Capacitive apparatus to monitor the integrity of a wall
First Claim
1. An apparatus for verifying the integrity of a wall having internal and external surfaces and adapted to cause an intervention when an aggressive act is committed against the wall, said apparatus comprising,(a) a sensor mounted on one of the external or internal surfaces of the wall, said sensor being a condenser having a surface area substantially matching the shape of the wall and having a first plate connected to the wall and a second plate connected to ground;
- (b) an electronic surveillance circuit on the internal side of the wall comprising a variable frequency oscillator having a control input connected to said first plate;
(c) means for detecting variation of frequency of an output signal of the variable frequency oscillator resulting from a variation in capacitance of the condenser, and for emitting a signal when an aggressive act on the wall causes a variation in surface area of the condenser which causes a variation in capacitance of the condenser.
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Accused Products
Abstract
An apparatus for verifying the integrity of a wall automatically sets off an intervention in the case of an act committed against the wall. A capacitive sensor is formed on the external or internal surface of the wall and consists of a thin planar condenser matching the shape of the wall. An oscillator having variable frequency has its control input connected to a plate of the condenser, the other plate being connected to ground, and a circuit detects the variation of frequency of the output signal of the oscillator resulting from a variation of condenser capacitance.
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Citations
11 Claims
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1. An apparatus for verifying the integrity of a wall having internal and external surfaces and adapted to cause an intervention when an aggressive act is committed against the wall, said apparatus comprising,
(a) a sensor mounted on one of the external or internal surfaces of the wall, said sensor being a condenser having a surface area substantially matching the shape of the wall and having a first plate connected to the wall and a second plate connected to ground; -
(b) an electronic surveillance circuit on the internal side of the wall comprising a variable frequency oscillator having a control input connected to said first plate; (c) means for detecting variation of frequency of an output signal of the variable frequency oscillator resulting from a variation in capacitance of the condenser, and for emitting a signal when an aggressive act on the wall causes a variation in surface area of the condenser which causes a variation in capacitance of the condenser. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for verifying the integrity of a wall having internal and external surfaces and to determine when an aggressive act is committed against the wall, said apparatus comprising:
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(a) a sensor mounted on one of the external or internal surfaces of the wall, said sensor being a condenser having a surface area substantially matching the shape of the wall and having a first plate connected to the wall and a second plate connected to ground; (b) an electronic surveillance circuit comprising means for generating a variable frequency connected to said first plate; (c) means for detecting variation of frequency of an output signal of said means for generating a variable frequency resulting from a variation in capacitance of the condenser when an aggressive act on the wall causes a variation in surface area of the condenser which causes a variation in capacitance of the condenser. - View Dependent Claims (10, 11)
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Specification