Matches 101 - 150 out of 212 < 1 2 3 4 5 >
Match Document Document Title
4794376 Automatic signal evaluation and transfer  
An improved process measurement system is disclosed which provides automatic signal evaluation and transfer in connection with redundant signals generated from a common data source over two input...
4772875 Intrusion detection system  
An intrusion detector has a first sensor for monitoring a first condition and a second sensor for monitoring a second condition in a space to be protected against intrusion; a change in the...
4768202 Signalling method and device for bidirectional digital transmission link  
A method of transmitting signalling along a bidirectional digital transmission link consists in transmitting from an intermediate equipment of the link a signalling message in two parts. One is a...
4764754 Fail-safe alarm circuit  
A fail-safe alarm system includes a device which allows current to flow in only one direction to insure that the supervisory current in an alarm circuit is flowing in the intended direction rather...
4752698 Emergency supervisory system  
The present invention relates to an emergency supervisory system which comprises a plurality of supervisory apparatus provided for respective supervisory regions and connected in parallel with each...
4751498 Single-wire loop alarm system  
A single-wire loop alarm system in which an identification module is placed across each alarm switch. Any module which is across an open switch is powered by the loop current and, in response to a...
4742334 Single-wire loop alarm system  
A single-wire loop alarm system in which the status of each alarm switch can be determined and which is relatively immune to the effects of noise. False alarms are avoided by incorporating an...
4728861 Light control apparatus for a vehicle  
A light control apparatus for a vehicle is integrated with headlamp driving relays, a light sensor, a lighting switch which selects a manual mode or an automatic mode, and a control unit which...
4725818 Walk through test system  
Walk through test system for testing devices such as pull stations, smoke detectors, alarm bells and the like for alarm and trouble conditions without the assistance of a central panel operator....
4725820 Composite detector  
A composite detector includes a plurality of sensors of the same or different types, a plurality of analog switches connected to outputs of the plurality of sensors, and an operation circuit, such...
4703312 Voice-override alarm system  
An emergency alarm system incorporating both signal generation and voice annunciation capabilities, for installation in a building or other structure. The system includes a standard fire alarm...
4692752 Moisture detector  
A moisture detector for detecting the presence of moisture between two electrodes includes an AC sensing network coupled to an indicator circuit by an opto-isolator to isolate impedances between...
4682144 Light transmission system for trains  
A light transmission system for a train which includes sub-train compositions. Ths subtrain compositions each have end vehicles, one of which forms a head and the other of which forms a tail with...
4673920 Fire alarm control and emergency communication system  
A multistationed integrated life safety system in which each station will be situated at a diffferent location and have complete capabilities in terms of local fire protection, fire detection,...
4665383 Security system with monitoring and warning circuits  
A central protection system suitable for the protection of a building from fire and other hazards includes a set of environmental sensors and circuitry for interrogating the sensors. The system...
4622539 Alarm system with alarm message supervision  
An alarm message generation and broadcast system having supervision including an alarm message generation circuit for generating an alarm message, an output for receiving the alarm message so that...
4622538 Remote monitoring system state machine and method  
A plurality of different types of operating systems in buildings organized in geographical groups, each group having a local service office, are monitored at both the local offices and central...
4612534 Method of transmitting measuring values in a monitoring system  
Measuring stations or locations are connected in cascade to signal lines and transmit measured or measuring values to a central signal station at which the measured values are linked or...
4611197 Malfunction-detecting status monitoring system  
A multiple-sensor status monitoring system for monitoring the status of an area while avoiding false alarms and detecting and identifying faulty sensors. The system uses a timer and logic to avoid...
4586028 Alarm system  
Alarm system providing a signal by turning on alarms, lights, sirens, automobile horns or wake-up signal based on interruption of a monitor loop. Monitor loop includes a resistor which connects to...
4573040 Fail-safe instrument system  
In an instrument system consisting of a transmitter in one location and a receiver in another location connected by a transmission medium, fail-safe operation is obtained by restricting the output...
4568923 Fire alarm system  
There is disclosed a fire alarm system wherein a plurality of fire detectors are connected to each alarm line and a light emission diode is connected in series between an alarm line and an electric...
4567471 Monitoring system  
A monitoring system for a protection loop that has a plurality of switches in series utilizes modules with inexpensive diodes and resistors, and is conveniently and easily added to existing burglar...
4555698 Detecting machine tool set-up errors  
A tool setting-aid comprising an anodized aluminum "button" and a support therefor is set up at a predetermined datum position on the worktable of a computer controlled machine tool, the machine...
4529970 Supervision system for monitoring the integrity of a transmission line  
The integrity of a two-conductor transmission line, over which d-c energizing voltage is supplied to a series of shunt-connected detectors (such as fire and/or smoke detectors) and which line is...
4529971 Alarm loop supervision  
Apparatus for indicating a break in the lines leading from a base station to a monitored instrumentality. Two pairs of wires conduct signals to each contact of a normally open switch-like element...
4524349 Security system having detector sensing and identification  
A security system including a plurality of sensor loops, each having a plurality of detectors and associated detector identification devices which upon actuation produce analog detector signals of...
4523183 Alarm-fault detecting system  
A microcomputer controlled circuit arrangement for sensing fire and burglar alarms in the presence of undesired fault conditions, such as opens or shorts, on monitored communication lines. The...
4520348 Multiple redundant suppression devices with provision of supervision and fault correction  
An electrical protection system including a plurality of suppressor units each activatable by either a first or a second electrical current responsive activator to suppress abnormal condition. The...
4459582 Local control apparatus for central station alarm system  
In a central station alarm system the alarm sensors associated with a particular subscriber's premises are monitored by a local control unit associated with those premises and controllable by the...
4458239 Fire extinguishing apparatus  
A fire extinguishing apparatus and an actuating system. The actuating system includes a plurality of actuators connected in parallel and a source of electrical signal for said actuators. Each...
4435700 Event detection and indication system  
The detection of events such as illegal entry detection, or the occurrence of predetermined hazards are detectable by a system including a circuit loop 2 which incorporates event actuatable...
4422067 Dynamic self-checking safety circuit means  
A safety circuit which connects a condition responsive circuit to a cyclic signal detecting circuit. In order to provide the cyclic signal detecting circuit with a continuous cyclic input, the...
4414540 Automatic redundant transducer selector for a steam turbine control system  
For use in combination with a turbine control system, an automatic signal selector to assure selection of a valid signal representation of an operating parameter of the controlled turbine....
4410884 Alarm system  
An Alarm system for furnishing an alarm signal in response to unauthorized entry through a passage connecting the outside to the interior of a building, wherein a first detecting device furnishes a...
4404548 Method for transmitting measuring values in a fire alarm system and apparatus for the performance of the aforesaid method  
In a fire alarm system individual fire alarms are connected in series by reporting lines with a central signal station. In order to be able to connect a greater number of fire alarms with the...
4402903 Control system for coupling redundant logic channels  
A control system for coupling redundant logic channels while maintaining electrical and physical isolation between channels. The separate redundant logic channels each include an electro-optic...
4401976 Multiple sensor interconnected alarm system responsive to different variables  
An alarm, safeguarding and monitoring system for a room zone includes a plurality of sensors disposed at different positions and responsive to different physical phenomena, such as an ultrasonic...
4378554 Fixed/movable supervised alarm loop  
An alarm sensing loop for selectively monitoring at least first and second alarm sensors includes terminals for connection to a source, a selection circuit connected to the terminals and having...
4369436 Anti-bridging cable supervision circuit  
In an intrusion alarm system, an anti-tamper system for detecting the bridging and removal of sensors connected in parallel along an interconnection cable includes means at each sensor for...
4361833 Multi-sensor alarm system and method of protecting a premises  
A multi-sensor alarm system and method of protecting a premises include at least one sensor circuit and an alarm circuit which together establish a two-wire closed loop electrical circuit path in...
4356476 Multiple alarm detector monitoring and command system  
A plurality of fire, smoke, security or other detectors of the type which respond to the existence of a predetermined condition are each connected to an input module which monitors the state of the...
4356474 Alarm system  
A digital alarm system of the type having first and second electrically conductive loops connected by an alarm switch. The alarm switch is normally open, but can be closed when an alarm state...
4348661 Self-balancing alarm system  
An alarm system includes a security loop comprising a plurality of sensors, a circuit connected to the security loop and an alarm. The circuit is responsive to a change in condition within the...
4331952 Redundant sensor adapter  
An adapter for a multiwire security and surveillance system which permits the connection of redundant sensors at one location, without affecting the operation of non-redundant sensors at other...
4318093 Logic circuit monitor  
A monitor for logic circuits detects loss of redundancy within the monitored circuit and designates that portion thereof which is out of service. Loss of redundancy is detected by sensing the...
4314238 Electric lighting installation  
An electric lighting installation in which is provided at least one central control panel for each light point group, an auxiliary switch which is connected in a parallel circuit with the...
4310835 Security equipment including trigger circuit  
Security equipment comprises a plurality of normally-open or normally-closed switch contacts connected in a loop circuit to a central control circuit. Each pair of switch contacts has a respective...
4283717 Monitoring system for a direct-wire alarm system  
A direct-wire alarm system for scanning and monitoring a plurality of security alarm systems located in various user's facilities. The device monitors each line sequentially and converts current...
4276645 Receiver for simultaneously transmitted clock and auxiliary signals  
A receiver for simultaneously transmitted clock signals of frequency F (HC) and auxiliary signals of frequency f (HS), F=kf, k=2, 3, 4, . . . , said clock and auxiliary signals being transmitted as...
Matches 101 - 150 out of 212 < 1 2 3 4 5 >