Security device
First Claim
1. A security device comprising in combination, a first monostable oscillator having an input terminal and an output terminal adapted to carry a potential thereon, the potential on the output terminal of the first monostable oscillator changing from a first potential to a second potential responsive to an electrical signal impressed on the input terminal of said first monostable oscillator and the output of said first monostable oscillator remaining at said second potential for a first period of time following each change to said second potential and returning to said first potential at the end of said first period of time, a sensor adapted to produce an electrical signal for actuating the first monostable oscillator electrically connected to the input terminal of said first monostable oscillator, an alarm electrically connected to the output terminal of the first monostable oscillator, said alarm being activated by the second output potential of the first monostable oscillator and inactivated by the first output potential of the first monostable oscillator, a second monostable oscillator having an input terminal electrically connected to the sensor and an output terminal adapted to carry a potential thereon, the potential on the output terminal of said second monostable oscillator changing from a third potential to a fourth potential responsive to an electrical signal impressed on the input terminal of said second monostable oscillator from the sensor and the potential on the output terminal of said second monostable oscillator remaining at said fourth potential for a second period of time and changing from said fourth potential to said third potential at the end of said second period of time, said second period of time being shorter than the first period of time, and means electrically connected to the output terminal of the second monostable oscillator for preventing actuation of the alarm during periods in which the fourth potential is applied to the output terminal of the second monostable oscillator, whereby actuation of the sensor results in actuation of the first and second monostable oscillators but actuation of the alarm is delayed during the second period of time.
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Accused Products
Abstract
A security system in which fire or intrusion signals may be impressed on a first and a second monostable oscillator connected in timing circuits, the first monostable oscillator producing an output for a first limited time period to excite an alarm, and coincidently in time a second monostable oscillator producing an output of shorter second time period for delaying actuation of the alarm to permit the operator to deactivate the unit prior to actuation of the alarm, each of the monostable oscillators using an integrated circuit and being reset by application of power to the unit and during function key switch position change. The fire channel has top priority over any other functional characteristics of the master control.
55 Citations
14 Claims
- 1. A security device comprising in combination, a first monostable oscillator having an input terminal and an output terminal adapted to carry a potential thereon, the potential on the output terminal of the first monostable oscillator changing from a first potential to a second potential responsive to an electrical signal impressed on the input terminal of said first monostable oscillator and the output of said first monostable oscillator remaining at said second potential for a first period of time following each change to said second potential and returning to said first potential at the end of said first period of time, a sensor adapted to produce an electrical signal for actuating the first monostable oscillator electrically connected to the input terminal of said first monostable oscillator, an alarm electrically connected to the output terminal of the first monostable oscillator, said alarm being activated by the second output potential of the first monostable oscillator and inactivated by the first output potential of the first monostable oscillator, a second monostable oscillator having an input terminal electrically connected to the sensor and an output terminal adapted to carry a potential thereon, the potential on the output terminal of said second monostable oscillator changing from a third potential to a fourth potential responsive to an electrical signal impressed on the input terminal of said second monostable oscillator from the sensor and the potential on the output terminal of said second monostable oscillator remaining at said fourth potential for a second period of time and changing from said fourth potential to said third potential at the end of said second period of time, said second period of time being shorter than the first period of time, and means electrically connected to the output terminal of the second monostable oscillator for preventing actuation of the alarm during periods in which the fourth potential is applied to the output terminal of the second monostable oscillator, whereby actuation of the sensor results in actuation of the first and second monostable oscillators but actuation of the alarm is delayed during the second period of time.
Specification