Input zone enhancer and method
OwnerCezary Jan Jaronczykinventor
Life of this patent
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Abstract
A burglar alarm system with an input zone enhancer using a power source with random variable timing or voltage to supply the zone loop. The input zone enhancer measures the current flowing through a zone loop of a burglar control unit. A method includes providing random variable timing and a voltage to supply the zone loop. A method includes directly measuring the current flowing through a hard wired zone loop of a burglary control unit in order to overcome sensitivities associated with electromagnetic noise. A method includes detecting compromise attempts by calculating a correlation of two signals, the zone loop current and the reference current, and by calculating the autocorrelation of the zone loop current with itself at different points in time.
Claims14
A burglar alarm system for preventing the defeat of mechanical barriers, the burglar alarm system comprising:
- a burglar alarm control unit having a zone input;
- a zone loop;
- an input zone enhancer connected to said zone loop and to said burglar alarm control unit, said input zone enhancer operating to provide a reference voltage having a random voltage value and to provide a zone loop voltage across said zone loop that has a voltage that corresponds to the voltage of said reference voltage;
- said input zone enhancer further operating to measure a voltage across said zone loop and calculate a difference between the voltage measured across said zone loop and said reference voltage;
- and
- said input zone enhancer further operating to output a status signal to said zone input of said burglar alarm control unit that is indicative of a state of said zone loop based upon the difference between said voltage measured across said zone loop and said reference voltage.
Dependencies are inferred from the claim text.