Abstract: A sensor system that constantly monitors an irradiance level of a UV lamp and is operated by power from a sensor thereof, wherein the UV lamp is powered by a ballast. The sensor system includes a current sensor, a UV sensor, a voltage comparator, and a display. The current sensor is disposed in the electronic assembly and picks-up current from the ballast, and in response thereto, powers the voltage comparator. The UV sensor is disposed externally to the assembly and picks-up the irradiance from the UV lamp. The voltage comparator is disposed in the electronic assembly, is in electronic communication with the current sensor and the UV sensor, is powered by the current sensor, and compares voltage from the UV sensor to a predetermined value. The display is visible from the electronic assembly, is in electronic communication with the voltage comparator, and indicates result of comparison of the voltage comparator to thereby determine status of the UV lamp.

Abstract: A sensor system that constantly monitors an irradiance level of a UV lamp and is operated by power from a sensor thereof, wherein the UV lamp is powered by a ballast. The sensor system includes a current sensor, a UV sensor, a voltage comparator, and a display. The current sensor is disposed in the electronic assembly and picks-up current from the ballast, and in response thereto, powers the voltage comparator. The UV sensor is disposed externally to the assembly and picks-up the irradiance from the UV lamp. The voltage comparator is disposed in the electronic assembly, is in electronic communication with the current sensor and the UV sensor, is powered by the current sensor, and compares voltage from the UV sensor to a predetermined value. The display is visible from the electronic assembly, is in electronic communication with the voltage comparator, and indicates result of comparison of the voltage comparator to thereby determine status of the UV lamp.

Abstract: There is disclosed an intrusion detection system employing vibration sensors which are arranged in a series loop consisting of first and second wires and which loop is terminated by a terminating impedance. Coupled to the wires is a processing circuit which supplies a square wave biasing waveform for the loop and a DC voltage determined by the terminating impedance. By detecting the magnitude of the DC level, the processor can determine if the loop has been opened or shorted or if any one of the sensors in the loop has been activated due to an intrusion. Thus the system described employs two wires for supplying both power and sensing of output signals from the loop being monitored.

Abstract: A seismic sensor is disclosed which essentially consists of a central annular member having an inner conductive periphery. The annular member is coaxially positioned around a center post located in a housing. The center post has four extending surface slots into which are inserted tines or upstanding flanges associated with first and second contact members. The contact members enable the sensor to be mounted in four distinct positions, thus giving the installer great flexibility.

Abstract: A digital transmission system comprises a transmitter and a receiver for use in a security system. An alarm code is set by means of switches in both the transmitter and receiver and is indicative of the address or location of a monitored location. The location as monitored contains a sensor which is in either an opened or a closed condition indicative of a secure or unsecure status. The transmitter operates to transmit a digital code for each change in the status of the loop. The code contains bits which define the alarm code or address, while additional bits define the loop status as opened or closed in conjunction with the condition of a battery which is used to power the transmitter. The receiver is adapted to receive the transmitted signal and is operative to compare the transmitted address with the code stored or programmed by the receiver switches. If a valid code is received within a predetermined interval, the receiver operates to decode the loop status by means of an updown counter.

Abstract: Apparatus for disabling an alarm after a predetermined operating period employs a relay which is operated by a gate circuit. A contact of the relay applies operating potential to an alarm. An oscillator energizes a counter circuit and after a predetermined selectable period, the counter circuit inactivates the relay via the gate to cease alarm operation.

Abstract: An intrusion detection system can be armed and disarmed from a plurality of remote locations by the use of a plurality of momentary switches, each one associated with one of said locations. Each switch when depressed, functions to change the state of a flip/flop. The flip/flop in one mode operates to disarm the intrusion detection system. When the flip/flop is in its other mode, the intrusion detection system is armed and activated. The apparatus monitors the state of the control loop associated with the detection system in order to indicate to a user that the system can be activated or armed when desired. If the control loop is not secure, the apparatus will indicate this fact to the user to enable him to secure the loop before arming the system by triggering of the flip/flop.

Abstract: An automatic telephone dialer is described which includes a dial tone detection circuit. The dial tone detection circuit responds to a series of tones which are prerecorded on a magnetic tape. The dial tone detection circuit operates to detect the tones and to provide a signal suitable to activate a dialing relay for tone bursts on the tape of a suitable predetermined duration. Upon receipt of a suitable duration tone burst, the tone detection circuit provides an accurate duration signal to provide a relatively identical delay at the beginning and end of a dialing pulse to thereby maintain an accurate dial mark/space ratio determined by the requirements of the telephone line which is accessed by the dialer.

Abstract: There is disclosed a digital dialing system operative to send a subscriber code and an alarm indication to a remote station via a communications link such as a telephone line. The digital dialer employs a memory which is preprogrammed to store a number of a central station to be dialed and which automatically transmits to that station when accessed, a code manifesting the location having the difficulty. The memory is further adapted to automatically transmit an additional signal indicative of the type of alarm condition such as a fire or a burglary which conditions are stored at predetermined locations in the memory. These memory locations are accessed by a memory address counter which is set at the end of a zone identification procedure by an alarm logic circuit.

Abstract: The alarms circuit provides a first signal indicative of a fire alarm and a second signal indicative of another intrusion such as a burglary. The circuit includes a high frequency RC oscillator which undesireably possesses a duty cycle different from fifty percent. The oscillator output is divided by a bistable multivibrator to produce at an output, a divided signal having a fifty percent duty cycle for application to a loud speaker to energize the same efficiently due to the proper duty cycle. In a burglary mode, the oscillator frequency is modulated by a sawtooth developed by a second bistable multivibrator to provide a wailing tone signal indicative of a burglary. This signal is also divided to produce a proper duty cycle signal for application to the loud speaker.

Abstract: A series loop is in series with a control relay coil which has a first and a second contact. The first contact is coupled to an alarm and the second contact is coupled to one end of the loop. A control arm of the relay is operated by the coil to coact with said first contact when the coil is not energized and to coact with the second contact when the coil is energized to cause said second contact to latch said relay when the series loop is closed. Power is selectively applied to the control arm of the relay and a unidirectional current conducting circuit is coupled between the control arm of the relay and the second contact. The circuit supplies energizing current to the coil in the loop for the application of power to the control arm. This causes the relay to operate and therefore to latch if the loop is closed upon application of power to the control arm.

Abstract: An automatic test circuit for a photo electric intrusion system incorporates an electronic attenuator which serves to reduce the sensitivity of the receiver when a light beam does not impinge on a photocell located at the receiver. As soon as the light beam appears on the photocell, the sensitivity of the receiver is increased to a normal operating value. In this manner, if the beam were misaligned to cause less light to impinge on the photocell, the receiver would indicate an alarm condition to thereby inform a user of the problem.

Abstract: An intrusion alarm system employs ultrasonic frequencies and operates in the presence of turbulence. The system includes a differentiator and an integrator, each coupled to a sample and hold circuit; the differentiated pulses determining the level from the integrator, which level is stored in the sample and hold circuit during a predetermined time interval. The level, as stored, will be relatively constant for the presence of an intruder and will exhibit excursions during turbulence. A threshold circuit is responsive to the steady level during a predetermined period to sound an alarm determinative of an intrusion. During turbulence, the signal stored fluctuates and is discriminated against by the threshold circuit to assure that the alarm will not occur for this condition.