A device designed to float in a home pool and sound an alarm when the water is disturbed, which is peculiarly sensitive to disturbances in the water, including a transducer for sensing noise in the water, a high frequency filter connected to the transducer, a saturable amplifier connected to the filter, an integrator connected to the amplifier, and a trigger circuit connected to the integrator for initiating an alarm. The integrator has a rise time on the order of fifty milliseconds so that it r...

It is herein disclosed a closed circuit alarm system comprising a number of alarm detectors, which system comprises an amplifier coupled through condensers to a first alarm relay and which is further coupled to a second relay the arrangement being such that when an electrical signal is generated in the first relay, in response to the bridging of any of the alarm detectors, such electrical signal is amplified and applied to such second relay thereby producing by said second relay an electrical si...

In an alarm system utilizing a bidirectional wired television system, there are provided a plurality of alarm signal generators which are located on the subscribers' side, the signal generators generating low frequency alarm signals of the frequencies common to respective group units, the frequencies being different for respective subscribers in respective group units, each alarm signal generator being provided for each subscriber's modulators for respective group units; modulators for respectiv...

An alarm system detects the electrical disconnection of electrical equipment such as an appliance which connects by a power plug to a power receptacle on an AC power line. The detection and alarm generating portion of this system is preferably located in a conventional AC power receptacle box and includes a power receptacle which accomodates a conventional power plug from the electrical equipment. When the detection and alarm system is active, a pair of switches is set upon insertion of the plug...

A burglar alarm has a sound generating circuit which is actuated when the two magnets are moved away from each other. The sound generating circuit includes two coils of wire wound on a common core, and a permanent magnet hammering device which is actuated by the coils for sounding. When the two magnets are moved away from each other, a switch closes so that intermittent current can flow through one of the coils which repels the hammering device for sounding and releases it under the action of th...

A theft alarm system which includes a transmitter and a receiver which may be fastened together during non-use, with the transmitter being secured to the equipment being protected. Removal of the receiver energizes both the transmitter and receiver. Subsequent movement of the transmitter or attempts to tamper with the transmitter produces a radio frequency signal. The signal is detected in the remote receiver and produces an alarm to alert the person carrying the receiver.

An alarm control circuit, designed as a unit package to be mounted in the interior of a vehicle, is adapted for connection to the ignition switch circuit, to a vehicle door or other closure operated light switch circuit, and to the vehicle battery, with the output being connected to the vehicle horn circuit. The alarm control circuit is completely automatic when operated through the vehicle ignition switch and a vehicle closure switch, and sounds the vehicle horn intermittently when a closure is...

An alarm device for use in a vehicle which utilizes an audio frequency oscillator to drive a buzzer or tone device audible to the occupants of the vehicle. The alarm includes a control circuit which automatically stops the alarm after a preselected interval and may include modulated or interrupted alarm.

A gas detector is disclosed which includes a CO sensor and a processor. The CO sensor senses an environmental CO concentration and provides a variable electrical output in response. The processor receives digitized samples of the sensor's electrical output and computes, with each measurement sample, a COHb level of a hypothetical person exposed to the CO concentration sensed. The computation involves determining an equilibrium COHb level for each measurement sample, which is compared with a prev...

An alarm module system including at least one electronic display module situated on a boat with a display for indicating the status of the vital functions of the engine of the boat. The electronic display is adapted to produce an activation signal upon detection of an anomaly within the engine. Further included is a direct current battery supply for supplying power and an alarm horn for generating an audible alarm upon the receipt of power. Also provided is an interconnection network including p...