
A wire-based safety electronic device for the detection of the theft of an object to be protected, the device comprising at least one detector ( 1 ) connected by a wire-based electric link ( 2 ) to a signalling unit ( 3 ), the detector, having at least one electrical status, being arranged in relation with an object to be protected, the link transmitting the electrical status to the unit in the form of a voltage determined on the link, the signalling unit comprising at least a threshold voltage comparator with inputs/outputs whereof at least one input is connected to the detector by the link and whereof at least one output indicates by signals at least the presence or the absence of the object in relation to the electrical status of the detector, the link comprising two wires whereof a first is connected to a common point and the second is connected via at least one first resistor (R 3 ) to a voltage generator with respect to the common point, the second wire being connected to the input of the comparator, the comparator comprising an analogue digital voltage converter ( 4 ) for digital measurements of the voltage and a digital calculation central unit controlled by an operating programme enabling the generation of signals in relation to the digital comparison between the measurement and digital reference thresholds, characterised in that the detector comprises a sensor and shows at least a first electrical status when the sensor is in relation with the object and a second electrical status when the object is detached from the sensor, and it comprises means to further generate a status linked with the absence or the presence of the detector on the link, a resistor being arranged between both wires of the link in the detector, in parallel with the sensor, the absence of the detector corresponding to a voltage at the input of the comparator approximately equal to the voltage of the voltage generator.