Napco Security Systems, Inc.

Raymond J Gaudio

An intrusion detection loop employing an end-of-line resistor that operates with a voltage window. As the voltage window is increased, the sensitivity of the system decreases. As the window is decreased, the sensitivity of the system increases. By utilizing two comparators each having one input coupled to the loop, one can specify one voltage window when the system is disarmed and hence place the system at maximum sensitivity thereby detecting any borderline problem. In any event, the same two comparators operate to provide a different voltage window when the system is armed and hence desensitizing the loop and therefore reducing alarm probability. In this manner one can determine during the disarmed condition that the loop is operating with a borderline resistance and still employ the system in the armed condition to assure that there will be a reduced alarm probability in view of an undesirable change of the loop resistance.

Verifying automatic line integrity diagnostic (V.A.L.I.D.) apparatus and

An intrusion detection system of the type employing a keypad utilizing the keys to conventionally enable a user to key in a secret code capable of arming or disarming the system. The present apparatus includes a hold-down feature whereby if any one of the plurality of keys on the keypad is depressed for a predetermined interval, the apparatus detects the predetermined timing interval and transmits an audible sound to the user indicating that the requisite timing interval has transpired. Upon receipt of the audible sound, as depending upon the test to be performed, the user is thus informed that the system will now commence the test procedure as defined by the selected key. Thus the system includes apparatus for detecting the requisite timing interval. Upon detection of the requisite timing interval a storage means is activated, which storage means is associated with the selected key. Upon activation of the storage means, the output of the storage means is directed to the intrusion system whereby the intrusion system is now programmed to undergo the test procedure or operating procedure which is defined by the selected key as depressed for the requisite timing interval.

Keyboard hold-down functions for a multi-zone intrusion detection system

A fault indicator apparatus employs a single indicating device such as a light emitting diode (LED) to provide an indication of all zones within a plurality of zones which exhibit a predetermined condition being monitored. In particular, the invention is employed in a multi-zone intrusion system where a single indicator provides an output indicative of all zones which are not secure. The apparatus causes the indicator to blink the zone numbers in a continuous sequence and for example, if zones 2 and 5 were not secure the indicator would provide two flashes indicative of zone 2 and then provide a predetermined pause while then providing 5 flashes indicative of zone 5. The user by counting the flashes can then immediately determine which zones in the plurality of zones have been violated.

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Babylon, NY, United States of America

Raymond J Gaudio