Abstract: An infra-red motion detector for monitoring motion in a monitored space is described. The motion detector includes, within a housing, an infra-red radiation sensor sensitive to infra-red radiation incident through a window. A refractive optical system within the housing selects incident infra-red radiation for redirection onto the infra-red sensor. An external light source mounted externally of the housing directs external light through the window providing a recognizable light input. A refractive Fresnel patch mounted externally to the window selects incident light from the external light source and redirects it to a tamper sensor within the housing. A detection controller processes signals output by both sensors in monitoring the space. The detection controller detects incident light from the external light source and trips a tamper alarm in failing detection, and further detects changes in infra-red radiation in the monitored space and trips an intrusion alarm upon detecting changes.

Abstract: A motion detector has an RF transceiver configured to transmit a first frequency RF signal and a second frequency RF signal into an area where motion is to be detected. A frequency difference between the first frequency signal and the second frequency signal is small and chosen to cause a calculated range dependent Doppler phase shift between the first frequency and the second frequency. The two resulting Doppler shift signals have a frequency dependent on the movement speed of an object in the area, and a difference in amplitude or signal strength between the Doppler shift signals remains relatively invariant as a function of range for a moving object in the area in comparison with an amplitude or signal strength of the Doppler shift signals. Signal level or signal power of a difference in amplitude between the Doppler shift signals is analyzed for the purpose of movement or range detection.

Abstract: An infra-red motion detector for monitoring motion in a monitored space is described. The motion detector includes, within a housing, an infra-red radiation sensor sensitive to infra-red radiation incident through a window. A refractive optical system within the housing selects incident infra-red radiation for redirection onto the infra-red sensor. An external light source mounted externally of the housing directs external light through the window providing a recognizable light input. A refractive Fresnel patch mounted externally to the window selects incident light from the external light source and redirects it to a tamper sensor within the housing. A detection controller processes signals output by both sensors in monitoring the space. The detection controller detects incident light from the external light source and trips a tamper alarm in failing detection, and further detects changes in infra-red radiation in the monitored space and trips an intrusion alarm upon detecting changes.

Abstract: A lens assembly for a passive infrared motion detector has one or more rows of far field Fresnel lenses arranged on a substantially cylindrical sheet and operative to collect light onto a sensor location. A plurality of rows of mid/near field Fresnel lenses are arranged on a basically spherical sheet, and the mid/near field lenses are operative to collect light onto the sensor location. An infrared motion detector also has an infrared sensor with a lens assembly having a plurality of lenses on a spherical surface collecting light from a corresponding number of zones onto said sensor, and a reflector mounted in the detector directs light collected by at least one of the lenses onto the sensor for providing one or more creep zones.

Abstract: Zones of a passive infrared (PIR) motion detector lens are staggered at close range to provide for pet immunity. In a dual sensor, dual lens configuration, the sensor signal is acted on to generate an alarm only when the sensor signal is simultaneous, indicating that an infrared emitting object big enough to cross both staggered zones of a zone pair has been detected. To further enhance sensitivity and immunity to noise, two dual element PIR sensors are arranged in opposite polarity with their elements vertically parallel. The sensor output is simultaneous and of opposite polarity, and noise can be suppressed by blocking like-polarity signals.

Abstract: The digital sampler circuit processes an output signal from a high gain analog amplifier having as input an infrared motion detector output signal and a negative low pass filtered feedback signal. The amplifier output signal is a substantially square pulse signal having an irregular frequency and duty cycle and has an average duty cycle indicative of a DC level and a slow change in the DC level of the detector output signal. The sampler circuit includes a detector circuit for detecting the amplifier output signal and discriminating at regular intervals a high/low state of the output signal, and generates a high/low feedback signal corresponding to the high/low state of the output signal detected. The high/low state of the output signal is analyzed over a predetermined number of the intervals to obtain a ratio value for producing an output digital signal sample value. The digital sample value is a measure of the DC level and the change in the DC level of the detector output signal.

Abstract: A data entry keypad assembly is provided for a system controlling a plurality of components. The keypad assembly includes a plurality of key zones arranged in an ordered matrix and each having a label identifier, and a plurality of key switches, provided in corresponding key zones. The keypad assembly also includes a plurality of light source means, each one of the light source means also provided in the corresponding key zones. Input controller connected to the key switches is provided for receiving data in the form of a sequence of key presses of the switches, and information displaying controller connected to the light indicator is provided for indicating a state of some of the components each associated with some of the label identifiers. When the data entry keypad assembly is used for a security system, it controls a plurality of detectors and warning devices, and displays a detection state of the detectors, while allowing activating/deactivating commands to be entered.

Abstract: A motion sensor has a parasitic response to at least one of radio frequency (RF) or electromagnetic (EM) impulse signals. The motion detection circuit for security systems has a dummy RF receiver for generating an RP response signal, the receiver having a response to at least one of radio frequency (RF) or electromagnetic (EM) impulse signals similar to the parasitic response. An alarm output signal is generated in response to intruder motion in the predetermined area while preventing false alarms due to the parasitic response.

Abstract: A simplified analog passive infrared motion detection circuit operates using only four operational amplifiers. A first amplifier is used as part of a bandpass amplifier circuit, a second is used in an inverter circuit, a third is used in an integrator circuit and a fourth is used in a threshold comparator circuit for generating an alarm output signal. The circuit is built using a single quad op amp IC package and is economical to manufacture. The third op amp can alternatively be used as a passive infrared sensor preamplifier and a transistor can be used in the integrator circuit, so that a regulated power supply for the circuit is not needed.

Abstract: The telephone line coupler circuit has a single transmit opto-coupler whose output includes a DC bias component connected to a gate of a line seize switch for connecting a DC line seize load across the ring and tip contacts of the telephone line. The line seize switch is saturated by the transmit opto-coupler bias output and the AC component of the transmit opto-coupler output is sent over the telephone lines. The receive opto-coupler is used both for receiving communications signal and for detecting the ring signal. The band pass filter connected to the output of the receive opto-coupler may be switched to pass a ring signal frequency band or a communications frequency band. The circuit operates using two opto-coupler devices while conventional circuits require four opto-coupler devices.

Abstract: A data entry keypad assembly is provided for a system controlling a plurality of components. The keypad assembly includes a plurality of key zones arranged in an ordered matrix and each having a label identifier, and a plurality of key switches, provided in corresponding key zones. The keypad assembly also includes a plurality of light source means, each one of the light source means also provided in the corresponding key zones. Input controller connected to the key switches is provided for receiving data in the form of a sequence of key presses of the switches, and information displaying controller connected to the light indicator is provided for indicating a state of some of the components each associated with some of the label identifiers. When the data entry keypad assembly is used for a security system, it controls a plurality of detectors and warning devices, and displays a detection state of the detectors, while allowing activating/deactivating commands to be entered.

Abstract: The Doppler shift motion detector has an effective motion detection range which can be changed by changing the power level and thus without changing the motion detection circuitry. The Doppler shift motion detector also has a self test for the wave transmitter and receiver which can be carried out without requiring placing a moving object in the monitoring area. The Doppler shift signal generated when the power level is changed is used to check the detector for the self test and is ignored by the detector alarm output circuitry when the power level is changed. An anti-masking feature is also provided.

Abstract: An audio indicator apparatus for locating boundaries of optically divided detection zones covered by a passive infrared detection system having a collector for collecting infrared rays from the zones of an area to be monitored, and a detector for passively detecting infrared rays collected by the collector and for generating a first signal having an amplitude responsive to the rays collected by the collector, which includes a signal generator to be connected to a speaker for producing a second signal responsive to the first signal, the second signal being indicative of activity of the detection system at a point, within the area to be monitored, where an infrared radiation emitting object is moved, to locate the boundaries of the zones.

Abstract: In a passive infrared intrusion detection system, a signal responsive to infrared radiation received from optically divided zones of an area to be monitored is integrated to produce an integral sum. The integral sum is used to generate an alarm indication. The alarm indication is thereby responsive to the energy of the signal responsive to the infrared radiation received, thus improving sensitivity of the detection system without increasing susceptibility of generating a false alarm.

Abstract: The telephone line coupler circuit has a single transmit opto-coupler whose output includes a DC bias component connected to a gate of a line seize switch for connecting a DC line seize load across the ring and tip contacts of the telephone line. The line seize switch is saturated by the transmit opto-coupler bias output and the AC component of the transmit opto-coupler output is sent over the telephone lines. The receive opto-coupler is used both for receiving communications signal and for detecting the ring signal. The band pass filter connected to the output of the receive opto-coupler may be switched to pass a ring signal frequency band or a communications frequency band. The circuit operates using two opto-coupler devices while conventional circuits require four opto-coupler devices.

Abstract: The digital sampler circuit processes an output signal from a high gain analog amplifier having as input an infrared motion detector output signal and a negative low pass filtered feedback signal. The amplifier output signal is a substantially square pulse signal having an irregular frequency and duty cycle and has an average duty cycle indicative of a DC level and a slow change in the DC level of the detector output signal. The sampler circuit includes a detector circuit for detecting the amplifier output signal and discriminating at regular intervals a high/low state of the output signal, and generates a high/low feedback signal corresponding to the high/low state of the output signal detected. The high/low state of the output signal is analyzed over a predetermined number of the intervals to obtain a ratio value for producing an output digital signal sample value. The digital sample value is a measure of the DC level and the change in the DC level of the detector output signal.

Abstract: The telephone line coupler circuit has a single transmit opto-coupler whose output includes a DC bias component connected to a gate of a line seize switch for connecting a DC line seize load across the ring and tip contacts of the telephone line. The line seize switch is saturated by the transmit opto-coupler bias output and the AC component of the transmit opto-coupler output is sent over the telephone lines. The receive opto-coupler is used both for receiving communications signal and for detecting the ring signal. The band pass filter connected to the output of the receive opto-coupler may be switched to pass a ring signal frequency band or a communications frequency band. The circuit operates using two opto-coupler devices while conventional circuits require four opto-coupler devices.